金配合物[Au(C≡C-4-LNO2)(PPh3)二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au(C≡C-4-LNO2)(PPh3),L=—C6H4(1),—C5H3N(2)]和自行设计的金配合物[Au(C≡C-4-C4H2N2NO2)(PPh3)L=—C4H2N2](3)的非线性光学性质.计算结果表明,3个配合物的二阶非线性性质变化规律为β1<β2<β3,与芳香性的变化规律正好相反.3个配合物的频率色散理论计算结果与实验观测值不符,暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一.     

有机金配合物催化的胺羰化制氨基甲酸酯及酰胺

使用一系列有机金配合物HAuCl4、Au(PPH3)Cl、Au(PPh3)2Cl、Au(PPh3)NO3和[Au(PPh3)]2S,催化胺类化合物羰化合氨基甲酸酯和酰胺。其中,Au(PPh3)Cl在合成氨基甲酸酯的反应中催化性能最好,而在合成酰胺的反应中[Au(PPh3)]2S的催化性能最好,两者均优于Pd(PPh32)2Cl2催化剂。     

光致发光配合物[Au_2(PPh_3)_2(μ-4,4′-bpy)](ClO_4)_2 and [Cu_2(PPh_3)_4(CH_3CN)_2(μ-4,4′-bpy)](BF_4)_2的合成和晶体结构

合成了两个在空气中稳定的Au(Ⅰ )和Cu(Ⅰ )配合物 ,并运用元素分析、红外光谱、荧光光谱和X射线单晶衍射结构表征 ,[Au2 (PPh3 ) 2 (μ 4 ,4′ bpy) ](ClO4 ) 2 (1) (4 ,4′ bpy为 4,4′ 联吡啶 ) ,单斜晶系 ,空间群P2 1c,晶胞参数a=1.2 2 5 5 (4 )nm ,b=0 .9973(3)nm ,c=1.85 0 6 (6 )nm ,β =10 1.732 (5 )°,V =2 .2 145 (11)nm3 ,Z =4,最终偏离因子R =0 .0 430 ,wR =0 .0 937.[Cu2 (PPh3 ) 4(CH3 CN) 2 (μ 4 ,4′ bpy) ](BF4 ) 2 (2 ) ,单斜晶系 ,空间群P2 1c,晶胞参数a =1.34 6 3(3)nm ,b =1.46 81(3)nm ,c =2 .0 6 0 8(4 )nm ,β =10 0 .387(4 )° ,V =4.0 0 6 6 (13)nm3 ,Z =2 ,最终偏离因子R =0 .0 45 0 ,wR =0 .116 3.两个双核配合物都是利用 4,4′ 联吡啶桥联配体 ,形成直线结构 ,直线的两端以PPh3 或CH3 CN为端基 .Au(Ⅰ )为 2配位 ,Cu(Ⅰ )为 4配位 .两个配合物均具有光致发光特性 ,其中配合物 1发光来自MLCT激发态 ,而配合物 2则是受配位金属影响的配体内部发光 .     

金配合物[Au（C=C-4-LNO2）（PPh3）二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au（C≡C-4-LNO2）（PPh3），L=-C6H4（1），-C5H3N（2）]和自行设计的金配合物[Au（C≡C-4-CdH：N2NO2）（PPh3）L=-C4H2N2]（3）的非线性光学性质．计算结果表明，3个配合物的二阶非线性性质变化规律为β1〈β2〈β3，与芳香性的变化规律正好相反．3个配合物的频率色散理论计算结果与实验观测值不符，暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一．     

铁硫和钴碳混合簇配合物μ-[(CO)_6Co_2PhC_2S](μ-RS)Fe_2(CO)_6的合成及表征

本文表明含炔键的单簇铁硫配合物(μ-PhC≡S)(μ-RS)Fe_2CO)_6 1,在乙醚和室温条件下与Co_2(CO)_8发生络合反应,生成铁硫和钴碳双簇配合物μ-[(OC)_5Co_2PhC_2S](μ-RS)Fe_2(CO)_5 2.本文还表征了双簇配合物2的结构并对R与硫桥原子所连的键型以及影响络合反应的空间位阻因素进行了讨论。     

