Harcourt RD, Klapötke TM. Comment on "A quantitative definition of hypervalency" by M. C. Durrant,
Chem. Sci., 2015,
6, 6614.
Chem Sci 2016;
7:3443-3447. [PMID:
29999045 PMCID:
PMC6007126 DOI:
10.1039/c5sc04866d]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/08/2016] [Indexed: 11/21/2022] Open
Abstract
Consideration is given to (electronically) hypervalent increased-valence structures, which possess 2c–1e bonds, fractional 2c–2e bonds, and usually normal 2c–2e bonds.
Consideration is given to (electronically) hypervalent increased-valence structures, which possess 2c–1e bonds, fractional 2c–2e bonds, and usually normal 2c–2e bonds. For singlet-spin electron-rich systems, increased-valence structures, with Heitler–London 2c–2e bond wavefunctions, are equivalent to resonance between non-hypervalent Kekulé and Dewar (or singlet diradical) type Lewis structures. Dewar structures are not considered in the Chem. Sci. 2015, 6, 6614 Edge article on hypervalency. Using one-electron delocalizations from lone-pair atomic orbitals into separate bonding molecular orbitals, increased-valence structures for PCl5, O3, SO42–, NO3–, N2O4 and SN2 reactions are derived from the Edge-article's Kekulé-type Lewis structures, and compared with the Edge article's hypervalent structures with 2c–2e bonds. It is also shown that Durrant's method to determine the γ parameter for XAY-type systems that possess a symmetrical 3c–4e bonding unit is related to the A-atom charge density.
Collapse