Classifications

• • 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
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/0803—Compounds with Si-C or Si-Si linkages
  • C07F7/081—Compounds with Si-C or Si-Si linkages comprising at least one atom selected from the elements N, O, halogen, S, Se or Te
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/40—Organosilicon compounds, e.g. TIPS pentacene
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
  • H10K85/60—Organic compounds having low molecular weight
  • H10K85/615—Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
  • H10K85/623—Polycyclic condensed aromatic hydrocarbons, e.g. anthracene containing five rings, e.g. pentacene
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K10/00—Organic devices specially adapted for rectifying, amplifying, oscillating or switching; Organic capacitors or resistors having potential barriers
  • H10K10/40—Organic transistors
  • H10K10/46—Field-effect transistors, e.g. organic thin-film transistors [OTFT]
  • H10K10/462—Insulated gate field-effect transistors [IGFETs]
  • H10K10/466—Lateral bottom-gate IGFETs comprising only a single gate

Definitions

• the present invention is related generally to silylethynyl pentacenes and compositions containing silylethynyl pentacenes.
• the present invention is further related generally to methods of making and using silylethynyl pentacenes, as well as compositions containing silylethynyl pentacenes.
• Organic -based transistors can be manufactured at lower cost and applied to a larger area format than their inorganic counterparts albeit with reduced performance.
• organic -based transistors utilize either small molecules or polymers as the semiconductor material.
• small molecule semiconductor materials have low solubility in organic solvents and thus require a vacuum deposition method to form films.
• Shadow mask or photolithographic methods are required to pattern multiple layers in order to make useful devices.
• Vacuum deposition and lithography require processes that cost much more than processes that do not require vacuum deposition and lithography (e.g., solution coating methods).
• One cost effective approach of producing inexpensive electronic devices is to apply an organic semiconductor material by any of the following exemplary coating processes: spin coating, knife -coating, roll-to-roll web-coating, and dip coating, as well as printing processes such as ink-jet printing, screen printing, and offset lithography.
• organic semiconductor materials are notoriously insoluble in solvents and those that are soluble are generally unstable in solution. Due to insolubility and instability concerns, the ability to apply organic semiconductor materials using the above-mentioned inexpensive coating steps to form inexpensive electronic devices is limited.
• Some organic semiconductors based on pentacene with 6, 13 -silylethynyl substitution have been shown to (i) be soluble in organic solvents, (ii) be stable in solution, and (iii) provide good performance in organic field effect transistors (OFETs).
• OFETs organic field effect transistors
• 6, 13-bis[(triisopropylsilyl)ethynyl]pentacene i.e., also referred to herein as "TIPS-pentacene”
• TIPS-pentacene provides limited solubility in some organic solvents, as well as limited performance in electronic devices (e.g., transistors), for example, as measured in terms of charge carrier mobility values.
• organic compounds that provide at least one of the following: (i) enhanced solubility in one or more organic solvents, (ii) enhanced stability when incorporated into a given organic solvent, and (iii) enhanced performance when incorporated into an electronic device as a semiconductor layer as measured, for example, by the charge carrier mobility value of the electronic device.
• the present invention addresses some of the problems in the art by the discovery of organic compounds, namely, pentacene compounds with 6,13-silylethynyl substitution, having one or more of the following properties: (i) enhanced solubility in one or more organic solvents (e.g., toluene), (ii) enhanced stability when incorporated into a given organic solvent (e.g., toluene), and (iii) enhanced performance when incorporated into an electronic device as a semiconductor layer as measured by the charge carrier mobility value of the electronic device.
• the pentacene compounds of the present invention may be utilized in coatable compositions in the production of electronic devices.
• the resulting electronic device may exhibit a charge carrier mobility value of greater than about 2.0 cm 2 /V-s or higher (e.g., greater than about 2.4 cm 2 /V-s, greater than about 3.0 cm 2 /V-s, or higher).
• the present invention is directed to pentacene compounds with specific 6,13- silylethynyl substitution.
• the present invention is directed to pentacene compounds having a chemical structure:
• each R independently comprises (i) a branched or unbranched, substituted or unsubstituted alkyl group, (ii) a substituted or unsubstituted cycloalkyl group, or (iii) a substituted or unsubstituted cycloalkylalkylene group; each R' independently comprises (i) a branched or unbranched, substituted or unsubstituted alkenyl group, (ii) a substituted or unsubstituted cycloalkyl group, or (iii) a substituted or unsubstituted cycloalkylalkylene group; R" comprises (i) hydrogen, (ii) a branched or unbranched, substituted or unsubstituted alkynyl group, (iii) a substituted or unsubstituted cycloalkyl group, (iv) a substituted
• the present invention is directed to pentacene compounds having Structure A above wherein R, R' and X are as defined above;
• the present invention is directed to pentacene compounds having Structure A above wherein R, R', R", x, y, z, and X are as defined above, and at least one of R or R' comprises (i) a substituted or unsubstituted cycloalkyl group or (ii) a substituted or unsubstituted cycloalkylalkylene group.
• compositions comprising (I) at least one pentacene compound having Structure A, wherein R, R', R", x, y, z and X are as described above; and (II) a solvent.
• the compositions of the present invention may comprise the at least one pentacene compound and solvent alone or in combination with one or more additional composition components, such as a polymer additive.
• the present invention is even further directed to a substrate having at least one coatable surface and a coated layer on the at least one coatable surface, wherein the coated layer comprises a pentacene compound having Structure A, wherein R, R', R", x, y, z and
• the substrate comprises an electronic device or an electronic device component.
• the present invention is also directed to electronic devices comprising a coated layer, wherein the coated layer comprises a pentacene compound having Structure A, wherein R, R', R", x, y, z and X are as described above; wherein the electronic device has a charge carrier mobility value greater than or equal to 2.0 cm /V-s.
• the present invention is also directed to methods of making pentacene compounds having Structure A, wherein R, R', R", x, y, z and X are as described above.
• the present invention is further directed to methods of using one or more pentacene compounds to form compositions (e.g., ink jet printable compositions), coatings, substrates having a coated layer thereon, electronic device components, and electronic devices, wherein at least one pentacene compound has Structure A, wherein R,
• R', R", x, y, z and X are as described above.
• FIG. 1 is a cross-sectional view of an exemplary thin film transistor comprising a semiconductor layer formed via solution deposition of a composition containing at least one pentacene compound of the present invention
• FIG. 2 is a cross-sectional view of another exemplary thin film transistor comprising a semiconductor layer formed via solution deposition of a composition containing at least one pentacene compound of the present invention
• FIG. 3 is a representative plot of transistor outputs (I DS and (I DS ) ⁇ ) as a function of sweeping gate bias;
• FIG. 4 is a representative thermogram of a Differential Scanning Calorimetry graph for TIPS-pentacene showing the thermal transitions
• FIG. 5 is a cross-sectional view of yet another exemplary thin film transistor comprising a semiconductor layer formed via solution deposition of a composition containing at least one pentacene compound of the present invention.