[μ-PhC(O)S](μ-RS)Fe_2(CO)_6与(μ-R~1S)(μ-XMgS)Fe_2(CO)_6新奇反应的研究——孪合簇合物[(μ-RS)Fe_2(CO)_6](μ_4-S)[μ-R~1S)Fe_2(CO)_6]的合成、鉴定及形成机理

通过(μ-RS)(μ-XMgS)Fe_2(CO)_6与PhC(O)Cl反应合成了4个新苯甲酰配合物[μ-PhC(O)S](μ-RS)Fe_2(CO)_6(R=Me,Et,n—Bu,CH_2=CHCH_2). 它们进一步与(μ-R~1S)(μ-XMgS)Fe_2(CO)_6反应得8个不同 R,R~1基的孪合簇合物[(μ-RS)Fe_2(CO)_6](μ_4-S)[(μ-R~1S)Fe_2(CO)_6].其中R=n-Bu,R~1=Ph的配合物经X射线单晶结构分析表明是由1个μ_4-S将2个碎片PhS Fe_2(CO)_6及n-BuSFe_2(CO)_6螺结在一起的.其空间群为P—1; a=9.028(3),b=10.386(1),c=16.723(5)A;α=87.70(2),β=75.67(2),γ=82.26(2)°; Z=2; D_x=1.743g/cm~3.最终偏离因子R=0.031.     

氨荒酸配合物([M(MeBnNCS_2)_3],M=Sb(Ⅲ),Bi(Ⅲ))的合成、晶体结构及抑菌活性

合成了2种新的N-甲基-N-苄基二硫代氨基甲酸锑[Sb(MeBnNCS2)3](1)和铋[Bi(MeBnNCS2)3](2)配合物。通过元素分析、红外光谱、1H NMR、热重对其进行表征,并用X-射线单晶衍射测定了晶体结构。配合物1和2均属于单斜晶系,P21/c空间群。配合物1的晶胞参数为:a=0.955 1(7)nm,b=1.357 5(10)nm,c=2.468 1(17)nm,β=104.01(2)°,Z=4,V=3.105(4)nm3,Dc=1.520 g·cm-3,F(000)=1 440,μ=1.314 mm-1,最终偏离因子R1=0.033 9,wR2=0.083 2,S=1.010;配合物2的晶胞参数为:a=1.339 0(6)nm,b=0.997 5(5)nm,c=2.426 1(5)nm,β=98.433(7)°,Z=4,V=3.205(2)nm3,Dc=1.653 g·cm-3,F(000)=1 568,μ=5.912 mm-1,最终偏离因子R1=0.039 8,wR2=0.086 4,S=1.089。在这2个配合物中,中心金属离子M(Ⅲ)与来自3个配体中的6个硫原子配位,配合物1形成6配位的畸变的八面体构型;配合物2则形成6配位的畸变的五角锥构型。在配合物2中,分子之间又通过Bi…S弱相互作用构成二聚体结构。利用琼脂扩散法测试了配合物的抑菌活性,结果表明配合物1对4种受试菌株具有较强的抑菌活性。     

三个巢式磷碳硼烷镍配合物的合成、光谱表征和晶体结构

合成了3个巢式磷碳硼烷镍配合物[NiCl(Py){7,8-(PPh2)2-7,8-C2B9H10}].CH2Cl2(1)、[Ni{7,8-(PPh2)2-7,8-C2B9H10}2](2)、[Ni{7,8-(OPPh2)-7,8-C2B9H10}{7,8-(PPh2)-7,8-C2B9H10}](3),并通过元素分析、红外光谱、核磁共振谱以及单晶衍射等手段对其进行了表征。单晶结构分析表明,镍离子的配位环境在这3个配合物中都是稍微扭曲的平面方形,其中2个配位位置由磷碳硼烷配体的两个磷原子占据,另外2个配位位置分别由氯离子、吡啶氮原子或者氧化的磷碳硼烷配体的氧原子占据。借助于分子间的C-H…Cl氢键或者C-H.H-B双氢键作用,3个配合物都可以形成一维超分子结构。     

