JEDRSKA KVADRUPOLNA RESONANCA 14N

 

                                   

 

Osnovno stanje jedra 14N ima spin 1 in je zato trikrat degenerirano. Sklopitev električnega kvadrupolnega momenta jedra z lokalnim nehomogenim električnim poljem odpravi degeneracijo. Frekvence prehoda med energijskimi nivoji imenujemo kvadrupolne resonančne frekvence. V primeru jedra s spinom 1 jih označimo kot ,in  Odvisne so od dveh parametrov: kvadrupolne sklopitvene konstante e2qQ/h in asimetrijskega parametra gradienta električnega polja, ki ga označimo z . Kvadrupolne resonančne frekvence, ki so v primeru 14N večinoma nižje od 4 MHz, so povezane s porazdelitvijo električnega naboja (predvsem elektronov) v okolici opazovanega jedra, strukturo molekul in kristalov ter kemijskimi vezmi. So tudi dober indikator strukturnih sprememb na primer pri faznih prehodih, kristalnih polimorfih itd.

 

Kratka teorija jedrske kvadrupolne resonance:

J. Seliger, Nuclear quadrupole resonance: theory, Poglavje v knjigi »Encyclopedia of Spectroscopy and Spectrometry«, Ed. J. C. Lindon, G. E. Tranter and J. L. Holmes, Academic Press, San Diego etc., 2000, p. 1672-1680

 

Objavljena dela:

1. R. Blinc, M. Mali, R. Osredkar, A. Prelesnik, J. Seliger,I. Zupančič, L. Ehrenberg,

     14N NQR spectroscopy of some amino acids and nucleic bases via double    

    resonance in the laboratory frame, J. Chem. Phys 57, 5087-5093 (1972)

2. R. Blinc, M. Mali, R. Osredkar, J. Seliger, L. Ehrenberg, 14N quadrupole

    resonance in polyglycine, Chem. Phys. Letters 28, 158-159 (1974)         

3. R. Blinc, M. Mali, R. Osredkar, J. Seliger,  Nitrogen and chlorine NQR in

    paraelectric and ferroelectric tris-sarcosine calcium chloride, J. Chem. Phys.

    63, 35-37 (1975)              

4. J. Seliger, R. Osredkar, M. Mali, R. Blinc, 14N quadrupole resonance of some

    liquid crystalline compounds in the solid, J.Chem. Phys. 65, 2887-2891 (1976)

5. J. Seliger, R. Blinc, H. Arend, R. Kind, Proton-14N double resonance study of the

    structural phase transitions in the perovskite type layer compound

    (CH3NH3)2CdCl4, Z. Phys. B 25, 189-195 (1976)                  

6. J. Seliger, R. Osredkar, V. Žagar, R. Blinc, Orientational order in biaxial liquid

    crystals, Phys. Rev. Letters 38, 411-415 (1977)

7. E. Hadjoudis, F. Milia, J. Seliger, R. Blinc, 14N quadrupole coupling in some

    thermochromic and photochromic N-salicylideneanilines, Solid State Commun. 21,

    541-543 (1977)

8. J. Seliger, V. Žagar, R. Blinc, 14N nuclear-quadrupole-resonance study of

    orientational ordering in the smectic phases of achiral TBBA and chiral TBACA,     

    Phys. Rev. A 17, 1149-1155 (1978)

9. E. Hadjoudis, F. Milia, J. Seliger, R. Blinc, Temperature dependence of the 14N

    quadrupole resonance in some thermochromic and photochromic

    N-salicylideneanilines, Phys. Stat. Sol. (a) 46, 239-244 (1978)     

10. E. Hadjoudis, F. Milia, J. Seliger, R. Blinc, 14N quadrupole coupling in

    thermochromic N-5-chlorosalicylideneaniline, Chem. Phys. Letters 56, 382-384

    (1978)                    

11. R. Blinc, J. Seliger, M. Vilfan, V. Žagar, Temperature dependence of

    orientational ordering in the smectic H and smectic VI phases of TBBA,

    J. Chem. Phys. 70, 778-783 (1979)     

12. E. Hadjoudis, F. Milia, J. Seliger, R. Blinc, V. Žagar, 14N quadrupole coupling in

     thermochromic and photochromic N-salicylideneanilines, Chem. Phys. 47,

    105-109 (1980)                                        

