ISSN:
0009-2940
Keywords:
Bis-ylenephosphoranes, cyclization of
;
Calculations, ab initio, MCSCF, SCF
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
On the bais of ab initio calculations of double-ζ quality at a SCF and MCSCF level, bonding in bis-ylenephosphoranes is compared with the one in phosphoranes. The investigations include the series H3PX, HPX2, HPX (X = CH2, NH, O, SiH2, PH, S). The bis-ylenephosphorane formation becomes more favorable with increasing electronegativity of X. An extreme case is the electropositive group X = SiH2. The resulting π-system suffers from the Jahn-Teller distortion, causing reduction from C2v to lower C2 symmetry in the corresponding bis-ylenephosphorane. Energetically, the corresponding ring systems are more stable than their bis-ylenephoshorane counterparts (for X = CH2 and PH). The electronic hypersurface of the hitherto unknown bis(phosphinylidene)phosphorane is explored in detail and compared in regard to bonding with its analog bis(methylene)phosphorane. For both cases π-push-pull substitution is important for stabilization of the planar allylic geometry.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250604
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