1983-26-2Relevant articles and documents
Nazarov et al.
, (1971)
A study of the reaction of phosphorus trichloride with paraformaldehyde in the presence of carboxylic acids
Troev,Todorov,Naydenova,Mitova,Vassilev
, p. 1147 - 1155 (2013)
We investigated the mechanism of the reaction of paraformaldehyde with phosphorus trichloride in the presence of carboxylic acids (acetic, propanoic, and formic). Our results revealed that bisphosphonic acids were obtained without the use of water. The structures of the reaction products were studied by 1D and 2D homonuclear and heteronuclear 1H-, 13C-, 31P- NMR spectroscopy. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional tables.]
[(Diphenoxyphosphinyl)methylidene]triphenylphosphorane - The double P +-stabilised carbanion: A crystallographic, computational and solution NMR comparative study on the ylidic bonding
Ch?cińska, Lilianna,Kudzin, Zbigniew H.,Ma?ecka, Magdalena,Nazarski, Ryszard B.,Okruszek, Andrzej
, p. 7681 - 7693 (2007/10/03)
The crystal and molecular structure of the title compound (1) was established by an X-ray diffraction analysis. Some geometrical parameters including a slightly pyramidal shape around its ylidic Cβ-atom were determined (trans-bent type conformation), providing evidence for a strong electron delocalisation in the PαCβP γOδ backbone. The charge density redistribution within this molecular unit and its other fully optimised geometries was evaluated in ab initio MO calculations using both the HF and DFT (B3LYP) formalism, which supported such a concept. As a result, the double zwitterionic form (structure C) was suggested as the best description of 1. The absence of an experimentally NMR observable 2JPα-Cβ -Hβ coupling was tentatively rationalised in terms of fast pyramidalisation of the Cβ-anionic site. Crystallographic and solution NMR data for ylide 1 were compared with those reported for the other mesomerically stabilised Wittig-type reagents and structurally related anionic species. It was concluded that all aforementioned systems have almost identical P-ylidic bonding most likely governed mainly by very strong electrostatic interactions, with a small contribution of negative hyperconjugation.
