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  • C07F1/00—Compounds containing elements of Groups 1 or 11 of the Periodic Table
  • C07F1/08—Copper compounds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F1/00—Compounds containing elements of Groups 1 or 11 of the Periodic Table
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  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F1/00—Compounds containing elements of Groups 1 or 11 of the Periodic Table
  • C07F1/12—Gold compounds
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  • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
  • C09K11/06—Luminescent, e.g. electroluminescent, chemiluminescent materials containing organic luminescent materials
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  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
  • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
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  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/30—Coordination compounds
  • H10K85/371—Metal complexes comprising a group IB metal element, e.g. comprising copper, gold or silver
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  • C09K2211/00—Chemical nature of organic luminescent or tenebrescent compounds
  • C09K2211/10—Non-macromolecular compounds
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  • C09K2211/00—Chemical nature of organic luminescent or tenebrescent compounds
  • C09K2211/10—Non-macromolecular compounds
  • C09K2211/1018—Heterocyclic compounds
  • C09K2211/1025—Heterocyclic compounds characterised by ligands
  • C09K2211/1029—Heterocyclic compounds characterised by ligands containing one nitrogen atom as the heteroatom
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  • C09K2211/00—Chemical nature of organic luminescent or tenebrescent compounds
  • C09K2211/18—Metal complexes
  • C09K2211/188—Metal complexes of other metals not provided for in one of the previous groups
• • H—ELECTRICITY
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  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K2101/00—Properties of the organic materials covered by group H10K85/00
  • H10K2101/10—Triplet emission

Definitions

• the present invention is concerned with transition metal complexes and their use in light-emitting devices (for example Organic Light Emitting Diodes, OLEDs). More particularly, this invention relates to two-coordinate copper, silver and gold complexes comprising one carbene ligand as neutral electron donor (L-type ligand) and a monodentate anionic ligand (X-type ligand), as well as organometallic complexes that exhibit rotationally accessed spin-state inversion (RASI) photoemission, and the use of these compounds as photoemissive materials.
• L-type ligand neutral electron donor
• X-type ligand monodentate anionic ligand
• RASI rotationally accessed spin-state inversion
• the present invention also relates to light-emitting devices which incorporate such complexes.
• OLEDs generally comprise, in sequence, an anode, optionally a hole-transporting zone, an emissive zone capable of emitting light, and a cathode.
• the arrangement may suitably be supported on a substrate.
• An electron-transporting zone may be present, between the emissive zone and the cathode.
• OLEDs are typically multilayer structures with each component part forming a layer or part of a layer. Depending on which side or sides of the device is/are to emit the light, layers may be independently selected to be transparent, translucent or opaque.
• FIG. 1 of the accompanying drawings An embodiment of an OLED is shown schematically in Figure 1 of the accompanying drawings, to illustrate a typical sequence of layers.
• a glass substrate is covered by a thin, optically transparent, layer of indium tin oxide (ITO), which acts as anode.
• ITO indium tin oxide
• a metal or metal alloy of low work function acts as cathode.
• the cathode and anode are separated by several layers of different organic molecules which are able to conduct charges, and provide the hole-transporting and emissive zones. Holes are injected into the organic layers from the anode, and electrons are injected from the cathode. The holes and the electrons migrate in opposite directions in the layers of the organic molecules and bind to form excitons.
• the anode injects into a hole-transporting layer (hole-transporting zone), which may, for example, comprise a hole-transporting material such as PEDOT:PSS [poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate polymer mixture], while the cathode injects into an electron-injection layer, which may, for example, comprise an electron-transporting material such as a metal oxide, salt or organic electron-transporting compound. Both the hole-transporting layer and the electron-injection layer serve to block the escape of the opposite-sign charge carrier. Between these layers is the emissive layer, which is a layer of organic compounds in which excitons form in a mixture of spin-0 singlet and spin-1 triplet states.
• a hole-transporting layer such as PEDOT:PSS [poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate polymer mixture]
• an electron-injection layer which may, for example,
• Layer devices such as that illustrated in Figure 1 are built up by successive deposition of the layers on the substrate.
• the deposition technique for each layer is selected from a range of available techniques.
• the cathode is typically generated by evaporating metal vapour on the top surface of the previously deposited layers.
• a common approach to forming the material of an emissive layer is to embed emitter molecules in a wider-bandgap organic matrix, usually at a level of 1 - 10 weight-percent.
• the role of the matrix is to allow excitons and charges to migrate to the emitter molecules. In use of the device, through charge or energy transfer, these emitter molecules are promoted to an excited state, which relaxes with the emission of light. This light can be of varying colour and can include white light.
• the emitter molecules can be of various types, such as, for example, organic compounds with no metal atoms, organometallic complexes of heavy transition metals, and metal coordination complexes.
• the key role of the heavy metals in the complexes is to enhance spin-orbit coupling and thus allow luminescence from the normally dark triplet exciton state, significantly increasing the achievable photon quantum yield.
• the device efficiency is improved when the emitters have excited states with short life times, reducing competition with non-radiative decay channels.
• the purpose of using heavy-metal emitters such as iridium is to enable fast inter-system crossing, so that the ligand-based excited triplet states can be harvested in the form of emitted light.
• excited triplet states in close proximity are known to suffer from triple-triplet annihilation, reducing electroluminescence yield.
• many existing organometallic emitter materials suffer from strong concentration quenching. Dilution within the host matrix is therefore necessary to achieve efficient luminescence, and gradual migration and aggregation of emitter molecules leads to device failure. There is therefore a need to develop emitters with high quantum efficiency in the solid state, reducing the impact of aggregation.
• emitters having high external quantum efficiency preferably in excess of 15%, and devices incorporating them, e.g. OLEDs.
• Solution processing means in this context that the compound is capable of being dissolved, dispersed or suspended in a liquid medium.
• a solution, dispersion or suspension should be suitable for producing layer structures in OLED devices by coating or printing from a liquid phase, such as, for example, spin-coating, ink-jet printing or suitable alternative techniques.
• the photoluminescence is reported to occur very efficiently by prompt rather than delayed fluorescence, with lifetimes in the sub-nanosecond range.
• the solid-state photoluminescence quantum yield of the copper compounds is: compound la 0.96 (96%); compound lb 0.61 (61%); compound lc 0.28 (28%).
• the solid-state photoluminescence quantum yield of the gold compounds is: compound 2a 0.09 (9%); compound 2b 0.13 (13%); compound 2c 0.18 (18%).
• the said publication Chem. Commun., 2016, 52, 6379-6382 is a disclosure made less than six months before the filing date and second priority date of the present patent application and the invention claimed herein, by at least one of the inventors of the present invention and/or by at least one other who obtained the disclosed subject-matter directly or indirectly from at least one of the inventors of the present invention.
• the invention embodied in the said publication is therefore being claimed in the present patent application for the purposes of patent or like protection in territories where such prior publications are excluded from the prior art for the analysis of novelty and inventive step.
• M is a metal atom selected from copper and silver
• L is a cyclic alkyl amino carbene (CAAC) ligand having a saturated cyclic structure in which the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom; and
• CAAC cyclic alkyl amino carbene
• X is a monoanionic ligand
• M is a gold atom
• L is a cyclic alkyl amino carbene (CAAC) ligand having a saturated cyclic structure in which the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom; and
• CAAC cyclic alkyl amino carbene
• X is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and J represents a cyclic organic group which may contain one or more rings; excluding the compound Ad L-Au-NTf2 in which
• Tf is CF 3 -S0 2 -.
• the complexes have a coordination number of 2. They are preferably electrically neutral, that is to say the metal M is present in the oxidation state (+1) and the monoanionic ligand X balances that charge.
• the carbene ligand L preferably has a neutral charge but may optionally carry an anionic (negatively charged) substituent.
• the carbene site of the ligand L provides a strong electron donating effect towards the metal atom M.
• the strong electron donation raises the energy of the d-orbitals on the metal atom M in the complex. Without wishing in any way to be bound by theory, it is hypothesized that this increase in the energy of the d-electrons of the metal facilitates the excitation process, for example facilitates metal-to-ligand charge transfer during the excitation process.
• the carbene C atom has an empty p- orbital which can act as electron acceptor. In copper complexes excited S 1 singlet and T 1 triplet states are close in energy, and there is the possibility that a thermal equilibrium between these two states is established.
• the triplet energy is lost, unless the S 1 and T 1 states are close in energy, and the exciton energy can be harvested by a process known as thermally-activated delayed fluorescence, which is well documented in the art. It has now been found that compounds of the present invention may show properties which indicate that the excited T 1 state is at higher energy than the S 1 state, and that the two states are related by rotation of parts of the molecule. When these compounds are used as emitter materials in electroluminescent devices, this property allows all the exciton energy to be harvested and results in high internal quantum yields of up to 100%.
• excited state lifetimes are very short, of the order of nanoseconds to low microseconds, so that emissive devices with high brightness can be constructed.
• Relaxation from triplet states is typified by phosphorescence, with excited state lifetimes of the order of ten to hundreds of microseconds, for example of the order of 100 microseconds, or more.
• the present invention provides a light-emitting device comprising, in sequence, an anode, optionally a hole-transporting zone, an emissive zone capable of emitting light when an electric current flows between the cathode and the anode, and a cathode, wherein the emissive zone capable of emitting light comprises at least one complex of the following Formula la: (L)M(X), (la) in which
• M is a metal atom selected from copper, silver and gold;
• L is a cyclic alkyl amino carbene (CAAC) ligand having a saturated cyclic structure in which the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom; and
• CAAC cyclic alkyl amino carbene
• X is a monoanionic ligand.
• a hole- transporting zone is present.
• a hole-transporting zone and an electron-transporting zone are present, the electron-transporting zone being disposed between the emissive zone and the cathode.
• the present invention provides a method of preparing complexes of Formula I according to the first aspect of the invention or complexes of Formula la for use in a light-emitting device according to the second aspect of the invention, the method comprising: A. contacting a compound of Formula II:
• M and X in the compound of Formula II each has the same exemplification and preferences as described below for the complex of Formula I or la.
