Synthesis of a Selenidostannate(IV), [Mn(tepa)·Sn₃Se₇]<i>_n</i>, Demonstrating the Transformation from Achiral to Chiral and Dimeric to Polymeric Structure

Although a number of chalcogenostannates have been obtained by using [M(amine)m]n+ as the structure director, these materials with chiral metal complex ions are usually achiral because they are a racemic mix of chiral complex cations. A chiral selenidostannate, [Mn(tepa)·Sn3Se7]n (1; tepa = tetraethylenepentamine), containing incorporated [Mn(tepa)]2+ units, is reported herein. The unique structure is just like a grapevine appended with chiral grapes. In the same reaction, a centrosymmetric compound, [Mn(tepa)]2(μ2-Sn2Se6) (2), in which the Sn2Se64- anion acts as a bridge coordinating to [Mn(tepa)]2+ cations, has also been obtained. This is a reaction-time-related process in which compound 2 transformed gradually to 1 after prolonging the reaction time. This phenomenon demonstrates a transformation from achiral to chiral and dimeric to polymeric selenidostannate.尽管已有诸多研究以[M(胺)ₘ]ⁿ⁺作为结构导向剂，成功制备出硫属锡酸盐（chalcogenostannates），但这类含手性金属配合离子的材料通常并不具有手性，原因在于其手性配合阳离子实际为外消旋混合物。本文报道了一种手性硒代锡酸盐：[Mn(tepa)·Sn₃Se₇]ₙ（化合物1；tepa = 四乙五胺(tetraethylenepentamine)），该材料中引入了[Mn(tepa)]²⁺结构单元。其独特结构宛如攀附着手性“葡萄”的葡萄藤。在同一反应体系中，同时得到了一种中心对称化合物：[Mn(tepa)]₂(μ₂-Sn₂Se₆)（化合物2），其中μ₂-Sn₂Se₆⁴⁻阴离子作为桥联配体，与[Mn(tepa)]²⁺阳离子配位。该过程与反应时间密切相关：延长反应时间后，化合物2会逐渐转化为化合物1。这一现象展现了从非手性到手性、从二聚体到聚合体硒代锡酸盐的结构转变。