• the present invention is directed to pentacene compounds having a chemical structure (also referred to herein as "Structure A”):
• each R independently comprises (i) a branched or unbranched, substituted or unsubstituted alkyl group, (ii) a substituted or unsubstituted cycloalkyl group, or (iii) a substituted or unsubstituted cycloalkylalkylene group; each R' independently comprises (i) a branched or unbranched, substituted or unsubstituted alkenyl group, (ii) a substituted or unsubstituted cycloalkyl group, or (iii) a substituted or unsubstituted cycloalkylalkylene group;
• each X independently comprises (i) hydrogen, (ii) a halogen, (iii) a branched or unbranched, substituted or unsubstituted alkyl group, (iv) a substituted or unsubstituted aryl group, (v) a branched or unbranched, substituted or unsubstituted alkenyl group, (vi) a branched or unbranched, substituted or unsubstituted alkynyl group, (vii) a substituted or unsubstituted heterocyclic group, (viii) a cyano group, (iv) an ether group, (x) a branched or unbranched, substituted or unsubstituted alkoxy group, (xi) a nitro group, or (xii) any two adjacent X groups form (a) a substituted or unsubstituted carbocyclic ring or (b) a substituted or unsubstituted alkyl group
• a substituted alkyl group refers to an alkyl group having one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms other than carbon and hydrogen either alone (e.g., a halogen such as F) or in combination with carbon (e.g., a cyano group) and/or hydrogen atoms
• a substituted alkenyl group refers to an alkenyl group having (i) one or more C-C double bonds, and (ii) one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms other than carbon and hydrogen either alone or in combination with carbon and/or hydrogen atoms;
• a substituted alkynyl group refers to an alkynyl group having (i) one or more C-
• each of the one or more substituents comprises a monovalent moiety containing one or more atoms other than carbon and hydrogen (e.g., Si) either alone or in combination with carbon and/or hydrogen atoms;
• a cycloalkyl group refers to a ring structure consisting of 3 or more carbon atoms in the ring structure (i.e., only carbon atoms in the ring structure) wherein a carbon atom of the ring structure is bonded directly to the silicon atom of the silyl group;
• a substituted cycloalkyl group refers to a cycloalkyl group having one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms (e.g., a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group);
• a cycloalkylalkylene group refers to a ring structure consisting of 3 or more carbon atoms in the ring structure (i.e., only carbon atoms in the ring structure) wherein the ring structure is separated from the silicon atom of the silyl group by a divalent alkyl spacer group having one or more carbon atoms (typically, from 1 to 3 carbon atoms, more typically, 1 carbon atom);
• a substituted cycloalkylalkylene group refers to a cycloalkylalkylene group having one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms (e.g., a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group);
• a substituted aryl group refers to an aromatic ring structure consisting of 5 to 10 carbon atoms in the ring structure (i.e., only carbon atoms in the ring structure), wherein a carbon atom of the ring structure is bonded directly to the silicon atom of the silyl group, and the ring structure has one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms (e.g., a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group);
• an arylalkylene group refers to an aromatic ring structure consisting of 5 to 10 carbon atoms in the ring structure (i.e., only carbon atoms in the ring structure), wherein the aromatic ring structure is separated from the silicon atom of the silyl group by a divalent alkylene spacer group having one or more carbon atoms (typically, from 1 to 3 carbon atoms, more typically, 1 carbon atom);
• a substituted arylalkylene group refers to an arylalkylene group having one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms (e.g., a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group);
• a substituted heterocyclic ring or "a substituted heterocyclic group” refers to a heterocyclic ring (i.e., a saturated, partially saturated, or unsaturated heterocyclic ring) comprising at least one of O, N, S and Se in the ring structure, and having one or more substituents bonded to one or more members of the ring structure, wherein the heterocyclic ring can be aromatic or non-aromatic and wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms (e.g., a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group);
• a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group
• a substituted carbocyclic ring refers to a ring (i.e., a saturated, partially saturated, or unsaturated carbocyclic ring) comprising C in the ring structure, and having one or more substituents bonded to one or more members of the ring structure, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms (e.g., a halogen such as F, an alkyl group, a cyano group, a hydroxyl group, or a carboxylic acid group);
• a substituted alkoxy group refers to an alkoxy group having one or more substituents thereon, wherein each of the one or more substituents comprises a monovalent moiety containing one or more atoms other than carbon and hydrogen either alone (e.g., a halogen such as F) or in combination with carbon (e.g., a cyano group) and/or hydrogen atoms (e.g., a hydroxyl group
• charge carrier mobility value refers to the drift velocity of a charge carrier (cm/s) per unit applied field (V/cm) with resulting measurement units of "cm /V-s" as measured using any test method for measuring the drift velocity of a charge carrier;
• charge carrier mobility value as measured by Mobility Value Test Method I or “charge carrier mobility value as measured by Mobility Value Test Method II” refers to the charge carrier mobility value of an electronic device measured using the specific Mobility Value Test Method I or Mobility Value Test Method II as described in the Test Method section of the examples below;
• charge carrier mobility value as measured by the Transistor Fabrication & Charge Carrier Mobility Value Test Method or “charge carrier mobility value as measured by the TF&CCMV Test Method” refers to the charge carrier mobility value of an electronic device that is fabricated using a specific device construction, specific device materials, and a specific device fabrication method, and is measured using a specific mobility value test method as described in the Test Method section of the examples below.
• Pentacene compounds having the above chemical structure have been found to possess at least one of the following properties: (i) increased solubility in various organic solvents, (ii) increased stability in various organic solvents, and (iii) increased charge carrier mobility values when used as a semiconductor layer in electronic devices.
• R groups i.e., R, R' and R
• X groups in the above chemical structure, one can tailor a resulting pentacene compound for a given application (e.g., as a semiconductor layer in an electronic device).
• a given pentacene compound of the present invention when a given pentacene compound of the present invention is to be used to form a semiconductor layer in an electronic device (e.g., a transistor), the ability of the pentacene compound to exhibit two-dimensional stacking (i.e., 2-D stacking of individual molecules) is an important consideration, which significantly impacts the charge carrier mobility value of the resulting semiconductor layer.
• the dimensionality of a given stacking configuration may be easily measured by examination of the single- crystal X-ray structure of a given material.
• a given material exhibiting two-dimensional, or "brickwork" stacking is characterized by having four nearest neighbors with contacts between aromatic carbon atoms lying roughly within the van der Waals radius of carbon (ideally, 3.3 - 3.6 A).
• any material that has two aromatic close-contact neighbors above the plane of the pentacene ring, and two aromatic close-contact neighbors below the plane of the pentacene ring is typically classified as having two-dimensional interactions or 2-D stacking. It is generally the case that molecules with two-dimensional pi-stacking yield superior thin-film morphologies for field-effect transistor applications, along with improved charge transport in the solid state.
• a common alternative case is one-dimensional stacking, where each molecule possesses one stacking neighbor above the plane of the aromatic ring, and one stacking neighbor below the plane of the aromatic ring.
• the separation between the aromatic faces is preferably within the van der Waals radius of carbon (ideally, 3.3 - 3.6 A).
• materials that exhibit 1-D stacking do not yield high-performance transistors when cast from solution, but these materials do exhibit enhanced performance in photovoltaic devices.
• Such 1-D stacked materials are suitable for use, for example, as the donor component of a photovoltaic device, or when substituents X are electron-withdrawing groups (e.g., fluoro, fluoroalkyl, cyano or nitro groups), the materials are potentially suitable for use as an acceptor in a photovoltaic device.
• pentacene compounds of the present invention exhibit 2-D or 1-D stacking. It has been discovered that pentacene compounds having the above chemical structure (i.e., Structure A), wherein R, R' and R" together comprise two sterically similar groups and one sterically dissimilar group exhibit 2-D stacking in the crystalline, solid state as shown, for example, by single crystal x-ray analysis.
• the two sterically similar groups are spatially oriented on opposite sides of a plane extending though the five ring structure of the pentacene compound, while the sterically dissimilar group is spatially oriented substantially within or along (i.e., substantially parallel with) the plane containing the five ring structure of the pentacene compound in the crystalline, solid state.
• the pentacene compounds of the present invention have Structure A, wherein R, R' and R" together comprise two sterically similar groups and one sterically dissimilar group, the two sterically similar groups being oriented on opposite sides of a plane extending though the five ring structure of the pentacene compound, and the sterically dissimilar group being substantially within the plane (i.e., the plane containing the five ring structure of the pentacene compound).
• the pentacene compounds of the present invention have Structure A, wherein R, R' and R" together comprise two identical groups and one dissimilar group, the two identical groups being oriented on opposite sides of a plane extending though the five ring structure of the pentacene compound, and the dissimilar group being substantially within the plane (i.e., the plane containing the five ring structure of the pentacene compound).
• the pentacene compounds may have two identical groups covalently bonded to the Si atom such as when (a)(i) two R groups independently comprise a branched or unbranched, substituted or unsubstituted alkyl group, or (a)(ii) two R' groups independently comprise a branched or unbranched, substituted or unsubstituted alkenyl group, and (b) the remaining group bonded to the Si atom comprises a substituent other than (i) a branched or unbranched, substituted or unsubstituted alkyl group, and (ii) a branched or unbranched, substituted or unsubstituted alkenyl group.
• the pentacene compounds may have two identical groups covalently bonded to the Si atom wherein the identical groups comprise (i) a substituted or unsubstituted cycloalkyl group or (ii) a substituted or unsubstituted cycloalkylalkylene group, and the dissimilar group comprise a substituent other than (i) a substituted or unsubstituted cycloalkyl group and (ii) a substituted or unsubstituted cycloalkylalkylene group (e.g., an allyl group or an isopropyl group).
