The platinum(II) complexes of multidentate N-heterocyclic carbenes, [Pt(L1)2Cl](PF6) (1, L1 = N-methyl-N-(2-pyrimidinyl)imidazolylidene), [Pt(L2)Cl](PF6) (2, L2 = N-butyl-N-(1,10-phenanthrolin-2-yl)imidazolylidene), [PtL3](PF6)2 (3, L3 = bis(N-picolylimidazolylidenyl)methane), [PtL4](PF6)2 (4, L4 = (bis(N-2-pyrimidylimidazolylidenyl)methane) (4) and [Pt(L5)2](PF6)2 [5, L5 = bis(N-pyridylimidazoliumyl)methane] have been synthesized and structurally characterized. All these complexes exhibit slightly distorted square-planar configuration. These complexes are efficient catalyst precursors for hydrosilylation of alkynes. Complexes 2 and 4 are much more active than complexes 1, 3 and 5. In the hydrosilylation of arylacetylenes, relatively long induction periods were observed for 1, 3 and 5.
多齿 N-杂环碳烯的
铂(II)配合物,[Pt(L1)2Cl](PF6) (1, L1 = N-甲基-N-(2-
嘧啶基)
咪唑亚基),[Pt(
L2)Cl](PF6) (2,
L2 = N-丁基-N-(
1,10-菲罗啉-2-基)
咪唑亚基),[PtL3](PF6)2 (3、4)和 [Pt(L5)2](PF6)2 [5, L5 = 双(N-
吡啶基
咪唑鎓)
甲烷]。所有这些复合物都呈现出略微扭曲的方平面构型。这些配合物是
炔烃氢化的高效催化剂前体。络合物 2 和 4 的活性远高于络合物 1、3 和 5。在芳基
乙炔的氢
硅化过程中,1、3 和 5 的诱导期相对较长。