Photochemistry and Redox Chemistry of an Unsymmetrical Bimetallic Copper(I) Complex

The bimetallic copper­(I) complex Cu2L2 (cis-1) is formed with high diasteroselectivity from [Cu­(NCCH3)4]­[BF4] and HL (4-tert-butyl phenyl­(pyrrolato-2-yl-methylene)­amine) in a kinetically controlled reaction. cis-1 features a rather short Cu···Cu distance of 2.4756(6) Å and is weakly emissive at room temperature in solution. Oxidatively triggered disproportionation of cis-1 yields elemental copper and the mononuclear copper­(II) complex CuL2 (trans-2). One-electron reduction of trans-2 gives cuprate [2]– with a bent bis­(pyrrolato) coordinated copper­(I) entity. The imine donor atoms of [2]– can insert an additional copper­(I) ion giving exclusively the bimetallic complex cis-1 closing the oxidation–elimination–reduction–insertion cycle.双金属铜(I)配合物Cu₂L₂（顺式-1）可由[Cu(NCCH₃)₄][BF₄]与HL（4-叔丁基苯基(吡咯烷-2-基亚甲基)胺）通过动力学控制反应以高非对映选择性生成。顺式-1具有极短的Cu···Cu间距，为2.4756(6) Å，在室温溶液中表现出弱发射特性。顺式-1经氧化诱导歧化反应后，可生成单质铜与单核铜(II)配合物CuL₂（反式-2）。对反式-2进行单电子还原，可得到铜酸盐[2]⁻，其包含一个弯曲双(吡咯根)配位的铜(I)结构单元。[2]⁻的亚胺配位位点可引入额外的铜(I)离子，专一地生成双金属配合物顺式-1，从而完成氧化-消除-还原-插入循环。