On the Tautomerism of Secondary Phosphane Oxides

• Published in: European Journal of Organic Chemistry Vol. 2010; no. 14; pp. 2733 - 2741
• Main Authors: Christiansen, Andrea, Li, Chuanzhao, Garland, Marc, Selent, Detlef, Ludwig, Ralf, Spannenberg, Anke, Baumann, Wolfgang, Franke, Robert, Börner, Armin
• Format: Book Review Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.05.2010; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Chemical reactivity; Chemistry; Exact sciences and technology; IR spectroscopy; NMR spectroscopy; Organic chemistry; Organometalloidal and organometallic compounds; P derivatives; Phosphorus; Preparations and properties; Reactivity and mechanisms; Tautomerism; Electronic properties; Theoretical study; Phosphorus; NMR spectrometry; Tautomerism; Tautomer; X ray diffraction; IR spectroscopy; Phosphorus Organic compounds; Infrared spectrometry; Tertiary phosphine oxide; Density functional method; NMR spectroscopy; Electron acceptor; Structural analysis
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201000037

The tautomeric behaviour of five secondary phosphane oxides (SPOs) with different electronic properties has been investigated by NMR and IR spectroscopy, density functional theory calculations and X‐ray structural analysis. Proof is given that only with strong electron‐withdrawing groups on the phosphorus atom can the relevant trivalent phosphinous acid be observed in the equilibrium, whereas in the case of electron‐rich phosphane oxides the pentavalent species dominates. For a detailed analysis of the IR spectra, the deconvolution programme BTEM has been successfully applied. The tautomeric behaviour of secondary phosphane oxides (SPOs) with different electronic properties has been investigated by NMR and IR spectroscopy, density functional theory calculations and X‐ray structural analysis. Proof is given that only with strong electron‐withdrawing groups on the phosphorus atom can the relevant trivalent phosphinous acid be observed in the equilibrium.