• the identical groups comprise (i) a substituted or unsubstituted cycloalkyl group or (ii) a substituted or unsubstituted cycloalkylalkylene group, and the dissimilar group comprise a substituent other than (i) a substituted or unsubstituted cycloalkyl group and (ii) a substituted or unsub
• the pentacene compounds have Structure A wherein R comprises isopropyl, and R' comprises isopropenyl.
• the pentacene compounds of the present invention have one of the following chemical structures:
• compounds I and II provide (i) exceptional solubility and stability in a variety or organic solvents, and/or (ii) exceptional mobility values when incorporated into a given electronic device (e.g., a TFT).
• Compound I namely, 6,13- bis(allyldiisopropylsilylethynyl)pentacene (also referred to herein as "allyl DIPS"), has been found to exhibit increased solubility in certain organic solvents, such as toluene, compared to known pentacene compounds such as TIPS-pentacene.
• compound I has a solubility in toluene of up to and greater than about 21 wt%.
• compound I When used in a semiconductor layer of an electronic device, compound I can provide the semiconductor layer with a maximum charge carrier mobility value of greater than 2.0 cm 2 /V-s (or greater than about 2.1 cm 2 /V-s, or greater than about 2.2 cm 2 /V-s, or greater than about 2.3 cm 2 /V-s, or greater than about 2.4 cm 2 /V-s) as measured using the TF&CCMV Test Method (described below).
• Compound II namely, 6,13-bis(isopropenyldiisopropylsilylethynyl)pentacene (also referred to herein as "IP-DIPS”), provides similar advantages over known pentacene compounds such as TIPS-pentacene.
• compound II When used in a semiconductor layer of an electronic device, compound II can provide the semiconductor layer with a maximum charge carrier mobility value of greater than 3.0 cm 2 /V-s (or greater than about 3.1 cm 2 /V-s, or greater than about 3.2 cm 2 /V-s, or greater than about 3.3 cm 2 /V-s, or greater than about 3.4 cm 2 W-s) as measured using the TF&CCMV Test Method.
• desired pentacene compounds have Structure A, wherein (1) two R groups independently comprise isopropyl groups, and R' comprises a substituted or unsubstituted cyclopropyl group or cyclobutyl group, more desirably, a cyclopropyl group, such as Compound IV shown below, or (2) one R group comprises an isopropyl group, and each R' group independently comprises a substituted or unsubstituted cyclopropyl group or cyclobutyl group, more desirably, a cyclopropyl group, such as Compound XIII shown below:
• a given pentacene compound may have Structure A, wherein two R groups independently comprise a substituted or unsubstituted cyclopropyl group or cyclobutyl group, desirably, a cyclopropyl group, and R' comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group such as, an isopropenyl group or an isopropenyl group having one or more substituents thereon (e.g., one or more F atoms).
• Another pentacene compound may have Structure A, wherein one R group comprises a substituted or unsubstituted cyclopropyl group or cyclobutyl group, desirably, a cyclopropyl group, and two R' groups comprise branched or unbranched, substituted or unsubstituted C2-C8 alkenyl groups such as, isopropenyl groups or isopropenyl groups having one or more substituents thereon (e.g., one or more F atoms).
• cycloalkylalkylene group e.g., a cyclopropylmethylene group
• each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alken
• Exemplary pentacene compounds may have the above chemical structure, wherein two R groups independently comprise a substituted or unsubstituted cyclopropylmethylene group or cyclobutylmethylene group, desirably, a cyclopropylmethylene group, and R' comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group such as, an isopropenyl group or an isopropenyl group having one or more substituents thereon (e.g., one or more F atoms).
• Another pentacene compound may have the above chemical structure, wherein one R group comprises a substituted or unsubstituted cyclopropylmethylene group or cyclobutylmethylene group, desirably, a cyclopropylmethylene group, and two R' groups comprise branched or unbranched, substituted or unsubstituted C2-C8 alkenyl groups such as, isopropenyl groups or isopropenyl groups having one or more substituents thereon (e.g., one or more F atoms). See, exemplary compounds in Table 1 below.
• a number of exemplary pentacene compounds of the present invention having this type of silyl substitution are shown in Table 2 below.
• exemplary pentacene compound of the present invention include pentacene compounds having Structure A, wherein (a) each R independently comprises a branched or unbranched, substituted or unsubstituted C1-C8 alkyl group; (b) each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group; and (c) R" comprises (i) a branched or unbranched, substituted or unsubstituted C2-C8 alkynyl group, (ii) a substituted aryl group, (iii) a substituted or unsubstituted arylalkylene group, (iv) an acetyl group, or (v) a substituted or unsubstituted heterocyclic ring comprising at least one of O, N, S and Se in the ring.
• the pentacene compounds have Structure A, wherein (a) each R independently comprises a branched or unbranched, substituted or unsubstituted C1-C8 alkyl group (or C1-C4 alkyl group); (b) each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group (or C2-C4 alkenyl group); and (c) R" comprises (i) a branched or unbranched, substituted or unsubstituted C2-C8 alkynyl group, (ii) a substituted aryl group, (iii) a substituted or unsubstituted arylalkylene group, (iv) an acetyl group, or (v) a substituted or unsubstituted heterocyclic ring comprising at least one of O, N, S and Se in the ring.
• pentacene compounds of the present invention include pentacene compounds having Structure A, wherein (a) each R independently comprises a branched or unbranched, substituted or unsubstituted C1-C8 alkyl group (or C1-C4 alkyl group such as an isopropyl group); (b) each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group (or C2-C4 alkenyl group such as an allyl group); and (c) R" comprises a substituted or unsubstituted aryl group (e.g., a p-tolyl group or p-methoxyphenyl). See, for example, exemplary compounds XXIV and XXXII in Table 2.
• pentacene compounds of the present invention include pentacene compounds having Structure A, wherein (a) each R independently comprises a branched or unbranched, substituted or unsubstituted C1-C8 alkyl group (or C1-C4 alkyl group such as an isopropyl group); (b) each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group (or C2-C4 alkenyl group such as an allyl group); and (c) R" comprises a substituted or unsubstituted arylalkylene group having a divalent alkylene spacer with from 1 to 3 carbon atoms between each aryl moiety and each silicon atom (e.g., a benzyl group). See, for example, exemplary compounds XXV and XXXIII in Table 2.
• exemplary pentacene compounds of the present invention include pentacene compounds having Structure A, wherein (a) each R independently comprises a branched or unbranched, substituted or unsubstituted C1-C8 alkyl group (or C1-C4 alkyl group such as an isopropyl group); (b) each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group (or C2-C4 alkenyl group such as an allyl group); and (c) R" comprises an acetyl group. See, for example, exemplary compounds XXVI and XXXIV in Table 2.
• exemplary pentacene compounds of the present invention include pentacene compounds having Structure A, wherein (a) each R independently comprises a branched or unbranched, substituted or unsubstituted C1-C8 alkyl group (or C1-C4 alkyl group such as an isopropyl group); (b) each R' independently comprises a branched or unbranched, substituted or unsubstituted C2-C8 alkenyl group (or C2-C4 alkenyl group such as an allyl group); and (c) R" comprises a substituted or unsubstituted heterocyclic ring comprising at least one of O, N, S and Se in the ring. See, for example, exemplary compounds XXVII to XXX and XXXV to XXXVIII in Table 2.
• pentacene compounds of the present invention may have Structure A, wherein the substituted or unsubstituted heterocyclic ring comprising at least one of O, N, S and Se in the ring comprises a substituted or unsubstituted furanyl group, a substituted or unsubstituted pyrrolyl group, a substituted or unsubstituted thienyl group, or a substituted or unsubstituted selenophenyl group.
• a number of exemplary pentacene compounds of the present invention having this type of silyl substitution are shown in Table 3 below.
• exemplary pentacene compounds of the present invention include pentacene compounds having three different R groups (e.g., R, R' and R”) bonded to the silicon atom of a given silyl group.
• XI 6,13-Bis[(3-but-l-enyl diisopropylsilyl)ethynyl]pentacene
• XXVI 6,13-Bis[(acetyl diisopropylsilyl)ethynyl]pentacene
• XXV 6, 13 -Bis [(benzyl diisopropylsilyl)ethynyl]pentacene;
• XXIX 6,13-Bis[(2-thienyl diisopropylsilyl)ethynyl]pentacene;
• LV 6,13-Bis[(allyl dicyclopropylsilyl)ethynyl]pentacene;
• LVI 6,13-Bis[((2-(l,3-dithianyl)ethyl, diisopropylsilyl)ethynyl]pentacene;
• LVII 6, 13 -Bis [(I -hydroxy ethyl diisopropylsilyl)ethynyl]pentacene;
• LVIII 6,13-Bis[(3,3-dimethylbut-l-ynyl diisopropylsilyl)ethynyl]pentacene
• LIX 6,13-Bis[(triisopropylsilylethynyl diisopropylsilyl)ethynyl]pentacene.
