Preferred Label : hard acid;
IUPAC definition : A Lewis acid with an acceptor centre of low polarizability. Other things being approximately
equal, complexes of hard acids and bases or soft acids and bases have an added stabilization
(sometimes called 'HSAB' rule). For example the hard O- (or N-) bases are preferred
to their S- (or P-) analogues by hard acids. Conversely a soft acid possesses an acceptor
centre of high polarizability and exhibits the reverse preference for coordination
of a soft base. These preferences are not defined in a quantitative sense.;
Origin ID : H02740;
See also
A Lewis acid with an acceptor centre of low polarizability. Other things being approximately
equal, complexes of hard acids and bases or soft acids and bases have an added stabilization
(sometimes called 'HSAB' rule). For example the hard O- (or N-) bases are preferred
to their S- (or P-) analogues by hard acids. Conversely a soft acid possesses an acceptor
centre of high polarizability and exhibits the reverse preference for coordination
of a soft base. These preferences are not defined in a quantitative sense.
