Webster Athena, Halling Merrill D, Grant David M
University of Utah, Chemistry Department, Salt Lake City, UT 84112, USA.
Carbohydr Res. 2007 Jul 2;342(9):1189-201. doi: 10.1016/j.carres.2007.03.008. Epub 2007 Mar 12.
The physicochemical characterization of metal complexed with chitosan (CS) and its glutaraldehyde cross-linked derivative (CSGA) was investigated. Seven metal ions from chromium through zinc of the first row of the transition metals were selected for complexation. Structural features pertinent to where and how metals bind into both polymers are our main interest. Studies using solid-state NMR spectroscopy and XRPD (X-ray powder diffraction) supported by ESR spectroscopy, ICP-OES (inductively couple plasma-optical emission spectroscopy) and far-FTIR spectroscopy for metal interaction with nitrogen sites at C-2 of the metal-polymer complexes were performed. Theoretical calculations of the metal-polymer ratio, the approximate charges on nitrogen for both amine and imino-linker, and the proton affinity between an alcohol group from the polymer and an amino/imino group are reported. A helical coiled chitosan model and a 2C1L (two-chitosans with one linker) model are proposed here. The metal uptake mechanism for both polymers is concluded to be absorption within the polymers, rather than adsorption on the polymer surface.
研究了金属与壳聚糖（CS）及其戊二醛交联衍生物（CSGA）形成的配合物的物理化学性质。选择了第一排过渡金属中从铬到锌的七种金属离子进行络合。我们主要关注与金属在两种聚合物中的结合位置和方式相关的结构特征。进行了固态核磁共振光谱和X射线粉末衍射（XRPD）研究，并辅以电子自旋共振光谱、电感耦合等离子体发射光谱（ICP-OES）和远红外光谱，以研究金属与金属-聚合物配合物中C-2位氮位点的相互作用。报道了金属-聚合物比例、胺和亚氨基连接基上氮的近似电荷以及聚合物中醇基与氨基/亚氨基之间质子亲和力的理论计算结果。本文提出了螺旋卷曲壳聚糖模型和2C1L（两个壳聚糖与一个连接基）模型。得出两种聚合物的金属吸收机制是在聚合物内部吸收，而不是吸附在聚合物表面的结论。
