Hydrogen bonds are weak, generally intermolecular bonds, which hold much of soft matter together as well as the condensed phases of water, network liquids, and many ferroelectric crystals. The small mass of hydrogen means that they are inherently quantum mechanical in nature, and effects such as zero-point motion and tunneling must be considered, though all too often these effects are not consi...

HO3-(O2)n clusters are formed by the sequential addition of the hydroxyl radical and O2 molecules to superfluid helium nanodroplets. IR laser spectroscopy in the fundamental OH stretching region reveals the presence of several bands assigned to species as large as n=4. Detailed ab initio calculations are carried out for multiple isomers of cis- and trans-HO3-O2, corresponding to either hydrogen...

In the title compound, C(12)H(12)O(5), mol-ecules are linked into anti-parallel hydrogen-bonded sheets through inversion dimers generated via two O-H⋯O hydrogen bonds. Using the R(2) (2)(8) motif as a building block, hydrogen-bonded chains of a C(2) (2)(8) superstructure are then generated.

Despite the success of reverse osmosis (RO) for water purification, the molecular-level physicochemical processes of contaminant rejection are not well understood. Here we carry out non-equilibrium molecular dynamics (NEMD) simulations on a model RO membrane to understand the mechanisms of transport and rejection of both ionic and inorganic contaminants in water. While it is commonly presumed t...

Hydrogen bond dynamics are explicated with exceptional detail using multidimensional infrared vibrational echo correlation spectroscopy with full phase information. Probing the hydroxyl stretch of methanol-OD oligomers in CCl4, the dynamics of the evolving hydrogen bonded network are measured with ultrashort (<50 fs) pulses. The data along with detailed model calculations demonstrate that vibra...

The measurement of the dimerization constants of hydrogen-bonded ruthenium complexes (12, 22, 32) linked by a self-complementary pair of 4-pyridylcarboxylic acid ligands in different redox states is reported. Using a combination of FTIR and UV/vis/NIR spectroscopies, the dimerization constants (KD) of the isovalent, neutral states, 12, 22, 32, were found to range from 75 to 130 M-1 (ΔG0 = -2.56...

The stacking interactions between FH--N hydrogen-bonded foldamers 1-3, bis-foldamer 4, and tris-foldamer 5 and C(60) and C(70) are described. Compound 4 contains two folded units, which are connected by an isophthalamide linker, whereas 5 has a C(3)-symmetrical discotic structure, in which three folded units are connected by a benzene-1,3,5-tricarboxamide unit. UV/Vis, fluorescence, and NMR exp...

Some heterobimetallic ion-pair complexes of Ni(II) with Mn(II), Co(II) and , Zn (II) using 1,10-phenanthroline (phen) and 1-tert-butylimidazole-2-thione (tm) ligands were prepared by co-crystallization of Ni(II)-phen cationic complex and Cl / tm containing anionic complex in acetonitrile / methanol solvent. The [Ni(phen)3][MnCl4] (1) contains two molecule of acetonitrile and [Ni(phen)3] 2+ is h...

Vibrational Stark effect spectroscopy was used to measure electrostatic fields in the hydrophobic region of the active site of human aldose reductase (hALR2). A new nitrile-containing inhibitor was designed and synthesized, and the X-ray structure of its complex, along with cofactor NADP(+), with wild-type hALR2 was determined at 1.3 Å resolution. The nitrile is found to be in the proximity of ...

Ionic liquids based on 1-alkyl-3-methylimidazolium cations and the hydrogen sulfate (or bisulfate) anion, HSO(4)(-), are much more viscous than ionic liquids with alkyl sulfates, RSO(4)(-). The structural origin of the high viscosity of HSO(4)(-) ionic liquids is unraveled from detailed comparison of the anion Raman bands in 1-ethyl-3-methylimidazolium hydrogen sulfate and 1-butyl-3-methylimida...