作者:Ranjeeta Sharma、Vishnu Shankar Tiwari、Alok Kumar Thakur、Rajesh Kumar、Nalin Kant Roy
DOI:10.14233/ajchem.2017.19926
日期:——
Three new polymolybdate heteropoly complexes were synthesized in the laboratory having Al3+, Co2+, Ni2+ and Cu2+ hetero cations. The synthesis of the three polymolybdate hetero poly complexes were prepared in acid medium at reflux temperature The products were isolated separately, washed in ethanol and dried. The dried residues obtained posses light and dark brown colour. All the three residues of polymolybdate are paramagnetic at room temperature having magnetic moment varying from 3.02 to 3.78 BM. The magnetic moment values of triheteropoly molybdate complexes suggest the six co-ordinated octahedral around Co(II) and Ni(II) environment in the weak field. The IR spectra of all the three residue exhibit strong absorption band of hydrogen bonded H2O group in the complexes along with metal-oxygen-metal and metal-oxygen, where metal may be Mo, Ni, Co or Al. The DTA and TGA curves of polymolybdate residues show decomposition of product in general two steps. The first step of residue involves measure loss in weight due to loss of water molecules and sodium oxide molecules, while the second step loss of weight due to loss of water of constitution. The analysis of all the product based on IR spectrum thermogravimetric studies, elemental estimation and molecular weight determination by cryoscopy method the molecular formula may be suggested as: Na4[NiAl2Mo12O42]·28H2O, Na4[CuCoMo12O40]·60H2O and Na8[CoAl2Mo12O44]·94H2O.
实验室合成了三种新的多钼酸盐杂质多络合物,其杂质阳离子分别为 Al3+、Co2+、Ni2+ 和 Cu2+。这三种多钼酸杂多络合物是在酸性介质中、回流温度下合成的。干燥后的残留物呈浅棕色和深棕色。室温下,聚钼酸盐的所有三种残留物都具有顺磁性,磁矩在 3.02 到 3.78 BM 之间。三聚钼酸盐复合物的磁矩值表明,在弱磁场中,Co(II)和 Ni(II)周围存在六配位八面体环境。所有三种残留物的红外光谱都显示出配合物中氢键 H2O 基团以及金属-氧-金属和金属-氧(其中金属可能是 Mo、Ni、Co 或 Al)的强吸收带。多钼酸盐残留物的 DTA 和 TGA 曲线显示,产品的分解一般分为两个步骤。第一步,由于水分子和氧化钠分子的损失,残留物的重量有所减少;第二步,由于成分中水分的损失,重量有所减少。根据红外光谱热重研究、元素估算和冷冻法分子量测定对所有产品进行分析,得出的分子式为Na4[NiAl2Mo12O42]-28H2O、Na4[CuCoMo12O40]-60H2O 和 Na8[CoAl2Mo12O44]-94H2O。