Au(Ⅰ)电荷转移配合物光谱性质的从头算研究

过渡金属电荷转移配合物的电荷分离是光能转化为电能的光物理过程,与配合物的电子结构密切相关.采用从头算方法探索了双核Au(Ⅰ)配合物,cis-[Au2(SHCH2PH2)2]2 (1),cis-[Au2(SHCH2S)2](2)和cis-[Au2(PH2CH2S)2](3)的电荷转移性质.采用MP2计算得到基态的Au(Ⅰ)—Au(Ⅰ)距离分别为0.2972,0.2888和0.2903 nm,表明Au(Ⅰ)之间存在弱吸引作用;电子激发使得配合物2和3的金属间的距离缩短了约0.016 nm,而配合物1仅增长了0.002 nm.CIS方法预测配合物1~3的3A激发态分别产生383,463和422 nm最低能发射,具有金属中心(Metal-centered,MC)跃迁和分子内电荷转移(Intramolecular Charge Transfer,ICT)的混合性质.     

Au(Ⅰ)电荷转移配合物光谱性质的从头算研究

过渡金属电荷转移配合物的电荷分离是光能转化为电能的光物理过程, 与配合物的电子结构密切相关. 采用从头算方法探索了双核Au(Ⅰ)配合物, cis-[Au2(SHCH2PH2)2]2+(1), cis-[Au2(SHCH2S)2](2) 和cis-[Au2(PH2CH2S)2](3)的电荷转移性质. 采用MP2计算得到基态的Au(Ⅰ)—Au(Ⅰ)距离分别为0.2972, 0.2888和0.2903 nm, 表明Au(Ⅰ)之间存在弱吸引作用; 电子激发使得配合物2和3的金属间的距离缩短了约0.016 nm, 而配合物1仅增长了0.002 nm. CIS方法预测配合物1~3的3A激发态分别产生383, 463和422 nm最低能发射, 具有金属中心(Metal-centered, MC)跃迁和分子内电荷转移(Intramolecular Charge Transfer, ICT)的混合性质.     

Syntheses, structures, and electrochemical properties of platinum(II) complexes containing di-tert-butylbipyridine and crown ether annelated dithiolate ligands

A series of new platinum(II) complexes containing both 4,4'-di-tert-butyl-2,2'-bipyridine (dbbpy) and the extended tetrathiafulvalenedithiolate ligands have been prepared and characterized. These complexes include [Pt(dbbpy)(C8H4S8)] (1; C8H4S82- = 2-{(4,5-ethylenedithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(ptdt)] (2; ptdt = 2-{(4,5-cyclopentodithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(mtdt)] (3; mtdt = 2-{(4,5-methylethylenedithio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(btdt)] (4; btdt = benzotetrathiafulvalenedithiolate), [Pt(dbbpy)(C8H6S8)] (5; C8H6S82- = 2-{4,5-bis(methylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), [Pt(dbbpy)(3O-C6S8)] (6; 3O-C6S82- = 2-{4,5-dithia-(3',6',9'-trioxaundecyl)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate), and [Pt(dbbpy)(4O-C6S8)] (7; 4O-C6S82- = 2-{4,5-dithia-(3',6',9',12'-tetraoxatetradecyl)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate). The crystal structures of a new ligand precursor (2-[4,5-dithia-(3',6',9',12'-tetraoxatetradecyl)-1,3-dithiol-2-ylidene]-4,5-bis(2-cyanoethylsulfanyl)-1,3-dithiole, IIIc) and complexes 5-7 have been determined by X-ray crystallography. Complexes 1-7 show intense electronic absorption bands in the UV-vis region due to the intramolecular mixed metal/ligand-to-ligand charge-transfer transition, and they display significant solvatochromic behavior. Redox properties of these compounds have been investigated by cyclic voltammetry, and complex 7 shows a significant response for Na+ ions with a large positive shift of ca. 45 mV.     

