CN103641851B - Organic hybrid Pb-Ag hybrid metal iodide of a kind of coordination function and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of organic hybrid Pb-Ag hybrid metal iodide of coordination function, it is characterized in that: the general formula of these iodide is [L _m(PbAgI ₃)] _nor [L _m(PbAg ₂i ₄)] n, wherein: L is the one in following ethylene polyamine part, and L and m meets following condition: when L is a kind of in quadrol, 1,2-propylene diamine and 1,3-propylene diamine, m=2; When L is a kind of in N, N, N ˊ, N ˊ-Tetramethyl Ethylene Diamine, triethylene tetramine and tetraethylene pentamine, m=1.The present invention, by the chelating ligands effect of organic constituent and metal, makes Pb-Ag hybrid metal iodide have different structures and photoelectric property, thus greatly improves the thermostability of iodide, obtain the controlled organic hybrid semiconductor material of energy gap with this.The present invention provides the preparation method of described hybrid metal iodide simultaneously, and it is by single step reaction synthesis hybrid metal iodide, and it is convenient that synthesis is simple, reaction raw materials is easy to get, product separation is purified, and yield is high, and product structure is clear and definite.

Description

A kind of organic hybrid Pb-Ag mixed metal iodide with coordination function and preparation method thereof

technical field

The invention relates to an organic hybrid Pb-Ag mixed metal iodide with coordination function and a preparation method thereof.

Background technique

Organic hybrid iodoleadate and iodosilverate are excellent semiconductor materials, optoelectronic materials and temperature-changing materials, and their optical, electrical and thermal properties are affected and controlled by their organic components, so in Inorganic-organic hybrid materials and composite materials have broad application prospects. _The structural units of iodopilumnate and _{iodosilvernate} are PbI ₆ octahedron and AgI ₄ tetrahedron respectively. Self-assembled in a coplanar manner to form [Pb _x I _y ] ^z– and [Ag _x I _y ] ^z– binary polymer ions with various structures, and their polymerization mode and degree of polymerization are related to the structure and type of organic cations , so the structure and properties of iodopilumnate and iodosilver acid can be influenced by structure-directing agents such as organic cations. However, due to the weak intermolecular force interaction between the organic component and the inorganic component of lead iodine and silver iodine, when this traditional organic hybrid metal iodide is heated, it often loses the organic compound in the temperature range of 80–150°C. The low thermal stability of this organic hybrid iodate greatly limits its application range.

On the other hand, I– ions have strong coordination ability with Pb ²⁺ and _Ag ⁺ ions, and have many pairs of lone pairs of electrons, which can be bridged by μ-I, μ ₃ -I and μ ₄ -I Coordinates with Pb ²⁺ and Ag ⁺ ions in a continuous coordination manner. Therefore, through the bridging effect of I– ions, PbI ₆ and AgI ₄ structural units can co-polymerize to form [Pb _x Ag _y I _z ] ^n– ternary iodide ions with a more complex structure. Under the synergy of the metal-to-metal interaction between Pb–Ag and the polar bond between Pb–I and Ag–I, this kind of ternary compound has more abundant photoelectric properties. At present, people have carried out relatively in-depth research on organic hybrid iodopilumnate and organic hybrid iodosilvernate, and synthesized a series of such binary lead iodide and silver iodide, but, for PbI-containing The study of coordination organic hybrid Pb _- Ag ternary iodides with mixed structural units of ₆ and AgI has not been reported.

Reports on organic hybrid iodolead salts: There are many literature reports on iodolead salts containing organic cations, and representative studies include:

