The preparation and crystal structure analysis of bis(L-Arginine)Cu(II)(acetate) 2trihydrate

Abstract

The crystal structure of bis(L-arginine)Cu(II)(acetate) 2trihydrate has been determined by X-ray analysis. The complex crystallizes in the monoclinic space group P2 1, with cell dimensions a = 15.948(2), b = 16.878(2), c = 10.378(2) Å, β = 108.47(1)°, Z = 4. There are two independent formula units in the asymmetric unit. The Cu atoms were located from a Patterson synthesis and the remaining atoms from difference Fourier syntheses. The structure was refined by least-squares to R = 0.079 and R = 0.11. Each copper atom has an essentially square planar coordination with the two arginine molecules chelated via the carboxy oxygens and the α-amino nitrogens, but with distorted six-fold coordinations completed by weak Cu…O (acetate) interactions. Electrostatic interactions between the acetates and the protonated ends of the amino acid residues link the two independent [Cu(L-arginine) 2(acetate) 2] units into dimers, which are then connected via hydrogen bonds, also involving the water molecules, into an infinite network.