Answer to Question #187335 in Inorganic Chemistry for SANWAYEE BISWAS

Question

Construct two molecules comprising of elements from B, C, H, and O that are isolobal to ethylene and acetylene. Can you comment on their stability?

Answer 1

Ethane has sp3 hybridisation so less s-character and lesser electronegativity compared to ethyne. Ethyne has high s-character and high electronegativity. Therefore the covalent character of sp3−sp3 in Ethyne should be stronger and have more stability right? the order would therefore be sp−sp > sp2−sp2 > sp3−sp3

Some online sites tell so, but others say since the C atoms are so close in ethyne that the nuclear repulsion would make it less stable. So ethane's C−C would be stronger and that therefore the order should be reversed.