• the present invention is directed to a number of pentacene compounds having Structure A above.
• the pentacene compounds of the present invention have Structure A above, wherein at least one of R or R' comprises (i) a substituted or unsubstituted cycloalkyl group or (ii) a substituted or unsubstituted cycloalkylalkylene group.
• the pentacene compounds have Structure A above, wherein R, R' and R" comprises a combination of (i) one or more branched or unbranched, substituted or unsubstituted alkyl groups, (ii) one or more branched or unbranched, substituted or unsubstituted alkenyl groups, (iii) one or more substituted or unsubstituted cycloalkyl groups, and (iv) one or more substituted or unsubstituted cycloalkylalkylene groups.
• the pentacene compounds have Structure A above, wherein R, R' and R" comprises a combination of (i) one or more branched or unbranched, substituted or unsubstituted alkenyl groups, and (iii) one or more substituted or unsubstituted cycloalkyl groups. See, for example, compound LV.
• R, R' and R" comprises a combination of (i) one or more branched or unbranched, substituted or unsubstituted alkenyl groups, and (iii) one or more substituted or unsubstituted cycloalkyl groups. See, for example, compound LV.
• R, R' and R" comprises a combination of (i) one or more branched or unbranched, substituted or unsubstituted alkenyl groups, and (iii) one or more substituted or unsubstituted cycloalkyl groups. See, for example, compound LV.
• R' and/or R" may be substituted with one or more substituents.
• Suitable substituents for the above-described R groups include, but are not limited to, halogens, hydroxyl groups, alkyl groups, cyano groups, amino groups, carbonyl groups, alkoxy groups, thioalkoxy groups, nitro groups, carboxylic acid groups, carboxylic ester groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, silyl groups (e.g., a trialkylsilyl group with each alkyl group having 1 to 8 carbon atoms), or combinations thereof. Exemplary combinations thereof include halogenated alkyl groups or halogenated alkoxy groups.
• Typical substituents for alkyl groups and alkenyl groups include, but are not limited to, -F, -OH, -CN, and -COOH.
• Typical substituents for cycloalkyl groups, cycloalkylalkylene groups, aryl groups, and arylalkylene groups include, but are not limited to, alkyl groups, -F, -OH, -CN, and -COOH.
• the pentacene ring may further comprise one or more of the above-described substituents X.
• One or more substituents X may be utilized to further tailor a given pentacene compound for a given application.
• substituents X may be utilized to provide one or more additional benefits including, but not limited to,: (1) to further enhance the ability of a given pentacene compound to exhibit two-dimensional stacking; (2) to enhance the compatibility of a given pentacene compound with other similar or dissimilar pentacene compounds or other components when used in a composition (e.g., a particular solvent); and (3) to tune the electronic nature of a given pentacene compound, for example, to change the dominant carrier type from holes to electrons.
• each X may independently comprise (i) hydrogen, (ii) a halogen,
• each X independently comprises (i) hydrogen or (ii) a halogen such as fluorine (-F). In some embodiments, each X independently comprises (i) hydrogen or (ii) a branched or unbranched, substituted or unsubstituted alkyl group such as a fluoroalkyl group (e.g., -CF 3 ). In some embodiments, each X independently comprises (i) hydrogen, (ii) a substituted or unsubstituted aromatic ring structure such as a phenyl group (-CeH 5 ), or (iii) a substituted or unsubstituted heterocyclic group such as a thienyl group (-C 4 H 3 S). In some embodiments, each X independently comprises (i) hydrogen or (ii) a nitro group (-NO 2 ).
• any two adjacent X groups may combine to form (a) a substituted or unsubstituted carbocyclic ring or (b) a substituted or unsubstituted heterocyclic ring.
• the carbocyclic or heterocyclic ring is fused to an aromatic ring of the pentacene portion of the compound.
• the resulting fused carbocyclic ring or heterocyclic ring may be partially saturated or completely saturated.
• the only unsaturation is contributed by the aromatic ring that is part of the pentacene portion of the compound. That is, the portion of the resulting fused carbocyclic or heterocyclic ring structure contributed by the two adjacent X groups is saturated.
• two adjacent X groups combine to form a substituted or unsubstituted heterocyclic ring containing oxygen within the ring structure (e.g., a dihydrofurano substituent).
• the pentacene compound of the present invention comprises Structure A above, wherein at least one X comprises (i) a halogen, (ii) a branched or unbranched, substituted or unsubstituted alkyl group, (iii) a substituted or unsubstituted aryl group, (iv) a branched or unbranched, substituted or unsubstituted alkenyl group, (v) a branched or unbranched, substituted or unsubstituted alkynyl group, (vi) a substituted or unsubstituted heterocyclic group, (vii) a cyano group, (viii) an ether group, or (ix) a nitro group.
• the pentacene compound of the present invention comprises Structure A above, wherein at least one X comprises (i) a fluorine atom, (ii) a fluoroalkyl group, (iii) an aryl group, (iv) a substituted or unsubstituted heterocyclic group, (v) a cyano group, or (vi) a nitro group.
• the pentacene compound of the present invention comprises Structure A above, wherein at least one X comprises (i) a fluorine atom, (ii) a trifluoromethyl group, (iii) a phenyl group, or (v) a thienyl group.
• LXI l,8-difluoro-6,13-Bis[(cyclopropyl, diisopropylsilyl)ethynyl]pentacene (and the 1,11 -difluoro isomer);
• LXII 2-cyano-6,13-Bis[(tricyclopentylsilyl)ethynyl]pentacene
• LXIII 2,3,9,10-tetramethyl-6,13-Bis[(cyclopropyl, diisopropylsilyl)ethynyl]- pentacene
• the pentacene compounds when used in applications such as electrical devices (e.g., transistors), desirably enable the formation of a semiconductor layer having a maximum charge carrier mobility value greater than or equal to 2.0 cm 2 /V- s. More desirably, the pentacene compounds enable the formation of a semiconductor layer having a maximum charge carrier mobility value greater than or equal to 2.0 cm /V-s as measured by the Mobility Value Test Method I, the Mobility Value Test Method II, and/or the TF&CCMV Test Method, each of which are described below in the Test Method section of the examples.
• the present invention is further directed to compositions comprising (I) one or more of the above-described pentacene compounds, and (II) a solvent.
• Typical solvents suitable for forming compositions of the present invention include, but are not limited to, organic solvents such as ketones, aromatic hydrocarbons, and the like. Suitable solvents include, but are not limited to, toluene, ethylbenzene, butylbenzene, chlorobenzene, dichlorobenzene, tetrahydrofuran, isophorone, anisole, tetrahydronaphthalene, and cyclohexanone.
• the composition comprises one or more of the above-described pentacene compounds, and a solvent such as toluene, butylbenzene, anisole or cyclohexanone.
• one or more of the above-described pentacene compounds are present in a given composition at a concentration of at least 0.1 wt% based on a total weight of the composition.
• the pentacene compound used to form a given composition is soluble in a given solvent, such as toluene, at a concentration of up to about 21 wt% (or greater than 21 wt%).
• compositions of the present invention comprise one or the above-described pentacene compounds at a concentration ranging from about 0.1 wt% to about 5.0 wt%, more typically, from about 1.5 wt% to about 3.0 wt%.
• compositions of the present invention comprise at least one of the above-described pentacene compounds and a solvent.
• compositions of the present invention comprise at least one of the above-described pentacene compounds and a solvent in combination with one or more additional composition components.
• suitable additional composition components include, but are not limited to, a polymer additive, a rheological modifier, or a combination thereof.
• the compositions comprise a polymer additive selected from the group consisting of polystyrene, poly(alpha- methylstyrene), poly(methyl methacrylate), poly(4-cyanomethyl styrene), poly(4- vinylphenol), or any other suitable polymer disclosed in U.S. Patent Publication No. 2004/0222412 Al or U.S. Patent Publication No. 2007/0146426 Al, the subject matter of both of which is hereby incorporated by reference in its entirety.
• the polymer additive comprises polystyrene, poly(alpha-methylstyrene) or polyvinylphenol.