(1) In 2004 and 2007, N. Mercier et al. used hydroxyl-containing organic amine OH(CH ₂ ) ₂ NH ₂ and halogenated organic amine X-(CH ₂ ) ₂ NH ₂ (X=Cl,Br) as Structure directing agent, [HO(CH ₂ ) ₂ NH ₃ ] ₂ PbI ₄ and [X(CH ₂ ) ₂ NH ₃ ] ₂ PbI ₄ with two-dimensional perovskite layered structure were synthesized respectively. [HO(CH ₂ ) ₂ NH ₃ ] ₂ PbI ₄ is a temperature-changing material. It undergoes phase transition at 96°C, from monoclinic phase to orthorhombic phase. This phase transition is reversible, and is caused by simultaneous It is caused by O–H···I and N–H···I hydrogen bonds. [X(CH ₂ ) ₂ NH ₃ ] ₂ PbI ₄ is an excellent semiconductor material with an energy gap of 2.2eV (see: N. Mercier, S. Poiroux, A. Riou and P. Batail, Inorg. Chem., 2004, 43 , 8361–8366; S. Sourisseau, N. Louvain, W. Bi, N. Mercier, D. Rondeau, F. Boucher, J.-Y. Buzaré and C. Legein, Chem. Mater., 2007, 19, 600-607);

(2) In 2007, N. Mercier et al. used NH ₂ (CH ₂ ) ₂ SS(CH ₂ ) ₂ NH ₂ as a structure-directing agent to synthesize iodolead salts containing protonated organic amine cations [NH ₃ (CH ₂ ) ₂ SS(CH ₂ ) ₂ NH ₃ ] ₄ Pb ₃ I ₁₄ ·I ₂ , [NH ₃ (CH ₂ ) ₂ SS(CH ₂ ) ₂ NH ₃ ] ₆ Pb ₅ I ₂₂ ·4H ₂ O and [NH ₃ (CH ₂ ) ₂ SS(CH ₂ ) ₂ NH ₃ ] ₆ Pb ₅ I ₂₂ ·2H ₂ O, the three compounds are all two-dimensional perovskite layered structure, in the temperature range of 37-87℃ Inside, it exhibits ionic conductivity, and the conductivity at 57°C is 6×10 ^-7 Scm ^-1 . (See: N. Louvain, W. Bi, N. Mercier, J.-Y. Buzaré, C. Legein and G. Corbel, Dalton Trans., 2007, 965–970);

(3) In 2008, GC Guo et al. synthesized the organic compound (EDAMP) _2n (Pb ₇ I ₁₈ ) _n 4nH ₂ O(EDAMP=Et ₂ NHC ₆ H ₄ -CH ₂ C ₆ H ₄ NHEt ₂ ), the compound has photochromic properties, the compound changes from yellow to light green after being irradiated with visible light with a wavelength of 550nm, and turns dark green again after being irradiated with light with a wavelength of 300nm. (See: ZJ Zhang, SC Xiang, GC Guo, G. Xu, MS Wang, JP Zou, SP Guo and J.S. Huang, Angew. Chem. Int. Ed., 2008, 47, 4149–4152);

Reports on organic hybrid iodosilvernates:

(1) In 1999, GCPapavassiliou et al. used quaternary ammonium salts Pr ₄ NBr and Me ₄ NBr as structure-directing agents to synthesize (Pr ₄ N) ₄ Ag ₄ I ₈ and (Me ₄ N) Ag ₂ I ₃ , two The compound is a semiconductor material with a low-dimensional structure, and has a strong absorption of light in the visible light region. (See: GC Pavassiliou, GAMousdis, A. Terzis and C.P. Raptopoulou. Z. Naturforsch. 1999, 54B, 109–112);

(2) In 2004, ZRChen et al. synthesized organic hybrid iodosilvernate [(EDP)(Ag ₂ I ₄ )] _n (EDP=N,N′-1,2-ethyl -dipyridinium) and [(EDO)(Ag ₂ I ₄ )] _n (EDO=N,N′-1,2-ethylence-bis(N,N′-dimethyloctaneammonium), in these two compounds, AgI ₄ tetrahedral The body forms a one-dimensional chain structure ion [Ag ₂ I ₄ ] _n ^2n- through co-transformation. (See: HHLi, ZRChen, CCHhuang, YGRenandQ.H.Chen, Chin.J.Struct.Chem.2004,23,288–291; HHLi, ZR Chen, CC Huang, YG Ren and G.C. Xiao, Chin. J. Struct. Chem., 2004, 23, 1009–1012);

