Wydział Chemii

Grażyna Bator

Lucjan Sobczyk

Wanda Sawka-Dobrowolska

J. Wuttke

Andrzej Pawlukojć

Eugeniusz Grech

J. Nowicka-Scheibe

2013

Chemical Physics

410

55-65

10.1016/j.chemphys.2012.10.012

Naukowa

Angielski

Artykuł

The almost planar molecular complex, formed by 3,4,7,8-tetramethyl-phenantroline (Me₄phen) and picric acid (2,4,6-trinitrophenol, PA), has been investigated by using X-ray diffraction, vibrational spectroscopy, tunnel splitting and theoretical analysis. In the crystal of Me₄phen·PA two short bifurcated hydrogen bonds N⁺–H···O⁻ [2.6238(14) Å] and N⁺–H···N [2.6898(15) Å] are created. Infra-red spectra show the hydrogen bonds are short. The neutron backscattering spectrum of Me₄phen⋅PA at 3 K shows two tunneling peaks at ca. 1 and 3 μeV. The number of the peaks is consistent with X-ray diffraction studies, which disclosed the inequivalence of methyl groups in the crystal structure. The comparison of the tunnel splitting for neat Me₄phen and for its complex with picric acid indicates that in the latter case the methyl groups are more strongly engaged in the intermolecular interactions, particularly with nitro group oxygen atoms of picric acid, leading to an increase of the CH₃ rotational barrier height.

Molecular complexes, Ion, lanthanides, symmetry, 8-tetramethyl-1, 10-phenantroline, molecule, 6-trinitrophenol, X-ray diffraction, crystal structure, Infrared spectroscopy, Neutron backscattering, DFT

http://dx.doi.org/10.1016/j.chemphys.2012.10.012

http://www.elsevier.com