Electrical properties and electronic states of molecular conductors based on unsymmetrical organometallic-dithiolene gold(III) complexes

The electronic properties of cation radical salts derived from organometallic mixed-ligand complexes [(ppy)Au(S-S)](ppy- = C-dehydro-2-phenylpyridine(-); S-S(2-) = dithiolene ligand) with Au(III)-C sigma-bond were investigated. A 2:1 salt complex [(ppy)Au(C8H4S8)]2[PF6] (C8H4S8(2-) = 2-((4,5-ethylenedithio)-1,3-dithiole-2-ylidene)-1,3-dithiole-4,5-dithiolate(2-)) exhibited semiconductive behavior under ambient pressure (rho rt = 2.6 Omega cm, Ea = 0.03 eV). Magnetic measurements show that it is a Mott insulator close to the metal-insulator boundary. Raman and infrared spectra have revealed that the complex has a quasi-one-dimensional dimeric structure consisting of uniformly charged donor molecules. The complex exhibits metallic behavior at pressures above 0.8 GPa. In contrast, a similar compound [(ppy)Au(C8H4S6O2)]2[BF4] (C8H4S6O2(2-) = 2-((4,5-ethylenedioxy)-1,3-dithiole-2-ylidene)-1,3-dithiole-4,5-dithiolate(2-)) is a band insulator.     

Trinuclear Mo3S7 clusters coordinated to dithiolate or diselenolate ligands and their use in the preparation of magnetic single component molecular conductors

A general route for the preparation of a series of dianionic Mo3S7 cluster complexes bearing dithiolate or diselenolate ligands, namely, [Mo3S7L3](2-) (where L = tfd (bis(trifluoromethyl)-1,2-dithiolate) (4(2-)), bdt (1,2-benzenedithiolate) (5(2-)), dmid (1,3-dithia-2-one-4,5-dithiolate) (6(2-)), and dsit (1,3-dithia-2-thione-4,5-diselenolate) (7(2-))) is reported by direct reaction of [Mo3S7Br6](2-) and (n-Bu)2Sn(dithiolate). The redox properties, molecular structure, and electronic structure (BP86/VTZP) of the 4(2-) to 7(2-) clusters have also been investigated. The HOMO orbital in all complexes is delocalized over the ligand and the Mo3S7 cluster core. Ligand contributions to the HOMO range from 61.67% for 4(2-) to 82.07% for 7(2-), which would allow fine-tuning of the electronic and magnetic properties. These dianionic clusters present small energy gaps between the HOMO and HOMO-1 orbitals (0.277-0.104 eV). Complexes 6(2-) and 7(2-) are oxidized to the neutral state to afford microcrystalline or amorphous fine powders that exhibit semiconducting behavior and present antiferromagnetic exchange interactions. These compounds are new examples of the still rare single-component conductors based on cluster magnetic units.     

A family of oxo-chalcogenide molybdenum and tungsten complexes, (n-Bu4N)2[M2O2(mu-Q)2(1,3-dithiole-2-thione-4,5-dithiolate)2] (M = Mo, W; Q = S, Se): new synthetic entries, structure, and gas-phase behavior

