Question

Which carbon is more electronegative?

• A. $s{p}^3$ hybridised carbon
• B. $sp$ hybridised carbon
• C. $s{p}^2$ hybridised carbon
• D. The electron attracting power of $C$ is always same irrespective of its hybrid state.

Answer 1

The correct option is B $sp$ hybridised carbon

atomic s character tends to concentrate in orbitals that are directed toward electropositive groups and atomic p character tends to concentrate in orbitals that are directed toward electronegative groups. This rule, which is experimentally observed and supported by molecular orbital calculations, is a useful tool in inorganic and organic chemistry. Bent based his rule on the perturbation theory, and suggests that isovalent orbital hybridization should transfer more s-character to the more electropositive-bonding orbital to maximize bonding energy Hybrid orbitals for main group elements consist of one s and three p orbitals, with the s orbital having lower energy. To have more s character, means that the bonding orbital is lower in energy and shaped more like an s orbital rather than a p orbital. In other words, ligand orbitals tend to be rich in p character because of higher electronegativity, with s character concentrated on the central metal. However, in cases where the metal has a lone pair, the lone pair orbital is high in s character. This is because s orbitals are closer to the nucleus, allowing for greater stabilization of the lone pair.