Bond indices, enthalpies and relative stabilities of real and hypothetical closo-BnHc−n clusters (n = 5–12; c = 0, 2 or 4) as revealed by the molecular-orbital bond index method

Robert Mulvey, M E ONEILL, K WADE, R SNAITH

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Bond indices (I) have been calculated, using the CNDO-based molecular-orbital bond index method, for real and hypothetical closo borane species, BnHc−n (n = 5–12; c = 0, 2 or 4), and used to infer their relative stabilities by means of the bond index (I)bond enthalpy [E (kJ mol−1)] equations E(BB) = 297.9I(BB) and E(BH) = 374.8I(BH). For the species able to tolerate n + 2 skeletal electron pairs (n = 8, 9 or 11) in closed-shell electronic configurations, estimates of the relative stabilities of alternative nido structures for the anions BnH4−n have been made. Detailed assessments of the changes in bond index with electron numbers of particular edge types for BnHc−n species (n = 8, 9 or 11; c = 0, 2 or 4) have been carried out, providing quantitative confirmation of earlier qualitative predictions, and showing that generally for the “normal” closo BnH2−n species addition or removal of an electron pair leads to the same type of polyhedral distortion, because, where the HOMO of BnH2−n is bonding for a particular edge, the LUMO is antibonding.
Original languageEnglish
Pages (from-to)1437-1447
Number of pages11
JournalPolyhedron
Volume5
Issue number9
DOIs
Publication statusPublished - 1986

Keywords

  • bond indices
  • enthalpies
  • molecular-orbital bond index method

Fingerprint Dive into the research topics of 'Bond indices, enthalpies and relative stabilities of real and hypothetical closo-BnHc−n clusters (n = 5–12; c = 0, 2 or 4) as revealed by the molecular-orbital bond index method'. Together they form a unique fingerprint.

  • Cite this