[Preparation, X-ray structural and spectroscopic studies of some D-lactobionic acid complexes with Cs(I), Fe(III) and di-n-butyltin(IV)].

D-Lactobionic acid (4-O-beta-D-galactopyranosyl-D-gluconic acid) complexes of Cs(I), Fe(III) and di-n-butyltin(IV)2+ ions were prepared in the solid state. The bonding sites of the ligands were verified by means of FTIR, Raman and 13C NMR spectroscopic measurements. The Cs(I)-D-lactobionate was obtained in single-crystal form. The X-ray crystallographic results on Cs(I)-D-lactobionate demonstarted that each Cs(I) ion is bonded to four D-lactobionate ions, forming an intricate 3D network. The asymmetric unit consists of one Cs(I), one D-lactobionate ion and one water molecule. For the di-n-butyltin(IV) complex, Mössbauer pqs calculations indicated octahedral and trigonalbipyramidal stereochemistry around the central tin atom in the oligomeric compound. In DMSO solution, the polymeric structure does not remain as shown by 13C NMR measurement. One solvent molecule is coordinated additionally to the tin center, and the carboxylate group has become monodentate. According to the EPR measurement, the Fe(III) complexes obtained at different pH have at least dimeric or oligomeric structure.