Oscillatory polarons generation by near IR and spin induced chirality studies in optically nonlinear 1,3-dinitrobenzene crystal

doi:10.1016/j.optmat.2012.12.010

Oscillatory polarons generation by near IR and spin ...

Bibliographic description

punktacja MNiSW [2013 A]: 35

title:	Oscillatory polarons generation by near IR and spin induced chirality studies in optically nonlinear 1,3-dinitrobenzene crystal
author:	Szostak Magdalena M., Chojnacki Henryk, Piela Katarzyna, Bidzińska Ewa , Dyrek Krystyna
Journal title:	Optical Materials
volume:	35
issue:	5
date of publication:	2013
pages:	1004-1012
ISSN:	0925-3467
eISSN:	1873-1252
DOI:	10.1016/j.optmat.2012.12.010
notes:	Krystyna Dyrek - Wydzial Chemii UJ
language:	English
Journal language:	English
abstract in english:	Paramagnetic species in the 1,3-dinitrobenzene ( m DNB) crystal have been detected by EPR spectroscopy and the intervalence (conductivity) band at 10,400 cm 1 along the polar c axis, and the band at 7400 cm 1 along the a axis, of unknown origin, have been found in its polarized NIR spectra. The radical anions occurrence and supposed helical superstructure formed due to nitro groups interactions have induced the chirality of solid m DNB confirmed by the CD spectra record and ab initio quantum chemical calculations. The several times irradiation of m DNB crystal samples by the 980 nm and 1550 nm laser diode beams have revealed temporal fluctuations of radical anions concentration (EPR) and of NIR band intensities, as well as CD spectra changes. An autocatalytic reduction by NIR is supposed to be responsible for the observed fluctuations. The proposed conclusions were reinforced by the density functional (DFT) calculations of electronic properties (ionization energy, electron affinity, dipole moment, hyperpolariz- ability) of m DNB neutral and charged clusters formed along the hypothetical helix and by the calculation of crystal band structure. The UV–Vis–NIR absorption and CD spectra of m DNB molecular systems were computed at non-empirical all-electron level by DFT method within the correlation consistent 6- 311G (2d,2p) basis set and hybrid B3LYP density functional.
affiliation:	Wydział Chemii : Zakład Chemii Nieorganicznej
type:	journal article
subtype:	academic paper