Chapter 1 - Cryosynthesis of Metal Complexes

Abstract

This chapter focuses on the process of cryosynthesis of metal complexes. The use of metal vapors in organic and inorganic chemistry has led to the creation of a new area of synthetic coordination chemistry: the “direct synthesis” of metal complexes starting from metal vapors in the gas phase. Coordination compounds can be obtained in the gas phase by direct interaction of vaporized atomic metals and ligands. However, the scope of this approach is strongly limited by the instability of complexes at high temperatures. The highest efficiency in gas-phase syntheses is attained by co-condensation of metal vapors and ligands at low temperature. The types of apparatus used for direct synthesis of metal complexes in the gas phase differ according to the methods of metal evaporation used and of the introduction of the ligand into the reaction chamber. Various organic and inorganic ligands are used in cryosynthesis with the participation of atomic metals at low temperatures, and pure gas-phase reactions without a condensed phase at high temperatures hold many possibilities for the synthesis of various types of complex, especially π-complexes of aromatic and cyclodiene ligands. The chapter discusses the processes of synthesis of metal complexes with simple inorganic ligands, cryosynthesis of metal π- and σ-complexes, and vapor synthesis of metal chelates, highlighting the advantages and disadvantages of cryosynthesis.