Synthesis And Crystal Structures Of Cadmium(Ii) Coordination Compounds Of Large Ring And Bicyclo Framework With A Bidentate Betaine Derivative

A new bidentate betaine derivative 1,5-bis(4-carboxypyridinium)-N-methyl-diethylamine (L) was prepared and allowed to react with cadmium salts leading to the formation of two new cadmium coordination compounds [Cd2Cl4(H2O)(2)L-2]center dot 2H(2)O and [Cd-2(SCN)(4)(mu-H2O)L-2], which were structurally characterized by IR spectoroscopy, single-crystal X-ray diffraction, elemental analysis, thermal analysis, etc. The single crystal X-ray diffraction structure analysis of these compounds shows the molecule of former consists of discrete 36-membered ring and that of latter bicyclo [17.17.1] structure. Owing to lacking strong intermolecular interactions in these compounds, weak interactions determine their packing pattern in crystalline state: the former forms 2D brick-wall network by the pi-pi stacking and C-H center dot center dot center dot pi interactions between pyridyl rings of adjacent molecules, and the latter zig-zag chains through S center dot center dot center dot S weak interactions between ligating SCN- anions. CCDC: 860582, 1; 860583, 2.