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od 2020-09-20

Dr Wiesław Suchański  | 1994-10 <> 2000-03

Starszy wykładowca

  6602997986  
Publikacje           Doktorzy      Magistrowie           Seminaria


22.

Suchański W., Minkin P., Jurga S.

Molecular dynamics in supercooled m-fluoroaniline Molecular dynamics of meta-fluoroaniline (mFA) - the system which makes a simple glass forming liquid - was examined by C-13 NMR and dielectric relaxation measurements. Spin-lattice relaxation times TI, nuclear Overhauser (NOE) factors of chemically non-equivalent carbons and dielectric retaxation in mFA were measured as a function of temperature. The analysis showed that the correlation function describing molecular dynamics in mFA could he well described in terms of an asymmetric distribution of correlation rimes predicted by the Davidson-Cole model. The overall correlation times of mFA. derived from the simultaneous fitting of our TI, NOE, and dielectric data (as well as of the dielectric data obtained by Roessler's group) to the Davidson-Cole model, follow the non-Arrhenius temperature type of the behaviour in accordance with the Vogel-Fulcher equation.
(C) 2001 Elsevier Science B.V. All rights reserved.

Journal of Molecular Structure, 559(1-3), 179-185 (2001)

DOI: 10.1016/S0022-2860(00)00695-5   (Pobrane:  2020-10-21)

21.

Suchański W., Jurga S., Pakuła T., Paluch M., Zioło J.

Molecular dynamics in supercooled di-isobutyl phthalate close to the glass transition The dynamics of the alpha -relaxation in a glass-forming low-molecular-weight system, diisobutyl phthalate (DIBP), has been studied by means of dielectric, nuclear magnetic and mechanical spectroscopies. By using these techniques we have covered a wide timescale ranging from 10(-11) to 10(2) s. Vogel-Fulcher con elation time behaviour and the Davidson-Cole distribution function make possible a simultaneous fitting of T-1, the nuclear Overhauser enhancement (NOE) factor and dielectric data over the temperature range (Tg - 4 K) < T < (Tg + 155 K). These results together with the viscosity data have been analysed in terms of the Debye diffusion.

Journal of Physics - Condensed Matter, 12(46), 9551-9562 (2000)

DOI: 10.1088/0953-8984/12/46/303

20.

Suchański W., Jurga S.

Local and global molecular dynamics in supercooled di-pentyl phthalate

Molecular Physics Reports, 29, 130-134 (2000)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)

19.

Suchański W., Szcześniak E., Jurga S.

Nuclear magnetic relaxation study of carbon-13 in di-pentyl phthalate Spin-lattice relaxation times T-1 and nuclear Overhauser enhancement factors of chemically non-equivalent carbons in di-pentyl phthalate (DPP), a simple glass-forming liquid, are measured as functions of temperature. The analysis shows that the correlation function describing the overall molecular dynamics in DPP can be well described in terms of an asymmetric distribution of correlation times predicted by the Davidson-Cole model. The distribution parameters beta of the successive chain carbons are derived and analysed in terms of internal motions occurring in DPP.

Journal of Physics-Condensed Matter, 11(19), 3907-3914 (1999)

DOI: 10.1088/0953-8984/11/19/310

18.

Suchański W., Szcześniak E., Jurga S.

13C NMR relaxation in supercooled di-methyl phthalate Spin-lattice relaxation times (T-1) and nuclear Overhauser enhancement factors (NOE) for the individual ring carbons in di-methyl phthalate (DMF) were measured over a wide range of temperatures. The results show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be well described by a Davidson-Cole distribution. The viscosity dependence of the reorientational correlation time tau derived is analysed to investigate the adequacy of the modified Debye equation to description of the microscopic behaviour of supercooled systems.

Journal of Physics-Condensed Matter, 10(28), 6243-6249 (1998)

DOI: 10.1088/0953-8984/10/28/006

17.

Szcześniak E., Głowinkowski S., Suchański W., Jurga S.

Dynamics of glass-forming di-n-butyl phthalate as studied by NMR Spin-lattice relaxation times T-1 and nuclear Overhauser effect (NOE) enhancement factors for the individual ring carbons in di-n-butyl phthalate (DBF) show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be described by a Davidson-Cole distribution. Measurements of proton spin-lattice relaxation times T-1 and T-1p, as well as H-1 NMR spectra at temperatures below the glass transition temperature, Tg, reveal that the same distribution holds also for description of local dynamics in glassy DBF. The activation parameters of the motions detected are derived.
(C) 1997 Elsevier Science B.V.

Solid State Nuclear Magnetic Resonance, 8(2), 73-79 (1997)

DOI: 10.1016/S0926-2040(96)01292-1   (Pobrane:  2020-10-21)

16.

Paluch M., Zioło J., Habdas P., Rzoska S.J., Suchański W.

