Página Inicial CNEA Laboratorio TANDAR Página Inicial TANDAR Historia del acelerador TANDAR Web interno Web mail
Inicio » Actividades I+D > Publicaciones 2011 > Conformations of diester triphenylphosph...
artículo con referato
"Conformations of diester triphenylphosphonium ylides with an ylidic ester or keto and ester ylidic groups"
F. Castañeda, P. Silva, C.A. Bunton, M.T. Garland and R. Baggio
Acta Cryst. C 67(8) (2011) o319-o323
Abstract
The structures of three related keto diester and diester ylides, namely diethyl 3-oxo-2-(triphenylphosphoranylidene)glutarate, C27H27O5P, (I), diethyl 3-oxo-2-(triphenylphosphoranylidene)glutarate acetic acid monosolvate, C27H27O5P·C2H4O2, (II), and diethyl 2-(triphenylphosphoranylidene)succinate, C26H27O4P, (III), are presented. The syn-keto anti-ester conformations in the crystalline keto diesters are governed by electronic delocalization between the P-C and ylidic bonds and an acyl group, and by intra- and intermolecular interactions. There are also intramolecular attractive and repulsive interactions of different types (C–HO and C–Hπ) controlling the molecular conformations. The mono-ylidic diester (III) has an anti-ester conformation, while those for (I) and (II) are related to pyrolytic formation of acetylene derivatives. The terminal nonylidic ester group in (I) was disordered over two sets of almost equally populated positions.
DEPARTAMENTO FISICA DE LA MATERIA CONDENSADA
Contacto
Av. Gral Paz y Constituyentes, San Martín, Pcia. de Buenos Aires, Argentina
Tel: (54-11) 6772-7007 - Fax: (54-11) 6772-7121