Logo image
Synthesis, structure, and spectroscopic properties of copper(II) compounds containing nitrogen-sulphur donor ligands; the crystal and molecular structure of aqua[1,7-bis(N-methylbenzimidazol-2′-yl)-2,6-dithiaheptane]copper(II) perchlorate
Journal article

Synthesis, structure, and spectroscopic properties of copper(II) compounds containing nitrogen-sulphur donor ligands; the crystal and molecular structure of aqua[1,7-bis(N-methylbenzimidazol-2′-yl)-2,6-dithiaheptane]copper(II) perchlorate

Anthony W Addison, T. Nageswara Rao, Jan Reedijk, Jacobus van Rijn and Gerrit C Verschoor
Dalton Transactions, (7), pp 1349-1356
1984

Abstract

The linear quadridentate N 2 S 2 donor ligand 1,7-bis( N -methylbenzimidazol-2′-yl)-2,6-dithiaheptane (bmdhp) forms mono- and di-hydrate 1 : 1 copper( II ) complexes which are significantly more stable toward autoreduction than those of the non-methylated analogue. The deep green monohydrate of the perchlorate salt crystallises as the mononuclear aqua-complex, [Cu(bmdhp)(OH 2 )][ClO 4 ] 2 , in the monoclinic space group P 2 1 / n , with Z = 4, a = 18.459(3), b = 10.362(2), c = 16.365(3)Å, and β= 117.14(1)°. The structure was solved and refined by standard Patterson, Fourier, and least-squares techniques to R = 0.047 and R ′= 0.075 for 3 343 independent reflections with l > 2σ( l ). The compound consists of [Cu(bmdhp)(OH 2 )] 2+ ions and ClO 4 - counter ions. The co-ordination around copper is intermediate between trigonal bipyramidal and square pyramidal, with Cu-N distances of 1.950(4) and 1.997(4)Å, Cu-O(water) 2.225(4)Å, and Cu-S 2.328(1) and 2.337(1)Å. In the solid state, the perchlorate dihydrate's co-ordination sphere may be a topoisomer of the monohydrate's. A new angular structural parameter, τ, is defined and proposed as an index of trigonality, as a general descriptor of five-co-ordinate centric molecules. By this criterion, the irregular co-ordination geometry of [Cu(bmdhp)(OH 2 )] 2+ in the solid state is described as being 48% along the pathway of distortion from square pyramidal toward trigonal bipyramidal. In the electronic spectrum of the complex, assignment is made of the S(thioether)→ Cu charge-transfer bands by comparison with those of the colourless complex Zn(bmdhp)(OH)(ClO 4 ). E.s.r. and ligand-field spectra show that the copper( II ) compounds adopt a tetragonal structure in donor solvents.

Details

UN Sustainable Development Goals (SDGs)

This publication has contributed to the advancement of the following goals:

#3 Good Health and Well-Being

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Collaboration types
Domestic collaboration
International collaboration
Web of Science research areas
Chemistry, Inorganic & Nuclear
Logo image