• Suitable examples of such compounds of Formula II are copper (I) chloride, copper (I) bromide, copper (I) iodide, silver chloride, silver bromide and silver iodide.
• M and X in the compound of Formula II please see the description below, including the Examples below of the specific complexes that have been prepared. The inventors have investigated the photoemissive properties of complexes of Formula I according to the first aspect of the present invention and complexes of Formula la as defined in the second aspect of the present invention.
• the complex is linear and two-coordinate, as in all complexes of the (L)M(X) geometry;
• the monoanionic ligand X includes an atom A which is displaced from the linear axis of the complex defined by the (L)M(X) geometry, whereby a plane PI of the ligand X is defined which includes M, the atom of X which is ionically bound to M on the linear axis of the complex, and A;
• the plane PI is rotatable in the solid state of the complex, relative to the plane P2 of the ring of the CAAC which includes the carbene site and consists of carbon atoms and one nitrogen atom, as a result of rotation of ligand X about the linear axis of the complex, the relative angle between the planes PI and P2 being termed the dihedral angle;
• the excited S 1 singlet state of the complex is associated with a different dihedral angle than the ground S° singlet state and the excited T 1 triplet state; the excited T 1 triplet state of the complex is energetically higher than the excited S 1 singlet state;
• the energy gap E g between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the CAAC ligand is small relative to CAAC complexes of the same metal M with other CAACs, for example less than or equal to about 5.0 eV, more preferably less than or equal to about 3.5 eV, for example less than or equal to about 3.0 eV.
• RASI photoemission arises in the following manner: in the ground S° state the CAAC and X ligands have a first dihedral angle between them; in the data presented in Example 29, for example, the first dihedral angle is about 0-20° (almost coplanar); in the excited T 1 state the CAAC and X ligands have a second dihedral angle between them, which may be the same as or different from the first dihedral angle; in the data presented in Example 29, for example, the second dihedral angle is about 0-20° (almost coplanar), in other words about the same as the first dihedral angle; in the excited S 1 state, the CAAC ligand and X ligands have a third dihedral angle between them, which may be the same as or different from the
• the vibrationally excited molecule has the option to relax, either directly to the ground S° state (fluorescence) or first to the T 1 state and subsequently to the ground S° state (phosphorescence); however, relaxation from the S 1 * to the T 1 state requires a change in spin, which is in principle quantum-mechanically forbidden, and relaxation from the T 1 state to ground S° state requires a further spin change and is typically a slow process; in RASI photoemission the excited S 1 singlet state of the complex is accessed by geometrical relaxation of the molecule through rotation of the plane P2 to the third dihedral angle; this may be an energetically more favoured pathway than the options of the previous paragraph occurring without rotation; photoemission by fluorescence results from the subsequent relaxation from the S 1 state to the ground S° state;
• the present invention provides a light-emitting device comprising an emissive zone capable of emitting light in response to introduced energy, wherein the emissive zone capable of emitting light comprises at least one organometallic complex which exhibits RASI photoemission.
• the light-emitting device according to the fourth aspect of the present invention may be an OLED.
• the present invention provides a method of generating light comprising: determining by specific investigation that at least one organometallic complex exhibits RASI photoemission;
• a light-emitting device comprising an emissive zone capable of emitting light in response to introduced energy, wherein the emissive zone capable of emitting light comprises at least one organometallic complex which has been so determined to exhibit
• the present invention provides the use of at least one organometallic complex which has been determined by specific investigation to exhibit RASI photoemission, in a light-emitting device for generating light.
• the organometallic complex(es) which exhibit(s) RASI photoemission may have at least the following combination of features:
• the complex is linear and two-coordinate, and consists of a carbene ligand L', a transition metal atom M' to which the carbene ligand L' is complexed via the carbene carbon atom, and a monoanionic ligand X' in a linear geometry;
• the monoanionic ligand X' includes an atom A 1 which is displaced from the linear axis of the complex defined by the linear (L')M'(X') geometry, whereby a plane PI of the ligand X' is defined which includes M', the atom of X' which is ionically bound to M' on the linear axis of the complex, and Al;
• the carbene ligand L' includes an atom A2 which is displaced from the linear axis of the complex defined by the linear (L')M'(X') geometry, whereby a plane P2 of the carbene ligand L' is defined which includes M', the atom of L' which is coordinated to M' on the linear axis of the complex, and A2;
• the plane PI is rotatable in the solid state of the complex, relative to the plane P2, the relative angle between the planes PI and P2 being termed the dihedral angle;
• the excited S 1 singlet state of the complex has been determined by specific investigation to be associated with a different dihedral angle than the ground S° singlet state and the excited T 1 triplet state;
• the excited T 1 triplet state of the complex has been determined by specific investigation to be energetically higher than the excited S 1 singlet state
• the energy gap E g between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the carbene ligand L' has been determined by specific investigation to be less than or equal to about 5.0 eV.
• the energy gap E g between the HOMO and the LUMO of the carbene ligand L' is less than or equal to about 3.5 eV, for example less than or equal to about 3.0 eV.
• the organometallic complex used in the fourth, fifth and/or sixth aspects of the present invention can be or include any organometallic complex provided that it exhibits RASI photoemission.
• the carbene ligand L' may be any carbene ligand that provides the required RASI photoemission.
• the carbene ligand L' may be as defined for L in relation to the complexes of Formula I or la of the present invention.
• the metal atom M' may be any transition metal atom that provides the required RASI photoemission.
• the metal atom M' may be as defined for M in relation to the complexes of Formula I or la of the present invention.
• the monoanionic ligand X' may be any monoanionic ligand that provides the required RASI photoemission.
• the monoanionic ligand X' may be as defined for X in relation to the complexes of Formula I or la of the present invention.
• the at least one organometallic complex used in the fourth, fifth and/or sixth aspects of the present invention may be or comprise at least one complex according to Formula I or la as described herein.
• the organometallic complex which exhibits RASI photoemission has been determined by specific investigation to be an organometallic complex in which, when the molecule is energetically excited in the solid state, an electron will be promoted to a vibrationally excited S 1 * state which has a higher energy than T 1 and S 1 .
• the organometallic complex which exhibits RASI photoemission has been determined by specific investigation to be an organometallic complex in which the excited S 1 state of the complex is accessed from the vibrationally excited S 1 * state by geometrical relaxation of the molecule through rotation of the plane P2 to the third dihedral angle, whereby photoemission by fluorescence results from the subsequent relaxation from the S 1 state to the ground S° state.
• the organometallic complex which exhibits RASI photoemission has been determined by specific investigation to be an organometallic complex in which, as the dihedral angle changes by rotation of the plane P2 to the third dihedral angle, and the energy level of the molecule changes from S 1 * to S 1 , the first being higher than the triplet state T 1 and the second being lower than the triplet state T 1 , at an intermediate point in the process the energy levels of the excited singlet and excited triplet state of the molecule are equal.
• the at least one organometallic complex which exhibits RASI photoemission used in the light- emitting device according to the fourth aspect of the present invention, provided in the method according to the fifth aspect of the present invention, or used in the sixth aspect of the present invention, may suitably be at least one complex according to the first aspect of the present invention.
• the light-emitting device according to the fourth aspect of the present invention, provided in the method according to the fifth aspect of the present invention, or used in the sixth aspect of the present invention may be a photoluminescent device or an electroluminescent device, for example a ROLED.
• an electroluminescent device it may suitably comprise, in sequence, an anode, optionally a hole-transporting zone, the emissive zone as defined in the fourth aspect of the present invention, and a cathode.
• an electron-transporting zone is provided between the emissive zone and the cathode.
• the present invention provides a light-emitting device comprising an emissive zone capable of emitting light in response to introduced energy, wherein the emissive zone capable of emitting light comprises at least one organometallic complex of Formula I or la as defined in the first and second aspects of the present invention.
• the present invention provides the use of at least one organometallic complex of Formula I or la as defined in the first and second aspects of the present invention, in a light-emitting device for generating light.
• the light-emitting device according to the seventh aspect of the present invention or used in the eighth aspect of the present invention may be a photoluminescent device or an electroluminescent device, for example a ROLED.
• the light-emitting device according to the seventh aspect of the present invention or used in the eighth aspect of the present invention is an electroluminescent device, it may suitably comprise, in sequence, an anode, optionally a hole-transporting zone, the emissive zone as defined in the fourth aspect of the present invention, and a cathode.
• an electron-transporting zone is provided between the emissive zone and the cathode.
• the light-emitting device referred to in connection with the seventh and eighth aspects of the present invention may exclude photoluminescent and optionally other devices in which the sole photoemissive organometallic complex of Formula I or la present in the device is one or more complex selected from complexes having the formula Ad L-M-X and individually designated la, lb, lc, 2a, 2b and 2c according to the following scheme:
• the light-emitting device referred to in connection with the seventh and eighth aspects of the present invention may exclude photoluminescent and optionally other devices in which any photoemissive organometallic complex of Formula I or la present in the device is one or more complex selected from the said complexes having the formula Ad L-M-X and individually designated la, lb, lc, 2a, 2b and 2c.
• the metal atom M may be selected from copper, silver and gold.
• the oxidation state of M in the complexes may be (+1).
• the coordination number in the complexes is 2, that is, a linear configuration of metal and ligands.
• a cyclic alkyl amino carbene (CAAC) ligand having a saturated cyclic structure in which the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom does not exclude the possibility that cyclic or non- cyclic structures which are not saturated may be linked to the ring which includes the carbene site.
• Such additional cyclic or non-cyclic structures may, for example, include aromatic rings.
• the expression "the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom” refers to the atoms actually forming the ring which includes the carbene site, and does not exclude the possibility that atoms other than carbon and nitrogen may be linked to one or more of those ring-forming atoms, for example in substituent groups.
