On the tautomerism, planarity, and vibrations of phospholes

The PH and CH tautomers of mono-, di-, tri-, tetra-, and pentaphospholes were calculated at the B3LYP/aug-cc-pVTZ level. Except for 1,2,3-triphosphole and pentaphosphole, the most stable phosphole form is one of the CH tautomers. For 1,2-diphosphole, 1,3-diphosphole, and 1,2,4-triphosphole, the ener...

Full description

Saved in:
Bibliographic Details
Published in:Chemical physics 2005-06, Vol.313 (1), p.123-132
Main Authors: Ozimiński, Wojciech P., Dobrowolski, Jan Cz
Format: Article
Language:English
Subjects:
DFT
Phosphole
Planarity
Tautomerism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The PH and CH tautomers of mono-, di-, tri-, tetra-, and pentaphospholes were calculated at the B3LYP/aug-cc-pVTZ level. Except for 1,2,3-triphosphole and pentaphosphole, the most stable phosphole form is one of the CH tautomers. For 1,2-diphosphole, 1,3-diphosphole, and 1,2,4-triphosphole, the energy difference between the tautomers is large and only one tautomer may be observed. For other phospholes, especially tetraphosphole, two tautomers may coexist. Non-planarity of the five membered ring is present only in the σ 3λ 3-P atom containing molecules, i.e., PH type of tautomers, while in the CH type of tautomers the ring is planar. As earlier reported by Nyulászi, the PH tautomers flatten, and the energy difference between PH phosphole and the planar transition state structure decreases, as the number of P atoms in the phosphole molecule is increased. Bond length changes were discussed in terms of configuration of the atoms attached to the bond, and the molecular frequency variations were examined according to the different surroundings of the appropriate vibrators.
ISSN:0301-0104
DOI:10.1016/j.chemphys.2005.01.006