Unraveling the Polymorphism of [(p-cymene)Ru(kappa N-INA)Cl-2] through Dispersion-Corrected DFT and NMR GIPAW Calculations

作者：Presti Davide; Pedone Alfonso^*; Menziani Maria Cristina

来源：Inorganic Chemistry, 2014, 53(15): 7926-7935.

DOI：10.1021/ic5006743

The structural and C-13/H-1 NMR parameters of the four crystal forms (1 alpha, 1 center dot H2O, 1 beta , and 1 gamma) of the solid wheel-and-axle (WAA) metal organic compound [(p-cymene)-Ru(kappa N-INA)Cl-2] have been studied by means of periodic DFT calculations. The quality of the results obtained strongly depends on a correct description of long-range interactions; thus, in the geometry refinement protocol used, the pure DFT functionals need to be coupled with a dispersion-correction term (B3LYP-D2, B3LYP-D*). The solid-state C-13/H-1 NMR delta(iso) parameters and C-13 MAS NMR spectra, calculated by means of the PBEGIPAW method, agree well with the experimental data for the four crystal forms (mean absolute deviations of the C-13 and H-1 delta(iso) data values lie in the ranges 1.3-2.9 and 0.3-1.0 ppm, respectively). In this context, some revisions in the experimental assignment of the C-13/H-1 NMR oiso parameters of the 1 center dot H2O, 1 beta and 1 gamma crystal forms can be suggested. The mismatch in the assignment seems to be due to the rotation of the -COOH moiety, which occurs at the 1 alpha-1 center dot H2O transition and was not considered in the experiments. Finally, the results obtained suggest the presence of two COOH center dot center dot center dot Cl hydrogen bonds of comparable strength established by the two molecules in the asymmetric unit of the 1 gamma polymorph, in partial disagreement with previous findings.

• 出版日期2014-8-4