Structure and bonding of a complexes

Recent studies have established the following generalizations regarding a (sigma-bond) complexes  

Electron donation in (a) 7t complexes and (b) a complexes. The filled orbitals are shaded. 

Jeffery, An Introduction to Hydro ten Bonding, Oxford University Press, Oxford, 1997. 

King (ed.), Encyclopedia of Inorganic Chemistry, Wiley, New York, 1994 (a) K. Yvon, Hydrides solid state transition metal complexes, pp. 1401-20 (b) M. Kakiuchi, Hydrogen inorganic chemistry, pp. 1444-71. 

Manchester (ed.), Metal Hydrogen Systems Fundamentals and Applications, vols. I and II, Elsevier Sequoia, Lausanne, 1991. 

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