13. M. Vilfan, R. Blinc, J. Seliger, V. Žagar, Molecular orientational ordering in the

     smectic C* and H* phases of chiral TBACA, Ferroelectrics 24, 211-214 (1980)

14. M. Vilfan, J. Seliger, V. Žagar, R. Blinc, 14N NQR and 1H NMR study of the

     smectic phase of IBPBAC, Phys. Letters A 79, 186-188 (1980)    

15. J. Seliger, V. Žagar, R. Blinc, H. Arend, G. Chapuis, 14N and 35Cl double

     resonance study of the phase transition in the intercalated bilayer compound

     C10H21NH3Cl, J. Chem. Phys. 78, 2661-2664 (1983)                      

16. S. Jurga, J. Seliger, R. Blinc, H. W. Spiess, 14N and 35Cl double resonance study

     of the low-temperature phase transition in CH3NH3ClO4, Phys. Letters A 116,

     295-298 (1986)   

17. J. Seliger, V. Žagar, R. Blinc, A. Novak, S. Rodin 17O and 14N quadrupole 

     coupling and the mechanism of the ferroelectric transition in diglycine nitrate,

     Ferroelectrics Letters 6, 93-102 (1986)           

18. J. Seliger, V. Žagar, R. Blinc, F. Milia, S. Giannacopoulos, R. Kind,  Proton-14N

     double resonance study of the ferroelectric phase transition in (CH3NH3)HgCl3,

     Solid State Commun. 59, 877-879 (1986)     

19. J. Seliger, V. Žagar, R. Blinc, R. Kind, H. Arend, F. Milia, 14N and 35Cl nuclear

     quadrupole double resonance study of the structural phase transitions in

     N-octylammoniumchloride, Z. Phys. B - Condensed Matter 67, 363-368 (1987)                       

20. J. Seliger, V. Žagar, R. Blinc, R. Kind, H. Arend, G. Chapuis, K. J. Schenk,

     F. Milia, 14N and 35Cl nuclear quadrupole double resonance study of the phase

     transitions in N-decylammoniumchloride and N-hexylammoniumchloride,      

     Z. Phys. B - Condensed Matter 69, 379-384 (1987)

21. J. Seliger, V. Žagar, R. Blinc, H. Arend, P. Gunter,  14N quadrupole coupling in

     COANP, Chem. Phys. Letters 142, 334-335 (1987)

22. S. V. Rodin, J. Seliger, R. Blinc, V. Žagar, JKR 14N i 17O v kristalle diglicinnitrata,

     Fizika Tverdogo Tela, 29, 1871-1873 (1987)

23. J. Seliger, V. Žagar, R. Blinc, 14N NQR study of the structural phase transitions in

     NH4NO3, Z. Phys. B - Condensed Matter 77, 439-443 (1989)       

24. J. Seliger, V. Žagar, R. Blinc, E. Hadjoudis, F. Milia, 1H-14N and 1H-17O nuclear

     quadrupole resonance in thermochromic N-5-chlorosalicylideneaniline,      

     Chem. Phys. 142, 237-244 (1990)                  

25. R. Blinc, P. Kerkoč, J. Hulliger, R. Kind, P. Gunter, J. Seliger, V. Žagar,

     14N quadrupole coupling in DAN and MBANP, Chem. Phys. Letters 167, 588-590

     (1990)       

26. R. Blinc, J. Seliger, V. Žagar, T. Apih, J. Dolinšek, H. Warhanek, A. Fuith,

      W. Schranz, 14N nuclear-quadrupole-resonance study of the structural phase

      transitions in NH4SCN, Phys. Rev. B 42, 8125-8132 (1990)

27. E. Hadjoudis, F. Milia, J. Seliger, V. Žagar, R. Blinc, 14N NQR investigation of

      some thermochromic and photochromic salicylideneanilines and related 

      compounds, Chem. Phys. 156, 149-155 (1991)      

28. J. Seliger, V. Žagar, 14N nuclear quadrupole resonance study of the structural

      phase transition in phenothiazine, J. Phys.: Condens. Matter 6, 6027-6033

      (1994)      

