Photoluminescence and quantum chemical studies of electronic and optical properties of m-nitroaniline and m-nitrophenol crystals

Szóstak, Mariusz; Kozankiewicz, Β.; Wójcik, Grażyna; Lipiński, Józef

doi:10.1039/a804982c

Cited by 25 publications

(1 citation statement)

References 29 publications

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“…There has been an ongoing research in our laboratory on molecular crystals exhibiting nonlinear optical properties. The group of crystals under study contained substituted benzenes with nitro groups, such as 3‐nitroaniline,1–11 3‐nitrophenol,12–14 and 2‐methyl‐4‐nitroaniline 15, 16. The crystal of 1,3‐dinitrobenzene (Fig.…”

Section: Introductionmentioning

confidence: 99%

The revision of intermolecular interactions in 1,3‐dinitrobenzene crystal—the role of nitro groups in optical nonlinearity

Trzebiatowska

Piela

Misiaszek

et al. 2010

J Raman Spectroscopy

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Polarized Fourier transform-infrared (FT-IR) reflectance spectra and powder Raman spectra have been measured for 1,3-dinitrobenzene crystal in order to revise the assignments of bands by means of the oriented gas model reinforced with quantum chemical [density functional theory (DFT)] calculations. Longitudinal optical/transverse optical (LO-TO) splitting of some bands is observed indicating medium strong, long-range, dipole-dipole interactions. The analysis of overtones in the polarized FT-NIR spectra has allowed us to estimate the anharmonicity of vibrations in the crystal. The molecular motions of the nitro groups are analyzed on the basis of temperature-dependent polycrystalline IR spectra. Based on the values of the energy difference ( ν el ) between the forbidden A 1g →B 2u transition in the benzene molecule in the gas phase and the first electronic transition in 1,3-dinitrobenzene, it has been concluded that the intermolecular interactions are medium strong. The nitro group interactions are proposed to play the main role in the optical nonlinearity.

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Section: Introductionmentioning

confidence: 99%

The revision of intermolecular interactions in 1,3‐dinitrobenzene crystal—the role of nitro groups in optical nonlinearity

Trzebiatowska

Piela

Misiaszek

et al. 2010

J Raman Spectroscopy

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Nitroanilines as Quenchers of Pyrene Fluorescence

et al. 2012

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The quenching of pyrene and 1-methylpyrene fluorescence by nitroanilines (NAs), such as 2-, 3-, and 4-nitroaniline (2-NA, 3-NA, and 4-NA, respectively), 4-methyl-3-nitroaniline (4-M-3-NA), 2-methyl-4-nitroaniline (2-M-4-NA), and 4-methyl-3,5-dinitroaniline (4-M-3,5-DNA), are studied in toluene and 1,4-dioxane. Steady-state fluorescence data show the higher efficiency of the 4-NAs as quenchers and fit with a sphere-of-action model. This suggests a 4-NA tendency of being in close proximity to the fluorophore, which could be connected with their high polarity/hyperpolarizability. In addition, emission and excitation spectra evidence the formation of emissive pyrene-NA ground-state complexes in the case of the 4-NAs and, in a minor degree, in the 2-NA. Moreover, time-resolved fluorescence experiments show that increasing amounts of NA decrease the pyrene fluorescence lifetime to a degree that depends on the NA nature and is larger in the less viscous solvent (toluene). Although the NA absorption and the pyrene (Py) emission overlap, we found no evidence of dipole-dipole energy transfer from the pyrene singlet excited state ((1)Py) to the NAs; this could be due to the low NA concentration used in these experiments. Transient absorption spectra show that the formation of the pyrene triplet excited state ((3)Py) is barely affected by the presence of the NAs in spite of their efficiency in (1)Py quenching, suggesting the involvement of (1)Py-NA exciplexes which--after intersystem crossing--decay efficiently into (3)Py.

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Spectroscopic, structural and theoretical studies of 2‐methyl‐4‐nitroaniline (MNA) crystal. Electronic transitions in IR

Okwieka

Szóstak

Misiaszek

et al. 2008

J Raman Spectroscopy

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Polarized FT-IR, Raman, neutron scattering (IINS), and UV-Vis-NIR spectra of 2-methyl-4-nitroaniline (MNA) crystal plates, powder, and solutions were measured in the 10-50 000 cm −1 range. The FT-IR spectrum of deuterated MNA (DMNA) in KBr pellet, the Raman spectrum of the DMNA powder as well as the EPR spectrum of the MNA powder were also recorded. Complete assignments of bands to normal vibrations have been proposed. Density functional theory (DFT) calculations of wavenumbers and potential energy distribution (PED) have been performed to strengthen the assignments. The analysis of vibrational and electronic spectra has revealed vibronic couplings in MNA molecules in solutions and in crystals. In the polarized FT-IR spectra of the crystal five unusually large bands are observed in MIR and NIR regions. Their origin is discussed in terms of N-H· · ·O, C-H· · ·O, C-H· · ·H-N hydrogen bonds, intermolecular charge transfers, electrostatic interactions, and ion radicals formation in the crystal. The role of a methyl group introduction to 4-nitroaniline is analyzed. The crystal structure of MNA at the room temperature was re-investigated.

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Photoluminescence and quantum chemical studies of electronic and optical properties of m-nitroaniline and m-nitrophenol crystals

Cited by 25 publications

References 29 publications

The revision of intermolecular interactions in 1,3‐dinitrobenzene crystal—the role of nitro groups in optical nonlinearity

The revision of intermolecular interactions in 1,3‐dinitrobenzene crystal—the role of nitro groups in optical nonlinearity

Nitroanilines as Quenchers of Pyrene Fluorescence

Spectroscopic, structural and theoretical studies of 2‐methyl‐4‐nitroaniline (MNA) crystal. Electronic transitions in IR

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