Showing papers in "Reviews in Inorganic Chemistry in 2002"
TL;DR: In this article, the authors describe the formation of most heteropolytung states by analogous successive reactions, which are often controlled by the nature of the cationic counter-ions in the solution, for example Na or K.
Abstract: Heteropolytungstates result from the acidic polycondensation of [WO4]\" anions around a heteroelement X. Despite their apparent great diversity, due to the different stereochemical and electronic properties of the heteroatoms, the formation of most heteropolytungstates can be described by analogous successive reactions. In a first step, 9-tungstoheteropolyanions are generally obtained in basic medium and have an open structure. Two types, A and B, and for each type two isomers, α and β, are known. In the next steps which occur at lower pH, closing of the framework or association of the open species directly or through tungsten atoms lead to miscellaneous heteropolytungstates. The reactions are often controlled by the nature of the cationic counter-ions in the solution, for example Na or K. Moreover, in these last steps, the tungsten atoms can be replaced by transition metal cations giving rise to polynuclear complexes. New monoor polyvacant species can be obtained by selective hydrolytic reactions of the heteropolyanions formed in acid solution, the nature of these species depending again on the nature of the heteroelement and of the counter-ions.
95 citations
52 citations
TL;DR: In this article, the authors propose a 2.0.ABBREVIATION (2.0) algorithm for unsupervised clustering, which can be used to find the optimal clustering.
Abstract: 0. ABBREVIATIONS
23 citations
TL;DR: In this article, a review of vanadium-sulfur bonds is presented for binary and ternary vanadium sulfides, as well as mononuclear and polynuclear vanadium complexes with ligands containing sulfur atoms as donors.
Abstract: This paper reviews the compounds containing vanadium-sulfur bonds: binary and ternary vanadium sulfides, as well as mononuclear and polynuclear vanadium complexes with ligands containing sulfur atoms as donors. The structural and spectral particularities as well as some specific properties are discussed in detail.
5 citations
TL;DR: In this article, the authors presented a method for the synthesis of the Ligands and the Synthesis of the Complexes using IR Spectra and H-NMR Spectra.
Abstract: 113 INTRODUCTION 114 MATERIAL AND METHODS 115 Synthesis of the Ligands 115 Synthesis of the Complexes 115 RESULTS AND DISCUSSION 115 IR Spectra 118 'H-NMR Spectra 118 Acknowledgment 123 REFERENCES 124
5 citations
TL;DR: In this article, the authors proposed a method to solve the problem of unstructured data in the context of data augmentation, and presented experimental results and results and discussion of the proposed method.
Abstract: 53 Introduction 54 Experimental 54 Results and Discussion 55 References 61
4 citations