Reaction of vanadium(V) with hydrazine sulfate in the presence of certain complexones

Conclusions The authors have investigated the kinetics of the redox reaction of V(V) with N₂H₄ · H₂SO₄ in the presence of complexones of ethylenediaminetetraacetic, diethylenetriaminepentaacetic, and nitrilotriacetic acids; two mechanisms of the redox processes are proposed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1933–1936, September, 1979.     

Coordination Numbers of Central Atoms in Coordination Compounds

A sample of structurally characterized 10000 complexes (X-ray diffraction data) was carefully selected from available databases for analysis of coordination numbers (CNs) of their central atoms (complexing agents). The coordination numbers of various chemical elements are tabulated for their different oxidation numbers (ONs). Variations in CN with the ordinal number of an element in the Periodic Table were followed. A general distribution of the sample complexes over the CNs of the central atom, as well as their distributions for particular ONs, is displayed. References to particular coordination compounds are given for extreme and very uncommon CNs of a central atom with different ONs. A general pattern of the observed variations in the CN of chemical elements can be useful for predicting the properties of complexes, constructing their stability models, designing compounds with rich and unique properties, and developing retrieval and graphic tools for chemical databases.