29. J. Seliger, V. Žagar, 1H NMR and 14N NQR study of the ferroelectric phase

      transition in (CH3)2NH2H2PO4, Phys. Rev. B 57, 8160-8165 (1998)

30. J. Seliger, V. Žagar, NMR and NQR study of molecular dynamics in a model

      bilayer compound C6H13NH3Cl, J. Chem. Phys. 108, 9783-9788 (1998)

31. J. N. Latosinska, J. Seliger, B. Nogaj, Electron density distribution in 2-nitro-

      5-methylimidazole derivatives studied by NMR-NQR double resonance,

      Magn. Res. Chem 37, 878-880 (1999)

32. J. N. Latosinska, J. Seliger, V. Grechishkin, J. Spychala,  Studies of the

      electronic structureof 4-N-cytosine derivatives by NMR-NQR double

      resonance spectroscopy, Magn. Res. Chem 37, 881-884 (1999)

33. Blinc, J. Seliger, D. Arčon, P. Cevc, V. Žagar, 1H-14N double resonance of

      TNT from a land mine, Phys. Stat. Solidi (a) 180, 541-545 (2000)

34. J. Seliger and V. Žagar,  14N nuclear quadrupole resonance in solid

      4,4′-azoxyanisole and 4,4′-bis(heptyloxy)azoxybenzene, Chemical Physics

      306, 309-314 (2004)

35. J. Seliger, V. Žagar, R. Blinc, F. Milia, Temperature dependence of 17O and
       14N NQR frequencies in commercial TNT, Applied Magnetic Resonance 29, 
       541-548 (2005)

36. R. Blinc, J. Seliger, A. Zidanšek, V. Žagar, F. Milia and H. Robert, 14N nuclear

      quadrupole resonance of some sulfa drugs, Solid State Nuclear Magnetic 

      Resonance 30, 61-68 (2006)

37. J. Seliger, V. Žagar, A. Zidanšek and R. Blinc, 14N nuclear quadrupole

      resonance of picolinic, nicotinic, isonicotinic and dinicotinic acids , Chemical

      Physics 331, 131-136 (2006)

38. T Asaji, J Seliger, V Žagar, M Sekiguchi, J Watanabe, K Gotoh, H Ishida,

      S Vrtnik, J Dolinsek, Phase transition and temperature dependent electronic

      state of an organic ferroelectric, phenazine-chloranilic acid (1:1), J. Phys.

      Condens. Matter 19, 226203 (2007)

39. J. Seliger, V. Žagar, 14N NQR study of nicotinamide and related compounds,

      Magn. Reson. Chem. 46, 58-62 (2008)

40.  J. Seliger, V. Žagar, 14N NQR Study of Diphenylamine, Z. Naturforsch. 63a,

      88 – 92 (2008)

41. J. Seliger, V. Žagar, Measurement of the 14N nuclear quadrupole resonance

      frequencies by the solid effect. J. Magn. Reson. 193, 54-62 (2008)     

42. J. Seliger, V. Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: http://www3.interscience.wiley.com/giflibrary/12/Zcaron.gifagar , T. Asaji , A. Konnai , Temperature dependence of

      nonequivalent potential wells for pyridinium ion reorientation in pyridinium

      tetrachloroiodate(III), PyHICl4, studied by 1H-14N nuclear quadrupole double

      resonance, Magn. Reson. Chem. 46, 756-760 (2008)  

43. J. Seliger, V. Žagar, Sensitivity of nuclear-quadrupole double-resonance

    detection of half-integer spin nuclei, J. Magn. Reson. 194, 175-181 (2008) 

    doi:10.1016/j.jmr.2008.06.021

44. J. Seliger, V. Žagar, T. Asaji, 14N nuclear quadrupole resonance and proton

    spin-lattice relaxation study of phase transition in pyridazine perchlorate, Solid

    State Commun. 149, 546-549 (2009) doi: 10.1016/j.ssc.2009.01.008

45. J. Seliger, V. Žagar, K. Gotoh, H. Ishida, A. Konnai, D. Amino, T. Asaji,

      Hydrogen bonding in 1,2-diazine–chloranilic acid (2:1) studied by a 14N

      nuclear quadrupole coupling tensor and multi-temperature X-ray diffraction

      Phys. Chem. Chem. Phys. 11, 2281-2286 (2009) DOI: 10.1039/b818318j

46. J. Seliger, V. Žagar, Double resonance experiments in low magnetic field.

     Dynamic polarization of protons by 14N and measurement of low NQR

     frequencies, J. Magn. Reson. 199, 199-207 (2009)

     doi:10.1016/j.jmr.2009.05.001

47. J.N. Latosińska , M. Latosińska, J. Seliger, V. Žagar, Z. Kazimierczuk,

     Electron density distribution in cladribine (2-chloro-2-deoxyadenosine) - a drug

     against leukemia and multiple sclerosis – studied by multinuclear nqr

     spectroscopy and dft calculations, Chem. Phys. Letters 476, 293-302 (2009)

     doi:10.1016/j.cplett.2009.06.038 

48. J. N. Latosinska, J. Seliger, V. Žagar, D. V. Burchardt, Hydrogen bonding and

     stacking π-π Interactions in solid 6-thioguanine and 6-mercaptopurine

     (antileukemia and antineoplastic drugs) studied by NMR-NQR double

     resonance spectroscopy and density functional theory

     J. Phys. Chem. A 113, 8781-8790 (2009) doi: 10.1021/jp904331z

49. J. Pirnat , J. Lužnik, V. Jazbinšek, V. Žagar, J. Seliger, T. M. Klapötke,

      Z. Trontelj, 14N NQR in the tetrazole family, Chemical Physics 364, 98–104

      (2009)

50. J. N. Latosinska, M. Latosinska, J. Seliger, V. Žagar, J. K. Maurin,

      A. Orzeszko, Z. Kazimierczuk, Structural Study of Selected Polyhalogenated

      Benzimidazoles (Protein Kinase CK2 Inhibitors) by Nuclear Quadrupole

      Double Resonance, X-ray, and Density Functional Theory, J. Phys. Chem. A

      114, 563–575 (2010) doi: 10.1021/jp9075492

51. J. Seliger, V. Žagar, T. Asaji, Y. Hasegawa, 14N NQR and proton NMR study

      of ferroelectric phase transition and proton exchange in organic ferroelectric

      (H2-TPPZ)(Hca)2, Phys. Chem. Chem. Phys. 12, 3254-3259 (2010),

       DOI:10.1039/ B925326B

52. T. Asaji, J. Seliger, V. Žagar, H. Ishida, Correlation between proton transfer

      and 35Cl NQR frequency as well as molecular geometry of chloranilic acid in

      co-crystals with some organic bases, Magn. Reson. Chem. 48, 531-536

      (2010) DOI: 10.1002/mrc.2613

53. Z. LavriDescription: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: ccaron, J. Pirnat, J. LuDescription: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: zcaronnik, J. Seliger, V. Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Zcaronagar, Z. Trontelj, S. Srčič,

      Application of 14N NQR to the study of piroxicam polymorphism, J. Pharm.

      Sci. 99, 4857-4865 (2010) DOI: 10.1002/jps.22186

54. J. Seliger, V. Žagar, J. N. Latosinska, 14 N NQR, 1H NMR and DFT/QTAIM

      study of hydrogen bonding and polymorphism in selected solid 1,3,4-

      thiadiazole derivatives, Phys. Chem. Chem. Phys. 12, 13007-13019 (2010)

      DOI: 10.1039/C0CP00195C

55. J. Seliger, V. Žagar, 14N NQR study of polymorphism and hydrogen bonding 
      in molecular complex isonicotinamide-oxalic acid (2:1), J. Phys. Chem. A 
      114, 12083-12087 (2010) DOI: 10.1021/jp105449w

56. T. Asaji, M. Hoshino, H. Ishida, A. Konnai, Y. Shinoda, J. Seliger, V. Žagar,

      Phase transition and proton exchange in 1,3-diazinium hydrogen chloranilate

      monohydrate, Hyperfine Interactions 198, 85-91 (2010)

      DOI: 10.1007/s10751-010-0205-4

57. J. Latosińska, M. Latosińska, M. Tomczak, J. Seliger, V. Žagar, 
      Supramolecular synthon pattern in solid clioquinol and cloxiquine (APIs of
      antibacterial, antifungal, antiaging and antituberculosis drugs) studied by 35Cl
      NQR, 1H-17O and 1H-14N NQDR and DFT/QTAIM, J. Mol. Model. 17, 1781-
      1800 (2011) DOI: 10.1007/s00894-010-0876-4