A new series of complexes with the general formula (n-Bu4N)2[M2O2(micro-Q)2(dmit)2] (where M = Mo, W; Q = S, Se; dmit = 1,3-dithiole-2-thione-4,5-dithiolate) have been prepared. Fragmentation of the trinuclear cluster (n-Bu4N)2[Mo3(micro3-S)(micro-S2)3(dmit)3] in the presence of triphenylphosphine (PPh3) gives the dinuclear compound (n-Bu4N)2[Mo2O2(micro-S)2(dmit)2] [(n-Bu4N)2[2]], which is formed via oxidation in air from the intermediate (n-Bu4N)2[Mo3(micro3-S)(micro-S)3(dmit)3] [(n-Bu4N)2[1]] complex. Ligand substitution of the molybdenum sulfur bridged [Mo2O2(micro-S)2(dimethylformamide)6]2+ dimer with the sodium salt of the dmit dithiolate also affords the dianionic compound (n-Bu4N)2[2]. The whole series, (n-Bu4N)2[Mo2O2(micro-Se)2(dmit)2] [(n-Bu4N)2[3]], (n-Bu4N)2[W2O2(micro-S)2(dmit)2] [(n-Bu4N)2[4]], (n-Bu4N)2[W2O2(micro-Se)2(dmit)2] [(n-Bu4N)2[5]], and (n-Bu4N)2[Mo2O2(micro-S)2(dmid)2] [(n-Bu4N)2[6]; dmid = 1,3-dithiole-2-one-4,5-dithiolate], has been synthesized by the excision of the polymeric (Mo3Q7Br4)x phases with PPh3 or 1,2-bis(diphenylphosphanyl)ethane in acetonitrile followed by the dithiolene incorporation and further degradation in air. Direct evidence of the presence of the intermediates with the formula [M3Q4(dmit)3]2- (M = Mo, W; Q = S, Se) has been obtained by electrospray ionization mass spectrometry. The crystal structures of (n-Bu4N)2[1], (PPh4)2[Mo2O2(micro-S)2(dmit)2] [(PPh4)2[2]; PPh4 = tetraphenylphosphonium], (n-Bu4N)2[2], (n-Bu4N)2[4], (PPh4)2[W2O2(micro-Se)2(dmit)2] [(PPh4)2[5]], and (n-Bu4N)2[6] have been determined. A detailed study of the gas-phase behavior for compounds (n-Bu4N)2[2-6] shows an identical fragmentation pathway for the whole family that consists of a partial breaking of the two dithiolene ligands followed by the dissociation of the dinuclear cluster.     

A new optical/electrochemical Na+ sensor based on platinum(II) complexes containing crown ether annelated dithiolate ligands

Two new platinum(II) complexes containing both 4,4'-di-tert-butyl-2,2'-bipyridine (dbbpy) and crown ether annelated dithiolate ligands, [Pt(dbbpy)(3O-C2S4)] (, 3O-C2S4(2-)=1,4,7-trioxa-10,13-dithiacyclopentadec-11-ene-11,12-dithiolate) and [Pt(dbbpy)(4O-C2S4)] (, 4O-C2S(4)2-=1,4,7,10-tetraoxa-13,16-dithiacyclooctadec-14-ene-14,15-dithiolate), have been prepared and characterized. These two complexes show intense electronic absorption bands in the UV-vis region due to the intramolecular mixed metal/ligand-to-ligand charge transfer transition, and they display solvatochromic behavior. The redox properties of these compounds have been investigated by cyclic voltammetry and complex shows a significant response for Na+ ions with a large positive shift of ca. 125 mV. Moreover, complex is very sensitive in detecting Na+ cations with an obvious change in color which can be conveniently observed with the naked eye.     

Unique Thermal Structural Phase Transitions Exhibited by Unsymmetrical Organometallic Gold(III)-Dithiolene Complexes with Pentylthio and Hexylthio Groups