• the CAAC ligand L is preferably a compound of Formula III:
• R 1 is selected from an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, and an optionally substituted heteroaryl group;
• D, E, F and G are independently selected from >CR'R", where R' and R" are, independently of each other and independently as between their occurrence as the different groups D, E, F and G, selected from hydrogen atoms or optionally substituted alkyl groups (for example, alkyl groups with 1 - 20 carbon atoms), or R' and R" are connected to form an optionally substituted saturated cyclic hydrocarbyl group, which may optionally contain more than one ring and/or one or more heteroatom; and d, e, f and g, independently from one another, are selected from 0, 1, 2, 3, 4, 5 and 6; provided that the compound of Formula III is cyclic.
• R 1 is an optionally substituted aryl or an optionally substituted heteroaryl group, it may for example be an optionally substituted phenyl, carbazole, indole, benzindole, benzofuran, dibenzofuran, benzothiophene, azacarbazole, azabenzofuran or azadibenzothiophene group.
• the aryl or heteroaryl group may, for example, carry from 1 to 5 substituents, which may be chosen, independently of each other, from optionally substituted alkyl, for example unsubstituted alkyl; optionally substituted alkenyl, for example unsubstituted alkenyl; optionally substituted alkynyl, for example unsubstituted alkynyl; optionally substituted alkoxy, for example unsubstituted alkoxy; optionally substituted amino, for example unsubstituted amino; optionally substituted aryl, for example unsubstituted, mono- or di-substituted aryl; or optionally substituted heteroaryl, for example unsubstituted or N-substituted heteroaryl.
• optionally substituted alkyl for example unsubstituted alkyl
• optionally substituted alkenyl for example unsubstituted alkenyl
• optionally substituted alkynyl for example unsubsti
• the example of a disubstituted phenyl group carrying two substituents in the 2- and 6-positions is specifically mentioned.
• the two substituents may be the same.
• the two substituents may suitably be alkyl, for example selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl iso-butyl and tert.- butyl, which two alkyl groups are suitably the same as each other.
• R 1 is a substituted phenyl group it may suitably be substituted by two isopropyl groups at the 2- and 6-positions.
• the heteroaryl group contains a nitrogen atom, the nitrogen may suitably be substituted by an alkyl group.
• N-alkylcarbazole N-alkylcarbazole
• the symbol > represents the two single bonds of the carbon atom C, one single bond to each of the two adjacent atoms of the ring system.
• R' and R" are linked to form an optionally substituted saturated cyclic hydrocarbyl group which may optionally contain one or more heteroatom
• the cyclic hydrocarbyl group may, for example, include one or more rings with 3 - 10 members, most preferably rings of six members, wherein the expression "members" refers to carbon atoms of the ring backbone and any heteroatoms present.
• the optionally substituted saturated cyclic hydrocarbyl group may, for example, be an optionally substituted C3-8 cycloalkyl group; for example, >CR'R" may represent a cyclohexylidene moiety, otherwise known as a spirocyclohexane ring. Where more than one ring is present in the moiety >CR'R", they may be fused rings, which may if desired provide a cage structure; for example, >CR'R" may represent an adamantylidene moiety, otherwise known as a spiroadamantane ring system.
• D, E, G, d, e, g, and f are as defined above and F is >CR f R ff , in which R f and R ff , which may be the same or different, are selected from optionally substituted alkyl groups with 1 - 10 C atoms, or R f , R ff and the carbon atom C to which they are linked form an optionally substituted cyclic hydrocarbyl group optionally containing one or more heteroatom in the ring.
• the optionally substituted saturated cyclic hydrocarbyl group may, for example, be an optionally substituted C3-8 cycloalkyl group (for example, >CR f R ff may represent a cyclohexylidene moiety or spirocyclohexane ring).
• D, E, G, d, e, g, and f are as defined above and F is >CMe2.
• D, E, G, d, e, g, and f are as defined above and F is >CR f R ff , in which R f and R ff and the carbon atom C to which they are linked form an optionally substituted fused bi-, trior poly-cyclic hydrocarbyl group optionally containing one or more heteroatom in at least one of the rings, for example a cage structure.
• F is an optionally substituted cycloalkylidene group (spirocycloalkane ring), preferably an unsubstituted adamantylidene group (spiroadamantane ring system).
• R 1 is selected from an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group and an optionally substituted heteroaryl group (for example an optionally substituted phenyl group; for example a disubstituted phenyl group carrying two alkyl substituents in the 2- and 6-positions, more preferably wherein the two substituents are the same, and more preferably wherein the two substituents in the 2- and 6-positions of the phenyl group are both isopropyl);
• R f and R ff which may be the same or different, are selected from optionally substituted alkyl groups with 1 - 10 C atoms (for example unsubstituted methyl, ethyl, n-propyl, isopropyl, n- butyl, sec-butyl iso-butyl and tert.-butyl, and more preferably where R f and R ff are the same); or
• R f , R ff and the carbon atom C to which they are linked form an optionally substituted cyclic hydrocarbyl group optionally containing one or more heteroatom in the ring (for example (i) a substituted or unsubstituted 6-membered ring, for example a substituted or unsubstituted cyclohexylidene group (spirocyclohexane ring), more preferably an unsubstituted cyclohexylidene group; or (ii) an optionally substituted fused bi-, tri- or poly-cyclic hydrocarbyl group optionally containing one or more heteroatom in at least one of the rings, for example a cage structure, more preferably an optionally substituted adamantylidene group (spiroadamantane ring system), for example an unsubstituted adamantylidene group).
• the CAAC ligand L may, for example, be a compound of Formula Ilia:
• R a , R b , R c and R d are Ct groups
• Ar represents a substituted phenyl group, for example a substituted phenyl group in which the one or more substituents are independently selected from the options set out in the discussion of the term "optionally substituted” below (more preferably a 2,6-dialkyl substituted phenyl group, and most preferably a 2,6-diisopropylphenyl group).
• the CAAC ligand L may be a spiroadamantane compound of Formula Illb:
• R a and R b are C3 ⁇ 4 groups and Ar represents a substituted phenyl group, for example a substituted phenyl group in which the one or more substituents are independently selected from the options set out in the discussion of the term "optionally substituted” below (more preferably a 2,6- dialkyl substituted phenyl group, and most preferably a 2,6-diisopropylphenyl group).
• CAAC ligand L may be selected from the following group of compounds:
• R represents a variable number n of 1 - 4 substituents, each of which is independently selected from the group comprising hydrogen, alkyl, alkenyl, alkynyl, alkoxy, amino, aryl and heteroaryl.
• n 2 and the 2- and 6-positions in the N-bound aryl ring are occupied by substituents R, which substituents R are preferably the same. More preferably, the substituents in 2- and 6-positions are isopropyl groups.
• X is a monoanionic ligand. Any inorganic or organic monoanion can be used, provided that the required 2 -coordination complex of Formula I is obtained.
• the ligand X may, for example, be selected from a halide, pseudo-halide, optionally substituted alkoxide (for example unsubstituted alkoxide), optionally substituted aryloxide (for example unubstituted aryloxide), optionally substituted arylacetylide (for example, unsubstituted phenylacetylide), optionally substituted amide (for example, unsubstituted amide), optionally substituted carboxylate (for example, unsubstituted carboxylate), optionally substituted anilide (for example, unsubstituted anilide), optionally substituted carbazole derivative, optionally substituted dihydroacridine, optionally substituted azepine, optionally substituted dibenzazepine, optionally substituted 10,11-dihydrodibenzazepine, optionally substituted phenazine, optionally substituted oxazine, optionally substituted acridone
• Ligands X may be compounds of Formula IV [E-Ar]- (IV) wherein Ar is an optionally substituted aryl or optionally substituted heteroaryl group, and
• E- is selected from C ⁇ XR 2 )-, 0-, S-, Se-, Te-, N(R)-, P(R)-, As(R)- and Sb(R)-,
• R, R 1 and R 2 are independently chosen from hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted allyl, optionally substituted aryl and optionally substituted heteroaryl.
• R, R 1 and R 2 groups, when present, may optionally be directly linked to the Ar moiety by one or more linker species as well as via the said C, N, P, As or Sb atom.
• Halides may suitably be selected from chlorides, bromides and iodides.
• pseudo-halides are cyanide, thiocyanate (SCN), cyanate (OCN), isocyanate (NCO) and isothiocyanate (NCS), isoselenocyanate (NCSe).
• SCN thiocyanate
• OCN cyanate
• NCO isocyanate
• NCS isothiocyanate
• Cz refers to carbazolate and DTBCz refers to S ⁇ -di ⁇ butylcarbazolate.
• alkoxides for use as ligand X include, but are not limited to, linear or branched chain alkoxides having from 1 to 20 carbon atoms.
• aryl oxides for use as ligand X include, but are not limited to, phenolate, 2- methylphenolate, 2-tert.butyl-5-methylphenolate, 2,6-dimethylphenolate, 3,5-dimethylphenolate, 3.5-di-f-butylphenolate, 3,5-bis(trifluoromethyl)phenolate, 2-chlorophenolate, 2,6- dichlorophenolate, 2,6-difluorophenolate, 2,6-dibromophenolate, 2,6-diiodophenolate, 4- fluorophenolate, 4-trifluoromethylphenolate, 1-naphtholate, 2-naphtholate, and the like.
• the aryloxide ligand may be substituted by one or more of carbazolyl, (N- alkyl)carbazolyl or (N-aryl)carbazolyl substituents, where each carbazolyl moiety may carry one or more oiprim.-, sec - or ferf.-alkyl substituents or any combination thereof.
• thiolates for use as ligand X include, but are not limited to, linear or branched chain thiolates having from 1 to 20 carbon atoms.
• thiophenolates for use as ligand X include, but are not limited to, thiophenolate, 2- methylthiophenolate, 2-tert.butyl-5-methylthiophenolate, 2,6-dimethylthiophenolate, 3,5- dimethylthiophenolate, 3.5-di-f-butylthiophenolate, 3,5-bis(trifluoromethyl) thiophenolate, 2- chlorothiophenolate, 2,6-dichlorothiophenolate, 2,6-difluorothiophenolate, 2,6- dibromothiophenolate, 2,6-diiodothiophenolate, 4-fluorothiophenolate, 4- trifluoromethylthiophenolate, 1 -thionaphtholate, 2-thionaphtholate, and the like.
