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1

Cavity Ring Down Measurement of the (1, 0) B ^{2}Σ_{u}^{+} - X ^{2}Σ_{g}^{+} Absorption Band of the N_{2}^{+} Cation

100%

Fulara J., Łapiński L., Morawski O., Prochorow J.

Acta Physica Polonica A

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1998

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vol. 93

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issue 5-6

723-730

EN

The ultraviolet (1, 0) B ^{2}Σ_{u}^{+} - X ^{2}Σ_{g}^{+} transition in the N_{2}^{+} cation was measured with the absorption cavity ring down technique. The N_{2}^{+} cations were produced in a stationary DC discharge in nitrogen under reduced ( ≈ 0.5 Tr) pressure. The weak band due to the (4, 0) A ^{2}Π_{u} - X ^{2}Σ_{g}^{+} transition in the red part of the spectrum was also recorded. Several of the observed transitions correspond to absorptions from the vibrationally excited (ν'=1) states of N_{2}^{+} and to absorptions from the neutral N_{2} molecules in the triplet state.

2

Laser Raman and Infrared Absorption Spectra of 2,4-dichloronitrobenzene

80%

Rastogi V., Jain D., Mital H., Sharma S.

Acta Physica Polonica A

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1991

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vol. 79

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issue 6

765-774

EN

The laser Raman and infrared absorption spectra of 2,4-dichloronitrobenzene have been recorded in pure liquid state. The vibrational spectra have been analysed assuming C_{s}, point group for the molecule. The assignments for fundamental vibrations, combination and overtone frequencies and internal modes of vibrations of NO_{2} group have been proposed.

3

Structure and Spectroscopic Behaviour of Adduct of 2,6-dichloro-4-nitrophenol with 2,4,6-trimethylpyridine

80%

Majerz I., Sawka-Dobrowolska W., Sobczyk L.

Acta Physica Polonica A

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1995

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vol. 88

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issue 2

349-357

EN

2,4,6-trimethylpyridinium 2,6-dichloro-4-nitrophenolate crystallizes in monoclinic system, space group Ρ2_{1}/c, a = 7.534(2), b = 26.673(5), c = 8.452(2) Å, β = 116.16(3)°, Z = 4. The planar molecules are arranged in the lattice as antiparallel oriented pairs with the symmetry centre. The O^{-}···Η-Ν^{+} hydrogen bonds are relatively long, 2.686(4) Å. The C-O bond length, 1.250(4) A, indicates an extended charge separation. The IR and UV-VIS spectra in KBr pellets confirm the ion pairs to be present in the solid state.

4

Identification of Structural and Spectral Features of 2-Amino 4-Chlorobenzoic Acid and 4-Amino 2-Chlorobenzoic Acid: A Comparative Experimental and DFT Study

80%

Kaya Kinaytürk N., Oturak H.

Acta Physica Polonica A

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2016

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vol. 130

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issue 1

276-281

EN

The structure and spectroscopic data of the molecules in the ground state were calculated using density functional theory employing B3LYP/6-311++G(d,p) basis set. The dipol moment, linear polarizability and first hyperpolarizability values were also computed using the same basis set. A study on the electronic properties, such as HOMO-LUMO energies, were performed by time-dependent density functional theory approach. A detailed description of spectroscopic behaviour of compounds was given based on the comparison of experimental data and theoretical computations.

5

Spectroscopy of 2-aminopurine: An MCSCF Study

80%

Rachofsky E., Ross J., Krauss M., Osman R.

Acta Physica Polonica A

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1998

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vol. 94

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issue 5-6

735-748

EN

2-aminopurine is a highly fluorescent isomer of adenine that can be incorporated into DNA as a probe of structure, dynamics, and protein-DNA interactions. Interpretation of the fluorescence of 2-aminopurine in DNA requires a model of the electronic structure of this fluorophore in its ground and excited states. To this end, electronic structures and energies of the ground and lowest singlet excited states of 2-amino-9-methylpurine were calculated by the multiconfiguration self-consistent field method supplemented by multiconfiguration perturbation theory. The molecular geometry was optimized in both of these electronic states to permit investigation of both electronic excitation and fluorescence emission. The predicted energies and transition dipoles were in good agreement with experiment. The permanent molecular dipole of 2-amino-9-methylpurine increased upon excitation, suggesting that both the absorption and emission spectra should shift to slightly lower energies in polar solvents. The anomalous spectral shifts observed in water suggest that 2-aminopurine undergoes hydrogen bonding that better stabilizes the ground state than the excited state. From the calculated electrostatic potentials of these two states, the position at which this hydrogen bond forms was predicted. These results form a basis for understanding the excited states and possible intermolecular interactions of 2-aminopurine in DNA.

6

Spectroscopy and Photophysics of Monoazaphenanthrenes I. Absorption and Fluorescence Spectra of Phenanthridine and 7,8-Benzoquinoline

80%

Norek M., Dresner J., Prochorow J.

