Role of the aromatic bridge on radical ions formation during reduction of diphosphaalkenes

Article Article scientifique Article Role of the aromatic bridge on radical ions formation during reduction of diphosphaalkenes eng 2011 author Lejeune Manuel 665858 author Grosshans Philippe 636539 author Berclaz Théo 24770 author Sidorenkova Cruz Gonzalez Elena 88481 author Besnard Céline 682138 author Pattison Phil author Geoffroy Michel 25153 2510 10.1039/c1nj20314b 1144-0546 http://xlink.rsc.org/?DOI=c1nj20314b Two molecules containing two phenylphosphaalkene moieties linked by an anthracene (1) or by a naphthalene (2) ring have been synthesized and their crystal structures have been determined. While electrochemical measurements show that these two systems are easily reduced, EPR spectra indicate that, at room temperature, the electronic structures of the two reduction compounds 1˙− and 2˙− are quite different. In 1˙−, in good accordance with DFT predictions, the unpaired electron is delocalized on the full molecule while in 2˙− it is confined on a single phosphaalkene moiety. This difference is attributed to the short distance between the two phenylphosphaalkene groups in 2˙− which hinders their reorientation after addition of an electron. The role of this motion is consistent with the fact that two additional paramagnetic species are detected at 145 K: the dianion 22− characterized by a rather small exchange coupling constant and the radical monoanion 2*˙− resulting from the formation of a one electron P–P bond. These two species are probably reaction intermediates which can lead to the formation of biphosphane. Dewey 540 38 Département de chimie physique 142 false 688 Groupe Geoffroy New journal of chemistry 35 11 43ad9070-cd74-4a72-8406-b94f3ef3a41f Article (Published version) Restricted ref01268.pdf 2328536 application/pdf restrictedAccess Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

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Role of the aromatic bridge on radical ions formation during reduction of diphosphaalkenes	New journal of chemistry			2011	725	0

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Lejeune, Manuel