Dielectric relaxation of glass-forming dibutyl phthalate under high pressure Measurements of complex electric permittivity in dibutyl phthalate for a wide range of pressures (up to 260 MPa) for isotherm T/K = 243 were performed. Relaxation times calculated from these measurements obey the generalised Vogel - Fulcher - Tammann law. It has been noticed that the full widths at half maximum of absorption curves increase with increasing pressure. Half-widths for isothermal and for isobaric measurements for the same relaxation times were compared. Dixon scaling of absorption curves for isothermal and isobaric data is also presented.

High Temperatures - High Pressures, 29(2), 155-157 (1997)

DOI: 10.1068/htec386   (Pobrane:  2021-12-23)

15.

Głowinkowski S., Jurga S., Suchański W., Szcześniak E.

Local and global dynamics in the glass-forming di-isobutyl phthalate as studied by 1H NMR Spin-lattice relaxation times T-1 and T1ρ as well as H-1 NMR spectra have been employed to study the dynamics of the glass-forming di-isobutyl phthalate in the temperature range extending from 100 K, through the glass transition temperature Tg, up to 340 K. Below Tg NMR relaxation is governed by local dynamics and may be attributed to rotation of methyl groups at low temperatures and to motion of isobutyl groups in the intermediate temperature interval. Above Tg the main relaxation mechanism is provided by overall molecular motion. The observed relaxation behavior is explained by motional models assuming asymmetrical distributions of correlation times. The motional parameters obtained from Davidson-Cole distribution, which yields the best fit of the data at all temperatures are given.
(C) 1997 Elsevier Science B.V.

Solid State Nuclear Magnetic Resonance, 7(4), 313-317 (1997)

DOI: 10.1016/S0926-2040(96)01266-0   (Pobrane:  2020-10-23)

14.

Głowinkowski S., Jurga S., Suchański W., Szcześniak E.

Dynamics of t-butyl groups in a series of related molecular solids The dynamics of the lowest temperature phase of a series of closely related t-butyl compounds (CH3)CXH, whre X=O, S, Se, has been studied using 1H NMR. The obtained data allowed the separation of the dynamics arising from methyl group and from t-butyl group. The activation parameters of the motions are given. It is shown that the t-butyl group is more mobile than constituent methyl groups and that coupling between these two motions is associated with the observed order-disorder phase transition.

Molecular Physics Reports, 14, 83-87 (1996)

WWW: http://www.ifmpan.poznan.pl/mol/
ISSN: 1505-1250   (Pobrane:  2021-01-07)

13.

Głowinkowski S., Suchański W., Szcześniak E.

Molecular dynamics in glassy di-isobutyl phalate as studied by 1H NMR This volume contains the proceedings of the International Workshop on "Non-Equilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials", held in Pisa in the early fall of 1995 as a joint initiative of the Unviersity of Pisa and of the Scuola Normale Superiore

World Scientific Series in Contemporary Chemical Physics - Non Equilibrium Phenomena in Supercooled Fluids, Glasses and Amorphous Materials, 12, Eds. Giordana M. et al., World Scientific, Singapore (1996)

WWW: http://www.worldcat.org/title/non-equilibrium-phenomena-in-supercooled-fluids-glasses-and-amorphous-materials-proceedings-of-the-workshop-a-euroconference-pisa-italy-25-29-september-1995
ISBN: 9789814530774   (Pobrane:  2021-01-14)

12.

Suchański W., Peplińska B., Kempka M.

Magnetic relaxation and anisotropic molecular reorientation of liquid 3-acetylpyridine The nuclear spin-lattice relaxation times of C-13 and N-14 as well as the nuclear Overhauser enhancement factor have been measured as a function of temperature for liquid 3-acetylpyridine. Principal components of the relational diffusion tenser have been determined. The results are discussed in terms of relative influence of molecular shape and attractive dipolar forces on anisotropy of the molecular reorientations.

Berichte der Bunsengesellschaft/Physical Chemistry Chemical Physics, 99(4), 595-599 (1995)

DOI: 10.1002/bbpc.19950990402

11.

Suchański W., Peplińska B., Kempka M.

Anizotropia reorientacji w molekułach pierścieniowych

Raport IBJ, Kraków, 1695/PL, 189 (1995)

WWW: http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/29/024/29024462.pdf

10.

Suchański W., Kempka M., Peplińska B., Pająk Z.

Magnetic relaxation and molecular motions in liquid 3,5-dimethylpyridine The nuclear spin-lattice relaxation times of N-14 have been measured as a function of temperature for liquid 3,5-dimethylpyridine. These results together with the values of the C-13 spin-lattice relaxation times and the factor of nuclear Overhauser enhancement for the ring C2,6 and C4 carbons presented previously [15], have been analyzed in terms of relative influence of molecular shape and attractive dipolar forces on anisotropy of the molecular reorientations. Principal components of the rotational diffusion tensor have been determined.

Berichte der Bunsengesellschaft/Physical Chemistry Chemical Physics, 98(6), 804-808 (1994)

DOI: 10.1002/bbpc.19940980607

9.

Suchański W., Kempka M., Peplińska B., Pająk Z.

Anisotropy of motions in derivatives of pyridine

Raport IBJ, Kraków, 1658/PL, 189 (1994)

8.

Suchański W.

