Visible, near-infrared (NIR) and IR spectra in the 15600-2500 cm(-1) region were measured for phenol and 2,6-difluorophenol, 2,6-dichlorophenol, and 2,6-dibromophenol in n-hexane, CCl(4), CHCl(3) and CH(2)Cl(2) to study hydrogen bonding effects and solvent dependences of wavenumbers and absorption intensities of the fundamental and the first, second, and third overtones of OH stretching vibrati...

In the centrosymmetric dinuclear title complex, [Cu(2)(C(5)H(6)O(4))(2)(C(20)H(14)N(4))(2)(H(2)O)(2)], the Cu atom displays a distorted square-pyramidal coordination environment with the basal plane occupied by two 5,6-diphenyl-3-(pyridin-2-yl)-1,2,4-triazine N atoms and two O atoms from different glutarate dianions, while a water mol-ecule is located at the apical position. Of the two water H ...

Controlling the number of monomers in a supramolecular polymer has been a great challenge in programmable self-assembly of organic molecules. One approach has been to make use of frustrated growth of the supramolecular assembly by tuning the balance of attractive and repulsive intermolecular forces. We report here on the use of covalent bond formation among monomers, compensating for intermolec...

Notable changes in the molecular conformations of 4-chlorobenzyl alcohol around the C(H2)-Car and O-C(H2) bonds were found to take place at the first-order phase transition point (Tc1 = 236 K). Quite similar phenomena were observed at Tc1 (217 K) of the isomorphic 4-bromo compound. The two kinds of conformational changes are considered to couple and cause the reversal of the direction of the li...

Hydrogen bond (H-bond) covalency has recently been observed in ice and liquid water, while the penetrating molecular orbitals (MOs) in the H-bond region of most typical water dimer system, (H2O)2, have also been discovered. However, obtaining the quantitative contribution of these MOs to the H-bond interaction is still problematic. In this work, we introduced the orbital-resolved electron densi...

The ubiquitous nature of water makes the study of water both practical and relevant. Yet in this advanced technological age, many important, fundamental questions remain unanswered about water and the aqueous interface. As we learn more about water, more questions arise. The fact that water molecules strongly hydrogen bond to one another explains, at the most basic level, the inherently high bo...

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...

Compton spectra of a-oxalic acid dihydrate single-crystal slices and powder samples were measured in a helium atmosphere using 59.537 keV 2 4 1 Am radiation. In the anisotropic case, the scattering vector was oriented parallel to the shortest hydrogen bond, in the direction of the C = O bond, parallel to the C — O bond and perpendicular to the (a, c)-plane. The comparison of theoretical recipro...

Intermolecular features like hydrogen bonding and π-type interactions play pivotal roles in stabilizing molecular structures in ionic liquids with planar rings and hydrogen-bond donors and acceptors. However, the delicate interplay among these interactions is complicated and depends on specific ion types. In this work, ab initio molecular dynamics simulations were performed to reveal competitiv...

Crystal structures of 2-aminotropone (1), N,N'-di(tropon-2-yl)piperazine (2), and 5-(4-ethoxyphenylazo)tropolone (3) have been elucidated by X-crystallographic analysis. 2-Aminotropone (1) contains three crystallographically independent molecules in the crystal lattice. The NH2 groups of 2-aminotropone unit of 1 participate in the N-H...O intermolecular hydrogen bonds. Two tropone units of N,N'...