• each additional composition component i.e., components other than the pentacene compound
• each additional composition component is independently present in an amount of greater than 0 to about 50 wt% based on a total weight of the composition.
• each additional composition component i.e., components other than the pentacene compound
• the polymer additive e.g., polystyrene
• the polymer additive is typically present in an amount of greater than 0 to about 5.0 wt%, more typically, from about 0.5 to about 3.0 wt% based on a total weight of the composition.
• the resulting composition desirably has composition properties (e.g., composition stability, viscosity, etc.) that enable the composition to be coated onto a substrate via conventional coating processes.
• Suitable conventional coating processes include, but are not limited to, spin coating, knife -coating, roll-to-roll web- coating, and dip coating, as well as printing processes such as ink-jet printing, screen printing, and offset lithography.
• the resulting composition is a printable composition, even more desirably, an ink jet printable composition.
• compositions may be coated onto a substrate.
• the resulting substrate has at least one coatable surface and a coated layer on the at least one coatable surface, wherein the coated layer comprises a pentacene compound having Structure A, wherein R, R', R", x, y, z and X are as described above.
• the coated layer may further comprise one or more additional composition components other than at least one of the above-described pentacene compounds.
• the compositions of the present invention may be coated onto a variety of substrates.
• Suitable substrates include, but are not limited to, polymeric films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyimides, and inorganic substrates such as silica, alumina, silicon wafers, and glass.
• the substrate comprises an electronic device or an electronic device component.
• compositions of the present invention may be coated onto a substrate so as to form a semiconductor layer of an electronic device such as a thin film transistor (TFT) or an organic light-emitting diode (OLED).
• TFT thin film transistor
• OLED organic light-emitting diode
• Compositions of the present invention may be coated onto a substrate so as to form a photovoltaic module or solar cell therein, or a sensor.
• the above described pentacene compounds and compositions made therefrom enable the formation of electronic devices (e.g., transistors) having a charge carrier mobility value greater than 2.0 cm 2 /V-s.
• the electronic device comprises a coated layer, wherein the coated layer comprises a pentacene compound having Structure A, wherein R, R', R", x, y and z are as described above.
• the resulting electronic device has a charge carrier mobility value greater than 2.0 (or greater than about 2.1, or greater than about 2.2, or greater than about 2.3, or greater than about 2.4, or greater than about 2.5, or greater than about 2.6, or greater than about 2.7, or greater than about 2.8, or greater than about 2.9, or greater than about 3.0, or greater than about 3.1, or greater than about 3.2, or greater than about 3.3, or greater than about 3.4, or greater than about 3.5) cm 2 /V-s as measured using the disclosed Mobility Value Test Method I and/or the disclosed Mobility Value Test Method II and/or the disclosed TF&CCMV Test Method and/or similar methods for measuring the charge carrier mobility value of an electronic device.
• Exemplary electronic devices of the present invention may have a top contact/bottom gate TFT construction as shown in FIG. 1.
• exemplary electronic device 10 comprises substrate 11, gate electrode 16, dielectric layer 12, semiconductor layer 13, source electrode 14, and drain electrode 15.
• Materials for forming substrate 11, gate electrode 16, dielectric layer 12, source electrode 14, and drain electrode 15 of exemplary electronic device 10 may comprise any materials typically used to form TFT electronic devices.
• Suitable materials for forming substrate 11 include, but are not limited to, glass, polyethylene terephthalate, polyethylene naphthalate, and polyimide.
• Suitable materials for forming dielectric layer 12 include, but are not limited to, any of a variety of polymers such as poly(4-vinylphenol), poly(methylmethacrylate), and poly(4-cyanomethylstyrene), which are typically deposited from solution, but may also be formed in place via curing of a formulation containing functional monomers and/or oligomers and a curing agent.
• the dielectric layer 12 may further include inorganic fillers such as, but not limited to, BaTi ⁇ 3, Si ⁇ 2 , Zr ⁇ 2 , which act to enhance the dielectric constant of dielectric layer 12.
• Suitable materials for forming semiconductor layer 13 comprise the above- described compositions of the present invention.
• Suitable materials for forming each of gate electrode 16, source electrode 14 and drain electrode 15 include, but are not limited to, carbon nanotubes, poly(3,4-ethylenedioxythiophene) (PEDOT), polyaniline (PANI), gold, silver, aluminum, copper, titanium, palladium, platinum, chromium, as well as blends thereof (e.g., blends, alloys, multi-layer composites of the various electrode materials).
• the substrate 11, the gate electrode 16, and the dielectric layer 12 are heavily-doped n-type silicon wafers with thermal oxide (such as those commercially available from Noel Technologies, Inc. (Campbell, CA)), wherein the heavily-doped n- type silicon wafer serves as both the substrate and gate electrode, and the thermal oxide serves as the dielectric layer.
• thermal oxide such as those commercially available from Noel Technologies, Inc. (Campbell, CA)
• one or more of the following layers are printable (e.g., ink jet printable) layers: gate electrode 16, dielectric layer 12, semiconductor layer 13, source electrode 14, and drain electrode 15.
• printable (e.g., ink jet printable) layers include gate electrode 16, dielectric layer 12, semiconductor layer 13, source electrode 14, and drain electrode 15.
• suitable printable compositions for forming dielectric layer 12, semiconductor layer 13, gate electrode 16, source electrode 14, and drain electrode 15 are disclosed in U.S. Patent Application Publication No. 20070114516 Al, now U.S. Patent No. 7,498,662, the subject of which is incorporated herein by reference in its entirety.
• Electronic devices of the present invention desirably comprise at least one of the above-mentioned pentacene compounds and have a charge carrier mobility value greater than 2.0 cm /V-s.
• Such electronic devices may comprise, for example, the following specific top contact/bottom gate TFT construction as shown in exemplary device 20 of FIG. 2: a gate electrode layer 16 comprising a heavily n-doped silicon wafer with a first dielectric layer 12a in the form of a thermal oxide (SiC ⁇ ) layer positioned over the gate electrode layer 16 (e.g., a heavily n-doped silicon wafer commercially available from Noel Technologies, Inc.
• SiC ⁇ thermal oxide
• a second dielectric layer 12b comprising a polymeric dielectric composition comprising SARTOMERTM SR-368 (Sartomer Company Inc. (Exton, PA)) (about 8.5 wt%), zirconia nanoparticles surface treated with gamma- methacryloxypropyltrimethoxysilane (SILQUEST ® A- 174 silane from OSi Specialties (South Charleston, WV)) and formed as disclosed in U.S. Patent Applications Serial Nos.
• pentacene compounds of the present invention may be prepared by a method comprising the steps of forming a substituted silyl acetylene having a desired combination of R, R' and R" substituents, and then reacting the substituted silyl acetylene with 6, 13-pentacenequinone.
• the step of forming a substituted silyl acetylene having a desired combination of R, R' and R" substituents may comprise a number of process steps including, but not limited to, a first substitution reaction wherein one or more first substituents bonded to the silicon atom of a given silyl acetylene (e.g., a trimethylsilyl acetylene) are replaced with one or more second substituents (e.g., an isopropyl group); and a second substitution reaction wherein one or more of the second substituents bonded to the silicon atom are replaced with one or more third substituents (e.g., an isopropenyl group).
• a first substitution reaction wherein one or more first substituents bonded to the silicon atom of a given silyl acetylene (e.g., a trimethylsilyl acetylene) are replaced with one or more second substituents (e.g., an isopropyl group)
• the methods of forming pentacene compounds of the present invention may further comprise one or more of the following method steps: purification by at least one and, in some cases, two or three recrystallization steps from a suitable solvent such as acetone, wherein the pentacene compound is dissolved in an amount of boiling acetone, which dissolves all solids and is then cooled to about 0-4 0 C while protecting the solution from light to prevent photodegradation. The solids are then collected by filtration and dried in vacuum to remove residual acetone.
• a suitable solvent such as acetone
• pentacene compounds of the present invention may be combined with a solvent and one or more additional components to form compositions, such as printable compositions.
• pentacene compounds of the present invention e.g., compounds I to LIV
• organic solvents e.g., toluene
• Additional composition components such as those described above (e.g., polystyrene) may be incorporated into the first composition to provide a final composition.
• the final composition is printable via an ink jet printing apparatus.
• compositions of the present invention containing at least one of the above-described pentacene compounds of the present invention may be used to form a variety of coatings, substrates having a coated layer thereon, electronic device components, and electronic devices.
