Deuterium isotope effects on ¹³C-NMR chemical shifts are investigated in a series of 10-hydroxybenzo[h]quinolines (HBQ's) The OH proton is deuteriated. The isotope effects on ¹³C chemical shifts in these hydrogen bonded systems are rather unusual. The formal four-bond effects are found to be negative, indicating transmission via the hydrogen bond. In addition unusual long-range effects are seen...

Understanding the origins and the fundamental nature of the chemical bond has been a central focus of chemists for decades. A chemical bond that has received considerable attention due to its importance in biological phenomena and in the relations between gas and condensed phases is the hydrogen bond, typically a relatively weak interaction involving an electronegative donor X, a hydrogen, and ...

A system capable of performing both DNA-templated chemical reactions and detection of bond formations is reported. Photocleavable DNA templates direct reactions. Products from bond-forming events re-ligate original templates, amplifiable by PCR, therefore distinguishing bond formation from background. This system provides a novel approach for discovering potential new chemical reactions.

The chemical bond overlap properties were obtained for alkali halides NaY (Y = F, Cl, Br), alkaline-earth chalcogenides MX (M = Ca, Mg and X = O, S, Se) and alkali and alkali-earth metals (Li, Na, and Mg) in diatomic and solid-state systems using an embedding approach based on the frozen density functional theory to simulate the crystalline effects. The computational protocol established provid...

he aromatic behavior of the azo-linked cyclopentadienide derivatives have been revealed in various natural compounds. In Tthis research, density functional theory (DFT) calculations at the B3LYP level are used to optimize the geometry of the compounds. In addition, we were interested in the evaluation of the aromaticity of the selected compounds using nucleus independent chemical shifts NIC...

19 HIgh-resolutIOn I5N NMR spectra of a vanety ofsohd ohgopeptIdes (X-Gly-Gly) contammg glycme resIdues have been measured, of whIch the crystal structures had already been determmed by X-ray dIffractIOn The expenmental '5N chemIcal shIfts of the glycme reSIdues were plotted agamst the N"'O hydrogen bond length and the N-H bond length m the :-C=O··· H-N; type hydrogen bond form, respectively It...

Chemical bonding is the stabilization of a molecular system by charge- and spin-reorganization processes in chemical reactions. These processes are said to be local, because the number of atoms involved is very small. With multi-configurational self-consistent field (MCSCF) wave functions, these processes can be calculated, but the local information is hidden by the delocalized molecular orbita...