Crystal structures of three complexes built from pyridyl-substituted phenol-based compartmental Ligand

A novel binuclear calcium complex[Ca₂L₂(NO₃)₂] (1) and a mononuclear cadmium complex[Cd(HL)(NO₃)₂] (2) have been successfully synthesized by using 2-(N, N-di(2-pyridylmethyl)aminomethyl)-6-aldehydo-4-methylphenol (HL) as a ligand. Complex 2 can be transformed to a binuclear cadmium complex[Cd₂L₂(NO₃)₂]·H₂O (3) under basic conditions. Complexes 1~3 have been characterized by FT-IR, ESI-MS, elemental analysis and single-crystal X-ray diffraction. Both 1 and 3 crystallize in monoclinic system, but with space group P2₁/c and C2/c, respectively, while 2 in triclinic system with space group P1. X-ray crystallography analysis reveals that 1 has a bi-calcium unit[Ca₂O₂] bridged by two phenolato O atoms, and each eight-coordinated Ca(Ⅱ) cation shows a distorted dodecahedron configuration[CaN₃O₅] with three N atoms and one phenolato O atom from one L-, one phenolato O atom and an aldehyde O atom from another L^- ligand, and two O atoms from one nitrate. 2 is a mononuclear cadmium complex and Cd(Ⅱ) cation is eight-coordinated by three N atoms and one phenol O atom from HL ligand and four O atoms from two nitrates to show a distorted dodecahedron configuration[CdN₃O₅], whereas the aldehyde group does not take part in coordination. 3 contains a bi-cadmium unit[Cd₂O₂] bridged by two phenolato O atoms, and each seven-coordinated Cd(Ⅱ) cation shows a distorted monocapped trigonal prism configuration[CdN₃O₄] with three N atoms and one phenolato O atom from one L^-, one phenolato O atom and an aldehyde O atom from another L^- ligand, and one O atom from one nitrate.