Abstract

The effect of bulky tridentate ligands on the geometry of carboxylate complexes was studied in relation to hexahydro-1,3,5-trimethyl-1,3,5-triazine (TACH). The reaction of [Co₂Gd(NO₃)(Piv)₆(MeCN)₂] (Piv is the pivalic acid anion) with TACH gave the complex [Co₂Gd(NO₃)(Piv)₆(TACH)₂] (I), in which the initial heterometallic moiety was retained and cobalt(II) ions coordinated the N-donor ligand to give a half-sandwich structure. The use of Cd(II) and Eu(III) pentafluorobenzoates in the reaction with TACH resulted in the isolation of only the homometallic complex [Cd(Pfb)₂(TACH)₂] (II) (Pfb is pentafluorobenzoic acid anion). Owing to high coordination number of cadmium(II) ion in II, a sandwich complex with two TACH molecules coordinated to the same metal ion was obtained. The structure of new complexes was determined by X-ray diffraction (CIF file CCDC nos. 2062230 (I) and 2062229 (II)). It was shown that binding of an N-donor ligand to a metal ion induces a significant distortion of the metal coordination polyhedra and a conformational change of hexahydro-1,3,5-trimethyl-1,3,5-triazine.

中文翻译：

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六氢-1,3,5-三甲基-1,3,5-三嗪在镉 (II) 和钴 (II) 羧酸配合物中的配位

摘要

研究了与六氢-1,3,5-三甲基-1,3,5-三嗪 (TACH) 相关的庞大三齿配体对羧酸盐配合物几何形状的影响。[Co ₂ Gd(NO ₃ )(Piv) ₆ (MeCN) ₂ ]（Piv是新戊酸阴离子）与TACH反应得到复合物[Co ₂ Gd(NO ₃ )(Piv) ₆ (TACH) ₂ ] ( I )，其中保留了最初的异金属部分，钴 (II) 离子与 N 供体配体配位，形成半夹心结构。在与 TACH 的反应中使用 Cd(II) 和 Eu(III) 五氟苯甲酸盐导致仅分离出均金属配合物 [Cd(Pfb) ₂ (TACH)₂ ] ( II ) (Pfb 是五氟苯甲酸阴离子)。由于镉的高配位数（II）在离子II，获得具有配位到相同的金属离子2个TACH分子夹心复合物。新配合物的结构由 X 射线衍射确定（CIF 文件 CCDC 编号 2062230 ( I ) 和 2062229 ( II )）。结果表明，N-供体配体与金属离子的结合会引起金属配位多面体的显着变形和六氢-1,3,5-三甲基-1,3,5-三嗪的构象变化。