Fu W F, Chan K C, Cheung K K, Che C M
Department of Chemistry, The University of Hong Kong, Hong Kong.
Chemistry. 2001 Nov 5;7(21):4656-64. doi: 10.1002/1521-3765(20011105)7:21<4656::aid-chem4656>3.0.co;2-d.
The complexes [Au2(dcpm)2]-Y2 (dcpm = bis(dicyclohexylphosphino)methane; Y=ClO4 (1), PF6- (2), CF3SO3- (3), Au(CN)2- (4), Cl- (5), SCN (6) and I- (7)) were prepared, and the structures of 1 and 4-7 were determined by X-ray crystallography. Complexes 1-4 display intense phosphorescence with lambdamax at 360-368 nm in the solid state at room temperature as well as in glassy solutions at 77 K. The solid-state emission quantum yields of the powdered samples are 0.37 (1), 0.74 (2), 0.53 (3) and 0.12 (4). Crystalline solid 5 displays both high-energy UV (lambdamax = 366 nm) and low-energy visible emissions (lambdamax = 505 nm) at room temperature, whereas either 6 or 7 shows only an intense emission with lambdamax at 465 or 473 nm, respectively. All the complexes in degassed acetonitrile solutions exhibit an intense phosphorescence with lambdamax ranging from 490 to 530 nm. The high-energy UV emission is assigned to the intrinsic emission of the 3[dsigmapsigma] excited state of [Au2(dcpm)2]2+, whereas the visible emission is attributed to the adduct formation of the triplet excited state with the solvent/counterion. The quenching rate constants of the visible emission of [Au2(dcpm)2]2+ in acetonitrile by various anions are 6.08 x 10(5) (ClO4-), 9.18 x l0(5) (PF6 ), 1.55 x 10(7) (Cl-) and 4.06 x 10(9) (I-) mol(-1) dm3s(-1). The triplet-state difference absorption spectra of 1-4 in acetonitrile show an absorption band with lambdamax at 350 nm and a shoulder/absorption maxima at 395-420 nm; their relative intensities are dependent upon the halide ion present in solution. Substrate binding reactions of the 3[dsigmapsigma] excited state with halide (X-) to give [Au2(dcpm)2X]+* would account for the lower energy absorption maxima in the triplet-state difference absorption spectra. With iodide as the counterion, complex 7 undergoes a photoinduced electron-transfer reaction with I- to give the radical anion I2-.
制备了配合物[Au2(dcpm)2]-Y2（dcpm = 双（二环己基膦基）甲烷；Y = ClO4-（1）、PF6-（2）、CF3SO3-（3）、Au(CN)2-（4）、Cl-（5）、SCN-（6）和I-（7）），并通过X射线晶体学确定了1和4 - 7的结构。配合物1 - 4在室温固态以及77 K的玻璃态溶液中在360 - 368 nm处显示出强烈的磷光。粉末样品的固态发射量子产率分别为0.37（1）、0.74（2）、0.53（3）和0.12（4）。晶体固体5在室温下显示出高能紫外发射（λmax = 366 nm）和低能可见光发射（λmax = 505 nm），而6或7仅分别在465或473 nm处显示出强烈发射。所有配合物在脱气乙腈溶液中均表现出强烈的磷光，λmax范围为490至530 nm。高能紫外发射归因于[Au2(dcpm)2]2 +的3[dsigmapsigma]激发态的本征发射，而可见光发射归因于三重态激发态与溶剂/抗衡离子的加合物形成。各种阴离子对乙腈中[Au2(dcpm)2]2 +可见光发射的猝灭速率常数分别为6.08×10(5)（ClO4-）、9.18×10(5)（PF6-）、1.55×10(7)（Cl-）和4.06×10(9)（I-）mol(-1) dm3 s(-1)。1 - 4在乙腈中的三重态差分吸收光谱显示在350 nm处有一个吸收带，在395 - 420 nm处有一个肩峰/吸收最大值；它们的相对强度取决于溶液中存在的卤离子。3[dsigmapsigma]激发态与卤离子（X-）发生底物结合反应生成[Au2(dcpm)2X]+*，这可以解释三重态差分吸收光谱中较低能量的吸收最大值。以碘离子作为抗衡离子时，配合物7与I-发生光诱导电子转移反应生成自由基阴离子I2-。
