Abstract
The origin of the relative stability of isomers of 1,2-diphosphinodisilene and related compounds is discussed. The geometries of 18 isomers of (H2X)HE=EH(XH2), (H2X)HE=EH(XH2)2+, and HX=EH-HE=XH (E = C, Si; X = P, N) have been optimized at the MP2/6-311++G(d, p) level of theory. Since nitrogen and phosphorus have lone-pair electrons, six electrons can delocalize in four orbitals of (H2X)HE=EH(XH2) (6e/4o), while four electrons can delocalize in four orbitals of (H2X)HE=EH(XH2)2+ and HX=EH-HE=XH (4e/4o). To examine the interaction that governs the structure and relative stability of their cis and trans (or cisoid and transoid) isomers, the π-σ* delocalization energies and isodesmic reaction energies of the compounds were calculated. It is concluded that the π-σ* delocalization affects the bending structure of disilene derivatives, and phosphorus substituents prefer 2e/4o and 4e/4o systems.
Original language | English |
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Pages (from-to) | 1721-1724 |
Number of pages | 4 |
Journal | Phosphorus, Sulfur and Silicon and Related Elements |
Volume | 177 |
Issue number | 6-7 |
DOIs | |
Publication status | Published - 2002 Jan 1 |
Externally published | Yes |
Keywords
- Ab initio MO calculation
- Disilene
- Isodesmic reaction
- Phosphorus
- π-σ* delocalization
ASJC Scopus subject areas
- Biochemistry
- Organic Chemistry
- Inorganic Chemistry