Metal-betaine interactions. II. Crystal structures of catena-dichloro(betaine)cadmium(II) and dimeric diaquabis(betaine)tetrachlorodicadmium(II)

Two cadmium(II) complexes of betaine (BET) have been prepared and characterized by X-ray crystallography. Cd(BET) (–Cl)₂] (1), is a one-dimensional polymer in which each cadmium atom is coordinated by two pairs of bridging chlorine atoms Cd-Cl=2.631(2), 2.614(2) Å] and two oxygen atoms from different bridging carboxylate groups Cd-O=2.291(6), 2.329(6) Å] in the form of a compressed octahedron. Cd(BET)(H₂O)Cl(–Cl)]₂ (2) is a dimer with each cadmium atom in a distorted octahedral coordination environment, being surrounded by a chelating bidentate carboxylate group 2.480(2), 2.332(3) Å], one aqua ligand 2.364(3) Å], two bridging chlorine atoms 2.659(1), 2.557(1) Å], and one terminal chlorine atom 2.480(1) Å].