配合物[Fe(CO)_3(PPh_2R)_2(HgCl_2)](R=pym,fur,py,thi)的Fe—Hg相互作用及31P化学位移  

Fe-Hg Interactions and ^(31)P Chemical Shifts in [Fe(CO)_3(PPh_2R)_2(HgCl_2)](R=pym,fur,py,thi)

作　　者：李勤瑜[1] 许旋[1] 

机构地区：[1]华南师范大学化学与环境学院,广州510631

出　　处：《物理化学学报》2007年第12期1875-1880,共6页Acta Physico-Chimica Sinica

基　　金：广东省自然科学基金(5005938)资助项目

摘　　要：用密度泛函理论(DFT)的PBE0方法对单核配合物Fe(CO)3(PPh2R)2(R=pym:1,fur:2,py:3,thi:4;pym=pyrimidine,fur=furyl,py=pyridine,thi=thiazole)及异双核配合物[Fe(CO)3(PPh2R)2(HgCl2)](R=pym:5,fur:6,py:7,thi:8)进行结构优化及相互作用能的计算,用DFT(PBE0)-GIAO法计算了化合物1-8的31P化学位移,研究了基团R对配合物的稳定性、Fe—Hg相互作用及31P化学位移的影响,并对Fe—Hg相互作用进行了NBO分析.得到以下结论:(1)双核配合物中含N的R基团的配合物稳定性较高,N原子个数越多,稳定性越高.(2)Fe—Hg相互作用是双核配合物稳定的主要因素.5和6中Hg以6s轨道与Fe的4s、3dz2组成的杂化轨道结合成Fe—Hg的σ键.7和8中则以σP—Fe→nHg和σC—Fe→nHg的Fe—Hg间接作用为主.(3)Fe—Hg相互作用拉动电荷由R向P、Fe、Hg转移,使双核配合物中P的电子密度增大,故双核配合物中P核周围的电子密度增大,其31P化学位移比单核配合物的小.In order to study the effects of R group on Fe—Hg interactions and 31P chemical shifts,the structures of mononuclear complexes Fe（CO）3（PPh2R）2（R=pym：1,fur：2,py：3,thi：4;pym=pyrimidine,fur=furyl,py=pyridine,thi=thiazole）and binuclear complexes [Fe（CO）3（PPh2R）2（HgCl2）]（R=pym：5,fur：6,py：7,thi：8）were studied by using the density functional theory（DFT）PBE0 method.The 31P chemical shifts were calculated by PBE0-GIAO method.Nature bond orbital（NBO）analyses were also performed to explain the nature of the Fe-Hg interactions.The conclusions can be drawn as follows：（1）The complexes with nitrogen donor atoms are more stable than those with O or S atoms.The more N atom there are,the higher is the stabilitity of the complex.（2）The Fe—Hg interactions play a dominant role in the stabilities of the complexes.In 5 or 6,there is a σ-bond between Fe and Hg atoms,However,in 7 and 8,the Fe—Hg interations act as σP—Fe→nHg and σC—Fe→nHg delocalization.（3）Through Fe→Hg interactions,there is charge transfer from R groups towards the P,Fe,and Hg atoms,which increases the electron density on P nucleus in binuclear complexes.As a result,compared with their mononuclear complexes,the 31P chemical shifts in binuclear complexes show some reduction.

关 键 词：DFT(PBE0) GIAO Fe—Hg相互作用 31PNMR NBO 

分 类 号：O641.4[理学—物理化学]