Di-μ-azido-diazidodi-μ-oxalato-dihistaminetetracopper(II) 0.9-hydrate

Chen Liu,Khalil A Abboud

doi:10.1107/s1600536813013329

Abstract

The title compound, [Cu4(C2O4)2(N3)4(C5H9N3)2]·0.9H2O, contains a tetranuclear CuII-based molecule composed of two oxalate-bridged CuII dimers linked through end-on azide ions and related by an inversion center. The tetranuclear unit contains two crystallographically independent CuII ions. One CuII ion coordinates to two N atoms of a histamine molecule, two O atoms of a bridging oxalate ligand, and an N atom of an end-on bridging azide ligand, leading to an elongated square-pyramidal coordination geometry in which the azide ion occupies the axial position. The other CuII ion, which has a square-planar coordination geometry, is coordinated by two O atoms of a bridging oxalate ligand and two N atoms of two different azide ligands, one which is bridging. In the crystal, a two-dimensional network parallel to (010) is formed by N—H⋯N and N—H⋯O hydrogen bonds. A partially occupied solvent water molecule refined to an occupancy of 0.447 (5). Two of the azide ligands were refined as disordered over two sets of sites with refined occupancies in the ratios 0.517 (8):0.483 (8) and 0.553 (5):0.447 (5).

Highlights

The title compound, [Cu4(C2O4)2(N3)4(C5H9N3)2]0.9H2O, contains a tetranuclear CuII-based molecule composed of two oxalate-bridged CuII dimers linked through end-on azide ions and related by an inversion center
CuII ion coordinates to two N atoms of a histamine molecule, two O atoms of a bridging oxalate ligand, and an N atom of an end-on bridging azide ligand, leading to an elongated squarepyramidal coordination geometry in which the azide ion occupies the axial position
Two of the azide ligands were refined as disordered over two sets of sites with refined occupancies in the ratios

Summary

Crystal data

Key indicators: single-crystal X-ray study; T = 173 K; mean (C–C) = 0.004 Å; Hatom completeness 91%; disorder in main residue; R factor = 0.029; wR factor =. The title compound, [Cu4(C2O4)2(N3)4(C5H9N3)2]0.9H2O, contains a tetranuclear CuII-based molecule composed of two oxalate-bridged CuII dimers linked through end-on azide ions and related by an inversion center. One. CuII ion coordinates to two N atoms of a histamine molecule, two O atoms of a bridging oxalate ligand, and an N atom of an end-on bridging azide ligand, leading to an elongated squarepyramidal coordination geometry in which the azide ion occupies the axial position. The other CuII ion, which has a square-planar coordination geometry, is coordinated by two O atoms of a bridging oxalate ligand and two N atoms of two different azide ligands, one which is bridging.

Data collection

Mo K radiation

Special details