L. Vrielynck, N. Dupuy, J. Kister
May 8, 2006
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Influential Citations
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Journal
Journal of Molecular Structure
Abstract
Abstract The crystal structure of isoproturon [ N -(4-isopropylphenyl)- N ′, N ′-dimethylurea] has been determined: the compound crystallizes in the space group Pbca with unit cell parameters a =10.186(2) A, b =11.030(2) A, c =20.981(4) A. The structure was solved and refined down to R 1=0.0508 and ωR 2=0.12470 for 3056 reflections. The crystalline molecular network of this pesticide is stabilized, as for many molecules of the same family, by π–π interactions but especially by a medium–strong N–H⋯C O intermolecular hydrogen bond (2.14 A). The X-ray parameters were then compared with the results of DFT quantum chemical calculation computed with the gaussian 94 package. A tentative assignment of the ATR–FT-IR and Raman spectra was proposed supported by vibrational mode calculation and spectroscopic data on benzenic and urea derivatives available in the literature. The presence of a tight band around 3300 cm −1 , which can be assigned to the NH bond stretching mode as well as the low frequency position of the amide I band at 1640 cm −1 , sensitive to solvent polarity, confirms the existence of a quite strong intermolecular hydrogen bond between neighboring molecules in the crystal of isoproturon.