Favoured conformations of methyl isopropyl, ethyl isopropyl, methyl tert-butyl, and ethyl tert-butyl 2-(triphenylphosphoranylidene)malonate.
Acta Crystallogr C
; 64(Pt 7): o405-10, 2008 Jul.
Article
em En
| MEDLINE
| ID: mdl-18599990
The conformations of organic compounds determined in the solid state are important because they can be compared with those in solution and/or from theoretical calculations. In this work, the crystal and molecular structures of four closely related diesters, namely methyl isopropyl 2-(triphenylphosphoranylidene)malonate, C(25)H(25)O(4)P, ethyl isopropyl 2-(triphenylphosphoranylidene)malonate, C(26)H(27)O(4)P, methyl tert-butyl 2-(triphenylphosphoranylidene)malonate, C(26)H(27)O(4)P, and ethyl tert-butyl 2-(triphenylphosphoranylidene)malonate, C(27)H(29)O(4)P, have been analysed as a preliminary step for such comparative studies. As a result of extensive electronic delocalization, as well as intra- and intermolecular interactions, a remarkably similar pattern of preferred conformations in the crystal structures results, viz. a syn-anti conformation of the acyl groups with respect to the P atom, with the bulkier alkoxy groups oriented towards the P atom. The crystal structures are controlled by nonconventional hydrogen-bonding and intramolecular interactions between cationoid P and acyl and alkoxy O atoms in syn positions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos Organofosforados
/
Malonatos
Idioma:
En
Revista:
Acta Crystallogr C
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Chile
País de publicação:
Estados Unidos