Mustafa Kumru

Thermal, vibrational and EPR studies of Cu(II) bromide bis(p-methylaniline) and bis(m-methylaniline) complexes.

[CuBr(2)(pMA)(2)] and [CuBr(2)(mMA)(2)] complexes (pMA: p-methylaniline, mMA: m-methylaniline) have been prepared and characterized by elemental analyses, thermogravimetric analyses, magnetic moment measurements, and IR, Raman and EPR spectroscopic studies. Coordination effects on the vibrational spectra of the ligands have been investigated. The room temperature EPR spectra of the complexes and their simulated spectra are also discussed in detail. The vibrational and EPR spectral studies suggest that the coordination sphere around Cu(II) consist of a distorted tetragonal structure.

Experimental and theoretical studies on IR, Raman, and UV–Vis spectra of quinoline-7-carboxaldehyde

Spectroscopic properties of quinoline-7-carboxaldehyde (Q7C) have been studied in detail both experimentally and theoretically. The FT-IR (4000-50 cm(-1)), FT-Raman (4000-50 cm(-1)), dispersive-Raman (3500-50 cm(-1)), and UV-Vis (200-400 nm) spectra of Q7C were recorded at room temperature (25 °C). Geometry parameters, potential energy surface about CCH(O) bond, harmonic vibrational frequencies, IR and Raman intensities, UV-Vis spectrum, and thermodynamic characteristics (at 298.15K) of Q7C were computed at Hartree-Fock (HF) and density functional B3LYP levels employing the 6-311++G(d,p) basis set. Frontier molecular orbitals, molecular electrostatic potential, and Mulliken charge analyses of Q7C have also been performed. Q7C has two stable conformers that are energetically very close to each other with slight preference to the conformer that has oxygen atom of the aldehyde away from the nitrogen atom of the quinoline.

Combined experimental and theoretical studies on the vibrational spectra of 2-quinolinecarboxaldehyde

Combined experimental and theoretical studies have been performed on the structure and vibrational spectra (IR and Raman spectra including far region) of 2-quinolinecarboxaldehyde. Hartree-Fock (HF) and density functional B3LYP calculations have been employed with the 6-311++G(d,p) basis set for investigating the structural and spectroscopic properties of two possible aldehyde rotamers of 2-quinolinecarboxaldehyde. When the O atom of the aldehyde is farther away than the nitrogen atom of the quinoline, 2-quinolinecarboxaldehyde has the lowest possible energy, and thus is in its ground state. The computed vibrational frequencies of this lowest energy rotamer agree also slightly better than those of the higher energy rotamer with the experimental frequencies after the computed frequencies are scaled.

Theoretical and experimental studies on the vibrational spectra of 3-quinolinecarboxaldehyde.

Combined experimental and theoretical studies have been performed on the structure and vibrational spectra (IR and Raman spectra including far region) of 3-quinolinecarboxaldehyde. Hartree-Fock (HF) and density functional theory (DFT) B3LYP calculations have been employed with the 6-311++G(d,p) basis set for investigating the structural and spectroscopic properties of the Rot 1 and Rot 2 conformers of 3-quinolinecarboxaldehyde. The B3LYP frequencies are closer to the experimental frequencies than the HF frequencies, but scaled frequencies of both HF and B3LYP agree almost perfectly with the experimental frequencies. The Rot 1 conformer has been found more stable than the Rot 2 conformer. The scaled vibrational frequencies of Rot 1 conformer also agree slightly better than those of the Rot 2 conformer compared with the experimental frequencies. These indicate that 3-quinolinecarboxaldehyde has Rot 1 conformation in its ground state.

Vibrational spectra of quinoline-4-carbaldehyde: Combined experimental and theoretical studies

The FT-IR (4000-50 cm(-1)), FT-Raman (4000-50 cm(-1)) and Dispersive-Raman (3500-50 cm(-1)) spectra of solid sample of quinoline-4-carbaldehyde (Q4C) have been recorded. The molecule structure, vibrational frequencies, IR intensities, Raman intensities and thermodynamic properties of the two possible aldehyde rotamers of Q4C have been obtained with the Hartree-Fock (HF) and density functional B3LYP calculations employing the 6-311++G(d,p) basis set. Q4C has two stable conformers, in one of which the O atom of the aldehyde is oriented to form a H-bond with one of the hydrogens of quinoline, while in the other there is no such a H bond. The conformer with an extra H-bond is more stable and, thus it is the ground state. The computed vibrational frequencies of the lowest energy conformer agree also slightly better than those of the higher energy rotamer with the experimental frequencies after the computed frequencies are scaled. The temperature dependence of the standard heat capacities (C), standard entropies (S) and standard enthalpy (H) changes of Q4C has been discussed.

