Bond paths and the bond critical point properties (the electron density (rho) and the Hessian of rho at the bond critical points (bcp's)) have been calculated for the bonded interactions comprising the nickel sulfide minerals millerite, NiS, vaesite, NiS(2), and heazlewoodite, Ni(3)S(2), and Ni metal. The experimental Ni-S bond lengths decrease linearly as the magnitudes of the properties each ...

The DRY motif with the highly conserved R3.50 is a hallmark of family A G protein-coupled receptors (GPCRs). The crystal structure of rhodopsin revealed a salt bridge between R135(3.50) and another conserved residue, E247(6.30), in helix 6. This ionic lock was shown to maintain rhodopsin in its inactive state. Thus far, little information is available on how interruption of this ionic bond affe...

A new high-performance liquid chromatography (HPLC) stationary phase was firstly synthesized based on the ionic liquid 2-ethyl-4-methylimidazole chloride. And the performances of the resulting stationary phase were determined by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and (13)C nuclear magnetic resonance (NMR) spectroscopy. The retention characteristics of the resu...

The nature of amphiphilic self-assembly in alkylammonium protic ionic liquids (PILs) is examined by systematically varying the ionic structure and composition, H-bonding capacity, and nanostructure of both the PIL and micelle-forming cationic surfactant, and contrasted with self-assembly in water. Using small-angle neutron scattering, micelle structure and concentrations are determined for prim...

In the title compound, [MeC5H4NCONHCH2C6H5]I or C14H15N2O+·I-, a cation and an anion form an ionic pair linked by a strong N-H⋯I hydrogen bond. In the crystal, ionic pairs linked by weak C-H⋯I hydrogen bonds form infinite ribbons along the crystallographic a axis. Polymorphism screening varying crystallization solvents (water, acetone 90%-water, ethanol 90%-water, 2-propanol 90%-water, DMF, DMS...

In the title salt, C7H8N3 (+)·BF4 (-), the 1,2,4-triazolo[4,3-a]pyridinium cation is planar [maximum deviation of 0.016 (2) Å for all non-H atoms]. The cation and anion constitute a tight ionic pair with an F⋯N [2.911 (4) Å] inter-molecular attractive inter-action. The ionic pairs form dimers via stacking inter-actions between inversion-related cations, the normal distance between the cation pl...

An energy decomposition analysis (EDA) for single chemical bonds is presented within the framework of Kohn-Sham density functional theory based on spin projection equations that are exact within wave function theory. Chemical bond energies can then be understood in terms of stabilization caused by spin-coupling augmented by dispersion, polarization, and charge transfer in competition with desta...

In the crystal structure of the title compound, C(20)H(44)NO(2) (+)·Br(-), the cation and anion are connected via an O-H⋯Br hydrogen bond, forming an ionic pair. The cation is disordered over two conformations related by a mirror plane, and the anion is situated on a mirror plane so that the asymmetric unit contains half of the ionic pair. The long alkyl chain in the cation adopts an all-trans ...