Three guanidine-derived tri-substituted ligands viz . N -pivaloyl- N ′, N ″-bis-(2-methoxyphenyl)guanidine (L 1 ), N -pivaloyl- N ′-(2-methoxyphenyl)- N ″-phenylguanidine (L 2 ) and N -pivaloyl- N ′-(2-methoxyphenyl)- N ″-(2-tolyl)guanidine (L 3 ) were reacted with Cu(II) acetate to produce the corresponding complexes. The significance of the substituent on N ″ for the resulting molecular structures and their packing in the solid state has been studied with respect to the structural specifics of the corresponding Cu(II) complexes. The key characteristic of the guanidine-based metal complexation with Cu(II) is the formation of an essentially square planar core with an N 2 O 2 donor set. As an exception, in the complex of L 1 , the substituent’s methoxy moiety also interacts with the Cu(II) center to generate a square-pyramidal geometry. The hydroxyl groups of the imidic acid tautomeric forms of L 1 –L 3 , in addition to N″, are also bonded to Cu(II) in all three complexes rather than the nitrogen donor of the guanidine motif.

中文翻译：

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三取代胍基铜（II）配合物的合成及晶体结构分析

三个胍衍生的三取代配体，即。N-新戊酰基-N'，N''-双-（2-甲氧基苯基）胍（L 1），N-新戊酰基-N'-（2-甲氧基苯基）-N''-苯基胍（L 2）和N-新戊酰基-N使′-（2-甲氧基苯基）-N″-（2-甲苯基）胍（L 3）与乙酸铜（II）反应以产生相应的络合物。关于相应的Cu（II）配合物的结构细节，已经研究了N''上取代基对于所得分子结构及其在固态中堆积的重要性。胍基金属与Cu（II）络合的关键特征是形成具有N 2 O 2供体组的基本呈方形的平面核。作为例外，在L 1的络合物中，取代基的甲氧基部分也与Cu（II）中心相互作用，以生成正方形的金字塔形几何形状。