Determination of structural and vibrational properties of 6-quinolinecarboxaldehyde using FT-IR, FT-Raman and dispersive-Raman experimental techniques and theoretical HF and DFT (B3LYP) methods.

The FT-IR (4000-50 cm(-1)), FT-Raman (4000-50 cm(-1)) and Dispersive-Raman (3500-50 cm(-1)) spectra of solid sample of 6-quinolinecarboxaldehyde (6QC) have been recorded. The structure, vibrational frequencies, IR intensities, Raman activities and thermodynamic properties of the two possible aldehyde rotamers of 6QC have been calculated at the Hartree-Fock (HF) and density functional B3LYP levels employing 6-311++G(d,p) basis set. The complete assignments were performed on the basis of the potential energy distribution (PED) of the all vibrational modes. Since HF and B3LYP mode definitions of this molecule are quite similar to each other, we only give in Table 3 PED of Rot1 calculated at B3LYP level for the sake of simplicity. Potential energy surface has been scanned over the C3-C2-C1O16 torsion angle. When the O atom of the aldehyde is farther away than the nitrogen atom of the quinoline, 6QC has the lowest possible energy, and thus is in its ground state. The scaled theoretical frequencies of the lowest energy rotamer agree also slightly better than those of the higher energy rotamer with the experimental frequencies. The thermodynamic characteristics of the ground state of 6QC have been theoretically investigated at 298.15 K temperature.

DFT calculations and experimental FT-IR, dispersive-Raman and EPR spectral studies of Copper (II) chloride complex with 3-amino-1-methylbenzene

In this study, we present the synthesis and the characterization of Copper (II) chloride complex with 3-amino-1-methylbenzene (3A1MB). This complex was characterized by vibrational and EPR spectroscopic techniques and elemental analysis. The molecular structure and spectrometry of this complex: Cu(3A1MB)2Cl2 and its ligand: 3A1MB have been investigated theoretically by performing DFT/B3LYP calculations. Cu(3A1MB)2Cl2 has been optimized as two conformers and the more stable conformer is determined. The optimized geometries and calculated vibrational frequencies have been evaluated via comparison with experimental values, and the normal modes were assigned on the basis of the percent potential energy distribution (PED). A good agreement between calculated and experimental data is observed.

Electron-conformational study for the structure-hallucinogenic activity relationships of phenylalkylamines

The structure-hallucinogenic activity relationships of a series of phenylethylamine and phenylisopropylamine derivatives have been investigated in the frameworks of electron-conformational method. The calculated geometry and electronic structure parameters accompanying to each atom and bond of each molecule in view were arranged as a matrix called electron-conformational matrix of contiguity (ECMC). The features that are responsible for strong and weak activity demonstrations have been found as submatrices of ECMCs belonging to some template compounds. Two electron-conformational features present in nonhallucinogenic compounds have been revealed. A quantitative model has been improved for predicting hallucinogenic activity numerically. A test series was used to verify the results obtained.

Structural characterization and vibrational studies of human urinary stones from Istanbul, Turkey.

Seven human urinary stones were collected from urinary bladders of patients hailing from Istanbul, Turkey. Their XRD, EDX, FT-IR and FT-Raman spectra as well as SEM images have been recorded to determine their chemical compositions, morphologies, crystal structures, and crystallite sizes. XRD and vibrational (FT-IR and FT-Raman) analyses indicate that six out of the seven stones have identical contents. The ratios of organic and inorganic contents of the stones have been determined by their thermogravimetric analyses. The stones have been found to contain calcium oxalate monohydrate and apatite as the major components.

COMBINED EXPERIMENTAL AND THEORETICAL STUDIES ON THE VIBRATIONAL AND ELECTRONIC SPECTRA OF 5-QUINOLINECARBOXALDEHYDE

Experimental and theoretical investigations have been performed on the structure, vibrational and electronic spectra of 5-quinolinecarboxaldehyde (5QC). The 4000-50 cm−1region FT-IR and FT-Raman and the 190-1100 nm region UV–Vis spectra of 5QC were recorded at the room temperature. Structural and spectroscopic properties of the cis and trans conformers of 5QC were calculated by Hartree-Fock (HF) and B3LYP density functional methods using the 6-311++G(d,p) basis set. Although calculated B3LYP frequencies are found to be closer to the experimental frequencies than the HF calculation results, scaled frequencies of both HF and B3LYP levels are in good agreement with the experimental spectra. The time-dependent density functional theory (TDDFT) is also used to find excitation energies, absorption wavelength, oscillator strengths and HOMO and LUMO energies of the title molecule.