270-MHz 1H NMR studies of the 11-21 suzukacillin fragment Boc-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-OMe (11-G) and its analogue Boc-Ala-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-OMe (11-A) have been carried out in CDCl3 and (CD3)2SO. The NH chemical shifts and their temperature coefficients have been measured as a function of peptide concentration in both solvents. It is established that re...

Ultralong organic phosphorescence (UOP) materials have received considerable attention in the field of optoelectronics due to their long lifetime, high exciton utilization, large Stokes shift, and so on. Great advancements been achieved through manipulating intermolecular interactions for high-performance UOP recent years. This review will discuss influence various interactions, including ?-? n...

In the ®rst of the title compounds, (2S)-2-(1-oxo-1H-2,3dihydroisoindol-2-yl)pentanoic acid, C13H15NO3, prepared from l-norvaline, a hydrogen-bonded network is formed in the solid state through OÐH O C, CÐH O C and CÐ H arene intermolecular interactions, with shortest O O, C O and C centroid distances of 2.582 (13), 3.231 (11) and 3.466 (3) AÊ , respectively. In the l-valine derivative, (2S)-3m...

      A novel podand based anion receptor bearing benzimidazole motifs as recognition sites was designed and synthesized by reaction of 1,7-bis(2'-methylbenzoate)-1,4,7-trioxaheptane and phenylenediamine. The binding properties of anionic guest with this receptor were studied using UV-Vis and fluorescence spectroscopy. These studies revealed that this receptor exhibit selective recognition towar...

density functional (dft) calculations at m05-2x/aug-cc-pvdz level were used to analyze the interactions between dimethyl sulfoxide (dmso) dimers. the structures obtained have been analyzed with the atoms in molecules (aims) and natural bond orbital (nbo) methodologies. four minima were located on the potential energy surface of the dimers. three types of interactions are observed, ch•••o, ch•••...

The structure of liquid ethylene glycol at room temperature is examined by performing molecular dynamics ~MD! simulation studies for several different liquid phase force fields. We compare the properties obtained and analyze the differences which arise from the use of these models. A thorough study of molecular conformation and intermolecular structure for the different potential models is carr...

this paper is a density functional theory (dft) calculation of intramolecular proton transfer (ipt) in 6-hydroxypicolinic acid (6hpa, 6-hydroxypyridine-2-carboxylic acid) tautomeric forms. the transition state for the enol-to-keto transition is reported in the gas phase and in four different solvents. the planar and non-planar dimer forms of 6hpa keto and enol, respectively, were also studied i...

The title compound, C(13)H(15)N(3)O(7), crystallizes as two independent molecules which differ in their conformation. Intermolecular hydrogen bonding between the amide and carboxylic acid groups as N-H.O=C interactions results in the formation of one-dimensional chains with N.O distances of 2.967 (6) and 3.019 (6) A. Neighbouring chains are linked by C=O.H-O interactions to form a two-dimension...

In the title compound, C(23)H(21)FN(6)O, the dihedral angle between the fluoro-phenyl and pyrimidinone rings is 75.9 (1)°, and the dihedral angle between the methyl-phenyl and pyrazole rings is 40.3 (1)°. In the crystal structure, weak C-H⋯π(arene) and C-N⋯π(arene) inter-actions and intermolecular C-H⋯N and N-H⋯O hydrogen-bonding inter-actions are present.

By moving the alkoxy group on the spacer from position 5 to position 4 to add another protocol for the algorithm for intermolecular and intramolecular hydrogen bonding interactions, highly regioselectivity of noncovalent synthesis of the hydrazide-based cyclic hexamers was achieved: one out of thirteen possible isomeric cyclic hexamers selectively formed and thus precise control of the two hydr...