二硫醇金（III）配合物的合成、分子结构与光谱学

Syntheses, Molecular Structures, and Spectroscopy of Gold(III) Dithiolate Complexes.

作者信息

Mansour M. Adnan, Lachicotte Rene J., Gysling Henry J., Eisenberg Richard

机构信息

NSF-Science and Technology Center for Photoinduced Charge Transfer, Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, and Imaging Research and Advanced Development, Eastman Kodak Company, Rochester, New York 14650-2109.

出版信息

Inorg Chem. 1998 Sep 7;37(18):4625-4632. doi: 10.1021/ic980032b.

DOI:10.1021/ic980032b

PMID:11670612

Abstract

Two Au(III) dithiolate complexes, [Au(dbbpy)(tdt)]PF(6) and Au(eta(2)-C,N-ppy)(tdt), (dbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine; tdt = 3,4-toluenedithiolate; ppy = C-deprotonated 2-phenylpyridine), have been prepared and structurally characterized by X-ray crystallography. The complexes have low-energy absorption bands that exhibit mild solvatochromism (lambda(max) = 444 nm (epsilon, 2310 M(-)(1) cm(-)(1)) in CH(2)Cl(2) and 406 nm (epsilon, 3170 M(-)(1) cm(-)(1)) in DMSO) and are tentatively assigned to a charge-transfer-to-diimine transition. This transition occurs at higher energy than the analogous charge-transfer transition in related Pt(II) complexes (e.g., Pt(dbbpy)(tdt), lambda(max) = 563 nm (epsilon, 7200 M(-)(1) cm(-)(1)). Whereas neither Au(III) complex is emissive, their respective dichloride precursors, [Au(dbbpy)Cl(2)]PF(6) and Au(eta(2)-C,N-ppy)Cl(2), luminesce in low-temperature glass matrixes from an excited state that is tentatively assigned as intraligand pi-pi. The neutral complex, Au(eta(2)-C,N-ppy)(tdt), is more easily oxidized (E(ox) = 0.925 V vs 1.589 V (vs NHE)) and less easily reduced (E(red) = -1.339 V vs -0.255 V (vs NHE)) than the cationic complex, [Au(dbbpy)(tdt)]PF(6). Both dithiolate complexes exhibit approximately square planar coordination. Yellow crystals of [Au(dbbpy)(tdt)]PF(6) (C(25)H(30)AuF(6)N(2)PS(2)) are triclinic, space group P&onemacr; (No. 2), with a = 7.1977(2) Å, b = 11.7292(1) Å, c = 17.5820(5) Å, alpha = 104.537(2) degrees, beta = 96.592(2) degrees, gamma = 102.455(2) degrees, V = 1380.41(6) Å(3), Z = 2, and final R = 0.050 (R(w) = 0.1062) for 3446 unique reflections. Orange crystals of Au(eta(2)-C,N-ppy)(tdt) (C(18)H(14)AuNS(2)) are monoclinic, space group P2(1)/c (No. 14), with a = 8.852(1) Å, b = 11.726(2) Å, c = 15.499(5) Å, beta = 101.34(2) degrees, V = 1577.5(6) Å(3), Z = 4, and final R = 0.0438 (R(w) = 0.0759) for 3685 unique reflections. A structural trans effect in Au(eta(2)-C,N-ppy)(tdt) results in a significantly longer Au-S distance (ca. 0.1 Å) trans to the Au-C bond than that trans to the Au-N bond. In the solid state, the Au(dbbpy)(tdt) cations are arranged in stacks with alternating intermolecular Au.Au separations of 3.60 and 3.75 Å while the Au(eta(2)-C,N-ppy)(tdt) molecules form stacks with an intermolecular Au.Au separation of 3.81 Å.

摘要

已制备出两种二硫醇金（III）配合物，[Au(dbbpy)(tdt)]PF₆ 和 Au(η²-C,N-ppy)(tdt)，（dbbpy = 4,4'-二叔丁基-2,2'-联吡啶；tdt = 3,4-甲苯二硫醇盐；ppy = C-去质子化的 2-苯基吡啶），并通过 X 射线晶体学对其进行了结构表征。这些配合物具有低能量吸收带，表现出温和的溶剂化显色性（在二氯甲烷中 λ(max) = 444 nm（ε，2310 M⁻¹ cm⁻¹），在二甲基亚砜中为 406 nm（ε，3170 M⁻¹ cm⁻¹）），并初步归属于电荷转移至二亚胺跃迁。该跃迁发生的能量高于相关 Pt(II) 配合物中的类似电荷转移跃迁（例如，Pt(dbbpy)(tdt)，λ(max) = 563 nm（ε，7200 M⁻¹ cm⁻¹））。虽然两种金（III）配合物均无发射，但它们各自的二氯化物前体，[Au(dbbpy)Cl₂]PF₆ 和 Au(η²-C,N-ppy)Cl₂，在低温玻璃基质中从一个初步归属于配体内 π-π 的激发态发光。中性配合物 Au(η²-C,N-ppy)(tdt) 比阳离子配合物 [Au(dbbpy)(tdt)]PF₆ 更容易被氧化（E(ox) = 0.925 V 对 1.589 V（对 NHE））且更难被还原（E(red) = -1.339 V 对 -0.255 V（对 NHE））。两种二硫醇盐配合物均表现出近似的平面正方形配位。[Au(dbbpy)(tdt)]PF₆（C₂₅H₃₀AuF₆N₂PS₂）的黄色晶体为三斜晶系，空间群 P&onemacr;（编号 2），a = 7.1977(2) Å，b = 11.7292(1) Å，c = 17.5820(5) Å，α = 104.537(2)°，β = 96.592(2)°，γ = 102.455(2)°，V = 1380.41(6) Å³，Z = 2，对于 3446 个独立反射，最终 R = 0.050（R(w) = 0.1062）。Au(η²-C,N-ppy)(tdt)（C₁₈H₁₄AuNS₂）的橙色晶体为单斜晶系，空间群 P2(1)/c（编号 14），a = 8.852(1) Å，b = 11.726(2) Å，c = 15.499(5) Å，β = 101.34(2)°，V = 1577.5(6) Å³，Z = 4，对于 3685 个独立反射，最终 R = 0.0438（R(w) = 0.0759）。Au(η²-C,N-ppy)(tdt) 中的结构反位效应导致与 Au-C 键反位的 Au-S 距离（约 0.1 Å）比与 Au-N 键反位的 Au-S 距离长得多。在固态中，[Au(dbbpy)(tdt)]⁺ 阳离子以堆叠形式排列，分子间 Au...Au 间距交替为 3.60 和 3.75 Å，而 Au(η²-C,N-ppy)(tdt) 分子形成堆叠，分子间 Au...Au 间距为 3.81 Å。