The coordination number of Cu(II)-chitosan coordination polymer

IR, ESR and XPS results show that the chitosan film(CS) soaked with aqueous cupric amine solution forms a Cu(II)-CS coordination polymer, which adsorb s partial Cu(II) too. The coordination number for the Cu(II)-CS polymer was studied by the shake-up effect observed in XPS spectra. The coordination b ond in Cu(II)-CS is formed as a result of the partial transfer of lone pair electrons from two N's and two O's of CS to dsp(2) hybrid orbitals of Cu(I I) in low spin state. So its coordination number is four. By the same metho d, coordination number of Cu(II)-PVA polymer is also studied. It is found t hat as a result of the partial transfer of the lone pair electrons on the s ide O in four chain unit of PVA to dsp(2) hybrid orbitals of Cu(II), the co ordination number for PVA is four, too. This verifies indirectly that the m ethod for studying coordination number of Cu(II)-CS coordination polymer is reliable.