• the thiophenolate ligand may be substituted by one or more of carbazolyl, (N-alkyl)carbazolyl or (N- aryl)carbazolyl substituents, where each carbazolyl moiety may carry one or more prim.-, sec- or ferf.-alkyl substituents or any combination thereof.
• X is a carboxylate group represented by RCOO " or a thiocarboxylate group represented by RCSO "
• the group R in those representations may, for example, be chosen from alkyl, alkenyl, aryl and heteroaryl.
• X can be a ketiminate represented by R 1 R 2 CN " , in which R 1 and R 2 may independently be chosen from one or more alkyl, alkenyl, aryl and heteroaryl groups.
• X may be a guanidinate represented by [(R 1 R 2 N)C(NR 3 )(NR 4 )] " , in which R 1 , R 2 , R 3 and R 4 are independently chosen from one or more alkyl, alkenyl, aryl and heteroaryl groups.
• the ligand X is an optionally substituted amide group having the following general formula in which the nitrogen atom N is an amide anionic nitrogen:
• Rn, Rm and Rk represent optional substituents of the respective aromatic rings, in which n, m and k are numbers from 0 to the maximum available and in each case the presence, number, position and/or identity of the said substituents may be the same or different as between different aromatic ring moieties; and, where n, m or k is more than 1, the identity of each R group of the substituents of a particular aromatic ring moiety may be the same or different as between each other; and
• R' is selected from hydrogen, optional
• the ligand X may be a diarylamide or carbazolate anion.
• the aryl groups in the diarylamide anion or the aromatic rings in the carbazolate anion may each be optionally substituted.
• the diarylamide anion may, for example, be a diphenylamide anion (NPI12 " ), in which the phenyl groups are each optionally substituted by one or more substituents, the presence, number, position and/or identity of which may be the same or different between the two phenyl groups.
• the substituent(s), when present, is/are suitably selected from the groups set out below in the discussion of the expression "Optionally substituted".
• An example of a preferred diarylamide ligand X is a diphenylamide anion.
• the carbazolate anion may, for example, be a carbazolate anion in which the aromatic rings are each optionally substituted by one or more substituents, the presence, number, position and/or identity of which may be the same or different between the two aromatic rings.
• the substituent(s), when present, is/are suitably selected from the groups set out below in the discussion of the expression "Optionally substituted”.
• Examples of preferred carbazolate ligands X are the carbazolate anion and the 3,6-di-t.butyl- carbazolate anion.
• Substituents within the definitions of Rn, Rm and Rk, and substituents of the diarylamide and carbazolate anions referred to above, may for example be selected from the group of alkyl, aryl, alkenyl, alkynyl, each of which may optionally be substituted (such substituted forms including, for example: haloalkyl (for example, fluoroalkyl containing one or more fluorine atoms, for example perfluoroalkyl), haloalkenyl (for example, fluoroalkenyl containing one or more fluorine atoms, for example perfluoroalkenyl), haloaryl (for example, fluoroaryl containing one or more fluorine atoms, for example perfluoroaryl)), NMe 2 , NO2, SO3H and COOH.
• haloalkyl for example, fluoroalkyl containing one or more fluorine atoms, for example perfluoroalky
• X is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings.
• Any monoanionic organic amide ligand X according to this definition may be present, such as those monoanionic organic amide ligands described above in relation to part A of the definition of Formula I of the present invention.
• Examples of complexes of Formula la used in the second aspect of the invention include those in which X is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings; and more preferably those in which M is copper or gold and X is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings.
• organic group refers to groups containing at least carbon covalently bonded to other atoms.
• X in a complexes of Formula I or la is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings; the organic group may preferably be an organic group containing at least carbon and hydrogen.
• Such an organic group may optionally contain one or more heteroatom, for example selected from B, N, O, P and S, and/or one or more halogen atom, for example selected from CI, F and I.
• M is copper
• L is a cyclic alkyl amino carbene (CAAC) ligand having a saturated cyclic structure in which the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom; and
• CAAC cyclic alkyl amino carbene
• X is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings.
• M is gold;
• L is a cyclic alkyl amino carbene (CAAC) ligand having a saturated cyclic structure in which the atoms of the ring which includes the carbene site consist of carbon atoms and one nitrogen atom; and
• CAAC cyclic alkyl amino carbene
• X is a monoanionic organic amide ligand having the formula in which R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings.
• Alkyl means an aliphatic hydrocarbon group.
• the alkyl group may be straight or branched. "Branched” means that at least one carbon branch point is present in the group.
• the alkyl group may suitably contain 1 - 20 carbon atoms, e.g. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms.
• Exemplary alkyl groups include methyl, ethyl, «-propyl, /-propyl, «-butyl, f-butyl, s-butyl, «-pentyl, 2-pentyl, 3-pentyl, «-hexyl, 2-hexyl, 3-hexyl, «-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 2-methyl-but-l- yl, 2-methyl-but-3-yl, 2-methyl-pent-l-yl, 2-methylpent-3-yl.
• the alkyl group may be optionally substituted, e.g. as exemplified below.
• Cycloalkyl means a cyclic non-aromatic hydrocarbon group.
• the cycloalkyl group may include non-aromatic unsaturation.
• Cycloalkyl groups may be mono- or polycyclic, and polycyclic cycloalkyl groups may be fused-ring, spiro, cage or combinations thereof.
• the cycloalkyl group preferably has 3 to 20 carbon atoms, e.g. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms.
• Exemplary cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentenyl, cyclohexenyl norbornyl, adamantyl.
• the cycloalkyl group may be optionally substituted, as defined below, e.g. as exemplified below.
• Alkenyl means an unsaturated aliphatic hydrocarbon group which contains one or more double bond.
• the alkenyl group may be straight or branched. "Branched” means that at least one carbon branch point is present in the group.
• the alkenyl group is preferably an alkenyl group, straight or branched, having 2 to 20 carbon atoms, e.g. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms.
• Exemplary alkenyl groups include ethenyl, «-propenyl, /-propenyl, but-l-en-l-yl, but-2-en-l-yl, but- 3-en-l-yl, pent-l-en-l-yl, pent-2-en-l-yl, pent-3-en-l-yl, pent-4-en-l-yl, pent-l-en-2-yl, pent-2-en-2- yl, pent-3-en-2-yl, pent-4-en-2-yl, pent-l-en-3-yl, pent-2-en-3-yl, pentadien-l-yl, pentadien-2-yl, pentadien-3-yl.
• the alkenyl group may be optionally substituted, e.g. as exemplified below.
• Alkynyl means an unsaturated aliphatic hydrocarbon group which contains one or more triple bond.
• the alkynyl group may be straight or branched.
• Branched means that at least one carbon branch point is present in the group.
• the alkynyl group is preferably an alkynyl group, straight or branched, having 2 to 20 carbon atoms, e.g. 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms.
• exemplary alkynyl groups include ethynyl, 1-propynyl, 1-butynyl, 2-butynyl.
• alkynyl group may be optionally substituted, e.g. as exemplified below.
• Aryl means any aromatic group, preferably having up to about 20 carbon atoms, e.g. 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms.
• the aryl group may comprise one, two or more rings. Where two or more rings are present they may if desired be fused.
• the aryl group preferably comprises one or more phenyl ring.
• Exemplary aryl groups include phenyl, naphthyl, biphenyl.
• the aryl group may be optionally substituted, e.g. as exemplified below.
• Heteroaryl means any aromatic monocyclic, bicyclic, or tricyclic ring which comprises carbon atoms and one or more ring heteroatoms, e.g., 1, 2, 3, 4, 5 or 6 heteroatoms, preferably independently selected from the group consisting of nitrogen, oxygen, phosphorus, silicon and sulfur. Heteroaryl groups preferably have a ring system containing from 5 to 20 ring atoms, e.g. 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 ring atoms. Where two or more rings are present they may if desired be fused.
• heteroaryl groups include pyridyl, pyrazinyl, pyrimidinyl, furayl, thiophenyl, pyrrolyl, oxazole, thiazole, pyrazole, imidazole, 1,2,3 -triazole, 1,2,4-triazole, tetrazole, indole, purine, carbazole, benzindole, benzufuran, dibenzofuran, benzothiphene, azacarbazole, azabenzofuran, azadibenzothiophene.
• the heteroaryl group may be optionally substituted, e.g. as exemplified below.
• Hydrocarbyl group means any group consisting only of carbon and hydrogen atoms, provided that if so specified it may optionally contain one or more heteroatom and/or be optionally substituted, as discussed below. Hydrocarbyl groups may be cyclic, straight or branched, and may be saturated, unsaturated or aromatic. Cyclic hydrocarbyl groups may be mono- or polycyclic, and polycyclic hydrocarbyl groups may be fused-ring, spiro, cage or combinations thereof.
• the hydrocarbyl group may optionally contain one or more heteroatom, e.g., 1, 2, 3, 4, 5 or 6 heteroatoms, independently selected from the group consisting of nitrogen, oxygen, and sulfur.
• the hydrocarbyl group may be optionally substituted, e.g. as exemplified below.
• aryloxide means an O-linked aryl group or the anionic form of the corresponding aryl- OH compound.
• aryloxide compounds include, but are not limited to, phenolate, 2-methylphenolate, 2- f-butyl-5-methylphenolate, 2,6-dimethylphenolate, 3,5-dimethylphenolate, 3.5-di-i-butylphenolate,
• amide refers for example to the [NRR'] " anion, where R and R' independently can be a hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, cycloalkyl, halogenated alkyl, or heterocycloalkyl group described above.
• R and R' may, for example, be connected to each other.
• An amide group may be optionally substituted, e.g. as exemplified below.
