Ring Strain Energies in Four-Membered Heterocycles Containing an Element of Groups 13-16.

ABSTRACT: The ring strain energy (RSE) of four-membered rings (4MRs) incorporating only one element from groups 13-16, exhibit moderate values of approximately 25 kcal·mol^-1 for compounds containing second-row elements, and decreasing to 14-19 kcal·mol^-1 as one progresses down the periodic table. 4MRs containing Bi, S, Se, Te and Po, exhibited higher RSEs than their three-membered analogues, which seems to be related to enhanced σ-antiaromaticity. The relationship between RSEs and some structural and electronic parameters was investigated. The strain-relieving effect observed with an increase in heteroatom size in all groups, may also coexist with that provided by the increase in the p-character of the AO used by the heteroatom in groups 15 and 16 in the endocyclic bonds. Furth

SUBMITTER: Rey Planells A 

PROVIDER: S-EPMC12728934 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature