Applications of the Hard-Soft Interaction Principle HSIP

6 Applications of the Hard-Soft Interaction Principle (HSIP) 

The hard-soft acid-base principle is not restricted to the usual types of Lewis acid-base interactions. It is a guiding principle for all types of interactions that species of similar electronic character interact best. Accordingly, we will refer to the principle as the hard-soft interaction 

Linkage isomers. Ions such as SCN- have two potential electron donor atoms. When bonding to metal ions, the bonding mode may be predicted by means of the HSIP. 

When three very large groups such as As(C6H5)3 are bound in the other three positions around Pt2+, the steric effects can cause SCN- to bond through the nitrogen atom. 

The HSIP also applies to precipitation of solids from solution. Ionic solids precipitate best from aqueous solutions when the ions are of similar size, preferably with the two ions having charges of the same magnitude. For the reaction 

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