• amide includes, for example, an optionally substituted amide group having the following general formula in which the nitrogen atom N is an amide anionic nitrogen:
• the ligand X may be a diarylamide or carbazolate anion.
• the aryl groups in the diarylamide anion or the aromatic rings in the carbazolate anion may each be optionally substituted.
• the diarylamide anion may, for example, be a diphenylamide anion (NPI12 " ), in which the phenyl groups are each optionally substituted by one or more substituents, the presence, number, position and/or identity of which may be the same or different between the two phenyl groups.
• the substituent(s), when present, is/are suitably selected from the groups set out below in the discussion of the expression "Optionally substituted".
• An example of a preferred diarylamide ligand X is a diphenylamide anion.
• the carbazolate anion may, for example, be a carbazolate anion in which the aromatic rings are each optionally substituted by one or more substituents, the presence, number, position and/or identity of which may be the same or different between the two aromatic rings.
• the substituent(s), when present, is/are suitably selected from the groups set out below in the discussion of the expression "Optionally substituted”.
• Examples of preferred carbazolate ligands X are the carbazolate anion and the 3,6-di-t.butyl- carbazolate anion.
• Substituents within the definitions of Rn, Rm and Rk, and substituents of the diarylamide and carbazolate anions referred to above, may for example be selected from the group of alkyl, aryl, alkenyl, alkynyl, each of which may optionally be substituted (such substituted forms including, for example: haloalkyl (for example, fluoroalkyl containing one or more fluorine atoms, for example perfluoroalkyl), haloalkenyl (for example, fluoroalkenyl containing one or more fluorine atoms, for example perfluoroalkenyl), haloaryl (for example, fluoroaryl containing one or more fluorine atoms, for example perfluoroaryl)), NMe2, NO2, SO3H and COOH.
• amide groups mentioned above is the substituted amide group having the following general formula:
• Rn and Rm are the same as each other and are perfluoroalkyl.
• thiophenylate refers to aryl thiolates.
• the aryl portion of the thiophenylate group may be optionally substituted, e.g. as exemplified below.
• thiophenylate compounds include, but are not limited to, thiophenolate, 2- methylthiophenolate, 2- ⁇ butyl-5-methylthiophenolate, 2,6-dimethylthiophenolate, 3,5- dimethylthiophenolate, 3.5-di- ⁇ butylthiophenolate, 3,5-bis(frifluoromemyl)thiophenolate, 2- chlorothiophenolate, 2,6-dichlorothiophenolate, 2,6-difluorothiophenolate, 2,6- dibromothiophenolate, 2,6-diiodothiophenolate, 4-fluorothiophenolate, 4- trifluoromethylthiophenolate, 1 -thionaphtholate, 2-thionaphtholate.
• Phosphiniminates 4- trifluoromethylthiophenolate, 1 -thionaphtholate, 2-thionaphtholate.
• phosphiniminate refers to the anionic form of compounds containing the [ ⁇ 3 ⁇ 43 ⁇ 4 3 ⁇ ] " moiety, where R 1 , R 2 and R 3 are independently chosen from organic groups optionally containing heteroatoms, preferably selected from Si, P, O, S or N.
• the organic groups may suitably be selected from alkyl, alkenyl, aryl or heteroaryl groups.
• the phosphiniminate group may be optionally substituted, e.g. as exemplified below.
• the organic groups may suitably be selected from alkyl, alkenyl, aryl or heteroaryl groups.
• the ketiminate group may be optionally substituted, e.g. as exemplified below. Guanidinates
• guanidinate refers to the anionic form of compounds of the formula (R 1 R 2 N)C(NR 3 )(NR 4 ), namely [(R 1 R 2 N)C(NR 3 )(NR 4 )] " , where R 1 , R 2 , R 3 and R 4 are independently chosen from organic groups optionally containing heteroatoms, preferably selected from Si, P, O, S or N.
• the organic groups may suitably be selected from alkyl, alkenyl, aryl or heteroaryl groups.
• the guanidinate group may be optionally substituted, e.g. as exemplified below.
• Optionally substituted as applied to any group means that the said group may if desired be substituted with one or more substituents, which may be the same or different, preferably one or more substituents which individually have a size which is small in relation to the parent group being substituted (e.g. less than about 20% of the largest molecular dimension).
• a group cannot be a substituent of its own kind if it would thereby form a group of that kind which would then fall outside the definition of the compounds (e.g. an alkyl group cannot be a substituent of another alkyl group so that an alkyl group having too many carbon atoms would result).
• suitable substituents include halo (e.g.
• Ci-20 alkyl C2-20 alkenyl, C2-20 alkynyl, C2-20 cycloalkyl, hydroxy, thiol, Ci-20 alkoxy, C2-20 alkenyloxy, C2-20 alkynyloxy, amino, nitro, Ci-20 alkylamino, C2-20 alkenylamino, di-Ci-20 alkylamino, Ci-20 acylamino, di-Ci-20 acylamino, Ce-io aryl, Ce-io heteroaryl, Ce-io arylamino, di-Ce-2o arylamino, Ce-io aroylamino, di-Ce-2o aroylamino, Ce-io arylamido, carboxy, Ci-20 alkoxycarbonyl or (Ce-io ar)(Ci-2o alkoxy)carbonyl, carbamoyl, sulphoxy (e.g., a)(Ci-2o alkoxy)carbonyl
• sulphoxide sulfone, sulphonyl, sulpho
• suitable substituents include halo (e.g.
• acyl means an H-CO- or Ci-20 alkyl-CO- group wherein the alkyl group is as defined below.
• Preferred acyls contain an alkyl.
• Exemplary acyl groups include formyl, acetyl, propanoyl, 2- methylpropanoyl and butanoyl.
• substituted alkyl groups include mono- or poly-aryl-substituted alkyl groups such as phenylmethyl, naphthylmethyl, diphenylmethyl, phenylethyl, naphthylethyl, diphenylethyl, phenylpropyl, naphthylpropyl, diphenylpropyl.
• Exemplary substituted cycloalkyl groups include mono- or poly-alkyl-substituted cycloalkyl groups such as 1 -methylcyclopropyl, 1 -methylcyclobutyl, 1-methylcyclopentyl, 1-methylcyclohexyl, 2- methylcyclopropyl, 2-methylcyclobutyl, 2-methylcyclopentyl, 2-methylcyclohexyl.
• Exemplary substituted aryl groups include, at any substitution position or combination of positions, Ci-20 alkoxyphenyl such as methoxyphenyl, hydroxyphenyl, (Ci-20 alkoxy)(hydroxy)phenyl such as methoxy-hydroxyphenyl, Ci-20 alkylphenyl such as methylphenyl, (Ci-20 alkyl)(hydroxy)phenyl such as methyl-hydroxyphenyl, monohalophenyl such as monofluorophenyl or monochlorophenyl, dihalophenyl such as dichlorophenyl or chlorofluorophenyl, carboxyphenyl, Ci- 20 alkoxycarbonylphenyl such as methoxycarbonylphenyl.
• complexes of Formula la have the same examples, embodiments and preferences as the complexes of Formula I, with the exception that the compound Ad L-Au-NTf2 in which Ad L is
• Tf is CF3-SO2- is excluded from complexes of Formula la.
• Complex 8C(e) the embodiment of complex 8C in which E is -S-, Rn and Rm are -NO2 at each of the 3 and 7 positions of the phenothiazine moiety.
• Additional examples of complexes of Formula I or la according to the present invention include:
• M is selected from copper, silver and gold, more preferably copper and gold;
• L is selected from compounds of Formula Ilia: wherein R a , R b , R c and R d are CH3 groups, and Ar represents a substituted phenyl group, for example a 2,6-dialkyl substituted phenyl group, for example a 2,6-diisopropylphenyl group; or R a and R b are methyl groups and R c and R d are ethyl groups, and Ar represents a substituted phenyl group, for example a 2,6-dialkyl substituted phenyl group, for example a 2,6- diisopropylphenyl group; or R a and R b are methyl groups and R c and R d together form an optionally substituted cycloalkylidene (spirocycloalkyl) group, for example cyclohexylidene (spiro-cyclohexyl), and Ar represents a substituted phenyl group, for example a 2,6-dialky
• R a and R b are CH3 groups and Ar represents a substituted phenyl group, for example a 2,6- dialkyl substituted phenyl group, for example a 2,6-diisopropylphenyl group; and
• X is a monoanionic organic amide ligand having the formula
• R' and R" are selected from hydrogen and organic groups, which when both organic groups may be the same or different; and 3 represents a cyclic organic group which may contain one or more rings; preferably having the following general formula in which the nitrogen atom N is an amide anionic nitrogen:
• Rn, Rm and Rk represent optional substituents of the respective aromatic rings, in which n, m and k are numbers from 0 to the maximum available and in each case the presence, number, position and/or identity of the said substituents may be the same or different as between different aromatic ring moieties; and, where n, m or k is more than 1, the identity of each R group of the substituents of a particular aromatic ring moiety may be the same or different as between each other; and
• the present invention provides a light-emitting device comprising, in sequence, an anode, optionally a hole-transporting zone, an emissive zone capable of emitting light when an electric current flows between the cathode and the anode, and a cathode.
• the emissive zone capable of emitting light comprises at least one complex of Formula I or Formula la.
• the light-emitting device is preferably constructed as a multilayer according to techniques known in the art.
• the basic layer arrangement stated above may be modified in a variety of ways known in the art, for example by incorporation of one or more additional layers or sub -layers, and by the provision of electrical conductors and means for housing and supporting the device in the desired position and orientation.
• the present invention also provides a light-emitting device comprising an emissive zone capable of emitting light in response to introduced energy, wherein the emissive zone capable of emitting light comprises at least one organometallic complex which exhibits RASI photoemission.
• the present invention provides a method of preparing a component for use in a light-emitting device according to the present invention, which comprises depositing on a substrate a layer of an organic emissive zone component from a solution thereof in a solvent, with the optional provision of one or more additional layers, components or combinations thereof on the substrate before, simultaneously with, and/or after the said deposition; and removing any solvent at any desired time to provide a component for use in a light emitting device.
