Haseloer Alexander, Denkler Luca Mareen, Jordan Rose, Reimer Max, Olthof Selina, Schmidt Ines, Meerholz Klaus, Hörner Gerald, Klein Axel
Universität zu Köln, Department für Chemie, Institut für Anorganische Chemie, Greinstraße 6, D-50939 Köln, Germany.
Dalton Trans. 2021 Mar 28;50(12):4311-4322. doi: 10.1039/d1dt00272d. Epub 2021 Mar 10.
New tetradentate phenolate O^N^N^S thiosemicarbazone (TSC) ligands and their Ni(ii), Pd(ii) and Pt(ii) complexes were studied. The diamagnetic and square planar configured orange or red complexes show reversible reductive electrochemistry and in part reversible oxidative electrochemistry at very moderate potentials. DFT calculations show essentially pyridyl-imine centred lowest unoccupied molecular orbitals (LUMO) while the highest occupied molecular orbitals (HOMO) receive contributions from the phenolate moiety, the metal d orbitals and the TSC thiolate atom in keeping with UV-vis spectroelectrochemistry. DFT calculations in conjunction with IR spectra showed details of the molecular structures, the UV-vis absorptions were modelled through TD-DFT calculation with very high accuracy. UPS is fully consistent with UV-vis absorption and TD-DFT calculated data and shows decreasing HOMO-LUMO gaps along the series Pd > Pt > Ni.
研究了新型四齿酚盐O^N^N^S硫代半卡巴腙（TSC）配体及其镍（II）、钯（II）和铂（II）配合物。具有抗磁性且呈平面正方形构型的橙色或红色配合物在非常适中的电位下显示出可逆的还原电化学性质，部分还显示出可逆的氧化电化学性质。密度泛函理论（DFT）计算表明，最低未占据分子轨道（LUMO）主要以吡啶基亚胺为中心，而最高占据分子轨道（HOMO）则受到酚盐部分、金属d轨道和TSC硫醇盐原子的影响，这与紫外可见光谱电化学一致。结合红外光谱的DFT计算揭示了分子结构的细节，通过含时密度泛函理论（TD-DFT）计算对紫外可见吸收进行了高精度建模。紫外光电子能谱（UPS）与紫外可见吸收以及TD-DFT计算数据完全一致，并且显示出沿着Pd > Pt > Ni这一系列，最高占据分子轨道与最低未占据分子轨道之间的能隙逐渐减小。