(3) In 2006, JQLi and others synthesized {[Et ₃ N(CH ₂ ) ₄ NEt ₃ ][Ag ₄ I ₆ ]} _n , {[Et ₃ N (CH ₂ ) ₆ NEt ₃ ][Ag ₅ I ₇ ]} _n and {[Me ₃ N(CH ₂ ) ₆ NMe ₃ ][Ag ₄ I ₆ ]} _n , these compounds have fluorescent properties, and the three compounds are in 438nm, 492nm and 445nm exhibit strong fluorescence emission. (See: HHLi, ZRChen, JQLi, CCHhuang, YF Zhang and G.X. Jia, Cryst. Growth Des., 2006, 6, 1813–1820);

Reports on organic hybrid Pb-Ag iodides:

(1) In 2006, L. Chen et al. used PbI ₂ , AgNO ₃ , NaI, PPh ₃ (triphenylphosphine) and Bu ₄ NI (tetrabutylammonium iodide) as raw materials, DMF as solvent, and iso Propanol diffusion, synthesized organic hybrid silver iodide compounds [PbAg ₂ (PPh ₃ ) ₂ I ₄ ]·[PbI ₂ (DMF) ₂ ] and [(Bu ₄ N)(PbAgI ₄ )], the yields were respectively 36.8% and 15.4%. [PbAg ₂ (PPh ₃ ) ₂ I ₄ ] and [(PbAgI ₄ )] ^– are one-dimensional chain structures. The energy gaps of the two are 2.82eV and 2.77eV respectively, [(Bu ₄ N)(PbAgI ₄ )] has fluorescence properties, and the maximum emission wavelength is 566nm respectively. (6. LQ Fan, LM Wu and L. Chen. Inorg. Chem. 2006, 45, 3149–3151).

However, the study of Pb-Ag ternary iodides containing mixed structural units of PbI ₆ and AgI ₄ with coordination organic hybridization has not been reported.

Contents of the invention

The purpose of the first aspect of the present invention is: to overcome the problem of poor thermal stability of traditional iodopilumnate and iodosilverate containing organic cations, to provide a kind of organic hybrid Pb-Ag mixed metal iodide with coordination function, Through the chelation and coordination of organic components and metals, Pb-Ag mixed metal iodides have different structures and photoelectric properties, thereby greatly improving the thermal stability of iodides, thereby obtaining organic heterogeneous materials with controllable energy gaps. chemical semiconductor materials.

In order to solve the above-mentioned first problem, the technical solution of the present invention is: an organic hybrid Pb-Ag mixed metal iodide with coordination function, characterized in that: the general formula of the iodide is [L _m (PbAgI ₃ ) ] _n or [L _m (PbAg ₂ I ₄ )] _n , wherein:

L is one of the following ethylene polyamine ligands, and L and m meet the following conditions:

When L is one of ethylenediamine, 1,2-propylenediamine and 1,3-propylenediamine, m=2;

When L is one of N,N,N',N'-tetramethylethylenediamine, triethylenetetramine and tetraethylenepentamine, m=1.

In the present invention, n in the general formulas of [L _m (PbAgI ₃ )] _n and [L _m (PbAg ₂ I ₄ )] _n above means that the iodide is a coordination polymer, and n can also be replaced by ∞.

Further, when the conditions are constant, the [L _m (PbAgI ₃ )] _n or [L _m (PbAg ₂ I ₄ )] _n -type iodide satisfies the following specific ion coordination structure:

(1) [L ₂ (PbAgI ₃ )] _n or [L ₂ (PbAg ₂ I ₄ )] _n -type iodide:

In the [L ₂ (PbA _g I ₃ )] _n -type compound, [Ag ₂ I ₆ ] ^4– combines with the Pb(II) ion in [PbL ₂ ] ²⁺ through the I atom to form a two-dimensional [PbAgI ₃ ] _n skeleton structure; in [L ₂ (PbAg ₂ I ₄ )] _n -type compounds, [Ag ₂ I ₄ ^2– ] _n one-dimensional ions interact with Pb(II) ions in [PbL ₂ ] ²⁺ through I atoms combined to form a three-dimensional [PbAg ₂ I ₄ ] _n framework structure;

In any of the above skeleton structures, there are two ethylene polyamine ligands L bound to each Pb(II) ion through a coordination bond, and the Pb(II) ion has an 8-coordination structure;

