Microsolvation of anions by molecules forming CH··X− hydrogen bonds

Motion of Water Molecules and Hydrogen Bonds

The *H N M R spin-lattice relaxation time 7 \ , C1 NQR frequency VQ, and C1 NQR spin-lattice relaxation time 7 \ Q of [ Z n ( H 2 0 ) 6 ] [SnCl6] (zinc hexachlorostannate(IV) hexahydrate) have been measured at temperatures between 77 and 350 K. The NQR spin echo signal with Vq— 15.689 MHz at 77 K showed a positive temperature coefficient attributable to O H C l type H-bonds in the crystal. vQ a...

Theoretical Studies on Hydrogen Bonds in Anions Encapsulated by an Azamacrocyclic Receptor

Hydrogen bonds in two halides encapsulated by an azamacrocyclic receptor were studied in detail by the density functional theory (DFT) approaches at B3LYP/6-311++G(d,p) and M06-2X/6-311++G(d,p) levels. The atoms in molecules (AIM) theory and the electron density difference maps were applied for characterizing the hydrogen bond patterns. The results suggest that the fluoride complex has a unique...

Urea, but not guanidinium, destabilizes proteins by forming hydrogen bonds to the peptide group.

The mechanism by which urea and guanidinium destabilize protein structure is controversial. We tested the possibility that these denaturants form hydrogen bonds with peptide groups by measuring their ability to block acid- and base-catalyzed peptide hydrogen exchange. The peptide hydrogen bonding found appears sufficient to explain the thermodynamic denaturing effect of urea. Results for guanid...

Urea destabilizes RNA by forming stacking interactions and multiple hydrogen bonds with nucleic acid bases.

Urea titration of RNA by urea is an effective approach to investigate the forces stabilizing this biologically important molecule. We used all atom molecular dynamics simulations using two urea force fields and two RNA constructs to elucidate in atomic detail the destabilization mechanism of folded RNA in aqueous urea solutions. Urea denatures RNA by forming multiple hydrogen bonds with the RNA...

Hydrogen Bonds