| isovalent hyperconjugation [¦ī·sǝ¦vā·lǝnt ´hī·pǝr´kän·jǝ`gā·shǝn] PHYSICAL CHEMISTRY An arrangement of bonds in a hyperconjugated molecule such that the number of bonds is the same in the two resonance structures but the second structure is energetically less favorable than the first structure; examples are H3≡C-C+H2 and H3≡C-CH2. |