Repozytorium

Organic-inorganic hybrid crystals, (2,4,6-CH3PyH)3Sb2Cl9 and (2,4,6-CH3PyH)3Bi2Cl9. Crystal structure characterization and tunneling of CH3 groups studied by 1H NMR and neutron spectroscopy.

Autorzy

Przemysław Szklarz

Ryszard Jakubas

Anna Piecha-Bisiorek

Grażyna Bator

Michał Chański

Wojciech Medycki

J. Wuttke

Rok wydania

2018

Czasopismo

Polyhedron

Numer woluminu

139

Strony

249-256

DOI

10.1016/j.poly.2017.10.030

Kolekcja

Naukowa

Język

Angielski

Typ publikacji

Artykuł

Streszczenie

The crystal structures of (2,4,6-CH3PyH)3Sb2Cl9 (TMPCA) and (2,4,6-CH3PyH)3Bi2Cl9(TMPCB) (Py – pyridine) have been determined at 100 K by the single crystal X-ray diffraction method. TMPCA and TMPCB crystallize in the monoclinic C2/c and triclinic P1 polar space group, respectively. In both cases the asymmetric part is comprised of three nonequivalent 2,4,6-trimethylpyridinium cations and a discrete M2Cl93− anion. The Bi2Cl93−moiety forms a face-sharing bi-octahedron, whereas in a case of Sb2Cl93− we deal with two pyramids connected by a corner. The inelastic neutron scattering spectra (INS) were recorded for TMPCA at low temperatures (4–50 K). Two peaks on each side of the central elastic line have been observed at ca. 4.8 and 2.9 μeV, the high energy peak exhibits an excitation energy value equal to ca. 6 meV. For TMPCA and TMPCB the 1H NMR spin–lattice relaxation times, T1, have been measured in the temperature region 15–410 K. The flattening of the T1 (spin–lattice) vs. reciprocal temperature, 1/T, dependence between 30 K and 15 K indicates the incoherent tunneling effect of the methyl group being treated as the quantum rotor. The conclusions drawn from the 1H NMR results as regards to the tunneling of the CH3 groups in the pyridinium cations are consistent with the tunneling peaks observed in the INS spectra.

Słowa kluczowe

Haloantimonates(III), Halobismuthates(III), Inelastic neutron scattering, atom, CH3 tunneling

Adres publiczny

https://doi.org/10.1016/j.poly.2017.10.030

Strona internetowa wydawcy

http://www.elsevier.com

Podobne publikacje
2008

Internal dynamics of (C3N2H5)5Bi2Cl11 studied by IINS,1H NMR and QC methods.

Hołderna-Natkaniec K., Natkaniec I., Jakubas Ryszard, Nowak D., Medycki Wojciech

2006

X-ray and neutron diffraction, IR and INS spectroscopic and DFT theoretical studies on the tetramethylpyrazine-1,2,4,5-tetracyanobenzene complex.

Sawka-Dobrowolska Wanda, Bator Grażyna , Czarnik-Matusewicz Bogusława, Sobczyk Lucjan, Pawlukojć Andrzej, Grech Eugeniusz, Nowicka-Scheibe J., Rundlöf H.

2021

Spectroscopic identification of hydrogen bond vibrations and quasi-isostructural polymorphism in N-salicylideneaniline

Hetmańczyk Łukasz, Goremychkin Eugene A., Waliszewski Janusz, Vener Mikhail V., Lipkowski Paweł, Tolstoy Peter M., Filarowski Aleksander