Publikationen
2026
- N.-P. Pook, M. Gjikaj, CrysEngComm, 2026. Crystal Packing and Interaction Hierarchies in EMPyOH–Cl and EMPy–OSbCl5 Crystals: Effects of Hydroxyl Functionalization and Antimony Oxochloride Formation Revealed by Combined Hirshfeld, Relativistic ETS–EDA/ETS–NOCV, and SAPT Analyses. Submitted.
2025
M. Söftje, P. Memmel, N. Anwar, V. A. Zapol’skii, M. Gjikaj, E. G. Hübner, J. C. Namyslo, D. E. Kaufmann. Eur. J. Org. Chem. 2025, 28, e202500234. Synthetic Access to the Class of 3-Amino-4-Cyano-Substituted Thiophenes. DOI: 10.1002/ejoc.202500234.
2023
V. A. Zapol’skii, S. Kaul, B. Karge, M. Brönstrup, M. Gjikaj, D. E Kaufmann. Molecules2023, 28, 2479-2499. A New Way to 2,3,4-Trisubstituted Benzo[h]quinolines: Synthesis, Consecutive Reactions and Cellular Activities. DOI: 10.3390/molecules28062479.
2021
- A. T. Storm, M. Nieger, M. Gjikaj, J. C. Namyslo, J. Adams, A. Schmidt, Eur. J. Org. Chem. 2021, 34, 4803-4815. 1,3-Thiazol-4-aminides: Syntheses and Characterizations of Fluorescent Mesoionic Compounds. DOI: 10.1002/ejoc.202100794.
- M. Söftje, T. Weingartz, R. Plarre, M. Gjikaj, J. C. Namyslo, D. E. Kaufmann. ACS Omega 2021, 6, 33542-33553. Surface Tuning of Wood via Covalent Modification of Its Lignocellulosic Biopolymers with Substituted Benzoates – A Study on Reactivity, Efficiency, and Durability. DOI: 10.1021/acsomega.1c04353.
- M. Haase, M. Gjikaj, Z. Anorg. Allg. Chem. 2021, 647, 1058-1064. New Dihydrogen-hypodiphosphates of Alkaline-Earth Metals: Preparation, Crystal Structure, Vibrational Spectrum and Thermal Behavior of AE[H2P2O6]·nH2O (AE = Ca, Sr and n = 1.5, 2). DOI: 10.1002/zaac.202100020.
2019
- S. Batsyts, E. G. Hübner, J. C. Namyslo, M. Gjikaj, A. Schmidt, Org. Biomol. Chem. 2019, 17, 4102-4114. Synthesis and characterization of propeller-shaped mono- to hexacationic quinolinium-substituted benzenes. DOI: 10.1039/c9ob00357.
- N.-P. Pook, A. Adam, M. Gjikaj. Acta Crystallogr. 2019, E75, 667–674. Crystal structure and Hirshfeld surface analysis of (μ-2-{4-[(carboxyl-atometh-yl)carbamo-yl]benzamido}-acetato- κ2O:O')bis-[bis-(1,10-phenanthroline-κ2N,N')copper] dinitrate N,N'-(1,4-phenyl-enedicarbon-yl) diglycine monosolvate octahydrate. DOI: 10.1107/S2056989019005164.
2018
- A.-L. Lücke, S. Wiechmann, T. Freese, M. Nieger, T. Földes, I. Pápai, M. Gjikaj, A. Adam, A. Schmidt, Tetrahedron 2018, 74, 2092-2099. Anionic N-heterocyclic carbenes by decarboxylation of sydnone-4-carboxylates. DOI: 10.1016/j.tet.2018.03.019.
- M. Haase, M. Gjikaj, Z. Anorg. Allg. Chem. 2018,644, 497-503. Three Crystal Structures, One Chemical Formula – Barium Dihydrogen-hypodiphosphate(IV)-dihydrate, BaH2P2O6·2H2O. DOI: 10.1002/zaac.201800020.
2017
- F. Uhrner, F. Lederle, J. C. Namyslo, M. Gjikaj, A. Schmidt, E. G. Hübner, Tetrahedron 2017, 73, 4472-4480. Reaction of N-heterocyclic carbaldehydes with furanones - An investigation of reactivity and regioselectivity. DOI: 10.1016/j.tet.2017.06.012.
