X-RAY STUDY OF CHITOSAN TRANSITION-METAL COMPLEXES

Clear fiber diffraction patterns of nine chitosan-transition metal sal t [CdSO4, CdCl2, Cd(NO3)2, Cd(CH3COO)2, ZnSO4, ZnCl2, Zn(CH3COO)2, CuS O4, and CuCl2] complexes were obtained by immersing a tendon chitosan, prepared by a solid-state N-deacetylation of a crab tendon chitin, in respective metal salt solutions. The extended 2-fold helix of the chi tosan molecule was retained even with the complex formation. The unit cells of all the salt complexes studied were orthorhombic though the c upric salt complexes showed some unindexed reflections. Their lattice parameters and number of water molecules in the cell depended on the c ounteranions of the metal salt and not on the metal ion. The ratio of glucosamine residue to metal salt was 2:1. The space group P2(1)2(1)2( 1) was suggested for all the complex crystals except the CuCl2 complex .