1. Two Conformational Isomers in a Crystal of trans-Dibromobis(2,2-dimethyl-1,3-propanediamine)chromium(III) Bromide
- Author
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Chang-Seop Lee, Dohyun Moon, and Jong-Ha Choi
- Subjects
Chromium(III) bromide ,Bond length ,Crystallography ,chemistry.chemical_compound ,Denticity ,chemistry ,Ligand ,Hydrogen bond ,General Chemistry ,Crystal structure ,Condensed Matter Physics ,Conformational isomerism ,Monoclinic crystal system - Abstract
A new salt complex, trans-[Cr(Me2tn)2Br2]Br (Me2tn = 2,2-dimethyl-1,3-propanediamine), was prepared and characterized by elemental, IR spectroscopic, and single-crystal X-ray diffraction analyses. The title complex crystallized in the space group C2/c of the monoclinic system with eight mononuclear formula units in a cell of dimensions a = 19.991(4), b = 11.489(2), c = 17.278(4) A, and β = 111.94(3)°. The chromium ion was in a distorted octahedral coordination with four N atoms of two chelating Me2tn and two bromine atoms in trans axial positions. The structural analysis showed that a single crystal contained two crystallographically independent complex ions which were anti and syn conformational isomers of each other. The mean Cr–N(Me2tn) and Cr–Br bond lengths are 2.091(1) and 2.476(1) A, respectively. The crystal lattice was stabilized by hydrogen bonding interactions between Br ligand, Br anion and NH groups of the Me2tn ligand. The X-ray crystallography result of trans-[Cr(Me2tn)2Br2]Br shows that the chromium atom is in a distorted octahedral environment, coordinated by two bidentate, 2,2-dimethyl-1,3-propanediamine ligands and two Br ligands in trans positions.
- Published
- 2014