Showing papers by "Ljupčo Pejov published in 2003"
TL;DR: In this paper, potential energy hypersurfaces (PESs) for four fluoroform complexes (with acetonitrile, ethyleneoxide, formaldehyde, and water) were explored at the HF, MP2, and B3LYP/6-311++G(d,p) levels of theory.
Abstract: Potential energy hypersurfaces (PESs) for four fluoroform complexes (with acetonitrile, ethyleneoxide, formaldehyde, and water) were explored at the HF, MP2, and B3LYP/6-311++G(d,p) levels of theory. Anharmonic C–H stretching vibrational frequency shifts are reported for all minima located on the studied PESs. In all cases, the lowest-energy minimum occurs for a C–H⋯O(N) hydrogen-bonded arrangement and is characterized by a significant C–H frequency blueshift (upshift), while additional minima [for “reversed” orientations, in which there is no direct C–H⋯O(N) contact] show only small C–H frequency upshifts. The large blueshifts found for the hydrogen-bonded arrangements are predominantly caused by the electronic exchange interaction, as revealed by Kitaura–Morokuma (KM) analysis, while the purely electrostatic+polarization interaction leads to C–H frequency redshifts, which was proven both by the KM analysis and the charge field perturbational (CFP) approach. The large net blueshifting effect of the excha...
115 citations
TL;DR: In this article, an FT-IR study of pyrrole self-association in CCl4 solutions was carried out, and a T-shaped minimum was located on B3LYP/6-31þþG(d,p) PES of a dimer characterized with a hydrogen bond of an N-H· · ·p type, with centers-of-mass separation of monomeric units of 4.520 A u,H · ·· p distance of 2.475 A u, the interplanar angle between the two
33 citations
TL;DR: In this paper, the global minimum on B3LYP, mPW1PW91 and PBE1PBE/6-31++G(d,p) potential energy surfaces (PESs) of the (phenol)2+ cationic radical dimer corresponds to O−H+⋯O hydrogen-bonded structure, with an additional, although much weaker C−H⋮O hydrogen bond, as revealed by AIM analysis.
23 citations
TL;DR: In this article, the Fourier transform infrared (FTIR) spectra of the dichlorodioxochromium (VI) complex with 2,2′-biquinoline 1 were studied in the 2000-400 cm −1 region, particular attention being paid to the vibrations of the CrO 2 group.
7 citations
TL;DR: In this paper, the Fourier transform IR and Raman spectra of chromate anions isomorphously isolated in potassium, rubidium and cesium sulfate matrices at room and low temperature (∼100 K).
4 citations
Journal Article•
TL;DR: On the nature of blue-shifting hydrogen bonds, this article performed a density functional analysis of several fluroform complexes and showed that blue-shift hydrogen bonds are a function of density.
Abstract: On the nature of blue-shifting hydrogen bonds. Ab initio and density functional studies of several fluroform complexes
2 citations