Experimental and theoretical X-ray charge density study of 1-cycloheptylidene-2-(2,4-dinitrophenyl) hydrazine: A hydrazone derivative

The experimental charge density of a hydrazone derivative has been determined from low temperature (100 K) single crystal X-ray diraction data by multipolar Hansen-Coppens formalism renement and gas phase ab initio theoretical calculations. The topology of the electron density within the molecule as well as the intramolecular and intermolecular interactions have been analyzed. The topological properties of electron density determined by the experiment were compared with the theoretical results obtained from Gaussian03 at the B3LYP/6-311++G** level of theory. The covalent nature of the bonds in the molecule has been established by (3, -1) bond critical points associated with relatively large electron densities (1.59 - 3.34 e.A??3) and highly negative Laplacian values (4.73 - 21.30 e.A??5). Numerical and analytical procedures were used to derive the charges integrated with each atomic basin. The highest charge magnitude (-0.66 e) was found in N2 and N4 atoms. The crystal packing is stabilized by the weak intermolecular ..., C-H...O and NO2(N)...(O)NO2 interactions, as conrmed by the presence of critical points in the topological analysis.