(2) When L takes one of N,N,N',N'-tetramethylethylenediamine, triethylenetetramine and tetraethylenepentamine, which have a large steric hindrance and a high number of coordination teeth [L(PbAgI ₃ )] _n or [L(PbAg ₂ I ₄ )] _n type iodide:

[PbAgI ₃ ] _n has a two-dimensional framework structure, and [PbAg ₂ I ₄ ] _n has a three-dimensional framework structure, and in either framework structure, there is an ethylene polyamine ligand L passing through each Pb(II) ion Coordinate bond combination, Pb(II) ion has a 6–8 coordination structure; due to the large steric hindrance of organic ligands, [Ag ₂ I ₆ ] ^4– and [Ag ₂ I ₄ ^2– ] _n and [PbL ] The binding force of Pb(II) ions in ²⁺ is weakened, which increases the bond length of Pb–I, thereby improving the binding strength of silver iodate ions and Pb(II) ions. That is, the binding strength of silver iodate ions and Pb(II) ions is affected by the large steric hindrance of organic ligands.

The second aspect of the present invention aims to provide a method for preparing an organic hybrid Pb-Ag mixed metal iodide with a coordination function, which uses an ethylene polyamine ligand with a coordination function as a template (structure-directing agent), Using the bridging effect of I ^- ions, the structural units of PbI ₆ and AgI ₄ were polymerized under solvothermal conditions to generate mixed metal iodide compounds, and iodides with different structures were obtained by changing the ratio of reactants. The method synthesizes mixed metal iodides through a one-step reaction, the synthesis is simple, the reaction raw materials are easily obtained, the product separation and purification are convenient, the yield is high, and the product structure is clear.

In order to solve the above-mentioned second problem, the technical solution of the present invention is: mix PbI ₂ , AgI, and KI in an organic solvent at a molar ratio of 2:1:4 to 1:2:4, and add ethylene polyamine ligand L , to ensure that the volume ratio of the amount of ethylene polyamine ligand to the organic solvent is 1:2 to 1:3, stir evenly, and react in the reactor at 80-100°C for 2-4 days; after the reaction is completed and cooled to room temperature, there is A large amount of solids are precipitated, filtered, and the filter cake is washed with ethanol and 2-butanone successively, and dried, and the obtained solid is [L _m (PbAgI ₃ )] _n -type product;

Alternatively, increase the amount of AgI, mix PbI ₂ , AgI, and KI in an organic solvent at a molar ratio of 1:3:6 to 1:4:6, and add ethylene polyamine ligand L to ensure the amount of ethylene polyamine ligand The volume ratio of the volume to the organic solvent is 1:2~1:3, stir evenly, and react in the reactor at 80-100°C for 2-4 days; after the reaction is completed and cooled to room temperature, a large amount of solids are precipitated, filtered, and the filter cake Wash with ethanol and 2-butanone successively, and drain, and the obtained solid is [L _m (PbAg ₂ I ₄ )] _n -type product;

Wherein: the organic solvent is one of N,N'-dimethylformamide and dimethyl sulfoxide or a mixed solution with a volume ratio of 1:1;

The ethylene polyamine ligand L is selected from ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, N,N,N',N'-tetramethylethylenediamine, triethylenetetramine, One of tetraethylenepentamine.

Preferably, the molar ratio of PbI ₂ and ethylene polyamine ligand L in the present invention is 1:1.2˜1:3.5.

The advantages of the present invention are:

1. The present invention uses ethylene polyamine with chelating coordination function as a ligand, utilizes its coordination with lead ions, and synthesizes Pb-Ag mixed metal iodine containing organic hybridization with coordination function under solvothermal conditions compounds. The synthesis reaction is completed in one step, the synthetic raw materials are easy to obtain, the product separation and purification are convenient, and the yield is high, the product structure is clear, and the structure change of the organic ligand L can affect the coordination mode and coordination of the iodosilverate ion and the lead ion. The ability to control the structure and photoelectric properties of the product.

