Mono substitution in octahedral complexes: Part I-Softness constant, a new parameter for the reactivity of octahedral complexes

Abstract

A new parameter, softness constant, E_L, is proposed for mono substitution in octahedral complexes according to the equation,<br /> <em>E</em>_L <em>= </em>T<em>E</em><img src="http://www.niscair.res.in/jinfo/plusn.gif" alt="" border="0" /> (MsL) <em>- </em>T<em>E</em><img src="http://www.niscair.res.in/jinfo/plusn.gif" alt="" border="0" /><br /> where T<em>E</em><img src="http://www.niscair.res.in/jinfo/plusn.gif" alt="" border="0" /> is the total softness value of a complex species,Mis the transition metal ion, s is the standard ligand capable of undergoing substitution reaction and L is the incoming ligand. This parameter is used to analyse the total softness values, T<em>E</em><img src='http://www.niscair.res.in/jinfo/plusn.gif' border=0><em>,</em>of various monosubstituted octahedral complexes (MsL) in terms of the linear approximation of equation,<br> T<em>E</em><img src='http://www.niscair.res.in/jinfo/plusn.gif' border=0> (MsL)= <em>E</em>’_S + β’<em>E</em>_L<br><br> where <em>E</em>’_S is a measure of the electron richness of the complex species Ms, and W is the measure of its polarisability.