Diammonium potassium citrate, (NH4)2KC6H5O7

The crystal structure of di­ammonium potassium citrate, 2NH(4) (+)·K(+)·C(6)H(5)O(7) (3−), has been solved and refined using laboratory X-ray powder diffraction data and optimized using density functional theory. The KO(7) coordination polyhedra are isolated. The ammonium cations and the hydro­phobic methyl­ene sides of the citrate anions occupy the spaces between the coordination polyhedra. Each hydrogen atom of the ammonium ions acts as a donor in a charge-assisted N—H⋯O, N—H⋯(O,O) or N—H⋯(O,O,O) hydrogen bond. There is an intra­molecular O—H⋯O hydrogen bond in the citrate anion between the hydroxide group and one of the terminal carboxyl­ate groups. [Image: see text

Crystal Structures of New Citrate Salts

The purpose of this project is to determine the crystal structures of Group I ammonium citrates using X-ray powder diffraction data and computational chemistry techniques. We have analyzed new compounds: diammonium potassium citrate, diammonium sodium citrate, disodium hydrogen citrate monohydrate, and dipotassium hydrogen citrate monohydrate. Knowledge of the crystal structure helps rationalize chemical and biological properties, and also facilitates qualitative and quantitative phase analysis. We have solved and refined the crystal structures using Monte Carlo simulated annealing, Rietveld refinement, and density functional theory (DFT) geometry optimizations. We will present the structures and discuss their intermolecular bonding in the solid state, particularly hydrogen bonding

Crystal Structures of Large Volume Commercial Pharmaceuticals

The purpose of this project is to determine the crystal structures of commercial pharmaceuticals using synchrotron X-ray powder diffraction data and computational chemistry techniques. Currently, we are analyzing four molecules with unpublished structures used to treat common maladies: tamsulosin hydrochloride (benign prostatic hyperplasia), pantoprazole sodium (gastric reflux disease), ipratropium bromide (COPD and asthma), and doxepin (chronic depression). Knowledge of the crystal structure helps rationalize chemical and biological properties, and also facilitates qualitative and quantitative phase analysis. We have solved and refined the crystal structures using Monte Carlo simulated annealing, Rietveld refinement, and density functional theory (DFT) geometry optimizations. We will present the structures and discuss their intermolecular bonding in the solid state, particularly hydrogen bonding. By understanding the structure of these compounds and how they interact with themselves, we can predict how they might interact with human biological pathways, knowledge which is essential in the creation of new pharmaceuticals