ABSTRACT
Organometallics or metallo-organic compounds are those in which carbon atom of the organic group (hydrocarbon) is attached to the metal atoms. The chapter deals with organoderivatives of transition elements in their lower valencies. Organometallic compounds are substances which contain at least one direct netal-to-carbon bond. There are several examples of one, two, three, four, five, six, seven and eight carbon ligands. Alkene complexes are synthesised by the interaction with metal carbonyls or metal chlorides with alkenes. Dibenzene chromium are dark brown crystals more sensitive to air than ferrocene. The organometallic compounds are largely covalent in character as shown by their properties. Organometallic compounds of alkali metals are not very stable thermodynamically but polymeric compounds are relatively stable. Ferrocene is resistant to catalytic hydrogenation than benzene because of delocalisation of -electron density of the ring. For better understanding of the nature of bonding one has to develop molecular orbital picture for cyclopentadienyl ligand and metal orbitals.