58. J.N.Latosińska, J.Seliger, V.Žagar, D.V.Burchardt, A comparative study of the

      hydrogen-bonding patterns and prototropism in solid 2-thiocytosine (potential

      antileukemic agent) and cytosine, as studied by 1H-14N NQDR and

      QTAIM/ DFT, J. Mol. Model. 18, 11-26 (2012)

      DOI: 10.1007/s00894-011-1021-8

59. J. Seliger, V. Žagar, T. Asaji, K. Gotoh, H. Ishida, 14N nuclear quadrupole

      resonance study of phase transitions and molecular dynamics in hydrogen

      bonded organic antiferroelectrics 55DMBP-H2ca and 1,5-NPD-H2ca,

      Phys. Chem. Chem. Phys. 13, 9165-9172 (2011) DOI: 10.1039/C0CP02873H

60. J. Lužnik, V. Jazbinšek, J. Pirnat, J. Seliger, Z. Trontelj, Zeeman shift – a tool

      for assignment of 14N NQR lines of nonequivalent 14N atoms in powder

      samples , J. Magn. Reson. 212, 149 -153Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: Description: http://www.sciencedirect.com/scidirimg/clear.gif (2011)

      DOI:10.1016/j.jmr.2011.06.023

61. J. Seliger, Nuclear quadrupole resonance study of hydrogen bonded solid

      materials, Acta Chim. Slov. 58, 471-477 (2011)

62. J. Seliger, V. Žagar, Phonon driven proton transfer in 3,5-pyridine

      dicarboxylic acid studied by 2H, 14N and 17O NQR, J. Phys. Chem. A 115,

      11652-11654 (2011) DOI: 10.1021/jp206897v

63. J. N. Latosińska and M. Latosińska , J. Seliger and V. Žagar , J. K. Maurin ,

       Z. Kazimierczuk, Nature of isomerism of solid isothiourea salts, inhibitors of

       Nitric oxide synthases, as studied by 1H–14N nuclear quadrupole double

       resonance, X-ray, and Density functional theory/Quantum theory of atoms in

       molecules, J. Phys. Chem. A 116, 1445-1463 (2012)

       DOI: 10.1021/jp210322p

64. J.N. Latosińska, M. Latosińska, J. Seliger, V. Žagar, An innovative method

      for the  non-destructive identification of photodegradation products in solid

      state. 1H-14N NMR-NQR and DFT/QTAIM study of photodegradation of

      nifedipine (anti-hypertensive) to nitrosonifedipine (potental antioxidative),

      Eur. J. Pharm. Sci. 47, 97-107 (2012)

      DOI: http://dx.doi.org/10.1016/j.ejps.2012.05.001

65. J. Seliger, V. Žagar, M. Latosińska, J. N. Latosińska, Electron configuration

      and hydrogen bonding pattern in several thymine and uracil analogues

      studied by 1H-14N NQDR and DFT/QTAIM, J. Phys. Chem. B 116, 8793-8804

      (2012) DOI: 10.1021/jp302659k

66. J. Seliger, V. Žagar, Nuclear quadrupole resonance characterization of

      carbamazepine cocrystals, Solid State Nucl. Magn. Reson. 47-48, 47-52

      (2012) http://dx.doi.org/10.1016/j.ssnmr.2012.09.001

67. J. Seliger, V. Žagar, New methods for detection of 14N NQR frequencies,

      Appl. Magn. Reson. 43, 469-484 (2012) DOI: 10.1007/s00723-011-0303-8

68. T. Asaji , Y. Ito , J. Seliger , V. Žagar , A. Gradisek, T. Apih, Phase transition

       and ring-puckering motion in a metal-organic perovskite 

       [(CH2)3NH2][Zn(HCOO)3], J. Phys. Chem. A 116, 12422-12428 (2012)

       DOI: 10.1021/jp310132a

69. J. Seliger, V. Žagar, T. Asaji, NQR investigation and characterization of

      cocrystals and crystal polymorphs, Hyperfine Interactions 222, 1-13 (2013)