• the component for use in the light-emitting device comprises at least the hole-transporting zone and emissive zone of the light-emitting device.
• the component for use in the light-emitting device can comprise layers or parts of the anode, the hole- transporting zone, the emissive zone and the cathode, optionally also an electron-injection layer.
• the depositions are simultaneous, sequential, or some of the layers are deposited simultaneously and some are deposited sequentially.
• the layers of the device according to the present invention may be deposited by any suitable method.
• preferred methods include thermal evaporation, ink-jet deposition (for example, as described in US Patents Nos. 6,013,982 and 6,087,196, the contents of which are incorporated herein by reference), organic vapour phase deposition (OVPD) (for example, as described in US Patent No.
• deposition by organic vapour jet printing examples include spin coating and other solution based processes. Solution based processes are preferably carried out in nitrogen or an inert gas atmosphere.
• preferred methods include thermal evaporation.
• Preferred patterning methods include deposition through a mask, cold welding such as described in US Patents Nos. 6,294,398 and 6,468,819 (the contents of which are incorporated herein by reference), and patterning associated with some of the deposition methods such as ink- jet and OVJD. Other methods may also be used.
• the materials to be deposited may be selected to make them compatible with a particular deposition method.
• substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 carbon atoms or more may be used, and 3-20 carbons is a preferred range. Materials with asymmetric structures may have better solution processibility than those having symmetric structures, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents may be used to enhance the ability of small molecules to undergo solution processing.
• solvents in which the complexes of the present invention may be dissolved or suspended for deposition in the manufacture of light-emitting devices include without limitation halogenated alkanes (for example, chloroform, dichloromethane, 1,2-dichloroethane or trichloroethane); aromatic solvents (for example, benzene, toluene, chlorobenzene, fluorobenzene, difluorobenzene or dichlorobenzene); ethers (for example, diethyl ether, tetrahydrofuran or methylated tetrahydrofuran); ketones (for example, acetone or methyl ethyl ketone); alcohols (for example, methanol or higher alcohols); acetonitrile; nitromethane; nitrobenzene; esters (for example, ethyl acetate); or any combination of one or more thereof.
• halogenated alkanes for example, chloroform, dichlorome
• Examples of light-emitting devices according to the present invention include organic light- emitting diodes (OLEDs), organic phototransistors, organic photovoltaic cells and organic photodetectors.
• OLEDs for example, are of interest for flat panel displays, illumination and backlighting. Examples of configurations and constructions of OLEDs are given in US Patent Nos. 5,844,363, 6,303,238 and 5,707,745, the contents of which are incorporated herein by reference.
• Light-emitting devices in accordance with the present invention may be incorporated into a wide variety of consumer products, including without limitation flat panel displays, computer monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads up displays, fully transparent displays, flexible displays, laser printers, telephones, cell phones, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, vehicles, a large area wall, theatre or stadium screen, or a sign.
• Pixel control systems and technologies may be used in known manner with the devices of the present invention, to control the images presented to the viewer. Such pixel control systems include without limitation passive matrix and active matrix technologies.
• the complexes of the present invention may, for example, be made by solution processing.
• the present invention provides a method of preparing the complexes, the method comprising contacting a compound of Formula II:
• M and X in the compound of Formula II each has the same exemplification and preferences as described herein for the complex of Formula I or la.
• One preference for X in the compound of Formula II is therefore halide.
• Suitable examples of compounds of Formula II are copper (I) chloride, copper (I) bromide, copper (I) iodide, silver chloride, silver bromide and silver iodide.
• the contacting of the reagents suitably takes place in water-free conditions, and preferably under an inert atmosphere (for example, nitrogen or argon).
• the complexing solvent may suitably be selected from halogenated alkanes (for example, chloroform, dichloromethane, 1,2-dichloroethane or trichloroethane); aromatic solvents (for example, benzene, toluene, chlorobenzene, fluorobenzene, difluorobenzene or dichlorobenzene); ethers (for example, diethyl ether, tetrahydrofuran or methylated tetrahydrofuran); ketones (for example, acetone or methyl ethyl ketone); alcohols (for example, methanol or higher alcohols); acetonitrile; nitromethane; nitrobenzene; esters (for example, ethyl acetate); and any combination of one or more thereof.
• halogenated alkanes for example, chloroform, dichloromethane, 1,2-dichloroethane or trichloroethane
• Recovery of the complex from the solvent may suitably be achieved by evaporation of the solvent or by the use of an appropriate countersolvent, for example an alkane (for example, hexane or light petroleum ether).
• the recovered complex may be dried, suitably under vacuum, to recover the dry material.
• the CAAC starting materials L may be readily prepared by methods known in the art. For example, the following general synthetic route, and variations thereof, is described in WO-A- 2006/138166, the content of which is incorporated herein by reference:
• CAACs Cyclic (Alkyl)(Amino)Carbenes
• the compound of Formula I or la may be prepared by a method comprising contacting a CAAC compound of Formula lb: L-Cu-X' (lb) in which L is as defined for Formula I and X' is CI, OH or O'Bu with a compound of formula V
• the present invention provides a further method of preparing the complexes, the method comprising contacting a CAAC compound of Formula Ic:
• the method of contacting the compound of Formula lb or Ic with the compound of Formula V or Va may, for example, be carried out in dry tetahydrofuran, optionally containingor sodium tert- butoxide, under an inert atmosphere, for example under an argon atmosphere.
• the mixture may, for example, be centrifuged and the solution containing the product separated.
• NHCs such as those of Formula VI mentioned above
• different types of carbene ligands differ significantly in their electronic properties.
• the structures, electronic and steric properties of carbenes and their coordination to metal centres have been summarised in several literature reviews, see for example: F. E. Hahn, M. C. Jahnke: “Heterocyclic Carbenes - Synthesis and Coordination Chemistry", Angewandte Chemie International Edition 2008, 47, 3122-3172; M. N. Hopkinson, C. Richter, M. Schedler, F.
• dicationic binuclear copper complexes where each metal centre is coordinated to two connected imidazole-type NHC ligands which hold the metal centres in close proximity, have been reported to show photoluminescent behaviour, with moderate quantum yield [K. Matsumoto et al., Dalton Transactions 2009, 6795-6801, which is incorporated herein by reference].
• charged complexes are undesirable, and linked bis(carbene) ligands involve an undesirable level of synthetic complexity.
• Three- coordinate copper complexes involving one NHC ligand per metal centre are also known to be photoemissive and have been described in detail for example in U.S. Pat.
• the complexes in the present invention differ from these prior known NHC-copper complexes in that they have a coordination number of 2, the carbene species contains only one ring nitrogen atom, and only one carbene species is present. Furthermore, as discussed above the complexes of the present invention have the potential to emit light via RASI photoemission, offering the possibility of light-emitting devices with high quantum efficiency.
• Bertrand "Cyclic (Alkyl)(Amino)Carbenes (CAACs): Stable Carbenes on the Rise", Accounts of Chemical Research 2015, 48, 256-266, and O. Back, M. Henry-Ellinger, C. D. Martin, D. Martin, and G. Bertrand: " 31 P NMR Chemical Shifts of Carbene-Phosphinidene Adducts as an Indicator of the ⁇ -Accepting Properties of Carbenes", Angew. Chem. Int. Ed. 2013, 52, 2939 -2943]. The same applies to carbenes of formula III with larger rings.
• the substituents on the CAAC ring carbon atom that is adjacent to the carbene centre provide steric hindrance.
• the steric hindrance is further increased by using a bulky N-substituent R 1 .
• further substituents may, if desired be introduced to make the steric effects even more pronounced.
• the strong electron donation raises the energy of the d-orbitals on the metal atom M, for example copper. Without wishing in any way to be bound by theory, it is hypothesized that this increase in the energy of the d-electrons of the metal facilitates metal-to-ligand charge transfer during the excitation process.
• the carbene C atom has an empty p-orbital which can act as electron acceptor.
• WO 2014/108430 for example, the content of which is incorporated herein by reference, in copper complexes excited S 1 singlet and T 1 triplet states are close in energy, and there is the possibility that a thermal equilibrium between these two states is established.
• the emission pathways from S 1 or T 1 states may, for example, include the RASI photoemission pathway described herein.
• the complexes of the present invention offer good solubility in organic solvents.
• Organic solvents are used during the construction of printed OLED devices, for example, and adequate solubility of the emissive complexes is important for their incorporation.
• the complexes of the present invention enable materials which potentially have very high internal quantum efficiency, for example equal to or greater than about 75%, e.g. equal to or greater than about 80%, equal to or greater than about 85%, equal to or greater than about 90%, equal to or greater than about 95%, equal to or greater than about 96%, equal to or greater than about 97% or equal to or greater than about 98%.
• Figure 1 Schematic representation of the OLED device structure. Additional electron transport and confinement layers may be added as required.
• FIG. 1 Crystal structure of independent molecules for ( Ad CAAC)CuCl / ( Ad CAAC)CuBr. Ellipsoids are shown at the 50% level. Hydrogen atoms are omitted for clarity. Selected bond lengths [A] and angles [°] : CulA-C IA 1.883(2) / 1.893(4), CulA-HallA 2.1099(5) / 2.2176(6), C1A-C2A 1.530(2) / 1.523(5), C 1A-N1A 1.305(2) / 1.301(5), ClA-CulA-HallA 175.33(5) / 177.59(1 1). Figure 3.
• FIG. 8 Crystal structure of ( Ad CAAC)CuCCPh. Ellipsoids are shown at the 50% level. Hydrogen atoms are omitted for clarity. Selected bond lengths [A] and angles [°] : Cul-C l 1.9005(16), Cul- C28 1.9044(17), C1-C2 1.526(2), C l-Nl 1.308(2), C28-C29 1.172(3), C29-C30 1. 144(3), Cl- Cul-C28 175.44(7), Cul-C28-C29 172.75(17).