Autorstwo lub wspólautorstwo książki, podręcznika akademickiego, monografii, zeszytów ćwiczeń i innych materiałów dydaktycznych, a także redakcja edytorska, słowo wstępne,
w wydawnictwach naukowych ISSN lub ISBN,
oraz w wydawnictwach popularno - naukowych.

Analiza wewnątrzmolekularnych ruchów stochastycznych: badania za pomocą magnetycznej relaksacji jądrowej 13C

Wydawnictwo Naukowe Uniwersytetu im. Adama Mickiewicza, 62, (1993)

WWW: http://www.press.amu.edu.pl/
ISSN: 0554-825 X

7.

Suchański W.

Magnetic relaxation under fast internal rotation in liquid The 13C nuclear spin-lattice relaxation times for ring and methyl carbons in liquid 3,5-lutydyne (3,5-dimethylpyridine, 3,5-DMP) have been measured as a function of temperature. The results have been analyzed in terms of two relaxation mechanisms: intramolecular dipole-dipole coupling and spin-rotation interaction. In order to separate these contributions, also the nuclear Overhauser enhancement factors have been studied. The results have been analyzed in terms of the theory of extended diffusion (ED) model for internal motion of methyl groups with a low barrier to internal rotation.

Berichte der Bunsengesellschaft fur Physikalische Chemie, 97(5), 720-726 (1993)

DOI: 10.1002/bbpc.19930970512

6.

Suchański W.

Magnetic relaxation under fast internal rotation in liquid part II). A variable temperature NMR study using 13C spin-lattice relaxation time measurements in liquid mesitylene The 13C nuclear spin-lattice relaxation times of ring and methyl carbons in liquid mesitylene (1,3,5-trimethyl-benzene, 1,3,5-TMB) have been measured as a function of temperature. The results have been analyzed in terms of two relaxation mechanisms: intramolecular dipole-dipole coupling and spin-rotation interaction. In order to separate these contributions, also the nuclear Overhauser enhancement factors have been studied. The results have been analyzed in terms of the theory of Gordon and Langevin models for internal motion of methyl groups with a low barrier to internal rotation and are in good agreement with predictions of both theories.

Berichte der Bunsengesellschaft fur Physikalische Chemie, 97(9), 1136-1142 (1993)

DOI: 10.1002/bbpc.19930970912

5.

Suchański W., Kempka M., Peplińska B., Pająk Z.

NMR and molecular anisotropic motion in 3 acetylpyridine

Proccedings of 15th Conference on Radio and Microwave Spectroscopy, Poznań (Poland), , 93-94 (1993)

4.

Suchański W., Kempka M., Peplińska B., Pająk Z.

Magnetic relaxation and molecular anisotropic rotational motion in liquid 3,5 dimethylpyridine

Proccedings of 26th Congres Ampere on Magnetic Resonance, Athens (Greece), , 596 (1992)

3.

Suchański W., Canepa P.C.

NMR relaxation studies and internal molecular rotation in liquid nitromethane Studies of the deuteron and proton relaxation rates of liquid nitromethane were made at various temperatures. The separation of the proton-proton intermolecular relaxation was accomplished by a dilution study in nitromethane-d3. It was found that the spin-rotation interaction contribution is discussed in terms of different models for the spin-internal and spin-overall rotation coupling. The resulting spin-rotation relaxation times offer evidence for large spin-rotation effects due to the internal rotation of the methyl group.

Journal of Magnetic Resonance (1969), 33(2), 389-399 (1979)

DOI: 10.1016/0022-2364(79)90256-7

2.

Angerer J., Suchański W.

NMR relaxation study of molecular motions in liquid chlorobenzotrifluorides The temperature dependences of the 1H and 19F nuclear spin-lattice relaxation times T1 in liquid o-, m-, and p-chlorobenzotrifluorides have been measured. The analysis of the temperature dependences of the 1H spin-lattice relaxation times leads to the conclusion that the overall molecular reorientational motion in o-, m-, and p-benzotrifluorides is nearly the same. Data for 1H and 19F spin-lattice relaxation times of o-chlorobenzotrifluoride jointly lead to the determination of the individual contributions to relaxation rate in the entire temperature range studied. A knowledge of these contributions for o-chlorobenzotrifluoride, together with the assumption of equal correlation times for overall molecular reorientation in o- and p-chlorobenzotrifluorides, leads to the determination of the spin-internal-rotation interaction contribution to relaxation for p-chlorobenzotrifluoride in the same range of temperature.

Journal of Magnetic Resonance (1969), 21(1), 57-65 (1976)

DOI: 10.1016/0022-2364(76)90253-5

1.

Suchański W., Pająk Z.

Proton spin-internal rotation coupling in toluene and xylenes The spin-internal rotation coupling contribution to spin-lattice relaxation has been separated from other mechanisms by using selective T1 measurements for the ring and methyl protons of toluene, p- and m-xylene in various solvents. This particular interaction is found to be an important part of the spin-lattice relaxation of methyl protons at room temperature.

Chemical Physics Letters, 26(2), 182-185 (1974)

DOI: 10.1016/0009-2614(74)85392-3

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