Hydrothermal Synthesis of Novel Solid-State Ternary and Quaternary Metal Telluride Compounds

9310431李本项目为女科学家、女工程师科研计划资助项目。介绍了水热合成新型固体三元和四元金属碲化物化合物的制备、结晶和结构表征的计划和方法。最初的研究将集中于前体的制备，主要是二元碱金属多碲化物，它们既可用作反应物，也可用作矿化剂。在随后的水热反应中，将选择额外的金属或金属配合物与前驱体反应，生成所需的三元或四相。最近对固态三元过渡金属碲化物的研究揭示了一些不寻常的结构特征，导致这些化合物表现出有趣的磁性和电学行为。它们大多采用独特的低维（链状或层状）结构。许多含有扩展的金属网络，具有很强的金属-金属结合。近年来，人们对碲化物的研究越来越感兴趣，认为合成具有实用性能和应用价值的新型碲化物材料具有很大的潜力。大多数已知的固态碲化物化合物都是在高温下制备的，而在较低温度下的研究很少。开发低温合成技术的必要性是显而易见的。水热合成已被证明是一种重要而有前途的低温合成和晶体生长方法。它在固体化学和材料科学中得到了广泛的应用。虽然许多新的分子和扩展体系，如沸石、石英、过渡金属磷酸盐、氧化物和主族硫化物，已经利用这种技术合成或结晶，包括最近成功合成了几种早期和晚期过渡金属多硒化物，但实际上还没有对固态碲化物化合物进行过研究。＊＊＊

9310431 Li The proposed work is a Research Planning Grant for Women Scientists and Engineers. It is concerned with plans and approaches in the preparation, crystallization and structure characterization of novel solid-state ternary and quaternary metal telluride compounds employing hydrothermal synthesis. Initial studies will focus on the preparation of precursors, largely the binary alkali-metal polytellurides that are to be used both as reactants and mineralizers. In subsequent hydrothermal reactions, additional metals or metal complexes will be selected for reaction with the precursors, leading to the desired ternary or quaternary phases. Recent work on the solid-state ternary transition metal tellurides has revealed a number of unusual structural features leading to interesting magnetic and electric behaviors exhibited by these compounds. Most of them adopt unique low dimensional (chain or layer) structures. Many contain extended metal networks with strong metal-metal bonding. An increasing interest in the studies of the tellurides has been exhibited in the last few years, and a great potential exists for synthesis of novel telluride materials with useful properties and applications. Most known solid-state telluride compounds have been prepared at high temperatures, and little has been explored in the lower temperature regime. The need to develop low temperature synthetic techniques is apparent. Hydrothermal synthesis has been proved to be an important and promising method of relatively low-temperature synthesis and crystal growth. It has been widely used and is finding increasing applications in solid state chemistry and material science. While numerous novel molecular and extended systems, such as zeolites, quartz, transition metal phosphates, oxides, and main group sulfides, have been synthesized or crystallized utilizing this technique,including the recent success in the synthesis of several early and late transition metal polyselenides, vi rtually no work has been conducted on the solid- state telluride compounds. ***