• Figure 9. UV-vis spectrum (left) for THF solution of ( Ad CAAC)CuCCPh; Emission spectrum (right) for ( Ad CAAC)CuCCPh in the solid state (excited aU ex 374 nm).
• Figure 12. X-ray structure of ( Ad CAAC)CuCz (CMA2). Ellipsoids are shown at the 50% level. Hydrogen atoms are omitted for clarity.
• FIG. 16 Photoluminescence decay data of ( Ad CAAC)Au(carbazolate) (CMA l) measured by time -correlated single photon counting (TCSPC).
• FIG. Temperature-dependent Photoluminescence decay data of ( Ad CAAC)Au(carbazolate) (CMAl) measured by an electrically-gated intensified charge coupled device (CCD).
• Figure 18. a External quantum efficiency (EQEs) of multi-layer OLEDs prepared according to Example 28 incorporating ( Ad CAAC)metal amide complexes.
• EQEs External quantum efficiency of multi-layer OLEDs prepared according to Example 28 incorporating ( Ad CAAC)metal amide complexes.
• EQEs External quantum efficiency of multi-layer OLEDs.
• E(Si) may be lowered sufficiently, so that the inversion of spin-state energies (i?(Ti) > £(Si)) can be achieved, b, ( Ad CAAC)AuCz (CMA l) and its analogues, c, Optimised molecular geometries of CMAl for its ground state (So), excited singlet (Si) and triplet (Ti) states, d, Highest-occupied molecular orbital (HOMO) and lowest- unoccupied molecular orbital (LUMO) of CMA l, obtained from DFT and time-dependent density functional theory (TD-DFT) calculations.
• HOMO Highest-occupied molecular orbital
• LUMO lowest- unoccupied molecular orbital
• Figure 20 DFT and TD-DFT calculations for CMA2-4.
• a Optimised molecular geometries for So, Si, and Ti.
• b HOMO and LUMO.
• FIG. 21 Photophysical characterisation and temperature-dependent emission kinetics of CMAl.
• a Absorption at 300K.
• b Evolution of PL spectra with time at 300K.
• c Temperature-dependent photoluminescent (PL) kinetics
• f Temperature-dependent decay rate kr, showing an activation energy of 45 meV above 100K.
• FIG 22 Temperature-dependent PL decay kinetics and activation energies for CMA2-4.
• Figure 23 Device performance and electroluminescence (EL) measurements, a, Structure and photographs of working devices, b, Energy levels of materials used to produce the prototype devices.
• CMAl is used as an example, c, external quantum efficiency (EQE) curves and EL spectra (inset), d, Histogram of the maximum EQE measured from 135 devices based on CMA4.
• EQE external quantum efficiency
• EQE external quantum efficiency
• EQE external quantum efficiency
• e Comparison of fast, slow PL and steady-state EL (for 20 wt% of CMAl in PVK host)
• f Transient- EL curves measured after holding a device based on CMAl at various steady-state current densities.
• Figure 24 Additional device performance data for Example 29.
• Luminance versus voltage b
• current density versus voltage c
• Angular emission profile of a representative device consistent with Lambertian emission characteristics as fitted by the red line
• d, e CIE coordinates as a function of EQE for ROLEDs fabricated from CMAl and CMA4.
• Figure 25 Crystal structures of a. (CAAC)AuNPh 2 (CMA3) and b. (CAAC)AuDTBCz (CMA4). Ellipsoids are shown at the 50% level. Hydrogen atoms are omitted for clarity.
• FIG. 26 Cyclic voltammogram. a, CMA 1. b, CMA2. Data was recorded using a glassy carbon electrode in MeCN solution with [n-Bu4N]PFe as supporting electrolyte with a scan rate of 0.1 V s ⁇
• FIG. 27 Photoluminescence spectra of representative gold complexes of NPh 2 and ring amide ligands (in the solid state, 298 K), showing the range of emission colours provided by these compounds.
• Example 2 Synthesis of ( Ad CAAC)CuBr. Prepared as described in Example 1 from 217 mg (0.58 mmol) of Ad CAAC and 82.5 mg (0.58 mmol) of CuBr as a white solid. Yield: 0.193 g (0.37 mmol, 64%).
• FIGS 4 and 5 show the emission spectra of ( Ad CAAC)CuCl in different solvents (tetrahydrofuran (THF), acetonitrile, 1,4-dioxane, ethanol, pyridine and acetone).
• THF tetrahydrofuran
• acetonitrile 1,4-dioxane
• ethanol 1,4-dioxane
• pyridine 1,4-dioxane
• the complex was prepared as described for Example 1 from Ad CAAC: (0.32 g, 0.86 mmol) and CuCN (77 mg, 0.86 mmol) as a white powder. Yield: 0.34 g (0.73 mmol, 86 %).
• the complex was prepared as described for Example 1 from Ad CAAC: (0.30 g, 0.80 mmol) and CuSCN (96 mg, 0.80 mmol) as a white powder. Yield 0.34 g (0.68 mmol, 86 %).
• the crystal structure is shown in Figure 6.
• Figure 8 shows the crystal structure of the complex.
• Figure 9 shows the UV/vis and emission spectra of ( Ad CAAC)Cu(CCPh).
• Example 7 Synthesis of ( Ad CAAC)CuOPh.
• a mixture of Ad CAACCuCl (0.20 g, 0.42 mmol), NaO'Bu (40 mg, 0.42 mmol) and phenol (39 mg, 0.42 mmol) were placed in a Schlenk flask under argon. Dry THF (10 mL) was added to and the mixture was stirred overnight. All volatiles were removed in vacuum. The residue was dissolved in dry toluene, centrifuged and decanted. A slightly yellow solution was evaporated to give a white solid. Yield 0.20 g (0.38 mmol, 91 %).
• Figure 10 shows the UV/vis and emission spectra of ( Ad CAAC)CuOPh.
• Example 8 Synthesis of ( Ad CAAC)Cu-2-terf-butyl-5-methylphenolate.
• Figure 11 shows the UV/vis and emission spectra of this complex.
• Example 9 Synthesis of ( Ad CAAC)CuNHPh.
• Figure 12 shows the X-ray structure of this complex (data given in the summary of Figure 12 above).
• Example 13 Photophysical Data on Complexes.
• the complexes according to the present invention offer several advantages for use in OLED devices, such as short excitation lifetimes in the range of nanoseconds to tens of microseconds.
• the photophysical properties of representative examples were determined and are shown in Table 1 below. It should be noted that some of the quantum yields were measured in air, which explains surprisingly low yields in some cases.
• Example 14 Synthesis of ( Ad CAAC)Au(carbazolate) (CMA1).
• Product usually contains THF as a solvate and therefor was kept under vacuum for 2 h at 80 °C to remove solvate molecules.
• Figure 25b shows the X-ray structure of this complex (data given in the summary of Figure 25b above).
• Example 16 Synthesis of ( Ad CAAC)AuNPh 2 (CMA3).
• Figure 15 shows the UV/vis and emission spectra of this complex and Figure 25a shows the X-ray structure of this complex (data given in the summary of Figure 25a above).
• Example 14 Following the procedure described in Example 14, the compound was made from Ad CAACAuCl (0.182 g, 0.30 mmol), NaOl u (31 mg, 0.32 mmol) and 2,6-dimethylphenol (37 mg, 0.3 mmol) as a white powder. Yield: 0.195 g (0.28 mmol, 93 %).
• Example 21 Synthesis of ( Ad CAAC)Au (oxazine). Following the procedure described for ( Ad CAAC)Au(carbazolate) (Example 14), the complex was made from ( Ad CAAC)AuCl (0.2 g, 0.33 mmol), NaO'Bu (33 mg, 0.33 mmol) and oxazine (61.5 mg, 0.33 mmol) as a red powder. Yield: 0.229 g (0.30 mmol, 91 %).
• Example 25 Synthesis of ( Ad CAAC)Au(l 0,1 l-dihydrodibenz[b,f] azepine). Following the procedure described for ( Ad CAAC)Au(carbazolate) (Example 14), the complex was made from ( Ad CAAC)AuCl (0.2 g, 0.33 mmol), NaOBu (33 mg, 0.33 mmol) and 10,11-dihydro- 5H-dibenz[b,fJazepine (64.3 mg, 0.33 mmol) as an orange powder. Yield: 0.230 g (0.30 mmol, 91 %).
• Example 26 Synthesis of ( Ad CAAC)Cu(10,ll-dihydrodibenz[b,f]azepine). Following the procedure described for ( Ad CAAC)Au(carbazolate) (Example 14), the complex was made from ( Ad CAAC)CuCl (0.2 g, 0.42 mmol), NaOBu (40 mg, 0.42 mmol) and 10,11-dihydro- 5H-dibenz[b,fJazepine (82 mg, 0.42 mmol) as an orange powder. Yield: 0.240 g (0.38 mmol, 90 %).
• the performance of the OLED devices based on CMAl-4 is shown in Figures 18, 23 and 24.
• a multi-layer device structure of Glass/ITO/PEDOT:PSS/TFB/PVK:CMA/BPhen/LiF/Al is used.
• the functions of the layers can be described in reference to the OLED structure shown in Figure 1.
• the PVK and CMA blend forms the emissive zone.
• PEDOT:PSS and TFB layers form the hole transporting layer.
• the electron injection layer is comprised of BPhen and LiF.
• Al is the cathode material.
• ITO Indium tin oxide
• PEDTO:PSS poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (Clevios P VP AI 4083)
• TFB poly(9,9-dioctyl-fluorene-co-N-4-butylphenyl-diphenylamine) (Cambridge Display Technology)
• PVK poly(9-N-vinylcarbazole) (PVK) (Sigma- Aldrich)
• CMA CAAC metal amide (the CMAs designated CMAl, CMA2, CMA3 and CMA4, the structures of which are shown in Figure 19b, were used)
• LiF lithium fluoride (99.99%, Sigma-Aldrich)
• Figure 16 shows photoluminescence (PL) decay data of ( Ad CAAC)Au(carbazolate) (CMAl) measured by time-correlated single photon counting (TCSPC).