Unsymmetrical gold(III)-dithiolene complexes are potential candidates for molecular materials that exhibit thermal structural phase transitions. In this study, unsymmetrical ppy-gold(III) (ppy⁻=C-deprotonated-2-phenylpyridine(−)) complexes [AuC5] and [AuC6] coordinated by dithiolene ligands containing tetrathiafulvalene (TTF) skeletons with pentylthio (2-{bis(pentylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate(2−)) and hexylthio groups (2-{bis(hexylthio)-1,3-dithiol-2-ylidene}-1,3-dithiol-4,5-dithiolate(2−)) were synthesized. Both complexes exhibited a large absorption band at approximately 508 nm, owing to intramolecular ligand-to-ligand charge transfer. One-dimensional columnar structures with head-to-tail molecular arrangements around the metal ions were constructed in the crystals. The flexible alkylthio groups were intercalated into crystalline spaces between dithiolene ligands in the columns. [AuC5] exhibits a simple phase transition at 198 °C between crystalline and isotropic phases irreversibly. The crystalline phase of [AuC6] observed at 25 °C melted at 148 °C. Another crystalline phase grew above 148 °C with a very slow crystallization rate from the liquid phase and was completely transformed into an isotropic phase at 200 °C.     

Penta- and hexaruthenium carbonyl 'raft' complexes supported by monocarborane cage ligands

Reaction between [PPh4][closo-4-CB8H9] and [Ru3(CO)12] in refluxing toluene affords the unprecedented hexaruthenium metallacarborane salt [PPh4][2,3,7-{Ru(CO)3}-2,6,11-{Ru(CO)3}-7,11,12-{Ru(CO)3}-3,6,12-(micro-H)3-2,2,7,7,11,11-(CO)6-closo-2,7,11,1-Ru3CB8H6] (1a), which contains a planar Ru6 'raft' supported by a {CB8} monocarborane cluster. Addition of [CuCl(PPh3)]4 and Tl[PF6] to a CH2Cl2 solution of 1a results in simple cation replacement, forming the analogous [Cu(PPh3)3]+ salt (1b). The phenyl-substituted monocarborane [NEt4][6-Ph-nido-6-CB9H11] reacts with [Ru3(CO)12] in refluxing 1,2-dimethoxyethane to afford the pentaruthenium cluster species [N(PPh3)2][2,3,7-{Ru(CO)3}-3,4,8-{Ru(CO)3}-7,8-(micro-H)2-1-Ph-2,2,3,3,4,4-(CO)6-hypercloso-2,3,4,1-Ru3CB8H6] (2), after addition of [N(PPh3)2]Cl. Treatment of 2 with [CuCl(PPh3)]4 and Tl[PF6] in CH2Cl2 forms the zwitterionic complex [10,12-{exo-Cu(PPh3)2}-2,3,7-{Ru(CO)3}-3,4,8-{Ru(CO)3}-7,8,10,12-(micro-H)4-1-Ph-2,2,3,3,4,4-(CO)6-hypercloso-2,3,4,1-Ru3CB8H4] (3). Substitution of CO by PPh3 with concomitant cation replacement occurs on introduction of [AuCl(PPh3)], Tl[PF6], and PPh3 to a CH2Cl2 solution of 2, forming [Au(PPh3)2][2,3,7-{Ru(CO)2PPh3}-3,4,8-{Ru(CO)2PPh3}-7,8-(micro-H)2-1-Ph-2,2,3,3,4,4-(CO)6-hypercloso-2,3,4,1-Ru3CB8H6] (4). Crystallographic studies confirmed the cluster architectures in 1b, 2, and 3.     

Synthesis of bis-fused tetrathiafulvalene with mono- and dicarboxylic acids

Bis-fused tetrathiafulvalenes with mono- and dicarboxylic acids, 2-{5-(1,3-dithiol-2-ylidene)-[1,3]dithiolo[4,5-d][1,3]dithiol-2-ylidene}-1,3-dithiole-4-carboxylic acid (1) and 2-{5-(1,3-dithiol-2-ylidene)-[1,3]dithiolo[4,5-d][1,3]dithiol-2-ylidene}-1,3-dithiole-4,5-dicarboxylic acid (2) have been synthesized. The electronic structure of 1 and 2 was examined from their optical absorption spectra and using density-functional calculations.     