• the resulting coating, substrate having a coated layer thereon, electronic device component, or electronic device comprises a pentacene compound having Structure A, wherein R, R', R", x, y, z and X are as described above.
• the resulting coating, substrate having a coated layer thereon, electronic device component, or electronic device comprises a pentacene compound having Structure A, wherein R, R' and R" together comprise two sterically similar groups and one sterically dissimilar group, the two sterically similar groups being oriented on opposite sides of a plane extending though the five ring structure of the pentacene compound, and the sterically dissimilar group being substantially within the plane extending though the five ring structure of the pentacene compound.
• the resulting coating, substrate having a coated layer thereon, electronic device component, or electronic device comprises one of pentacene compounds I, II and IV shown above.
• a transistor's performance characteristics are measured in air under ambient lighting using two Source Measure Units (Model 2400 from Keithley Instruments, Inc. (Cleveland, OH)).
• the devices were placed on a SIGNATONETM 1160 Series probe station and probes connected using SIGNATONETM S-725-PRM manipulators (Signatone Corp. (Gilroy, CA)).
• the drain to source bias voltage (V DS ) was held at -40 V, while the gate to source bias (V GS ) was incremented over the range +10 V to -40 V in 1 V steps.
• FIG. 3 graphically displays exemplary measured parameters.
• traces labeled "A" indicate measured drain current (I DS ) as a function of
• V GS - Traces labeled “B” indicate the square root of measured drain current (I DS ) versus VQ S
• traces labeled “C” indicate measured gate current (I G s) versus V G s-
• the saturated field effect mobility ( ⁇ ) can be calculated from the slope (m) of the square root of drain current versus V GS (trace “B") using the following equation: where C 1 is the specific capacitance of the gate dielectric, W is the channel width, and L is the channel length.
• the charge carrier mobility value reported is the maximum charge carrier mobility value observed over the range of measurement.
• a transistor is formed using the specific materials and process steps as outlined in Example 4 below. Once formed, the transistor's charge carrier mobility value was measured using Mobility Value Test Method I described above. Thermal Analysis Test Method
• a TA Instrument (New Castle, DE) Model Q200 DSC with an autosampler was used in the characterization. 2 to 10 milligrams of the material to be characterized were placed in an aluminum pan (Standard or TzeroTM available from TA Instruments) and a lid was crimped according to the requirements of the specific pan used. The pan was placed in the autosampler for automatic loading into the DSC sample cell. An empty pan of the same type was used as the reference.
• thermogram A second scan was conducted using a newly prepared sample wherein the temperature was ramped to a temperature about 10 0 C above the highest temperature endotherm associated with a solid-solid transition while staying below the temperature at which the melt and subsequent Diels-Alder reaction occurred. The temperature was then decreased at a controlled rate (5°C/min.) to a temperature below the lowest temperature thermal event and then once again increased at 5°C/min. to beyond the temperature at which the material underwent irreversible transformation (Diels-Alder reaction). The events present in the thermogram were analyzed using the "Integrate Peak
• thermogram of the second scan of TIPS Pentacene is shown in FIG. 4, which reveals that the event occurring at ⁇ 124°C is reversible as is the event present at ⁇ 180°C. At ⁇ 266°C there is evidence of the onset of an endotherm followed by a significant exotherm. Observations of TIPS Pentacene on a Fisher-John melting point apparatus confirmed that the two lower thermal events are solid-solid transitions and the material indeed melts (solid-liquid transition) at ⁇ 266°C. The results of thermal analysis for pentacene compounds of the present invention are show in Table 8 below.
• Trimethylsilyl acetylene (2.36 g, 24.0 mmol) and anhydrous THF (12 mL) were added to a separate dry 100-mL round bottom flask equipped with a stir bar.
• the 100-mL flask reaction mixture was cooled to 0 0 C, and n-butyllithium (9.2 mL, 23 mmol, 2.5 M in hexane) was added dropwise, followed by stirring for 90 minutes to form a second mixture.
• the 250-mL reaction mixture (i.e., the first mixture) was then cooled to 0 0 C, and the second mixture was added dropwise via syringe. The combined mixture was allowed to stir overnight. The combined mixture was then poured into 100 mL saturated NH 4 Cl solution, and rinsed with a 1 : 1 hexane: diethyl ether mixture (100 mL). The organic layer was separated, and the water layer was extracted again with 50 mL of 1 : 1 hexane: diethyl ether mixture (100 mL). The organic portions were combined, washed with water (50 mL) and brine (25 mL), then dried over MgSO 4 , filtered, and concentrated via rotary evaporation.
• the product was taken up in THF (50 mL), and MeOH saturated with K 2 CO 3 (100 mL) was added, followed by stirring for 2 hours. Water (50 mL) and hexane (100 mL) were added, and the organic layer was separated. The water layer was extracted again (20 mL hexane) and the organic layers were combined. The combined organic layers were washed with water (20 mL), dried over MgSO 4 and filtered, followed by solvent evaporation. The product was purified by column chromatography (5: 1 hexane:DCM), yielding 1.7 g of a colorless oil (9.4 mmol, 44 %).
• the reaction flask was emptied into a saturated NH 4 Cl solution (100 mL), and then a 1 : 1 hexane: diethyl ether mixture (100 mL) was added. The organic layer was separated, and the water layer was extracted again with the 1 : 1 hexane: diethyl ether mixture (20 mL). The organic portions were combined, washed with water (20 mL) and brine (20 mL), then dried over MgSO 4 , filtered, and concentrated via rotary evaporation.
• IP-DIPS 6.13-Bis(isopropenyldiisopropylsilylethynyl)pentacene
• Example 3 - 6J3-Bis(diisopropenylisopropylsilylethvnyl)pentacene (DIIP-IPS) Synthesis of Diisopropenyrisopropylsilyl Acetylene: 2-Bromopropene (14.5 g, 120 mmol) and anhydrous THF (100 mL) were combined in a dry 500-mL round-bottom flask with a stir bar, and then cooled to -78°C. n-Butyllithium (47.5 mL, 119 mmol, 2.5 M in hexane) was added dropwise.
• DIIP-IPS Diisopropenyrisopropylsilyl Acetylene
• the reaction flask was emptied into a saturated NH 4 Cl solution (100 mL), then a 1 : 1 hexane: diethyl ether mixture (100 mL) was added. The organic layer was separated, and the water layer was extracted again with the 1: 1 hexane: diethyl ether mixture (20 mL). The organic portions were combined, washed with water (20 mL) and brine (20 mL), then dried over MgSO 4 , filtered, and concentrated via rotary evaporation.
• DIIP-IPS 6, 13-Bis(diisopropenylisopropylsilylethvnyl)pentacene
• n-type silicon wafer with thermal oxide i.e., silicon ⁇ 100> wafer highly doped n+ (arsenic) with a resistivity of ⁇ 0.005 ohm-cm, and supplied with a 1000 A thermal oxide (SiO 2 ) on the front surface and coated with 100 A TiN and 5000 A aluminum on the back surface from Noel Technologies, Inc. (Campbell, CA)) was (i) washed with acetone and dried with N 2 , (ii) washed with isopropyl alcohol (IPA) and dried with N 2 , (iii) washed with deionized water (DI) water and dried with N 2 , and (iv) then treated with UVVO 3 for 10 minutes.
• thermal oxide i.e., silicon ⁇ 100> wafer highly doped n+ (arsenic) with a resistivity of ⁇ 0.005 ohm-cm, and supplied with a 1000 A thermal oxide (SiO 2 ) on the front surface
• the wafer sample was then (i) coated with a ZrOAc solution having a viscosity of 15.3 mPa by spin coating (acceleration rate of 415 RPM/s, final speed of 2000 RPM for 30 seconds), (ii) then heated on a hot plate at 100 C for 10 minutes followed by (iii) exposure to UV (i.e., 254 nm germicidal lamp) in a nitrogen atmosphere for 15 minutes and then (iv) a post heating on a hotplate at 100 C for 10 minutes.
• the ZrOAc solution comprised 8.5 wt% of SARTOMERTM SR-368, 40.0 wt% of zirconia nanoparticles surface treated with silane A- 174 (as described in U.S.
• TIPS-pentacene the ink formulation was a solution of 2.0 wt% TIPS-pentacene and 1 wt% polystyrene (PS) in n-butylbenzene.
• allyl-DIPS the ink formulation was a solution of 2.0 wt% allyl-DIPS and 1 wt% polystyrene (PS) in n-butylbenzene.