- M. Haase, M. Gjikaj, Z. Anorg. Allg. Chem. 2017,643, 962–967. Preparation, Crystal Structure and Vibrational Spectra of Ca2P2O6·2H2O and [Ca(H2O)3(H2P2O6)]· 0.5(C12H24O6)·H2O. DOI: 10.1002/zaac.201700111.
2016
V. A. Zapol’skii, J. C. Namyslo, M. Gjikaj, D. E. Kaufmann. Heterocycles 2016, 93, 628-646. Chemistry of Polyhalogenated Nitrobutadienes, 15: Synthesis of Novel 4-Nitro-3-amino-1H-pyrazole-5-carbaldehydes and Pyrazolo[3,4-f]indazole-4,8-diones. DOI: 10.3987/COM-15-S(T)46.
2015
- V. A. Zapol’skii, J. C. Namyslo, G. Sergeev, M. Brönstrup, M. Gjikaj, Dieter E. Kaufmann, Eur. J. Org. Chem.2015, 7763-7774. Chemistry of Halonitroethenes, III: Reinvestigation of the Nitration of Trichloreethene-Subsequent Reactions of the Products and Evaluation of their Antimicrobial and Antifungal Activity. DOI: 10.1002/ejoc.201501066.
- Z. Guan, M. Gjikaj, A. Schmidt, Z. Naturforsch. 2015, 70b,83-89. 2-Ethyl-1-phenylindazolium hexafluorophosphate. N-Heterocyclic carbene formation, rearrangement, ring-cleavage reactions, and rhodium complex formation. DOI 10.1515/znb-2014-0188
- P. Wu, N.-P. Pook, M. Gjikaj, Z. Anorg. Allg. Chem. 641 (2015) 1755-1761. Preparation, Crystal Structure, Vibrational Spectra, and Thermal Behaviorof Tl2H2P2O6 and Tl4P2O6. DOI: 10.1002/zaac.201500174.
- N.-P. Pook, P. Hentrich, M. Gjikaj. Acta Crystallogr. 2015, E71, 910-914. Crystal structure of bis[tris(1,10-phenanthroline-κ2N,N′)cobalt(II)] tetranitrate N,N′-(1,4-phenylenedicarbonyl)-diglycine solvate octahydrate. DOI:10.1107/S2056989015013006.
- M. Gjikaj, M. Haase, Acta Crystallogr.2015,E71, 867-869. Crystal structure of catena-poly-[[tetraaquamagnesium]-μ-(dihydrogen hypodiphosphato)-κ2O,O′]. DOI: 10.1107/S205698901501203.
2014
- A. S. Lindner, E. Geist, M. Gjikaj, A. Schmidt, J. Heterocycl. Chem. 2014, 51, 423-431. Syntheses of N10-substituted 7-Arylpyrrolo[2,1-c]-[1,4]benzodiazepine-5,11-diones. DOI 10.1002/jhet.1775.
- V. A. Zapol’skii, J. C. Namyslo, M. Gjikaj, D. E. Kaufmann. Beilstein. J. Org. Chem. 2014, 10, 1638-1644. Chemistry of Polyhalogenated Nitrobutadienes, 14: Efficient Synthesis of Functionalized (Z)-2-Allylidene-thiazolidin-4-ones. DOI: 10.3762/bjoc.10.170.
- Z. Guan, M. Gjikaj, A. Schmidt, Heterocycles 2014, 10, 2356-2367. Syntheses of acridines and quinazoline-2,4(1H,3H)dithiones by rearrangements of N-heterocyclic carbenes of indazole. DOI: 10.3987/com-14-13082.
- N.-P. Pook, A. Adam, M. Gjikaj, Acta Crystallogr. 2014, E70, m160-m161. Bis[bis(2,2′-bipyridine-κ2N,N′)(carbonato-κ2O,O′)cobalt(III)]2-{4-[(carboxylatomethyl)carbamoyl]benzamido}acetate hexahydrate. DOI: org/10.1107/S160053681400631X.
- P. Wu, M. Gjikaj, Z. Anorg. Allg. Chem. 2014, 640,189-194. Transition Metal Complexes Containing Dihydrogen Hypodiphosphate in Eclipsed Conformation as Ligand: Preparation, Crystal Structure, Vibrational Spectra, and Thermal Behavior of K2[M(H2P2O6)2(H2O)2]·H2O (M = Co, Ni, Cu, and Zn). DOI: 10.1002/zaac.201300305.
