کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5418468 1506996 2006 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
DFT analysis of diclofenac activity and cation type influence on the theoretical parameters of some diclofenac complexes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
DFT analysis of diclofenac activity and cation type influence on the theoretical parameters of some diclofenac complexes
چکیده انگلیسی
The twisted structure of diclofenac sodium that is behind the excessively remarkable reactivity of this drug, was investigated by DFT calculations at the B3LYP/6-311G (d) level of theory. The repulsion forces, existing within the molecule because of the simultaneous presence of the acetate moiety as well as the two Cl atoms, created a twisted (74°) diphenylamine structure to yield a preferred orientation. B3LYP/ 6-311G (d) calculations of diclofenac and its complexes, ML2 (L=Ca, Mg, Zn), showed that distortions of the geometric parameters were due to the differing hybridizations depending on the cation type in question. The energy gap values, ΔE, increased in the order Mg>Zn>Ca, pointing out that the energy associated with electron pairing is greatest in the Mg2+ complex, due to the [Ne]3s2 configuration and large charge to radius ratio (3.3) of the metal. The charge density contour plots of the complexes showed the negative charge as condensed around the N atom, indicating a very highly polarized M-N coordinate bond. Both the acid form and sodium salt displayed the typical weak N-H⋯O hydrogen bond association which is absent in the Mg, Ca and Zn complexes. The distance between H and O in all three (3.837 Mg, 3.307 Ca and 4.277 Zn Å) exceeded the possible limit of 3.0 Å.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 761, Issues 1–3, 17 March 2006, Pages 151-157
نویسندگان
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