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.