Solid state and ethanolic solution behaviour of N-tosylglycinate–copper(II) complexes. Crystal and molecular structure of a strongly coupled polymeric N-tosylglycinatocopper(II) complex

Abstract

The interaction between N-tosylglycine and the copper(II) ion in ethanolic solution has been examined. Two compounds of formula [{Cu(tsglyO)₂}_n](green) and Na₂[Cu(tsglyNO)₂](blue)(tsglyO and tsglyNO =N-tosylglycinate monoanion and dianion, respectively) were isolated. Crystals of [{Cu(tsglyO)₂}_n] are monoclinic, space group P2₁/n with Z= 4 in a unit cell of dimensions a= 24.655(3), b= 7.697(2), c= 12.378(3)Å, and β= 87.34(8)°. Full-matrix least-squares refinement, using 1 677 independent reflections, reached R= 0.052. The structure is built up of one-dimensional polymeric chains of binuclear units, showing the copper(II) acetate structure, linked via Cu–O(sulphonic) bonds. Its magnetic and spectroscopic properties are interpreted on the basis of the crystal structure. In particular it shows an exchange integral (–2J) of 353 ± 4 and a zero-field splitting, D, of 0.35 cm^–1. The i.r. spectrum shows multiple sulohonamide absorotion bands because only half of the SO₂grouos are co-ordinated. By polagraphic measururements in ethanol, the number and type of complex species, the equilibria in which they are involved, and their stability constants have been determined. For c_naOH/c_complexrations between 1 and 3 the species [cu(tsglyO)₂] is the only one persent; for ratios >4, [cu(tsglyO)₂]^2– prevails.