2. A Pb-Ag mixed metal iodide with coordination function organic hybridization of the present invention is obtained through one-step reaction, the synthesis is simple, and the reaction raw materials are easy to obtain. This type of compound has a two-dimensional layered or three-dimensional network Pb-Ag-I ternary skeleton structure. Ethylene polyamine is combined with Pb(II) ions in the Pb-Ag-I inorganic layer through a coordination bond, and the chelating effect Under the action, the thermal stability of organic hybrid metal iodide compounds is improved. Utilizing the steric hindrance and the number of teeth of the ethylene polyamine ligand can not only control the content of organic components in the product, but also affect the coordination mode and binding ability of the iodosilverate ion and the Pb(II) ion, so that the Pb-Ag mixed metal iodide Compounds have different structures and optoelectronic properties, and organic hybrid semiconductor materials with controllable energy gaps are obtained.

detailed description

The abbreviations involved in the following examples are explained as follows:

en is ethylenediamine; pda is 1,2-propylenediamine; dap is 1,3-propylenediamine;

tmeda is N,N,N',N'-tetramethylethylenediamine; trien is triethylenetetramine; tepa is tetraethylenepentamine;

DMSO is dimethylsulfoxide; DMF is N,N'-dimethylformamide.

Example 1: The chemical formula of the product is [(en) ₂ (PbAgI ₃ )] _n , and its specific preparation method is as follows:

_PbI2 (0.462 g, 1.0 mmol), AgI (0.117 g, 0.5 mmol) and KI (0.332 g, 2 mmol) were added to 2 mL of DMSO and 1 mL of ethylenediamine (en) mixed solution, stirred After 10 minutes, the mixture was put into a polytetrafluoroethylene stainless steel reactor, and reacted at 100° C. for 2 days. After cooling to room temperature, pale yellow crystals were precipitated, filtered, and successively washed with cold 5 milliliters of ethanol and 5 milliliters of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture). Butanone) was washed to obtain 0.35 g of crystals, with a yield of 86%. Elemental analysis: C5.75, H1.79, N6.76%, C ₄ H ₁₆ N ₄ PbAgI ₃ theoretical value: C5.89, H1.98, N6.87%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3671(s), 3547(s), 3247(s), 3120(s), 2938(s), 2869(s), 1600(s), 1582(s) ),1486(s),1381(m),1328(m),1316(m),1159(w),1099(w),1080(s),1028(s),821(w),640(m ), 514(w), 441(m), 402(w). Solid-state absorption spectroscopy measurement: semiconductor energy gap E _g =2.87eV. The decomposition temperature under N ₂ gas atmosphere is 210°C.

Example 2: The chemical formula of the product is [(en) ₂ (PbAg ₂ I ₄ )] _n , and its specific preparation method is as follows:

_PbI2 (0.231 g, 0.5 mmol), AgI (0.468 g, 2.0 mmol) and KI (0.498 g, 3 mmol) were added to a mixed solution of 3 mL of DMSO and 1 mL of ethylenediamine (en), and stirred After 10 minutes, the mixture was put into a polytetrafluoroethylene stainless steel reaction kettle, and reacted at 100° C. for 3 days. After cooling to room temperature, yellow crystals were precipitated, filtered, and successively washed with 5 ml of cold ethanol and 5 ml of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture) Ketone) was washed to obtain 0.41 g of crystals, with a yield of 78%. Elemental analysis: C4.51, H1.46, N5.08%, C ₄ H ₁₆ N ₄ PbAg ₂ I ₄ theoretical value: C4.57, H1.53, N5.33%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3392(w)3292(s)3231(m)2921(w)2350(w)1557(m)1456(w)1386(s)1319(w)1097( w) 1009(s) 597(m) 464(m). Solid-state absorption spectrometry: semiconductor energy gap E _g =2.57eV. The decomposition temperature under N ₂ gas atmosphere is 208°C.