- P. Wu, W. Brockner, M. Gjikaj, Z. Anorg. Allg. Chem. 2014, 640, 379-384. Preparation, Crystal Structure, Vibrational Spectra, and Thermal Behavior of Rb2H2P2O6·2H2O. DOI: 10.1002/zaac.201300341.
2013
- J. Maischkowski, M. Gjikaj, E. G. Hübner, B. Bergmann, I. B. Müller, D. E. Kaufmann. Eur. J. Org. Chem. 2013,2091-2105. Chemistry of Functionalized Quinoxaline N-Oxides, Part I: Efficient Synthesis of New Quinoxaline Derivatives by Selective Modification of 3-Chloro-6-fluoroquinoxalin- 2(1H)-one 4-Oxide. DOI: 10.1002/ejoc.201201569.
- M. Gjikaj, N.-P. Pook, F. Qarri, Acta Crystallogr. 2013, E69, m689. μ-Hexathiometadi-phosphato-bis[(1,4,7,10,13,16-hexaoxacyclooctadecane-κO)rubidium] acetonitrile disolvate. DOI: 10.1107/S1600536813032121.
- N.-P. Pook, M. Gjikaj, A. Adam, Acta Crystallogr. 2013, E69, o1731. Ethane-1,2-diaminium 2,2′-[terephthaloylbis(azanediyl)]diacetate tetrahydrate. DOI: 10.1107/S1600536813029632.
- M. Gjikaj, P. Wu, N.-P. Pook. Acta Crystallogr.2013, E69, i83. Hexaaquanickel(II) dihydrogen hypodiphosphate. DOI: 10.1107/S1600536813030717.
- T. Xie, Z. Guan, N.-P Pook, M. Gjikaj. Z. Naturforsch. 2013, 68b, 1095-1102. Ionic Liquids Based on Hexachloridometalate(V) Anions (Sb, Nb and Ta) and Nitrile-functionalized Pyridinium Cations. In: / DOI: 10.5560/ZNB.2013-3138.
2012
- V. A. Zapol’skii, E.-J. Vogt, M. Gjikaj, D. E. Kaufmann. Heterocycles 2012, 86, 1431-1447.Chemistry of Polyhalogenated Nitrobutadienes, 12: Synthesis of Novel, Highly Substituted Bi- and Tricyclic 5,6,7,8-Tetrahydro-4H-Chromen-5-ones. DOI: 10.3987/com-12-S(N)108.
- V. A. Zapol’skii, X. Yang, J. C. Namyslo, M. Gjikaj, D. E. Kaufmann. Synthesis 2012, 44, 885-894. Chemistry of Halonitroethenes, Part 2: Trichloronitroethane as a Building Block for the Novel Synthesis of 5-Chloro(nitro)-methyl-Substituted 1-Aryltetrazoles. DOI: 10.1055/s-0031-1289716.
- A. Dreger, N. Münster, B. Nieto-Ortega, F. J. Ramírez, M. Gjikaj, A. Schmidt. Arkivoc 2012, iii, 20-37. Pyrazolium-sulfonates. Mesomeric betaines possessing iminium-sulfonate partial structures. DOI: 10.3998/ark.5550190.0013.303.
- A. Rahimi, I. Pápai, Á. Madarász, M. Gjikaj, J. C. Namyslo, A. Schmidt, Eur. J. Org. Chem. 2012, 754-763. A Cyclobutene-1,2-bis(imidazolium) Salt as Preligand for Palladium-Catalysed Cross-Coupling Reactions: Properties and Applications. DOI: 10.1002/ejoc.201101378.
- M. Gjikaj, P. Wu, W. Brockner. Z. Anorg. Allg. Chem. 2012,638, 2144-2149. New Quaternary Alkali-Metal Hypodiphosphate Hydrates: Preparation,Crystal Structure, Vibrational Spectrum, and Thermal Behavior of K4P2O6·8H2O and Na2K2P2O6·8H2O in Comparison to Na4P2O6· 10H2O. DOI: 10.1002/zaac.201200130.
