Home – Home – Jornals – Chemistry for Sustainable Development 2002 number 1-2

Deformed molecules exhibit anomaly in various aspects. Mechanical stressing, being anisotropic in nature, on the molecular crystals inevitably brings about quenched deformation of constituent molecules. When we deal with coordination compounds, deformation of the molecule results in disproportionation of ligands to change them into asymmetric, and hence develops distribution of ligand field strength. Consequences of introducing such asymmetry are very diverse. Gradual spin crossover and substitution of ligands by counter ions are only a few examples. Solid state ligand exchange is particularly of importance, since this opens up a new way for synthesizing various coordination compounds using neither solvents nor catalysts. Evidences of distribution of ligand field strength are shown for ferrous coordination compounds. Subsequently, application to the synthesis of some ferrous pyridyl compounds is demonstrated.