Synthesis and structure of dilead(II) and dimanganese(II) complexes of macrocycles derived from 3,6-diformylpyridazine
作者:Sally Brooker、Robert J. Kelly
DOI:10.1039/dt9960002117
日期:——
An improved synthesis of 3,6-diformylpyridazine I has been elaborated. The macrocyclic complexes Pb2L1(ClO4)41 and [Pb2L2][ClO4]42 were prepared from this precursor, 1,3-diaminopropane and lead(II) perchlorate in 1 : 1 : 1 and 2 : 2 : 1 ratios respectively. The ability of lead(II) perchlorate to template the formation of the two macrocycle ring sizes, L1=(2 + 2) and L2=(4 + 4), simply by alteration of the reagent ratio is unprecedented. Transmetallation of 1 or 2 with manganese(II) perchlorate and an excess of sodium thiocyanate led to the formation of [Mn2L1(NCS)4]3. Single-crystal X-ray analyses of 2 and 3 revealed that on transmetallation a ring contraction, (4 + 4) to (2 + 2), occurs. The two manganese(II) ions have irregular geometries and are inequivalent; one is six- whilst the other is seven-co-ordinate. Unusual single-atom > NCS bridging of the manganese ions occurs.
一种改进的3,6-二甲酰基吡嗪I的合成方法已被 elaborated。以该前体、1,3-二氨基丙烷和氯酸铅(II)按1:1:1和2:2:1的比例制备了大环复合物Pb2L1(ClO4)41和[ Pb2L2][ClO4]42。氯酸铅(II)通过简单改变试剂比例来模板形成两种不同的大环尺寸,L1=(2 + 2)和L2=(4 + 4),这一能力前所未有。与过量的硫氰酸钠和氯酸锰(II)进行转金属化反应,形成了[Mn2L1(NCS)4]3。对2和3的单晶X射线分析显示,在转金属化过程中,环的收缩从(4 + 4)到(2 + 2)发生。两个锰(II)离子具有不规则的几何构型,且不等价;一个为六配位,另一个为七配位。锰离子之间发生了不寻常的单原子> NCS桥接。