• IP-DIPS isopropenyl-DIPS
• IP-DIPS isopropenyl-DIPS
• PS polystyrene
• the ink solutions were filtered through a 0.2 micron filter and loaded into a print cartridge designed for a DIMATIXTM 2800 series ink jet printer (DMP, manufactured by Fujifilm Dimatix, Inc. (Santa Clara, CA)).
• DMP DIMATIXTM 2800 series ink jet printer
• a 30 mm x 20 mm area was printed on each sample using the semiconductor ink with the following DMP parameters: a liquid crystalline polymer (LCP) cartridge having a drop volume of 10 picoliter (pL); a cartridge head temperature of 28°C; a platen temperature of 30 0 C; and a drop spacing of 20 micrometer ( ⁇ m).
• An ink jet drop matrix of 1501 x 1001 drops was deposited onto the substrate, the drops wetted together such that the ink solution covered the area.
• exemplary device 20 shown in FIG. 2 depicts gate electrode 16 as a single layer, in the present example, a three-layered structure, namely, a heavily doped n-type silicon wafer layer, an intermediate 100 A TiN layer, and a lower 5000 A aluminum layer represents the gate electrode of this exemplary device.
• An n-type silicon wafer with thermal oxide as in Example 4 was (i) washed with acetone and dried with N 2 , (ii) washed with isopropyl alcohol (IPA) and dried with N 2 , (iii) washed with deionized water (DI) water and dried with N 2 , and (iv) then treated with UV generated ozone (UvVO 3 ) for 10 minutes.
• the sample was then spin coating with a solution of ZrOAc and cured as described in Example 4.
• a semiconductor ink was prepared consisting of a solution of 2.0 wt% TIPS-pentacene and 1 wt% polystyrene (PS) in n-butylbenzene. The ink solution was filtered through a 0.2 ⁇ m filter and loaded into a print cartridge designed for the DIMATIX dot matrix printer (DMP) used in Example 4.
• DMP DIMATIX dot matrix printer
• a 30 mm x 20 mm area was printed with semiconductor ink on this sample using the following DMP parameters: a LCP cartridge having a drop volume of 10 pL; a cartridge head temperature of 28°C; a platen temperature of 30 0 C; and a drop spacing of 20 um.
• An ink jet drop matrix of 1501 x 1001 drops was deposited onto the substrate; the drops wetted together such that the ink solution covered the area.
• the semiconductor layer was allowed to dry at room temperature followed by printing silver source and drain contacts at 304 dpi using a SPECTRATM inkjet print head SM-128 having a 50 pL drop volume and Cabot silver ink.
• the sample was heated to 120 0 C for 10 minutes.
• the sample gave a charge carrier mobility value of 0.08 to 0.122 cm 2 /V-s as measured by Mobility Test Method I.
• Electronic devices having a construction as shown in FIG. 5 were prepared as follows. Heavily n-doped silicon wafers were used as gate electrode layer 16, while 250 nm of thermally-grown oxide served as dielectric layer 12. Source and drain electrodes 14 and 15 respectively were formed by evaporating gold or silver through a shadow mask under high vacuum conditions. The source and drain electrodes 14 and 15 respectively defined a channel with channel width, W, of 1,000 ⁇ m and channel length, L, of 100 ⁇ m. For the devices with gold electrodes, the substrates were cleaned by exposure to UV/0 3 for 15 min. at 85°C.
• the electrode surfaces were treated with a number of thiol-based monolayers to improve crystallization of the semiconductor and shift metal work function to improve charge injection as disclosed in IEEE Elect. Dev. Lett. (2001), 22, 571 (Gundlach et al.), the subject matter of which is incorporated herein by reference in its entirety.
• Thiol-based monolayer treatments included, but were not limited to, octanethiol, dodecanethiol, decanedithiol, benzenethiol, 4-methoxybenzenethiol, pentachlorobenzenethiol, and pentafluorobenzenethiol.
• pentafluorobenzenethiol-treated electrodes yielded thin films with the best morphology.
• HMDS hexamethyldisilazane
• Neat HMDS was deposited across the surface of the device, and was spun off under a blanket of nitrogen (1000 rpm for 30 s, then 4000 rpm for 120 s).
• the device substrate was then placed in a 120 0 C oven for 2 minutes to anneal the monolayers.
• a semiconductor layer 13 was deposited by drop-casting a 1 wt% solution of at least one pentacene compound of the present invention (dissolved in toluene, ethylbenzene, butylbenzene or chlorobenzene) over the source/drain electrodes.
• the solvent was allowed to evaporate slowly (by covering the substrate with a watch glass). Once the bulk of the solvent had evaporated and the semiconductor was clearly crystallized on the device surface, the substrate was placed in a 90 0 C oven for 120 seconds to drive off the remaining solvent.
• - threshold voltage varied from 12 to -22 V; and - on/off current ratio varied from 10 2 to 10 4 .
• - threshold voltage varied from 10 to -25 V; and - on/off current ratio varied from 10 2 to 10 5 .
• This material was prepared using methods similar to those used to synthesize Allyl DIPS-pentacene (Example 1), simply substituting (l-methylenepropyl)diisopropylsilyl acetylene for allyldiisopropylsilyl acetylene.
• a heavily doped n-type silicon wafer with 1000 Angstroms of thermal oxide as in Example 4 was used as a substrate. Substrates were treated for 3 minutes in a Plasma Cleaning System (Model YES-GlOOO from Yield Engineering Systems, Inc. (Livermore, CA)) using a power setting of 500W and oxygen flow of 1 standard cubic centimeter per minute (seem). The sample was then (i) coated with a semiconductor solution using a dip- coating apparatus (NIMA DlL from Nima Technology LTD (Coventry, England)) using a draw speed of 3 mm/min., and (ii) then allowed to dry at room temperature. Approximately 800-1000 Angstroms of gold was vapor deposited thereon through a shadow mask. Transistors were then characterized according to Mobility Value Test Method I.
• Each semiconductor solution was a 1.8 - 2.0 wt% solution in n-butylbenzene solvent, which had been filtered prior to use (Pall Life Sciences ACRODISC ® CR 25 mm, 0.2 um PTFE syringe filter).
• the semiconductor solution was placed into a dip-coating tank approximately 50 mm wide, 5 mm deep, and 30 mm high. Approximately 5 mL of solution was used. After coating, long crystals were present on the SiC ⁇ surface of the substrate, and typically oriented parallel to the dip axis. Source and drain contacts were oriented relative to the semiconductor crystals such that the crystals bridged the contacts.
• IP-DIPS 6,13-Bis- [(isopropenyldiisopropylsilyl)ethynyl]pentacene
• IP-DIPS 6,13-Bis-[(allyl-diisopro- pylsilyl)ethynyl]pentacene
• Allyl-DIPS 6, 13-Bis((l-methylenepropyl)diisopropyl- silylethynyl)pentacene (2-but-l-enyl DIPS); and
• the percentage of substrate surface covered by crystals was measured by (i) taking three digital photos of the substrate at high magnification (100X), then (ii) using a photo editing tool such as ADOBE ® PHOTOSHOP ® photo editing software to identify and render areas of exposed substrate as uniform black (0,0,0) coloration in L,a,b color space, then (iii) using the histogram feature of PHOTOSHOP ® photo editing software to identify the percentage of photo with luminosity (L) ⁇ 15, and then (iv) averaging the result of the three photos to give a value for surface coverage of the substrate.
• the value of surface coverage was then used to calculate the effective channel width of the TFTs, and this effective channel width was used to calculate charge carrier mobility values.
• the following formula was used to calculate effective channel width:
• W e ff is the effective channel width
• W dep is the length of source and drain contacts (as-deposited)
• C ov is the surface coverage (in percent). For example, if the source and drain electrodes were 1000 microns long and the surface coverage was 80 percent, then the effective channel width would be 800 microns.
• Charge carrier mobility values for the semiconductors in this example are shown in Table 6 below and were measured using Mobility Value Test Method I described above.
• the quenched reaction mixture was poured in a slow stream into the cold methanol solution and stirred for 20 minutes, then placed back in the refrigerator for 1 hr.
• the solid was collected by filtration, air-dried, then taken up in 9: 1 hexane:dichloromethane and rinsed through a thin pad of silica. Removal of solvent yielded a shiny blue powder, which recrystallized from acetone to yield blue needles (0.1 g, 5 %).
