完全脱乙酰化壳聚糖与Zn(Ⅱ)的配位作用  

COORDINATION OF FULLY DEACETYLATED CHITOSAN WITH Zn(Ⅱ) IONS

作　　者：王爱勤[1] 周金芳[1] 俞贤达[1] 

机构地区：[1]中国科学院院兰州化学物理研究所,兰州730000

出　　处：《高分子学报》2000年第6期688-691,共4页Acta Polymerica Sinica

基　　金：中国科学院兰州分院院长基金!(基金号F96 12 )

摘　　要：在均相反应条件下 ,完全脱乙酰化的壳聚糖与ZnSO4 进行配位反应 .用元素分析、IR、固体13 C NMR、UV vis、TGA和X 衍射等表征方法研究了Zn(Ⅱ )与壳聚糖所形成配位聚合物的组成和结构 .在pH =7时 ,一个Zn(Ⅱ )The coordination of a fully deacetylated chitosan with zinc ion was studied in the homogeneous reaction condition.The composition and structure of chitosan\|Zn(Ⅱ)complex were investigated by elemental analysis,infrared and UV\|visible spectrometry solid state 13 C\|NMR,thermogrativimetric analysis and X\|ray diffraction.The results of elemental analysis show that the ratio of glucosamine repeat unit to Zn(Ⅱ) was 2∶1 with the complex formation in a pH=7 solution.The absorption at 3420cm -1 due to O—H and N—H stretching shifted to 3391cm -1 ;the absorptions at 1597cm -1 due to N—H stretching and at 1093cm -1 due to secondary alcohol —OH stretching shifted to 1620cm -1 and 1062cm -1 ,respectively.But the absorption at 1038cm -1 due to primary alcohol —OH did not shift supporting that both the amino and secondary hydroxyl groups of chitosan molecules are coordinated to Zn(Ⅱ).Comparing the 13 C\|NMR spectra of chitosan and chitosan\|Zn(Ⅱ) complex,the shifts of the key bands showed that Zn(Ⅱ) is coordinated to the —NH\-2 and secondary alcohol —OH of chitosan molecules.Marked difference of the characteristic peaks of both chitosan and chitosan Zn(Ⅱ) complex was not observed in the x\|ray diffraction pattern,indicating that the extended 2\|fold helical conformation of the chitosan molecule is retained even after the complexation.Final decomposed product of the complex is sulfate zinc,and the residue percentage is 28.8% and is correspond to the calculated value of 29.0%,accordign to the composition of elemental analysis of chitosan\|Zn(Ⅱ) complex.The structure of the complex seems to correspond to Zn(chitosan) \-2SO\-4·4H\-2O at pH=7.The complex is insoluble in water,acetone and ethanol,partly soluble in dilute formic acid solution,DMF and DMSO,completely soluble in dilute hydrochloric acid solution.

关 键 词：壳聚糖 结构表征 配合物 配位反应 

分 类 号：O614.241[理学—无机化学] O636.1[理学—化学]