- P. Wu, Th. Wiegand, H. Eckert, M. Gjikaj. J. Solid State Chem. 2012, 194, 212-2018. New hypodiphosphates of the alkali metals: Synthesis, crystal structure and vibrational spectra of the hypodiphosphates(IV) M2[(H2P2O6)(H4P2O6)] (M=Rb and Cs). DOI: 0.1016/j.jssc.2012.05.015
2010
- M. Albrecht, M. Gjikaj, A. Schmidt, Tetrahedron 2010, 66, 7149-7154. Switchable pi-Complexes of Punicine Derivatives. DOI: 10.1016/j.tet.2010.06.079.
- V. A. Zapol’skii, J. C. Namyslo, M. Gjikaj, D. E. Kaufmann. Z. Naturforsch. 2010, 65b, 843-860. Chemistry of Polyhalogenated Nitrobutadienes, Part 9: Acyclic and Heterocyclic Nitro-enamines and Nitroimines from 2-Nitroperchlorobuta-1,3-diene. DOI: 10.1515/znb-2010-0710.
- M. Gjikaj, C. Ehrhardt. Acta Crystallogr. E66 (2010) i55. Strontium disodium hexathiodiphosphate(IV) octahydrate. DOI: 10.1107/S1600536810025316.
- M. Gjikaj, C. Ehrhardt. Acta Crystallogr. 2010, E66, i54. Calcium disodium hexathiodi-phosphate(IV) octahydrate. DOI: 10.1107/S1600536810025304.
- T. Xie, W. Brockner, M. Gjikaj. Z. Anorg. Allg. Chem. 2010, 636, 2633-2640. New Ionic Liquid Compounds Based on Tantalum Penta-chloride TaCl5: Synthesis, Structural, and Spectroscopic Elucidation of the (μ-Oxido)-Chloridotantalates(V) [BMPy][TaCl6], [BMPy]4 [(TaCl6)2(Ta2OCl10)], and [EMIm]2 [Ta2OCl10]. DOI: 10.1002/zaac.201000213.
- M. Gjikaj, J.-Ch. Leye, T. Xie, W. Brockner. CrystEngComm, 2010, 12, 1474-1480. Structural and spectroscopic elucidation of imidazolium and pyridinium based hexachloridophosphates and niobates. DOI: 10.1039/B919368E.
2009
- A. Schmidt, A. Rahimi, M. Gjikaj. Synthesis2009, 14, 2371-2378. Sulfanyl-Substituted [3]Cumulenes and Buta-1,3-dienes from a Tetrakis(pyridinium)-Substituted Butadiene. DOI: 10.1055/s-0029-1216861.
- E. Schaumann, G. Harms, F. Genrich, M. Gjikaj, G. Adiwidjaja. Tetrahedron 2009, 65, 5577-5587. Functionalized Esters as bis-Electrophiles in a Silicon-Induced Domino Synthesis of Annulated Carbocycles. DOI: 10.1016/j.tet.2009.01.119.
- S. Scherbakow, J. C. Namyslo, M. Gjikaj, A. Schmidt, Synlett 2009, 12, 1964-1968. Syntheses of Amidines from Thioamides, Mediated by the N-Heterocyclic Carbene Indazol-3-ylidene. DOI: 10.1055/s-0029-1217539.
- F. Stiemke, M. Gjikaj, D. E. Kaufmann. J. Organomet. Chem. 2009, 694,5-13. Novel Triphenylarsinyl-functionalized N-Heterocyclic Carbene Ligands in Palladium-catalyzed Reactions. DOI: 10.1016/j.jorganchem.2008.09.038.
- J.–Ch. Leye, M. Gjikaj, A. Adam, Eur. J. Inorg. Chem. 2009, 32,4837-4843. Syntheses, Crystal Structures, Thermal Properties and Spectroscopic Characterization of Complex Chloridotitanates(IV) with Ionic Liquids. DOI: 10.1002/ejic.200900507.
- T. Xie, W. Brockner, M. Gjikaj. Z. Naturforsch. 2009, 64b, 989-994. Formation and Crystal Structure of 2,3,5-TriphenyltetrazoliumHexachlorophosphate and Dichloro-phosphate(V), [TPT]+[PCl6]– and [TPT]+[PO2Cl2]–. DOI: 10.1515/znb-2009-0901.