Example 3: The chemical formula of the product is [(pda) ₂ (PbAgI ₃ )] _n , and its specific preparation method is as follows:

_PbI2 (0.231 g, 0.5 mmol), AgI (0.234 g, 1.0 mmol) and KI (0.332 g, 2 mmol) were added to 2 mL of DMF and 1 mL of 1,2-propylenediamine (pda) mixed solution, stirred for 10 minutes, the mixture was put into a polytetrafluoroethylene stainless steel reaction kettle, and reacted at 80°C for 4 days. After cooling to room temperature, pale yellow crystals were precipitated, filtered, and successively washed with cold 5 milliliters of ethanol and 5 milliliters of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture). Butanone) was washed to obtain 0.37 g of crystals, with a yield of 87%. Elemental analysis: C8.41, H2.31, N6.50%, C ₆ H ₂₀ N ₄ PbAgI ₃ theoretical value: C8.54, H2.39, N6.64%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3308(s), 3220(s), 3122(s), 2933(s), 2874(s), 1582(s), 1510(m), 1384(m ),1329(m),1156(w),1114(w),1029(s),1000(s),949(s),810(w),603(m),574(m),481(m ), 452(m). Measurement of solid-state absorption spectroscopy: semiconductor energy gap E _g =2.85eV. The decomposition temperature under N ₂ gas atmosphere is 219°C.

Example 4: The chemical formula of the product is [(dap) ₂ (PbAg ₂ I ₄ )] _n , and its specific preparation method is as follows:

Add _PbI2 (0.231 g, 0.5 mmol), AgI (0.468 g, 2.0 mmol) and KI (0.498 g, 3 mmol) to 3 mL of DMF and 1 mL of 1,3-propylenediamine (dap) and mix solution, stirred for 10 minutes, the mixture was put into a polytetrafluoroethylene stainless steel reaction kettle, and reacted at 90°C for 3 days. After cooling to room temperature, yellow crystals were precipitated, filtered, and successively washed with 5 ml of cold ethanol and 5 ml of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture) Ketone) was washed to obtain 0.44 g of crystals, with a yield of 81%. Elemental analysis: C6.53, H1.66, N5.04%, C ₆ H ₂₀ N ₄ PbAg ₂ I ₄ theoretical value: C6.68, H1.87, N5.19%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3447(w)3215(m)2848(m)1579(m)1446(m)1374(s)1075(s)936(s)815(m)581( w) 482(w). Solid-state absorption spectrometry: semiconductor energy gap E _g =2.51eV. The decomposition temperature under N ₂ gas atmosphere is 224°C.

Example 5: The chemical formula of the product is [(tmeda)(PbAgI ₃ )] _n , and its specific preparation method is as follows:

Add _PbI2 (0.231 g, 0.5 mmol), AgI (0.234 g, 1.0 mmol) and KI (0.332 g, 2 mmol) to 2 mL of DMF and 1 mL of N,N,N',N'-tetra Methylethylenediamine (tmeda) mixed solution, stirred for 10 minutes, the mixture was put into a polytetrafluoroethylene stainless steel reactor, and reacted at 90° C. for 3 days. After cooling to room temperature, pale yellow crystals were precipitated, filtered, and successively washed with cold 5 milliliters of ethanol and 5 milliliters of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture). Butanone) was washed to obtain 0.31 g of crystals, with a yield of 76%. Elemental analysis: C8.78, H1.83, N3.32%, C ₆ H ₂₀ N ₄ PbAgI ₃ theoretical value: C8.88, H1.99, N3.45%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3050(w), 2920(w), 1662(s), 1582(m), 1510(s), 1422(s), 1338(w), 1254(w ), 1139(m), 1097(m), 844(s), 772(m), 726(s), 662(m), 502(w), 422(m). Solid State Absorption Spectrometry: Semiconductor Energy Gap E _g =2.71eV. The decomposition temperature under _N2 gas atmosphere is 234 °C.

