Preferred Label : contributing structure;
IUPAC definition : The definition is based on the valence-bond formulation of the quantum mechanical
idea of the wavefunction of a molecule as composed of a linear combination of wavefunctions,
each representative of a formula containing bonds that are only single, double or
triple with a particular pairing of electron spins. Each such formula represents a
contributing structure, also called 'resonance structure' to the total wavefunction,
and the degree to which each contributes is indicated by the square of its coefficient
in the linear combination. The contributing structures, also called 'canonical forms',
themselves thus have a purely formal significance: they are the components from which
wavefunctions can be built. Structures may be covalent (or non-polar) or ionic (or
polar). The representation is frequently kept qualitative so that we speak of important
or major contributing structures and minor contributing structures. For example, two
major non-equivalent contributing structures for the conjugate base of acetone are:;
Origin ID : C01309;
See also
The definition is based on the valence-bond formulation of the quantum mechanical
idea of the wavefunction of a molecule as composed of a linear combination of wavefunctions,
each representative of a formula containing bonds that are only single, double or
triple with a particular pairing of electron spins. Each such formula represents a
contributing structure, also called 'resonance structure' to the total wavefunction,
and the degree to which each contributes is indicated by the square of its coefficient
in the linear combination. The contributing structures, also called 'canonical forms',
themselves thus have a purely formal significance: they are the components from which
wavefunctions can be built. Structures may be covalent (or non-polar) or ionic (or
polar). The representation is frequently kept qualitative so that we speak of important
or major contributing structures and minor contributing structures. For example, two
major non-equivalent contributing structures for the conjugate base of acetone are:
