The influence of different substituents on the geometrical changes in the heterocyclic moiety of 1,2-diphospholes

GRAPHICAL ABSTRACT

ABSTRACT

It is shown that increase of steric bulk of R group of 1R-1,2-diphospholes results in decrease of the pyramidality of P(III) atom, but has little impact on a planarity of the entire heterocycle in the case of R = Alk. At the same time, planarization of the heterocycle reported elsewhere for R = SnMe₃ or SiMe₃ is accompanied by moderate increase of the P(III) pyramidality relative to the case of R = Alk. This difference could be related to effects of π-σ conjugation between P-Sn/P-Si moiety and the dienic system of the 1,2-diphosphole.

KEYWORDS:

• Conjugation
• 1,2-diphospholes
• DFT
• UV/vis-spectra
• Raman spectra

Funding

This work was supported by the Council on Grants of the President of Russian Federation (MK-7748.2015.3) and Russian Foundation for Basic Research (14-03-00920).