Paulat Florian, Lehnert Nicolai
Department of Chemistry, The University of Michigan, 930 N. University, Ann Arbor, Michigan 48109-1055, USA.
Inorg Chem. 2007 Mar 5;46(5):1547-9. doi: 10.1021/ic070023f. Epub 2007 Feb 8.
The effect of trans thiolate ligation on the coordinated nitric oxide in ferric heme nitrosyl complexes as a function of the thiolate donor strength, induced by variation of NH-S(thiolate) hydrogen bonds, is explored. Density functional theory (DFT) calculations (BP86/TZVP) are used to define the electronic structures of corresponding six-coordinate ferric [Fe(P)(SR)(NO)] complexes. In contrast to N-donor-coordinated ferric heme nitrosyls, an additional Fe-N(O) sigma interaction that is mediated by the dz2/dxz orbital of Fe and a sigma*-type orbital of NO is observed in the corresponding complexes with S-donor ligands. Experimentally, this is reflected by lower nu(N-O) and nu(Fe-N) stretching frequencies and a bent Fe-N-O moiety in the thiolate-bound case.
研究了硫醇盐配体连接对铁血红素亚硝酰配合物中配位一氧化氮的影响，该影响是通过改变NH-S（硫醇盐）氢键来诱导硫醇盐供体强度变化的函数关系。采用密度泛函理论（DFT）计算（BP86/TZVP）来确定相应六配位铁[Fe(P)(SR)(NO)]配合物的电子结构。与氮供体配位的铁血红素亚硝酰不同，在具有硫供体配体的相应配合物中，观察到一种额外的由铁的dz2/dxz轨道和一氧化氮的σ*型轨道介导的Fe-N(O)σ相互作用。在实验上，这表现为硫醇盐结合情况下较低的ν(N-O)和ν(Fe-N)伸缩频率以及弯曲的Fe-N-O部分。