Embodiment 6: The chemical formula of the product is [(trien)(PbAgI ₃ )] _n , and its specific preparation method is as follows:

PbI ₂ (0.462 g, 1.0 mmol), AgI (0.117 g, 0.5 mmol) and KI (0.332 g, 2 mmol) were added to 3 mL of DMF and 1.5 mL of triethylenetetramine (trien) mixed solution, Stir for 10 minutes, put the mixture into a polytetrafluoroethylene stainless steel reactor, and react at 90° C. for 3 days. After cooling to room temperature, pale yellow crystals were precipitated, filtered, and successively washed with cold 5 milliliters of ethanol and 5 milliliters of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture). Butanone) was washed to obtain 0.37 g of crystals, with a yield of 88%. Elemental analysis: C8.44, H2.20, N6.55%, C ₆ H ₁₈ N ₄ PbAgI ₃ theoretical value: C8.56, H2.15, N6.65%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3447(w), 3245(m), 2847(s), 2761(s), 1582(s), 1460(s), 1381(m), 1328(m ), 1155(m), 1080(m), 1029(s), 1009(s), 945(m), 841(m), 790(m), 511(w), 446(m). Solid state absorption spectrum Measurement: semiconductor energy gap E _g =2.88eV. The decomposition temperature under N ₂ gas atmosphere is 273°C.

Example 7: The chemical formula of the product is [(trien)(PbAg ₂ I ₄ )] _n , and its specific preparation method is as follows:

_PbI2 (0.231 g, 0.5 mmol), AgI (0.352 g, 1.5 mmol) and KI (0.498 g, 3 mmol) were added to 3 mL of DMF and 1.5 mL of triethylenetetramine (trien) mixed solution, Stir for 10 minutes, put the mixture into a polytetrafluoroethylene stainless steel reactor, and react at 90° C. for 3 days. After cooling to room temperature, yellow crystals were precipitated, filtered, and successively washed with 5 ml of cold ethanol and 5 ml of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture) Ketone) was washed to obtain 0.48 g of crystals, with a yield of 89%. Elemental analysis: C6.55, H1.57, N5.09%, C ₆ H ₁₈ N ₄ PbAg ₂ I ₄ theoretical value: C6.69, H1.68, N5.20%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3425(w)3197(m)2908(w)2223(w)1551(m)1468(m)1374(s)1329(m)1190(w)1136( s)1041(s)882(w)748(m)704(m)531(m)476(m). Solid-state absorption spectrometry: semiconductor energy gap E _g =2.49eV. The decomposition temperature under N ₂ gas atmosphere is 284 °C.

Embodiment 8: The chemical formula of the product is [(tepa)(PbAg ₂ I ₄ )] _n , and its specific preparation method is as follows:

_PbI2 (0.231 g, 0.5 mmol), AgI (0.352 g, 1.5 mmol) and KI (0.498 g, 3 mmol) were added to 3 mL of DMF and 1.5 mL of tetraethylenepentamine (tepa) mixed solution, Stir for 10 minutes, put the mixture into a polytetrafluoroethylene stainless steel reactor, and react at 90° C. for 3 days. After cooling to room temperature, pale yellow crystals were precipitated, filtered, and successively washed with cold 5 milliliters of ethanol and 5 milliliters of 2-butanone (cold ethanol and cold 2-butanone refer to ethanol and 2-butanone after cooling with ice-water mixture). Butanone) was washed to obtain 0.47 g of crystals, with a yield of 85%. Elemental analysis: C8.49, H2.01, N6.12%, C ₈ H ₂₃ N ₅ PbAg ₂ I ₄ theoretical value: C8.58, H2.07, N6.25%. Infrared absorption spectrum data (KBr, cm ^-1 ): 3232(s), 3135(s), 2899(m), 2835(m), 2325(w), 1645(w), 1565(m), 1443(m ),1359(w),1312(m),1177(m),1118(m),1004(s),941(s),882(m),818(s),607(m),527(m ), 490(m), 422(w). Solid-state absorption spectrometry: semiconductor energy gap E _g =2.49eV. The decomposition temperature under N ₂ gas atmosphere is 344°C.

