Liang Binyong, Wang Xuefeng, Andrews Lester
Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319, USA.
J Phys Chem A. 2009 Apr 9;113(14):3336-43. doi: 10.1021/jp810795q.
Laser-ablated Ni, Pd, and Pt atoms were reacted with sulfur molecules emerging from a microwave discharge in argon during condensation at 7 K. Reaction products were identified from matrix infrared spectra, sulfur isotopic shifts, spectra of sulfur isotopic mixtures, and frequencies from density functional calculations. The strongest absorptions are observed at 597.9, 596.1, and 583.6 cm(-1), respectively, for the group 10 metals. These absorptions show large sulfur-34 shifts and 32/34 isotopic frequency ratios (1.0282, 1.0285, 1.0298) that are appropriate for S-S stretching modes. Of most importance, mixed 32/34 isotopic 1/4/4/2/4/1 sextets identify this product with two equivalent S(2) molecules containing equivalent atomic positions as the bisdisulfur pi complexes M(S(2))(2). Our DFT calculations find stable D(2h) structures with B(1u) ground states and intense b(1u) infrared active modes a few wavenumbers higher than the observed values. A minor Ni product at 505.8, 502.7 cm(-1) shows the proper sulfur-34 shift for assignment to (58)NiS, (60)NiS. Another major product with Pt at 512.2 cm(-1) reveals an asymmetric triplet absorption with mixed sulfur 32/34, which is appropriate for assignment to the SPtS disulfide molecule. A weak 491.7 cm(-1) peak exhibits the sulfur-34 shift expected for PtS, and this assignment follows.
在7K冷凝过程中，激光烧蚀的镍、钯和铂原子与氩气微波放电产生的硫分子发生反应。通过基质红外光谱、硫同位素位移、硫同位素混合物光谱以及密度泛函计算频率来鉴定反应产物。对于第10族金属，分别在597.9、596.1和583.6cm⁻¹处观察到最强吸收。这些吸收显示出大的硫-34位移和32/34同位素频率比（1.0282、1.0285、1.0298），这与S-S伸缩模式相符。最重要的是，混合的32/34同位素1/4/4/2/4/1六重峰将该产物鉴定为具有两个等效S₂分子且原子位置等效的双二硫π配合物M(S₂)₂。我们的密度泛函计算发现具有D₂h结构且基态为B₁u且b₁u红外活性模式强度比观测值高几个波数的稳定结构。在505.8、502.7cm⁻¹处的一个次要镍产物显示出适合归属于⁵⁸NiS、⁶⁰NiS的硫-34位移。在512.2cm⁻¹处与铂形成的另一个主要产物显示出混合硫32/34的不对称三重峰吸收，这适合归属于SPtS二硫化物分子。一个491.7cm⁻¹的弱峰显示出PtS预期的硫-34位移，因此可如此归属。
