Intermolecular Hydrogen Bonding of Steroid Compounds: PFG NMR Diffusion Study, Cold-Spray Ionization (CSI)-MS and X-Ray Analysis

Abstract

An extensive analysis of hydrogen bonding of steroid compounds in diluted solution is preformed by pulsed field gradient (PFG) NMR and cold-spray ionization (CSI)-MS, in the solid state by X-ray crystallographic analysis. The formation of hydrogen bond interaction are quantified and discussed. Although X-ray analysis in the crystalline state and CSI-MS measurement in solution suggested that the observed diffusion coefficient D_obs of the steroid compounds may vary in accordance with the number of hydrogen bonds, the actual observed D_obs value determined from the diffusion studies diminished constantly without correlation on the decreasing numbers of hydrogen bonds. Comparison of two different calibration profiles of calculated molecular volume (V_cal) vs. D_obs, which are obtained from compounds possessing no hydrogen bonding and the steroid compounds, formation of a chain structure (cluster) based on intermolecular hydrogen bonding of the steroid compounds is unambiguously confirmed.