Hybrid organic-inorganic perovskites represent a special class of metal-organic framework where a molecular cation is encased in an anionic cage. The molecule-cage interaction influences phase stability, phase transformations, and the molecular dynamics. We examine the hydrogen bonding in four AmBX3 formate perovskites: [Am]Zn(HCOO)3, with Am+ = hydrazinium (NH2NH3+), guanidinium (C(NH2)3+), di...

We have synthesized poly(methyl methacrylate- b-4-vinylpyridine) (PMMA- b-P4VP) and poly(styrene- r-vinylphenol) (PS- r-PVPh) copolymers by using anionic and free radical polymerizations, respectively. Well-defined micelles through hydrogen bonding have been prepared by mixing PMMA- b-P4VP diblock copolymer and PS- r-PVPh random copolymer in a single solvent. Block copolymers were mixed with ra...

Environmental remediation requires ion-selective polymers that operate under a wide range of solution conditions. In one example, removal of trivalent and divalent metal ions from waste streams resulting from mining operations before they enter the environment requires treatment at acidic pH. The monoethyl ester phosphate ligands developed in this report operate from acidic solutions. They have...

Classically, the MH2 bonding is viewed as cis-M(H)2 (or dihydride complex), however in complexes such as Mo(CO)3(PPr3)2H2, the dihydrogen (η-H2) ligand was found with it’s H-H bond intact (dihydrogen complex). To compare and contrast the classical and nonclassical views of the MH2 bonding, neutron diffraction analysis of classical and nonclassical complexes were compared. A proton NMR method ba...

By preparation and characterization of a series of pesudorotaxanes based on DB24C8 and paraquat derivatives, it was found that these complexes were stabilized by N⋅⋅⋅O interactions, C-H⋅⋅⋅O hydrogen bonding, and face-to-face π-stacking interactions. Because methyl protons of paraquat are involved in hydrogen bonding to the host, the substitution of any methyl hydrogen on paraquat causes apparen...

The dynamic interplay between the intramolecular hydrogen bonding and intramolecular vibrational redistribution is found to be critical in nonadiabatic reaction dynamics. Herein, it has been demonstrated that the molecular planarity, directed by the intramolecular hydrogen bonding, plays an important role in the nonadiabatic passage of the reactive flux at the conical intersection in the photod...

Dispersions of hydrophilic fumed silica are investigated in a range of polar organic media. The silica forms stable, low-viscosity sols exhibiting shear thickening behavior in a host of liquids, including ethylene glycol and its oligomers and short-chain alcohols, such as n-propanol. In contrast, the silica flocculates into colloidal gels in other liquids, such as glycols with methyl end-caps a...

The title compound, C(33)H(36)N(2)O(8), is the first example of a disubstituted peptidic pentacycloundecane (PCU) diol. The structure displays an array of inter- and intra-molecular hydrogen bonding by both amide and alcohol functional groups. This hydrogen-bonding system connects the mol-ecules into a three-dimensional network.

In the title compound, C(6)H(17)N(3) (2+)·2ClO(4) (-), the piperazine ring adopts a chair conformation with the ethyl-ammonium fragment occupying an equatorial position. In the crystal, the dications and perchlorate anions are linked through N-H⋯O hydrogen bonding and weak C-H⋯O hydrogen bonding into a three-dimensional supra-molecular network.

We investigate the hydrogen bonding percolation threshold of water molecules at the surface of the liquid-vapor interface. We show that the percolation temperature agrees within statistical accuracy with the high-temperature inflection point of the water surface tension. We associate the origin of this surface tension anomaly of water with the sudden breakup of the hydrogen-bonding network in t...