Acta Physica Polonica A

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2003

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vol. 104

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issue 5

425-439

EN

The absorption and fluorescence spectra of phenaentridine and 7,8-benzoquinoline have been measured in liquid solutions of non-polar, aprotic hydrocarbon solvents (n-hexane and cyclohexane) and in strongly polar (and hydrogen-bonding) methanol. The analysis of the Stokes' shift between absorption and fluorescence spectra has shown that for both molecules the observed solvent effects on their absorption and fluorescence spectra can be described in terms of universal solvent-solute interactions (no evidence of specific solvent-solute interactions, of the type of hydrogen bond formation with participation of lone-pair electrons of nitrogen atom, has been found). On the other hand, the measured decay time profiles of fluorescence are visibly longer in methanol solution than in non-polar, aprotic solvents and these observations are consistent with the observed increase in fluorescence intensity of both molecules in strongly polar methanol solution. The radiative lifetimes of the first excited singlet state do not differ noticeably for both molecules, but it has turned out that in the case of phenanthridine the nonradiative processes are getting less effective in methanol solution than in the case of 7,8-benzoquinoline, which can presumably be related to the role of different position of the substitution of nitrogen atom in these two molecules.

7

Polarisation Labelling Spectroscopy of Highly Excited (Rydberg) ^1Π_u States in Potassium Dimer

80%

Jastrzebski W., Kowalczyk P.

Acta Physica Polonica A

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2005

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vol. 108

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issue 3

457-465

EN

Two previously unknown electronic states of K_2, both of ^1Π_u symmetry, have been observed by polarisation labelling spectroscopy technique in the energy region of 31500-33100 cm^{-1} above the bottom of the molecular ground state potential well. Major molecular constants have been determined for these states and the potential curves have been constructed using the Rydberg-Klein-Rees method. The correlation of the observed states with atomic limits is discussed.

8

Structural and Spectroscopic Characterization of 1-(5-Bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one: An Analysis of Electronic and NLO Properties

70%

Tamer Ö., Avcı D., Atalay Y.

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vol. 126

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issue 3

679-688

EN

The molecular structure of 1-(5-bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one with C_{13}H_8BrNO_3S empirical formula was simulated using B3LYP and CAM-B3LYP levels of density functional theory. After BTNP was optimized on the ground state, its characterization was enhanced via IR, NMR and UV-vis spectroscopies. Conformational analysis was performed based on B3LYP level so as to find the stable conformers of BTNP. Electronic transitions were calculated, and the important contributions from the molecular orbitals to the electronic transitions were investigated. HOMO and LUMO energies were calculated, and obtained energies displayed that charge transfer occurs in BTNP. It was displayed that BTNP is an efficient NLO material due to the coplanar of phenyl-nitro group and carbonyl group. NBO analysis also proved that charge transfer, conjugative interactions and intramolecular hydrogen bonding interactions occur through BTNP.

9

Experimental and Quantum Chemical Calculations of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile

61%

Oturak H., Kaya Kinaytürk N., Topuz M., Kutlu N., Kaynaker E., Talıp P., Sert Y.

Acta Physica Polonica A

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2017

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vol. 132

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issue 3

1192-1199

EN

Vibrational frequencies of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile were calculated using density functional (DFT/B3YLP) method with 6-311++G(d,p) basis set by Gaussian 09. The assignments of the vibrational frequencies have been done by potential energy distribution analysis, using VEDA 4 software. The density functional theory and time dependent density functional theory methods have been used to study the electronic properties of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital method. All computed spectroscopic properties were compared with experimental ones. The simulated spectra of the molecule show excellent agreement with the experimental spectra.

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Cavity Ring Down Measurement of the (1, 0) B ^{2}Σ_{u}^{+} - X ^{2}Σ_{g}^{+} Absorption Band of the N_{2}^{+} Cation

Laser Raman and Infrared Absorption Spectra of 2,4-dichloronitrobenzene

Structure and Spectroscopic Behaviour of Adduct of 2,6-dichloro-4-nitrophenol with 2,4,6-trimethylpyridine

Identification of Structural and Spectral Features of 2-Amino 4-Chlorobenzoic Acid and 4-Amino 2-Chlorobenzoic Acid: A Comparative Experimental and DFT Study

Spectroscopy of 2-aminopurine: An MCSCF Study

Spectroscopy and Photophysics of Monoazaphenanthrenes I. Absorption and Fluorescence Spectra of Phenanthridine and 7,8-Benzoquinoline

Polarisation Labelling Spectroscopy of Highly Excited (Rydberg) ^1Π_u States in Potassium Dimer

Structural and Spectroscopic Characterization of 1-(5-Bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one: An Analysis of Electronic and NLO Properties

Experimental and Quantum Chemical Calculations of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile