Structural Chemistry of Polyanion Clusters of p-Block Elements

本研究旨在通过穆斯堡尔谱对锌化合物、碱金属或碱土金属与过渡后元素之间的金属间化合物以及锌阴离子等相关化合物的结构和成键的认识。为了实现这一目标，人们进行了几次尝试；制备了锌化合物，并用电化学方法合成了锌离子。在对反应条件进行了多次考察后，在氮气气氛下，从含有化学计量比的碱金属和锑的熔体中结晶得到了锌化合物。用该方法合成了K_3Sb、KSb、KSb_2、Na_3Sb、NaSb和Mg_3Sb_2等二元化合物。在真空石英管中从熔体中结晶制备了锑和过渡元素之间的二元金属间化合物。在20K下测量了金属间化合物的穆斯堡尔谱。M-Sb系化合物(M=Na，K)的穆斯堡尔谱表明，M_3Sb和Mg_3Sb_2是由M^+和Sb^&lt；3-&gt；离子组成的离子化合物，与Xe的电子构型相同。另一方面，对于MSb和KSb_2，Sb原子之间存在较大的共价相互作用，多余的电子主要保持在Sb的5p轨道上。被接受电子数按MSb_2&lt；MSb&lt；M3Sb的顺序递增，表明这些化合物具有离子性质。Cu3Sb、Cu2Sb、Ag3Sb、aUb2和ZnSb的穆斯堡尔谱揭示了这些化合物的共价性。

This research have been done to obtain and promote the knowledge on the structure and bond in the Zintl compounds, the intermetallic compounds between the alkali or alkaline earth metals and posttransition elements, and the related compounds such as Zintl anions by means of Mossbauer spectroscopy. To perform this purpose, several attempts have been carried out ; the preparation of Zintl compound and synthesis of Zintl anion by a electrochemical method were carried out.After the many reviews of the reaction condition, the Zintl compounds have been prepared by the crystallization from the melt containing the stoichiometric amount of the alkali metal and antimony in an aluminum crucible under the nitrogen atmosphere. The binary compound K_3Sb, KSb, KSb_2, Na_3Sb, NaSb and Mg_3Sb_2 were prepared by this method. The binary intermetallic compound between antimony and the transition elements were prepared by the crystallization from the melt in a evacuated quartz tube. The attempt to prepare the Zintl anion by electrochemical method has been failed in spite of much effort.The ^<121>Sb Mossbauer spectra for the intermetallic compounds have been measured at 20K.The spectra for the compounds of M-Sb system (M = Na, K) shows that M_3Sb and Mg_3Sb_2 are an ionic compounds consist of the M^+ and Sb^<3-> ions, the same electron configuration as that of Xe. For MSb and KSb_2, on the other hand, much covalent interactions between antimony atoms are suggested and the excess electrons are mainly held in the Sb 5p orbitals. The order of the number of the accepted electrons are increased in the order MSb_2 <MSb <M_3Sb, indicating the ionic character of these compounds. The Mossbauer spectra for Cu_3Sb, Cu_2Sb, Ag_3Sb, AuSb_2, and ZnSb suggest the covalent nature for these compounds.