- A. Rahimi, M. Gjikaj, A. Schmidt, Synlett 2009, 16, 2583-2588. Thieme Chemistry Journal Awardees - Where are they now? [3]-Cumulenes, Sulfanyl-substituted Butadienes and Functionalized Thiophenes Starting from Polypyridinium Salts. DOI: 10.1055/s-0029-1217952.
- M. Gjikaj, T. Xie, W. Brockner. Z. Anorg. Allg. Chem. 2009, 635, 2273-2278. Synthesis, Crystal Structure and Vibrational Spectrum of 2,3,5-Triphenyltetrazolium Hexachlorido-niobate(V) and Oxidotetrachloridoniobate(V) Aceto-nitrile, [TPT][NbCl6] and [TPT][NbOCl4 (CH3CN)]. DOI: 10.1002/zaac.200900174.
- M. Gjikaj, T. Xie, W. Brockner. Z. Anorg. Allg. Chem. 2009, 635, 1036-1046. Uncommon Compounds in Antimony Pentachloride Ionic Liquid Systems: Synthesis, Crystal Structure and Vibrational Spectra of the Complexes [TPT][SbCl6] and [Cl-EMIm][SbCl6]. DOI: 10.1002/zaac.200801392.
2008
- V. A. Zapol’skii, J. C. Namyslo, C. Altug, M. Gjikaj, D. E. Kaufmann. Synthesis 2008, 304-310. Chemistry of Polyhalogenated Nitrobutadienes, 6: A New Ring Closure Approach to Perfunctionalized 5-Nitropyrimidines. DOI: 10.1055/S-2007-990948.
- A. Schmidt, B. Snovydovych, M. Gjikaj, Synthesis 2008, 17, 2798-2804. N-Heterocyclic Carbenes of Indazole. Ring Enlargement Reactions by alpha-Haloketones and Dehalogenations of Vicinal Dihalides. DOI: 10.1055/s-2008-1067215.
- M. Gjikaj, P. Wu. Z. Anorg. Allg. Chem. 2008, 634, 1749–1754. [1,2-P2S8 ]2– – a New Member of the Thiophosphate Family: Synthesis, Crystal Structure and Vibrational Spectrum of [NH4(2.2.2-cryptand)]2[1,2-P2S8] and [NH4(18-crown-6)]2[1,2-P2S8]·H2O. DOI:10.1002/zaac.200800183.
- M. Gjikaj. Z. Kristallogr. NCS2008, 223, 1–2. Crystal structure of sodium strontium monothiophosphate nonahydrate, NaSr[PO3S]·9H2O. DOI 10.1524/ncrs.2008.0001.
- M. Gjikaj, J. Namyslo, W. Brockner. A. Adam. CrystEngComm2008, 10, 103-110. Crown-ether enclosure generated by ionic liquid components-Synthesis, crystal structures and Raman spectra of imidazolium-based salts and 18-crown-6. DOI: 10.1039/b708724c.
- M. Gjikaj. Z. Kristallogr. NCS2008, 223, 379-380. Crystal structure of bis(1,3-dimethyl-imidazolium hydrogen sulfate)-18-crown-6 (2:1), [C5H9N2]2[HSO4]2·C12H24O6. DOI 10.1524/ncrs.2008.0166
2007
- A. Schmidt, B. Snovydovych, T. Habeck, P. Dröttboom, M. Gjikaj, A. Adam, Eur. J. Org. Chem. 2007, 4909-4916. N-Heterocyclic Carbenes of 5-Haloindazoles Generated by Decarboxylation of 5-Haloindazolium-3-carboxylates. DOI: 10.1002/ejoc.200700192.
- V. A. Zapol’skii, J. C. Namyslo, M. Gjikaj, D. E. Kaufmann. Synlett 2007, 10, 1507-1512. Chemistry of Polyhalogenated Nitrobutadienes, 5: Synthesis and Reactions of Dichloromethyl Nitrovinylidene Ketones of Heterocycles. DOI: 10.1055/S-2007-982554.
- M. Gjikaj, W. Brockner. Z. Naturforsch. 2007, 62b, 1102–1106. Crystal structure,vibrational spectum and thermal behaviour of the ammonium hexathiohypodiphosphate dihydrate, (NH4)4[P2S6]·2H2O. DOI: 10.1002/chin.200740015.
