Publication Date:
2014-08-30
Description:
The crystal structure of dichlorido(4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane)chromium(III) hexafluoridophosphate, [CrCl2(C12H26N4)]PF6, (I), has monoclinic symmetry (space groupP21/n) at 150 K. The structure of the related dichlorido(4,11-dimethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane)chromium(III) hexafluoridophosphate, [CrCl2(C14H30N4)]PF6, (II), also displays monoclinic symmetry (space groupP21/c) at 150 K. In each case, the CrIIIion is hexacoordinate with twocischloride ions and two non-adjacent N atoms boundcisequatorially and the other two non-adjacent N atoms boundtransaxially in acis-V conformation of the macrocycle. The extent of the distortion from the preferred octahedral coordination geometry of the CrIIIion is determined by the parent macrocycle ring size, with the larger cross-bridged cyclam ring in (II) better able to accommodate this preference and the smaller cross-bridged cyclen ring in (I) requiring more distortion away from octahedral geometry.
Electronic ISSN:
1600-5368
Topics:
Chemistry and Pharmacology
,
Geosciences
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