Conformations of Bridged Diphenyls. IX. Crystal Structure of 2-(4-Carbomethoxy-2-nitrothiophenyl)-1,3,5-trimethylbenzene
Heijden, SVD; Chandler, W; Robertson, B
The structure of 2-(4-carbomethoxy-2-nitrothiophenyl)-1,3,5-trimethylbenzene, C17H17-NO4S, has been determined by X-ray diffraction. The crystals are monoclinic, a=18.616(15), b=5.739(8), c=15.712(14), =101.97(3), P21/cwith Z=4. The intensities of 3820 independent reflections were measured on a four circle diffractometer; 2825 reflections were used in the refinement of the structure to give a final least-squares weighted residual of 0.059 and a traditional Rfactor of 0.054. The presence of electron-withdrawing groups on one of the phenyl rings increases the conjugation between the ring and the sulfur atom in a similar manner as that observed in diphenyl ethers. The mesityl ring is nearly orthogonal to the CSC plane.On a dtermin la structure cristalline du (carbomthoxy-4 nitro-2 thiophnyl)-2 trimthyl-1,3,5 benzne, C17H17NO4S, par diffraction de rayons-X. Les cristaux sont monocliniques, a=18.616(15), b=5.739(8), c=15.712(14), =101.97(3), P21/cavec Z=4. On a msure les intensits de 3820 rflexions indpendantes l'aide d'un diffractomtre quatre cercles. On a utilis 2825 de ces rflexions pour affiner la structure jusqu' une valeur de Rpondre de 0.059 et une valeur de Rconventionnelle de 0.054. La prsence de groupes lectroaffinitaires sur un des groupes phnyle augmente, d'une faon similaire celle observe dans les diphnyl thers, la conjugaison entre le cycle et l'atome de soufre. Le cycle msityle est presque perpendiculaire au plan CSC. [Traduit par le journal]