title: A new monoclinic polymorph of 3-diethyl-amino-4-(4-meth-oxy-phen-yl)-1,1-dioxo-4H-1λ,2-thia-zete-4-carbonitrile.
abstract: A new monoclinic form of the title compound, C(14)H(17)N(3)O(3)S, has been found upon slow crystallization from water. Another monoclinic form of the compound was obtained previously from a mixture of dichloro-methane and diethyl ether [Clerici et al. (2002 ▶). Tetra-hedron, 58, 5173-5178]. Both phases crystallize in space group P2(1)/n with one mol-ecule in the asymmetric unit. The formally single exocyclic C-N bond that connects the -NEt(2) unit with the thia-zete ring is considerably shorter than the adjacent, formally double, endocyclic C=N bond. This is likely to be due to the extended conjugated system between the electron-donor diethyl-ammine fragment and the electron-withdrawing sulfonyl group. In the newly discovered polymorph, the meth-oxy group is rotated by almost 180° around the phen-yl-OCH(3) bond, resulting in a different mol-ecular conformation.
authors: Ahmed M
authors: AM
authors: Orlando
authors: Leonardo
authors: L
authors: Lo Presti
authors: Raffaella
authors: R
authors: Soave
references: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references: 18156677
references: J Phys Chem A. 2008 Oct 30;112(43):10993-7
references: 18828576