• 4,5-c-Dihydrofurano-l,2-dihydroxymethylbenzene was oxidized to the corresponding aldehyde using Swern conditions in 90% yield.
• the resulting 4,5-c- dihydrofurano-l,2-diformylbenzene was reacted with 0.5 equivalents of cyclohexane-1,4- dione in THF using 15 % aqueous sodium hydroxide as catalyst for the quadruple aldol condensation to yield the desired quinone in 60-96 %.
• the reaction was quenched by the addition of 0.5 mL saturated ammonium chloride, followed by the addition of a cold solution of 1.6 g (7.0 mmol) stannous chloride dihydrate and 2 mL 10% aqueous hydrochloric acid in 5 mL methanol. The resulting mixture was stirred for 30 minutes in an ice bath. Subsequently, 1 mL 10% HCl in 150 mL MeOH was added. The solution was stirred for one hour and was placed in the refrigerator for 3 hours.
• cyclopropylmagnesium bromide was formed by the addition of an anhydrous diethyl ether solution of cyclopropyl bromide (9.1 g, 75 mmol, in 40 mL Et 2 O) to magnesium (1.7 g, 70 mmol) in anhydrous diethyl ether (7 mL), followed by refluxing for 4 hr.
• the newly formed Grignard reagent was then removed from the heat, and the crude allyldichloro(trimethylsilylethynyl)silane from the first step was added to this reagent, followed by refluxing overnight.
• the reaction was quenched by the addition of water, then dilute sulfuric acid to dissolve the salts, and extracted into hexane (2 x 50 mL).
• the organic layer was washed with water (5 x 20 m L) and brine, dried over magnesium sulfate, filtered, and concentrated under vacuum to yield a light brown liquid. Further purification by chromatography on silica gel with hexane as an eluent yielded the trimethylsilyl-capped product as a colorless liquid.
• the trimethylsilyl cap was removed by stirring in THF and MeOH with 3 drops of 15% sodium hydroxide solution for 30 minutes.
• the reaction was quenched by the addition of 2 mL of a saturated ammonium chloride solution, which caused the solids to dissolve, then diluted with methanol (50 mL).
• methanol 50 mL
• stannous chloride dihydrate 2.5 g, 12 mmol
• methanol 200 mL
• 10% hydrochloric acid solution 2 mL
• the quenched diol was added in a slow stream to the stannous chloride solution and stirred for 30 minutes, then chilled for 1 hr.
• the solid was filtered and rinsed with methanol, redissolved in minimal dichloromethane and diluted with hexane (about 9: 1 hexane:dichloromethane), and rinsed through a pad of silica gel using 9: 1 hexane:dichloromethane as an eluent.
• the solvent was removed to yield 750 mg of crude product as a blue solid, which was recrystallized from about 125 mL acetone to yield 0.58 g (0.92 mmol, 30 % from quinone) blue needles.
• DiisopropyKtrimethylsilylethvnvDsiryl bromide Diisopropyl(trimethylsilylethynyl)silane (6.9 g, 33 mmol) was dissolved in dichloroethane (20 mL) in a round-bottom flask equipped with a stir bar and placed in an ice bath. N-Bromosuccinimide (36 mmol, 6.5 g) was added scoopwise over 30 minutes, and stirring was continued for 15 more minutes or until the solution began to turn bright orange. Solvent was removed using rotary evaporation, pentane was added to the resulting solid, and the remaining solid succinimide residues were removed by filtration. The pentane solution was again evaporated, the process repeated, and the pentane was removed to yield 8.6 g (29 mmol, 89 %) of a product as a pale brown oil.
• a 250 mL round-bottom flask with stir bar was flame-dried, cooled under nitrogen, and placed in an ice bath.
• To this flask was added 20 mL heptane, 10 mL anhydrous diethyl ether, and 5.0 g (37 mmol) 2-methyl-l,3-dithiane via syringe.
• n-Butyllithium (14.9 mL, 2.5 M in hexane) was added via syringe over 30 minutes. The solution was allowed to stir for 1.5 hr at O 0 C, and was then placed in a water bath at room temperature and allowed to stir for another 1.5 hr, then placed back in the ice bath.
• the crude product was purified by chromatography using a 2: 1 hexane:dichloromethane solution as an eluent, yielding 3.6 g (11 mmol, 29%) of the trimethylsilyl-capped acetylene as a clear oil.
• This acetylene was taken up in 24 mL of a 1: 1 solution of methanol and THF, then 3 drops of 15% aqueous sodium hydroxide solution were added and the reaction was allowed to stir at room temperature for 30 minutes. Hexane and water were added, and allowed to stir for another 30 minutes. The resulting solution was extracted into hexane (2 x 30 mL), and the organic layers were combined, washed with water and dried over magnesium sulfate.
• n-Butyllithium (1.34 mL, 2.5 M in hexane) was added dropwise and the solution was stirred for 30 minutes, then pentacene quinone (0.44 g, 1.4 mmol) was added and stirring was continued for 12 hr.
• the reaction was quenched by the addition of 3 drops of a saturated ammonium chloride solution, then a solution of stannous chloride dihydrate (1.3 g, 6.2 mmol) in 2 mL aqueous hydrochloric acid was added and the reaction was stirred for 10 minutes.
• Dichloromethane (20 mL) and water (25 mL) were added and the entire solution was flushed through CELITETM filter material using additional dichloromethane.
• stannous chloride dihydrate (1.4 g, 6.4 mmol) was dissolved in methanol (100 mL), and 1 mL of a 10% hydrochloric acid solution was added, then this solution was refrigerated for 1 hr.
• the reaction mixture was quenched by the addition of 0.5 mL of a saturated ammonium chloride solution, then diluted with methanol (20 mL).
• the quenched reaction mixture was poured in a slow stream into the stannous chloride mixture with stirring, and rinsed in with additional methanol. Stirring was continued for 30 minutes, then the entire mixture was refrigerated for 3 hr.
• Example 4 was used as a substrate. Substrates were treated for 3 minutes in a Plasma Cleaning System (Model YES-GlOOO from Yield Engineering Systems, Inc. (Livermore, CA)) using a power setting of 500W and oxygen flow of 1 standard cubic centimeter per minute (seem). The sample was then (i) coated with a semiconductor solution using a dip- coating apparatus (NIMA DlL from Nima Technology LTD (Coventry, England)) using a draw speed of 3 mm/min., and (ii) then allowed to dry at room temperature. Approximately 800-1000 Angstroms of gold was vapor deposited thereon through a shadow mask. Transistors were then characterized according to Mobility Value Test Method I.
• Each semiconductor coating solution was a 2.0 wt% semiconductor and 1 wt% polystyrene (PS) in a solvent blend comprising 91 wt% n-butylbenzene and 9 wt% decane.
• the semiconductor solution had been filtered prior to use (Pall Life Sciences ACRODISC ® CR 25 mm, 0.2 um PTFE syringe filter).
• the semiconductor solution was placed into a dip-coating tank approximately 50 mm wide, 5 mm deep, and 30 mm high. Approximately 5 mL of solution was used. After coating, long crystals were present on the Si ⁇ 2 surface of the substrate, and typically oriented parallel to the dip axis. Source and drain contacts were oriented relative to the semiconductor crystals such that the crystals bridged the contacts.
• Semiconductors used in this example were: (i) 6,13-Bis[(allyl dicyclopropylsilyl)- ethynyl]pentacene (A-DCPS) and (ii) 6,13-Bis-[(cyclopropyldiisopropylsilyl)ethynyl]- pentacene (Cyclopropyl DIPS).
• Effective channel width was measured as in Example 9 for the purposes of mobility calculation.
• Charge carrier mobility values for the semiconductors in this example are shown in Table 7 below and were measured using Mobility Value Test Method I described above.
• Example 19 Thermal Analysis of Materials TIPS Pentacene is known to exhibit a crystal transformation at about 124°C and, upon melting at about 266°C, exhibit an irreversible reaction, which is suspected to be a Diels-Alder reaction between an acetylene in the side group of one molecule and the aromatic structure of another molecule forming, at a minimum, a dimer. These transitions and reactions are readily observed using differential scanning calorimetry (DSC). For TIPS Pentacene in an upward temperature ramp, evident are an endotherm at ⁇ 124°C (a solid-solid crystal transition) and the onset of an endotherm at ⁇ 266°C (solid-liquid transition) which is overcome by the exotherm (Diels-Alder reaction).
• DSC differential scanning calorimetry

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