تسجيل الدخول

تسجيل

Reactions Involving the Coordination Shell

المؤلف:  Geoffrey A. Lawrance

المصدر:  Introduction to Coordination Chemistry

الجزء والصفحة:  179

2026-03-28

272

Reactions Involving the Coordination Shell

Often simple commercially-available hydrated salts of metal ions (chlorides, sulfates or nitrates in particular) are the starting point of much synthetic chemistry involving the coordination shell. Oxides are occasionally used, but tend to be highly insoluble and their use can involve dissolution with acid to form simple salts as a first step in any case. Further, anhydrous simple salts (dominantly halides) may be employed, particularly where reaction is to proceed in nonaqueous solvent; however, some of these are polymeric and as a result are often converted first to monomeric compounds that include coordinated solvent, which are more soluble and reactive. For example, polymeric TiCl₃ is reacted in tetrahydrofuran (THF) to form the monomer [TiCl₃(THF)₃] and polymeric MoCl₄ is reacted in acetonitrile (MeCN) to form the monomer [MoCl₄(MeCN)₂]. Ligand substitution reactions using precursors where a didentate chelate ligand is replaced by stronger chelates is another approach; typical complexes for such reactions are [M(CO₃)₃]x- and neutral [M(acac)n] featuring chelated carbonate and acac− 2.4-dioxopentan-3-ido) ligands respectively. Much organometallic chemistry relies on metal carbonyl compounds, such as [Cr (CO)₆] as starting points for the substitution chemistry. However, ligand substitution can occur with an almost infinite number of starting materials, providing thermodynamics and kinetics for the proposed reaction are appropriate.