[C5H5NH]3[PMo12O40]·4.5H2O的合成与表征
来源期刊：中南大学学报(自然科学版)2006年第1期
论文作者：李洁 孙容 陈启元 尹周澜 张平民
文章页码：58 - 62
关键词：12-钼磷酸;吡啶;电荷转移盐;合成;表征
Key words：12-molybdophosphoric acid; pyridine; charge-transfer salt; synthesis; characterization
摘 要：以12-钼磷酸和吡啶为原料合成了一种电荷转移盐。通过C, N, Mo和P元素分析和热重分析确定其组成为[C5H5NH]3[PMo12O40]·4.5H2O,各元素的质量分数分别为(括号内为理论值)C 8.82 %(8.42%), N 1.69%(1.96%), P 1.40%(1.45%)和Mo 52.98%(53.78%);采用红外光谱、紫外-可见漫反射光谱、X射线粉末衍射和循环伏安法等分析手段对该化合物进行了表征。结果表明:所合成的新型电荷转移化合物的杂多阴离子保持Keggin结构特征;相对于H3PMo12O40·xH2O, [C5H5NH]3[PMo12O40]·4.5H2O中由于离域π键的存在,对紫外-可见光的吸收从紫外区拓展到可见光区,并且在波长为370 nm处出现新的吸收峰;其还原电位为0.21 V,较H3PMo12O40·xH2O的还原电位(0.32 V)低,故其还原能力增强。
Abstract: A charge-transfer salt was synthesized with 12-molybdophosphoric acid and pyridine in aqueous solution. Its molecular formula was determined as [C5H5NH]3[PMo12O40]·4.5H2O by element analysis and TG thermal analysis. The mass fractions of elements are (the numbers in bracket are theoretical values) C 8.82 %(8.42%), N 1.69%(1.96%), P 1.40%(1.45%) andMo 52.98%(53.78%). The compound was characterized by X-ray powder diffraction analysis,IR and UV-Vis spectra as well as cyclic voltammetry. The results indicate that it keeps the Keggin structure of anion, but the Keggin structure is more or less transformed under the influence of pyridine. Because of the delocalizedπbond, a new absorption peak of ultraviolet absorption spectrum appears at 370 nm. Its reduction potential is 0.21 V and it has higher redox activity than 12molybdophosphoric acid with reduction potential of 0.32 V.