- V. A. Zapol’skii, J. C. Namyslo, M. Gjikaj, D. E. Kaufmann. Arkivoc2007, i, 76-93. Chemistry of polyhalogenated nitrobutadienes, 4: Reactions of Mono-, Bis-, and Tris(4-tolylthio) Derivatives of 2-Nitroperchlor-1,3-butadiene with α,β-Bifunctional Nucleophiles. DOI: 10.3998/ark.5550190.0008.109.
- A. Schmidt, T. Habeck, A. S. Lindner, B. Snovydovych, J. C. Namyslo, A. Adam, M. Gjikaj, J. Org. Chem. 2007, 72, 2236–2239. Translation of Pseudo-Cross-Conjugation into Chemistry: Cycloadditions of Mesomeric Betaines to the New Ring System Spiro[indazole-3,3´-pyrrole]. DOI: 10.1021/jo062391r.
- M. Gjikaj, C. Ehrhardt. Z. Anorg. Allg. Chem. 2007, 633, 1048–1054. New Hexachalcogeno–Hypodiphosphates of the Alkali Metals: Synthesis, Crystal Structure and Vibrational Spectra of the Hexathiodiphosphate(IV) Hydrates K4[P2S6]·4H2O, Rb4[P2S6]·6H2O, and Cs4[P2S6]· 6H2O. DOI: 10.1002/zaac.200600339.
2006
- C. Ehrhardt, M. Gjikaj. Z. Kristallogr. NCS2006, 221, 437–438. Crystal structure of strontium hexathiodiphosphate(IV) decahydrate, Sr2[P2S6]·10H2O. DOI 10.1524/ncrs.2006.0144.
- F. Hinrichs, M. Gjikaj. Z. Kristallogr. NCS2006, 221, 121-122. Crystal structure of hexaaquamagnesium diammonium hexathiodiphosphate(IV) dihydrate, [Mg(H2O)6] (NH4)2[P2S6]·2H2O. DOI: 10.1524/ncrs.2006.0006.
- M. Gjikaj, C. Ehrhardt, W. Brockner. Z. Naturforsch. 2006, 61b, 1049-1053. Rb2P2S6 – A New Alkali Thiophosphate: Crystal Structure and Vibrational Spectra of Rubidium Hexathiodiphosphate(V).
- M. Gjikaj, A. Adam. Z. Anorg. Allg. Chem. 2006, 632, 2475-2480. Complexation of Alkali Triflates by Crown Ethers: Synthesis and Crystal Structure of [Na(12-crown-4)2][SO3CF3], [Na(15-crown-5)][SO3CF3], [Rb(18-crown-6)][SO3CF3], and [Cs(18-crown-6)][SO3CF3]. DOI: 10.1002/zaac.200600189.
- M. Gjikaj, W. Brockner, A. Adam. Z. Anorg. Allg. Chem. 2006, 632, 279-283. Stabilization of Highly Reactive “Naked Anions”: Synthesis, Crystal Structure and Vibrational Spectrum of [Na(12-crown-4)2]2[P2S6] · CH3CN.
2005
- W. Brockner, R. Branscheid, M. Gjikaj, A. Adam. Z. Naturforsch. 2005, 60b, 175-179. Synthesis, Crystal Structure and Vibrational Spectrum of Cobalt(II)orotate Trihydrate, [Co(C5N2O4H2)·3H2O. DOI: 10.1515/znb-2005-0208.
- M. Gjikaj, A. Adam, M. Duewel, W. Brockner. Z. Kristallogr. NCS2005, 220, 67-68. Crystal structure of bis[(18-crown-6)potassium] hexathiodiphosphate(V) acetonitrile disolvate, [K(18-Krone-6)]2[P2S6]·2CH3CN. DOI: 10.1524/ncrs.2005.220.14.
- M. Gjikaj, W. Brockner. Vib. Spectrosc. 2005, 31, 262-265. Synthesis and vibrational spectrum of potassium (18-crown-6)hexathiodiphosphate(V) acetonitrile solvate, [K(18-crown-6)]2[P2S6] ·2CH3CN. DOI: 10.1016/j.vibspec.2005.05.001.
- C. Ehrhardt, M. Gjikaj, W. Brockner. Thermochim. Acta2005, 432, 36-40. Thermal decomposition of cobalt nitrato compounds: Preparation of anhydrous cobalt(II)nitrate and its characterisation by Infrared and Raman spectra. DOI: 1.1016/j.tca.2005.04.010.