Polymorphism of dinitro[tris(2-aminoethyl)amine]cobalt(III) chloride

Ilia A Guzei; Charmaine Arderne

doi:10.1107/S205322961501270X

Polymorphism of dinitro[tris(2-aminoethyl)amine]cobalt(III) chloride

Acta Crystallogr C Struct Chem. 2015 Aug;71(Pt 8):695-700. doi: 10.1107/S205322961501270X. Epub 2015 Jul 15.

Authors

Ilia A Guzei¹, Charmaine Arderne²

Affiliations

¹ Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, USA.
² Department of Chemistry, University of Johannesburg, PO Box 524, Auckland Park, 2006, South Africa.

PMID: 26243417
DOI: 10.1107/S205322961501270X

Abstract

Three polymorphs of bis(nitrito-κN)[tris(2-aminoethyl)amine-κ(4)N,N',N'',N''']cobalt(III) chloride, [Co(NO2)2(C6H18N4)]Cl, have been structurally characterized in the 100-300 K temperature range. Two orthorhombic polymorphs are related by a solid-state enantiotropic order-disorder k2 phase transition at ca 152 K. The third, monoclinic, polymorph crystallizes as a nonmerohedral twin. In the structure of the high-temperature (300 K) orthorhombic polymorph, the Co(III) complex cation resides on a crystallographic mirror plane, whereas the Cl(-) anion occupies a crystallographic twofold axis. In the unit cell of the monoclinic polymorph, the cationic Co(III) complex is in a general position, whose charge is balanced by two halves of two Cl(-) anions, each residing on a crystallographic twofold axis.

Keywords: DFT calculations; cobalt(III) complex; disorder; polymorphism; single-crystal X-ray analysis; solid-state phase transition; tris(2-aminoethyl)amine; twinning.

MeSH terms

Amines / chemistry*
Cobalt / chemistry*
Coordination Complexes / chemistry*
Crystallization
Ions / chemistry*

Substances

Amines
Coordination Complexes
Ions
dinitro(tris(2-aminoethyl)amine)cobalt(III) chloride
Cobalt