title: Optical nonlinearity and electric conductivity origin study on sucrose crystal by using IR, Raman, INS, NMR, and EPR spectroscopies.
abstract: The supposed importance of hydrogen bonds toward the origin of second harmonic generation (SHG) and electric conductivity in crystalline sucrose was investigated by IR (4000-10cm(-1)), INS (2000-10cm(-1), at 35K), polarized Raman (3600-50cm(-1)) spectra, and (1)H NMR second moment line records in the temperature range 450-80K. The temperature dependence of NIR (7000-5500cm(-1)) polarized spectra gave information about -CH2 motions complementary to NMR results concerning -CH2OH group rearrangements. The EPR spectra were applied to study the generation of radical ions by exposure to NIR radiation. Density functional theory quantum chemical calculations were performed to reproduce the vibrational spectra in order to complete as far as possible the assignments of bands observed by us and in the literature in sucrose crystals, and to throw more light on the possible reasons of sucrose electric conductivity and optical nonlinearity by the knowledge of theoretical values of dipole moments, polarizabilities, first order hyperpolarizabilities of sucrose molecule and clusters as well as ionization energy and electron affinity. The proton transfer in one specific hydrogen bond parallel to the helical axis b is proposed to be the most important in SHG and conductivity origin.
authors.affiliation: Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
authors.forename: M Magdalena
authors.initials: MM
authors.lastname: Szostak
authors.affiliation: Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland. Electronic address: katarzyna.piela@pwr.edu.pl.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Piela
authors.affiliation: Institute of Physics, Adam Mickiewicz University, Umultowska 85, 61-606, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Hołderna-Natkaniec
authors.affiliation: Institute of Physics, Adam Mickiewicz University, Umultowska 85, 61-606, Poland; Frank Laboratory of Neutron Physics, JINR, Dubna 141980, Russia.
authors.forename: Ireneusz
authors.initials: I
authors.lastname: Natkaniec
authors.affiliation: Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Bidzińska
mesh_terms: D003460:Crystallization; D004553:Electric Conductivity; D006860:Hydrogen Bonding; D011522:Protons; D011789:Quantum Theory; D013057:Spectrum Analysis / Q000379:methods; D013395:Sucrose / Q000737:chemistry*; D013696:Temperature
chemical_list: D011522:Protons; D013395:Sucrose
keywords: Hydrogen bonds; Proton transfer; –CH(2)OH group rearrangements