The above examples are only some implementations of the present invention, but should not be construed as limiting the patent scope of the present invention. It should be noted that, for those of ordinary skill in the art, these all belong to the protection scope of the present invention without departing from the concept of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (4)

1. an organic hybrid Pb-Ag mixed metal iodide of a coordination function, characterized in that: the general formula of the iodide is [L _m (PbAgI ₃ )] _n or [L _m (PbAg ₂ I ₄ )] _n , where: L is one of the following ethylene polyamine ligands, and L and m meet the following conditions: When L is one of ethylenediamine, 1,2-propylenediamine and 1,3-propylenediamine, m=2; When L is one of N,N,N',N'-tetramethylethylenediamine, triethylenetetramine and tetraethylenepentamine, m=1. 2. the organic hybrid Pb-Ag mixed metal iodide of a kind of coordination function according to claim 1, is characterized in that described [L _m (PbAgI ₃ )] _n or [L _m (PbAg ₂ I ₄ ) ] The _n -type iodide satisfies the following specific ion coordination structure: (1) [L ₂ (PbAgI ₃ )] _n or [L ₂ (PbAg ₂ I ₄ )] _n -type iodide: In the [L ₂ (PbAgI ₃ )] _n -type compound, [Ag ₂ I ₆ ] ^4– combines with the Pb(II) ion in [PbL ₂ ] ²⁺ through the I atom to form a two-dimensional [PbAgI ₃ ] _n Skeleton structure; in [L ₂ (PbAg ₂ I ₄ )] _n -type compounds, [Ag ₂ I ₄ ^2– ] _n one-dimensional ions combine with Pb(II) ions in [PbL ₂ ] ²⁺ through I atoms, Form a three-dimensional [PbAg ₂ I ₄ ] _n framework structure; In any of the above skeleton structures, there are two ethylene polyamine ligands L bound to each Pb(II) ion through a coordination bond, and the Pb(II) ion has an 8-coordination structure; (2) When L takes one of N,N,N',N'-tetramethylethylenediamine, triethylenetetramine and tetraethylenepentamine, which have a large steric hindrance and a high number of coordination teeth [L(PbAgI ₃ )] _n or [L(PbAg ₂ I ₄ )] _n type iodide: [PbAgI ₃ ] _n has a two-dimensional framework structure, and [PbAg ₂ I ₄ ] _n has a three-dimensional framework structure, and in either framework structure, there is an ethylene polyamine ligand L passing through each Pb(II) ion Coordinate bond combination, Pb(II) ion has a 6–8 coordination structure; due to the large steric hindrance of organic ligands, [Ag ₂ I ₆ ] ^4– and [Ag ₂ I ₄ ^2– ] _n and [PbL ] The binding force of Pb(II) ions in ²⁺ is weakened, which increases the bond length of Pb–I, thereby improving the binding strength of silver iodate ions and Pb(II) ions. 3. a kind of preparation method of the organic hybrid Pb-Ag mixed metal iodide of coordination function as described in claim 1 or 2 any one, it is characterized in that: Mix PbI ₂ , AgI, and KI in an organic solvent at a molar ratio of 2:1:4 to 1:2:4, add ethylene polyamine ligand L to ensure the volume ratio of the amount of ethylene polyamine ligand to the organic solvent 1:2～1:3, stir evenly, react in the reaction kettle at 80-100°C for 2-4 days; after the reaction is completed and cooled to room temperature, a large amount of solids precipitate, filter, and the filter cake is successively washed with ethanol and 2-butyl Washing with ketone and draining, the solid obtained is [L _m (PbAgI ₃ )] _n -type product; Alternatively, increase the amount of AgI, mix PbI ₂ , AgI, and KI in an organic solvent at a molar ratio of 1:3:6 to 1:4:6, and add ethylene polyamine ligand L to ensure the amount of ethylene polyamine ligand The volume ratio of the volume to the organic solvent is 1:2~1:3, stir evenly, and react in the reactor at 80-100°C for 2-4 days; after the reaction is completed and cooled to room temperature, a large amount of solids are precipitated, filtered, and the filter cake Wash with ethanol and 2-butanone successively, and drain, and the obtained solid is [L _m (PbAg ₂ I ₄ )] _n -type product; Wherein: the organic solvent is one of N,N'-dimethylformamide and dimethyl sulfoxide or a mixed solution with a volume ratio of 1:1; The ethylene polyamine ligand L is selected from ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, N,N,N',N'-tetramethylethylenediamine, triethylenetetramine, One of tetraethylenepentamine. 4. The preparation method according to claim 3, characterized in that the molar ratio of the PbI ₂ and the ethylene polyamine ligand L is 1:1.2 to 1:3.5.