• PL photoluminescence
• PL decay curves at three different temperatures inset: 0-5 ns data). Note that the contribution of slow emission at low temperatures is artificially enhanced by the 2.5 MHz repetition rate of excitation pulses.
• Figure 17 shows temperature-dependent photoluminescence decay data of ( Ad CAAC)Au(carbazolate) (CMAl) measured by an electrically -gated intensified charge coupled device (CCD).
• Figure 18a shows the external quantum efficiency in OLEDs incorporating ( Ad CAAC) metal carbazolate CMA complexes, as a function of current density.
• Example 29 Further studies
• CAAC 2-coordinate cyclic (alkyl)(amino)-carbene
• Cyclic voltammograms of CMA l and CMA2 are shown in Figure 26.
• the complexes CMAl to CMA4 are soluble in a range of organic solvents, do not undergo ligand rearrangement reactions in solution, and are thermally stable to > 270 °C, as shown in Table 2:
• Table 2 Decomposition temperatures for CMAl-4 by thermal gravimetric analysis (TGA).
• the excited state energies of CMA 1 -4 were computed using density functional theory (DFT) and time -dependent density functional theory (TD-DFT) with optimisation of the molecular geometry.
• DFT density functional theory
• TD-DFT time -dependent density functional theory
• the ground state So and the relaxed triplet state Ti correspond to a geometry with the carbene and carbazole ligands being co-planar
• the relaxed singlet state Si corresponds to a geometry with the carbazole ligand being rotated by 90°.
• Solid films of CMAl -4 are photoluminescent, as has been observed in carbene metal halide compounds 14 .
• Absorption spectra for a spin-coated film of CMA 1 has an onset at approximately 450 nm ( Figure 21a), in good agreement with the DFT calculations.
• Figure 21a the emission mechanism of this class of compounds.
• All compounds show a fast component to the PL decay with lifetime of approximately 1 ns (see Figure 16) and a slow component whose lifetime is strongly dependent on temperature, as discussed further below.
• Time-resolved PL spectra of CMA l on ⁇ - ⁇ timescales at 300K, Figure 21b, show a red shift of the PL peak position from approximately 500 nm at early times (0-2 ns), to approximately 540 nm at 2 ⁇ .
• the emissive species at early times is therefore spectrally distinct from the emissive species at late times, in contrast to the behaviour of thermally activated delayed fluorescence (TADF) compounds 5 .
• the lifetime of the red-shifted slow component decreases from approximately 5 at 4K to approximately 350 ns at 300K (Figure 21c), while its intensity increases, leading to an increase in the total PL intensity with temperature (Figure 21d). This contrasts with phosphorescent compounds such as Ir(ppy)3 15 , for which the PL intensity is not sensitive to temperature and no fast emission is observed.
• FIG. 23a The performance of molecular rotation-based OLED (ROLEDs) is shown in Figure 23a.
• the energy levels of the materials used are shown in Figure 23b.
• HOMO/LUMO energies of CMAl -4 are shown in Table 4: Table 4: Formal electrode potentials for the compounds. Formal electrode potentials (Em for irreversible and E' for reversible processes (*) vs. FeCp2), onset potentials (E vs. FeCp2), EHOMO/ELUMO (eV) and band gap values (E g , eW) for the redox changes exhibited by the complexes under study in MeCN solution (0.
• TFB 17 was deposited on PEDOT:PSS to form the hole-transporting layer, while CMAl-4 dispersed in a wide-bandgap polymer host PVK 4 18 were used as the emissive layer, followed by BPhen/LiF electron-injection layer.
• Angular emission profiles for the devices showed Lambertian emission (Figure 24c), as is typical for OLEDs without microcavity outcoupling 19 , and allowed accurate estimation of EQE from on- axis irradiance. Consistent with this, the Commission Internationale de l'Eclairage (CIE) colour coordinates of the devices showed no observable variation with EQE ( Figures 24d and 24e).
• Figure 23d shows the maximum EQE histogram of 135 ROLEDs using CMA4, which produced the most efficient devices. Performance metrics are summarised in Table 2 above.
• the EQEs of the best devices at practical brightness (100 & 1000 cd m "2 ), higher than 25%, are higher than the best solution-processed LEDs 7, 20 without enhanced optical outcoupling, while the peak EQE of our best device reached 27.5%.
• Inversion of the usual ordering of the excited singlet and triplet states allowed by molecular rotation provides a mechanism to drive excitations to the lowest energy singlet, where they can emit efficiently.
• Spin-state inversion opens a new route for the design of organic optoelectronics. For example, spontaneous down-conversion from triplets to singlets is highly desirable for the realisation of electrically-pumped organic lasers.
• the possibilities of modulating the rotational motion of the emissive molecules with thermal and electromagnetic energies could allow the present invention to be used in the development of optoelectronic nanomachines.
• TCSPC Time-correlated single photon counting
• the solid-state samples for TCSPC studies were spin-coated from anhydrous tetrahydrofuran solutions (10 mg/mL) onto pre-cleaned quartz substrates. The samples were placed under high vacuum for 15 min to remove the solvent. The samples were photoexcited using a 407 nm pulsed laser with pulse width ⁇ 200 ps, at a repetition rate of 2.5 MHz. The photoluminescence was detected by a Si-based single-photon avalanche photodiode. The instrument response function has a lifetime of about 200 ps. A 420 nm long-pass filter was used to screen out any scattered laser signal in the optical path.
• Time-resolved PL spectra were recorded using an electrically-gated intensified CCD (ICCD) camera (Andor iStar DH740 CCI-010) connected to a calibrated grating spectrometer (Andor SR303i).
• a 420 nm long-pass filter was used to prevent scattered laser signal from entering the camera.
• Temporal evolution of the PL emission was obtained by stepping the ICCD gate delay with respect to the excitation pulse.
• the minimum gate width of the ICCD was approximately approximately 2.5 ns.
• the cooling of the samples was provided by liquid helium, and the temperature of the samples was regulated using a temperature-controlled cryostat.
• the slow PL process has a general decay rate of the form: where ko is a temperature-independent rate constant, and kr is a temperature-dependent rate, given by
• EA is the thermal activation energy
• 3 ⁇ 4 is Boltzmann constant
• T is the temperature in Kelvin
• ⁇ is a constant
• the EL spectra of the devices were recorded using the calibrated IC CD-spectrometer set-up used in the PL measurements. The accuracy of the spectral data was cross-checked against a Labsphere CDS-610 spectrometer, as well as a Minolta CS-1000 luminance meter. Current density-voltage- luminance (J-V-L) characteristics were measured using a Minolta CS-200 luminance meter and a Keithley 2400 source-meter. The EQE of the devices were calculated based on the Lambertian emission profile measured.
• the devices were electrically excited by a function generator using 1 kHz square voltage (current) pulses with a pulse width of 0.5 ms for the on-cycles (forward bias).
• the off-cycles of the device operation were provided by a reverse bias of -4 V to eliminate charge accumulation effects.
• the instrument response time of the function generator was approximately 10 ns.
• the transient-EL of the samples was recorded by the same ICCD spectrometer used in the PL measurements.
• Cyclic voltammetry was performed using a three-electrode configuration consisting of either a glassy carbon macrodisk working electrode (GCE) (diameter of 3 mm; BASi, Indiana, USA) combined with a Pt wire counter electrode (99.99%; GoodFellow, Cambridge, UK) and an Ag wire pseudoreference electrode (99.99%; GoodFellow, Cambridge, UK).
• GCE glassy carbon macrodisk working electrode
• Pt wire counter electrode 99.99%; GoodFellow, Cambridge, UK
• Ag wire pseudoreference electrode 99.99%; GoodFellow, Cambridge, UK
• the Ag wire pseudoreference electrodes were calibrated to the ferrocene/ferrocenium couple in MeCN at the end of each run to allow for any drift in potential, following IUPAC recommendations 82 . All electrochemical measurements were performed at ambient temperatures under an inert Ar atmosphere in MeCN containing complex under study (0.14 mM) and supporting electrolyte [n- Bu4N][PF 6 ] (0.13 mM). Data were recorded with Autolab NOVA software (v. 1.11). Elemental analyses were performed by the London Metropolitan University. X-Ray crystallography
• the crystals suitable for X-ray study for CMA2 and CMA4 were obtained by layering CH2CI2 solution with hexanes at -20 °C.
• Alert B is originated from the restriction of the resolution range of the data which was imposed by SHEL statement on the final refinement step.
• One of the 'Bu-groups was disordered into two positions with equal occupancies for CMA4.
• DFIX statement was used to adopt a tetrahedral geometry for the disordered groups of atoms.
• the structures were solved by direct methods and refined by the full-matrix least-squares against F 2 in an anisotropic (for non-hydrogen atoms) approximation.
• the ground states were fully optimised by the hybrid density functional PBEO method S5 S6 in combination with def2-TZVP basis set of Ahlrichs and coworkers S7 S8 .
• Relativistic effective core potential of 60 electrons was used to describe the core electrons of Au S9 S10 .
• the excited states were calculated for both relaxed and ground state geometries using TD-DFT sn .
• the methods and basis sets have been previously employed with success in studies of luminescent Cu- and Au-complexes si2,si3 calculations were carried out by Gaussian 09 S14 .
• Eqn. S9 By inspecting Eqn. S9, it is clear that a is a constant between 0 and 1.
• the temperature-dependent part of Eqn. S6 can then be written as which corresponds to the temperature-dependent emission rate described in the main text. Then Eqn. S6 can be simplified to Therefore, the function to describe the slow PL process can be written as
• EA is the thermal activation energy
• 3 ⁇ 4 is Boltzmann constant
• T is the temperature in Kelvin
• ⁇ is a constant
• ⁇ n ⁇ k T ) -(3 ⁇ 4 ⁇ + C (S 14).

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