      DOI: 10.1007/s10751-012-0665-9

70. J. Seliger, V. Žagar, Tautomerism and possible polymorphism in solid

       hydroxypyridines and pyridones studied by 14N NQR, J. Phys. Chem. A 117,

      1651-1658 (2013) DOI: 10.1021/jp3117038

71. J. Seliger, V. Žagar, Hydrogen Bonds in Cocrystals and Salts of 2-Amino-4,6-

      Dimethylpyrimidine and Carboxylic Acids Studied by NQR, J. Phys. Chem. B

      117, 6946-6956 (2013) DOI: 10.1021/jp403617e

72. J. Seliger, V. Žagar, Crystallization of an amorphous solid studied by nuclear

       quadrupole double resonance, Chem. Phys. 421, 44-48 (2013)

       DOI: 10.1016/j.chemphys.2013.06.005

73.  J. Seliger, V. Žagar, Nuclear quadrupole resonance study of hydrogen bonds

       in solid 2-methylbenzimidazole and 5,6-dimethylbenzimidazole, J Phys.

       Chem. C 117, 20193-20200 (2013) DOI: 10.1021/jp4071746

74. J. Seliger, V. Žagar, Nuclear Quadrupole Resonance Investigation of

      Hydrogen Bonding in Some Cocrystals of 2,3,5,6-Tetramethylpyrazine and

      Carboxylic Acids, J. Phys. Chem. B 118, 996-1002 (2014)

      DOI: 10.1021/jp412332p

75. J. Lužnik, J. Pirnat, V. Jazbinšek, Z. Lavrič, V. Žagar, S. Srčič, J. Seliger,

      Z. Trontelj, 14N Nuclear Quadrupole Resonance Study of Polymorphism in

      Famotidine, J. Pharm. Sci. 103, 2704-2709 (2014) DOI: 10.1002/jps.23956

76. J. Seliger, V. Žagar, Hydrogen bonding and proton transfer in cocrystals of

      4,4’-bipyridil and organic acids studied by nuclear quadrupole resonance,

      Phys. Chem. Chem. Phys. 16, 18141-18147 (2014)

      DOI: 10.1039/C4CP02665A (prost dostop)

77. J. N. Latosińska, M. Latosińska, J. Seliger, V. Žagar, Z. Kazimierczuk,

      An Insight Into Prototropism and Supramolecular Motifs in Solid-State

      Structure of Allopurinol, Hypoxanthine, Xanthine and Uric Acid. A 1H-14N

      NQDR Spectroscopy and Hybrid DFT/QTAIM and Hirshfeld Surface-Based

      Study J. Phys. Chem. B 118, 10837-10853 (2014) DOI: 10.1021/jp504871y

      naslovnica

78. J. N. Latosińska, M. Latosińska, G. Olejniczak, J. Seliger, V. Žagar, Topology

      of the Interactions Pattern in Pharmaceutically Relevant Polymorphs of

      Methylxanthines (Caffeine, Theobromine and Theophiline). Combined

      Experimental (1H-14N NQDR) and Computational (DFT and Hirshfeld –

      Based) Study, J. Chem. Inf. Model. 54, 2570-2584 (2014)

      DOI: 10.1021/ci5004224

79. J. N. Latosińska, M. Latosińska, J. Seliger, V. Žagar, D. V. Burchardt,

       K. Derwich, Unusual case of desmotropy. Combined spectroscopy (1H-14N

       NQDR) and quantum chemistry (Periodic hybrid DFT/QTAIM and Hirshfeld

       surface-based) study of solid dacarbazine (anti-neoplastic), Solid State Nucl.

       Magn. Reson. 68-69, 13-24 (2015) doi:10.1016/j.ssnmr.2015.04.005

80. J. N. Latosińska, M. Latosińska, M. Szafrański, J. Seliger, V. Žagar,

      D. V. Burchardt, Impact of structural differences in carcinopreventive agents

      Indole-3-carbinol and 3,3’- diindolylmethane on biological activity. An X-ray,

      1H-14N NQDR, 13C CP/MAS NMR, and Periodic Hybrid DFT Study
      Eur. J. Pharm. Sci. 77, 141-153 (2015) doi:10.1016/j.ejps.2015.06.003

81. J. Seliger, V. Žagar, T. Apih, A. Gregorovič, M. Latosińska, G. Olejniczak,

      J. N. Latosińska, Polymorphism and Disorder in Natural Active Ingredients.

      Topological Insights into of Two Anhydrous Polymorphs of Caffeine:

      Spectroscopic (1H-14N NMR-NQR/14N NQR) and Solid-State Computational

      Modelling (DFT/QTAIM/RDS) Study, Eur. J. Pharm. Sci. 85, 18-30 (2016)

      doi: 10.1016/j.ejps.2016.01.025

82. T. Apih, V. Žagar, J. Seliger, NMR and NQR Study of Above-Room-

      Temperature Molecular Ferroelectrics Diisopropylammonium Chloride and

      Diisopropylammonium Perchlorate, J. Phys. Chem. C 120, 6180-6189 (2016)

      DOI: 10.1021/acs.jpcc.5b12116

83. T. Apih, A. Gregorovič, V. Žagar, J. Seliger, Nuclear Quadrupole Resonance

      Study of Proton and Deuteron Migration in Short Strong Hydrogen Bonds

      Formed in Molecular Complex 3,5-Dinitrobenzoic Acid–Nicotinic Acid and in

      Deuterated 3,5-Pyridinedicarboxylic acid, J. Phys. Chem. C 120, 9992-10000

      (2016) DOI: 10.1021/acs.jpcc.6b02639

84. A. Gregorovič, T. Apih, J. Seliger, 1H-14N Cross-Relaxation Spectrum

      Analysis in Sildenafil and Sildenafil Citrate, Solid State Nucl. Magn. Reson.

      78, 16-23 (2016) doi: 10.1016/j.ssnmr.2016.05.003

85. J. N. Latosinska, M. Latosinska, M. Szafranski, J. Seliger, V. Žagar,

      Polymorphism and Thermal Stability of Natural Active Ingredients. 3,3’-

      Diindolylmethane (Chemopreventive and Chemotherapeutic) Studied by a

      Combined X-Ray, 1H – 14N NMR-NQR, DSC and Solid-State DFT/3D

      HS/QTAIM/RDS Computational Approach, Cryst. Growth Des. 16,

      4336-4348 (2016) DOI: 10.1021/acs.cgd.6b00456

86. A. Gregorovič, T. Apih, V. Žagar, J. Seliger, 14N NQR Reveals Proton

      Position in N-H...N Bonds: A Case Study with Proton Sponges, Phys. Chem.

      Chem. Phys. 21, 306-313 (2019) http://dx.doi.org/10.1039/C8CP05183F

87. A. Gregorovič, T. Apih, V. Žagar, J. Seliger, A Study of Donor-Acceptor

       Interaction in Halogen Bonded Complexes of N-iodosuccinimide by 14N

       NQR, Chem Phys 523, 12-17 (2019)

       https://doi.org/10.1016/j.chemphys.2019.04.003

88. T. Apih, V. Žagar, J. Seliger, NMR and NQR Study of Polymorphism in

      Carbamazepine, Solid State Nucl. Magn. Reson. 107, 101653 (2020)

      https://doi.org/10.1016/j.ssnmr.2020.101653

89. Z. Trontelj, J. Pirnat, V. Jazbinšek, J. Lužnik, S. Srčič, Z. Lavrič, S. Beguš,

      T. Apih, V. Žagar, J. Seliger Nuclear Quadrupole Resonance (NQR)- A

      Useful Spectroscopic Tool in Pharmacy for the Study of Polymorphism,

      Crystals 10, 450 (2020) doi:10.3390/cryst10060450

90. J. N. Latosinska, M. Latosinska, J. Seliger, V. Žagar, T. Apih, P. Grieb,

      Elucidating the Role of Noncovalent Interactions in Favipiravir,a Drug Active

      against Various Human RNA Viruses; a 1H-14N NQDR/Periodic

      DFT/QTAIM/RDS/3D Hirshfeld Surfaces Combined Study

      Molecules 28, 3308 (2023). https://doi.org/10.3390/molecules28083308

91. J. N. Latosinska, M. Latosinska, J. Seliger, V. Žagar, Exploring Partial

     Structural Disorder in Anhydrous Paraxanthine Through Combined

     Experiment, Solid-State Computational Modelling, and Molecular Docking

     Processes 11, 2740 (2023) https://doi.org/10.3390/pr11092740