Nemykin Victor N, Olsen Joseph G, Perera Eranda, Basu Partha
Department of Chemistry and Biochemistry, University of Minnesota at Duluth, Duluth, Minnesota 55812, USA.
Inorg Chem. 2006 May 1;45(9):3557-68. doi: 10.1021/ic051653p.
The synthesis, spectroscopic, and structural characterization of the (Me2Pipdt)Mo(CO)4 complex (Me2Pipdt = N,N'-piperazine-2,3-dithione) are presented in this paper. The title complex crystallizes in the P2(1)/n space group with a = 25.541(3) A, b = 10.3936(14) A, c = 10.9012(12) A, beta = 92.261(9) degrees , V = 2891.6(6) A(3), and Z = 8. Gas- and solution-phase structural and electronic features of (Me2Pipdt)Mo(CO)4 and Me2Pipdt have been investigated using density functional theory. The molecular structure underscores the flexibility of the NC(S)C(S)N fragment in both the free ligand and the metal complex. On the basis of structural, spectroscopic, and theoretical results, the bidentate ligand in (Me2Pipdt)Mo(CO)4 is considered to be in the dithione, not dithiolate, form. Time-dependent density functional theory has been used for the investigation of the excited states and solvatochromic properties of (Me2Pipdt)Mo(CO)4. The calculated vertical excitation energies in solution are consistent with the experimental data, showing that the metal-to-ligand charge-transfer transitions, in both the visible and UV regions, dominate over the ligand-based pi-pi transitions.
本文介绍了(Me2Pipdt)Mo(CO)4配合物（Me2Pipdt = N,N'-哌嗪-2,3-二硫酮）的合成、光谱和结构表征。标题配合物结晶于P2(1)/n空间群，a = 25.541(3) Å，b = 10.3936(14) Å，c = 10.9012(12) Å，β = 92.261(9)°，V = 2891.6(6) Å(3)，Z = 8。利用密度泛函理论研究了(Me2Pipdt)Mo(CO)4和Me2Pipdt的气相和溶液相结构及电子特征。分子结构强调了NC(S)C(S)N片段在游离配体和金属配合物中的灵活性。基于结构、光谱和理论结果，(Me2Pipdt)Mo(CO)4中的双齿配体被认为是二硫酮形式，而非二硫醇盐形式。含时密度泛函理论已用于研究(Me2Pipdt)Mo(CO)4的激发态和溶剂化显色性质。计算得到的溶液中的垂直激发能与实验数据一致表明，在可见光和紫外区域，金属到配体的电荷转移跃迁比基于配体的π-π跃迁占主导。
