title: A computational study on 3-azonia-, 3-phosphonia-, and 3-arsoniaspiro[2.2]pentanes and related three-membered heterocycles.
abstract: A theoretical study at the ab initio MP2/6-311++G(d,p) level of theory is carried out to characterize several heterocyclic spiro[2.2]pentane cations with N, P, and As as spiro atoms. The strain and relative stability of the spiropentanes are obtained through isodesmic reactions. Nucleus-independent chemical shifts (NICS) and 3D NICS isosurfaces show σ-aromatic characteristics, similar to those found in cyclopropane. The interaction with the Cl(-) anion, which results in four different stationary structures, is studied and characterized by means of the atoms in molecules methodology, and Cl⋅⋅⋅pnicogen, Cl⋅⋅⋅H, and Cl⋅⋅⋅C interactions are found. The most stable structure in all cases corresponds to opening of one of the three-membered rings, due to the attack of the Cl atom, and C-Cl bond formation. Furthermore, the reaction with the 3-boranuidaspiro[2.2]pentane anion results in the formation of a new compound through cleavage of one ring of both reactants.
authors.affiliation: School of Chemistry, Trinity Biomedical Sciences Institute, Trinity College, 152-160 Pearse St. Dublin 2 (Ireland).
authors.forename: Cristina
authors.initials: C
authors.lastname: Trujillo
authors.forename: Goar
authors.initials: G
authors.lastname: Sánchez-Sanz
authors.forename: Ibon
authors.initials: I
authors.lastname: Alkorta
authors.forename: José
authors.initials: J
authors.lastname: Elguero
mesh_terms: D006571:Heterocyclic Compounds / Q000737:chemistry*; D008956:Models, Chemical; D010420:Pentanes / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*; D055672:Static Electricity; D013816:Thermodynamics
chemical_list: D006571:Heterocyclic Compounds; D010420:Pentanes; D013141:Spiro Compounds; C033353:pentane
keywords: aromaticity; density functional calculations; pnicogens; spiro compounds; strained compounds