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https://scholarbank.nus.edu.sg/handle/10635/123026
DC Field | Value | |
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dc.title | 13C NMR SPECTROSCOPIC EVALUATION OF NUCLEOPHILICITY/BASICITY AND CAFFEINE-DERIVED N-HETEROCYCLIC CARBENE COMPLEXES | |
dc.contributor.author | KOH SIOK BEE | |
dc.date.accessioned | 2016-04-13T18:00:13Z | |
dc.date.available | 2016-04-13T18:00:13Z | |
dc.date.issued | 2015-12-28 | |
dc.identifier.citation | KOH SIOK BEE (2015-12-28). 13C NMR SPECTROSCOPIC EVALUATION OF NUCLEOPHILICITY/BASICITY AND CAFFEINE-DERIVED N-HETEROCYCLIC CARBENE COMPLEXES. ScholarBank@NUS Repository. | |
dc.identifier.uri | http://scholarbank.nus.edu.sg/handle/10635/123026 | |
dc.description.abstract | REACTION OF CAFFEINE WITH ALKYL HALIDES IS ONLY SUCCESSFUL WITH IODOMETHANE YIELDING (1-H)+I?. THE LOW REACTIVITY OF SUCH XANTHINES WAS EVALUATED BY 13C NMR SPECTROSCOPY USING COMPLEXES OF THE TYPE TRANS-[PDBR2(IPR2-BIMY)(L)] (IPR2-BIMY = 1,3-DIISOPROPYLBENZIMIDAZOLIN-2-YLIDENE; 2, L = CAFFEINE; 3, L = BN-XANT; 4, L = IPR-XANT). IT WAS FOUND THAT CAFFEINE AND THE BENZYL-SUBSTITUTED DERIVATIVE HAVE SIMILAR NUCLEOPHILICITY, WHILE THE ISOPROPYL ANALOGUE IS SLIGHTLY MORE NUCLEOPHILIC IN ACCORDANCE WITH THE INDUCTIVE EFFECTS OF THE SUBSTITUENTS. USING (1-H)+I? BIS- AND MONO-NHC COMPLEXES TRANS-[PDX2(IPR2-BIMY)(1)] (5) AND TRANS-[PDI2(CH3CN)(1)] (6) WERE PREPARED. HALIDE SCRAMBLING DUE TO DIFFERENT ANIONS IN THE ONE-POT REACTION MIXTURE WAS ENCOUNTERED AND STUDIED FOR THE FORMER. IN RELATION TO THE NUCLEOPHILICITY STUDY, A LINEAR CORRELATION (R2 = 0.8079) WAS FOUND TO EXIST BETWEEN THE 13CCARBENE NMR SHIFT OF IPR2-BIMY AND PKB VALUES OF COORDINATED AMINES IN TRANS-[PDBR2(IPR2-BIMY)(AMINE)] C | |
dc.language.iso | en | |
dc.subject | Caffeine, Carbene, NHC complexes, Ligand donor strength, Pd(II) complexes, Secondary amines | |
dc.type | Thesis | |
dc.contributor.department | CHEMISTRY | |
dc.contributor.supervisor | HUYNH, HAN VINH | |
dc.description.degree | Master's | |
dc.description.degreeconferred | MASTER OF SCIENCE | |
dc.identifier.isiut | NOT_IN_WOS | |
Appears in Collections: | Master's Theses (Open) |
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