Crystal and molecular structures of mer ( N)-dinitro-{ N, N-bis(3-aminopropyl)glycinato} cobalt(III) and of bromide, perchlorate and nitrate salts of mer ( N)-aquachloro-{ N, N-bis(3-aminopropyl)glycinato} cobalt(III)

Abstract

X-ray structural analyses have been made on single crystals of mer( N)-[Co(5-dptma)(NO 2) 2] ( A), mer( N)-[CoCl(5-dptma)(H 2O)] Br ( B), mer( N)-[CoCl(5-dptma)(H 2O)]ClO 4 ( C) and mer( N)-[CoCl(5-dptma)(H 2O)] NO 3 ( D), where H(5-dptma) is N, N-bis(3-aminopropyl)glycine. Complex A crystallizes in the monoclinic space group P2 1/c as a racemate; complex B in the monoclinic space group P2 1/ n as a racemate; complex C in the orthorhombic space group P2 12 12 1 as a conglomerate; and complex D in the orthorhombic space group Pna2 1 as a racemate. In these complexes, the tripod quadridentate 5-dptma coordinates to cobalt(III) with its three nitrogen atoms on a meridian of the coordination octahedron and with the six-membered chelate rings assuming the chair conformation. In A the molecular planes of the NO 2 − ligands are anchored by intramolecular and intermolecular hydrogen bonds to the amine protons. The molecular planes of the aqua ligands in B, C and D are anchored by two intermolecular hydrogen bonds; one with the carbonyl oxygen atom and the other with the counter anion.