Synthesis, structural characterization, and theoretical studies of gold(I) and gold(I)-gold(III) thiolate complexes: quenching of gold(I) thiolate luminescence

The gold(I) thiolate complexes [Au(2-SC6H4NH2)(PPh3)] (1), [PPN][Au(2-SC6H4NH2)2] (2) (PPN = PPh3=N=PPh3), and [{Au(2-SC6H4NH2)}2(mu-dppm)] (3) (dppm = PPh2CH2PPh2) have been prepared by reaction of acetylacetonato gold(I) precursors with 2-aminobenzenethiol in the appropriate molar ratio. All products are intensely photoluminescent at 77 K. The molecular structure of the dinuclear derivative 3 displays a gold-gold intramolecular contact of 3.1346(4) A. Further reaction with the organometallic gold(III) complex [Au(C6F5)3(tht)] affords dinuclear or tetranuclear mixed gold(I)-gold(III) derivatives with a thiolate bridge, namely, [(AuPPh3){Au(C6F5)3}(mu2-2-SC6H4NH2)] (4) and [(C6F5)3Au(mu2-2-SC6H4NH2)(AudppmAu)(mu2-2-SC(6)H4NH2)Au(C6F5)3] (5). X-ray diffraction studies of the latter show a shortening of the intramolecular gold(I)-gold(I) contact [2.9353(7) or 2.9332(7) A for a second independent molecule], and short gold(I)-gold(III) distances of 3.2812(7) and 3.3822(7) A [or 3.2923(7) and 3.4052(7) A] are also displayed. Despite the gold-gold interactions, the mixed derivatives are nonemissive compounds. Therefore, the complexes were studied by DFT methods. The HOMOs and LUMOs for gold(I) derivatives 1 and 3 are mainly centered on the thiolate and phosphine (or the second thiolate for complex 2), respectively, with some gold contributions, whereas the LUMO for derivative 4 is more centered on the gold(III) fragment. TD-DFT results show a good agreement with the experimental UV-vis absorption and excitation spectra. The excitations can be assigned as a S --> Au-P charge transfer with some mixture of LLCT for derivative 1, an LLCT mixed with ILCT for derivative 2, and a S --> Au...Au-P charge transfer with LLCT and MC for derivative 3. An LMCT (thiolate --> Au(III) mixed with thiolate --> Au-P) excitation was found for derivative 4. The differing nature of the excited states [participation of the gold(III) fragment and the small contribution of sulfur] is proposed to be responsible for quenching the luminescence.     

Transition metal complexes based on thiophene-dithiolene ligands

The chemistry of transition metal dithiolene complexes based on thiophene-dithiolene ligands (TD) is reviewed, from the ligand synthesis and complex preparation to the molecular structure and solid state physical properties of different compounds based on them. The ligands considered are based mainly either on simple thiophene-dithiolates (α-tpdt = 2,3-thiophenedithiolate, dtpdt = 4,5-dihydro-2,3-thiophenedithiolate, and tpdt = 3,4-thiophenedithiolate), or in more extended and delocalised dithiolate ligands (α-tdt = 3-({5-[(2-cyanoethyl)thio]-2-thieno[2,3-d][1,3]dithiol-2-ylidene-1,3-dithiol-4-yl}thio)propanenitrile and dtdt = 3-{5-[(2-cyanoethyl)thio]-2-(5,6-dihydrothieno[2,3-d][1,3]dithiol-2-ylidene-1,3-dithiol-4-yl)thio}propanenitrile) that besides the thiophenic ring also incorporates a fused TTF moiety. Dithiolene complexes based on ligands containing appended thiophenic units will also be briefly considered. The structural variability of these complexes that in addition to the usual square planar coordination geometry, M(TD)₂, can also present dimeric, [M(TD)₂]₂, or cluster structures such as [Cu₄(TD)₃] and [Ni₄(TD)₆], is addressed. The role of the thiophene group and its ability to enhance electronic delocalisation from the metal dithiolene core throughout the ligand and to establish solid state networks of S?S interactions is discussed. The importance of these complexes as useful building blocks to prepare molecular materials with very interesting magnetic and transport properties, ranging from metamagnets to Single Component Molecular Metals, is illustrated by different compounds based on them.