In the title compound, C(23)H(18)N(2)O(3), the inter-planar angle between the benzoyl units is 80.51 (6)° while the dihedral angles between the hydrazinyl-idene and benzoyl groups are 43.43 (6) and 54.16 (6)°. In the crystal, a strong resonance-assisted intra-molecular N-H⋯O hydrogen bond is observed. The mol-ecules form an inversion dimer via a pair of weak C-H⋯O hydrogen bonds and a π-π inter...

Cooperative behaviors of the hydrogen bonding networks in proteins have been discovered for a long time. The structural origin of this cooperativity, however, is still under debate. Here we report a new investigation combining excess infrared spectroscopy and density functional theory calculation on peptide analogs, represented by N-methylformamide (NMF) and N-methylacetamide (NMA). Interesting...

The title compound, C(17)H(14)Cl(2)N(2)O(3)S(2), and the 4-methyl-anilino analogue reported in the following paper have been used as starting materials to develop benzothia-zine derivatives with anti-malarial activity. The mol-ecule displays an E (trans) configuration about the central double bond. Due to conjugation in the C=C-C N group, the putative single bond shows a significant shortening ...

In the anion of the title salt hydrate, H5N2+·C7H5N2O4-·2H2O, the carboxyl-ate and nitro groups lie out of the plane of the benzene ring to which they are bound [dihedral angles = 18.80 (10) and 8.04 (9)°, respectively], and as these groups are conrotatory, the dihedral angle between them is 26.73 (15)°. An intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is noted. The main feature of th...

The title compound, C(17)H(14)Cl(2)N(2)O(2)S(2), and the 3-methoxy-anilino analogue reported in the preceding paper have been used as starting materials to develop benzothia-zine derivatives with anti-malarial activity. The mol-ecule displays an E (trans) configuration about the central double bond. Due to conjugation in the C=C-C N group, the putative single bond shows a significant shortening...

Complexes and clusters bridge the gap between molecular and macroscopic levels by linking individual gaseous molecules to newly formed nanoparticles but the driving forces and mechanism for the formation of complexes and clusters in the atmosphere are not well understood. We have performed ab initio and density functional quantum chemical calculations to elucidate the role of organic acids in t...

The title mol-ecule, C(20)H(21)NO(6), adopts a keto-amine tautomeric form. An intra-molecular N-H⋯O hydrogen bond, classified as a resonanse-assisted hydrogen bond, influences the mol-ecular conformation; the two benzene rings form a dihedral angle of 24.6 (1)°. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules into chains propagating along [001].

We present a systematic study on the gas-phase hydrogen-bonded complexes formed between formic acid and hydroperoxyl radical, which has been carried out by using B3LYP and CCSD(T) theoretical approaches in connection with the 6-311+G(2df,2p) basis set. For all complexes we have employed the AIM theory by Bader and the NBO partition scheme by Weinhold to analyze the bonding features. We have fou...

the interaction of dppa which is an important component in cellular membrane with molecules of water asmedia, cause some changes in geometry of dppa .in this study we focused our attention on comparing thismolecule with related hydrated complexes employing different basis sets at hartree-fock levels of theory. thetheoretical nmr shielding tensor of some imported atoms were also reported.