- Resonance Raman investigation on the interaction of styrene and 4-methyl styrene oligomers on sulphated titanium oxide
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In order to understand the nature of the interaction that gives rise to the yellow-orange colour observed when styrene or 4-methyl styrene are put in contact with sulphated TiO2, the resonance Raman spectra of such systems, including deuterated styrene (ring-deuterated d5 and perdeuterated d8) and allylbenzene were investigated. In all cases a substantial enhancement of the ring v(CC) stretching mode was observed. A charge transfer process involving a transition from the ring π-electrons to the empty d-π orbitals of titanium was ascribed responsible for the absorption in the visible. Two types of resonance Raman spectra were observed depending on the excitation wavelength, which can be explained by the presence of two kinds of oligomers, saturated and unsaturated, on the surface of the oxide with the former giving rise to a Raman enhancement at a higher excitation energy.
- Noda,Sala
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- Palladium-Catalyzed Distal C?H Selenylation of 2-Aryl Acetamides with Diselenides and Selenyl Chlorides
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A convenient and effective method of palladium-catalyzed C?H selenylation of the 2-aryl acetamides assisted with removable 8-aminoquinoline with readily available diselenides and selenyl chlorides has been developed. This selenylation reaction is scalable and tolerates a wide range of functional groups, providing a straightforward way of the preparing unsymmetrical diaryl selenides and dibenzoselene-pinone. Preliminary mechanistic studies indicated that a single-electron transfer type mechanism and facile C?H metalation are operative. (Figure presented.).
- Gu, Linghui,He, Meicui,Ma, Wenbo,Tan, Yuqiang,Wang, Yang,Wang, Yuchi,Zhang, Chunran
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supporting information
p. 5708 - 5715
(2020/12/01)
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- Distal Weak Coordination of Acetamides in Ruthenium(II)-Catalyzed C?H Activation Processes
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C?H activations with challenging arylacetamides were accomplished by versatile ruthenium(II) biscarboxylate catalysis. The distal C?H functionalization offers ample scope—including twofold oxidative C?H functionalizations and alkyne hydroarylations—throug
- Bu, Qingqing,Rogge, Torben,Kotek, Vladislav,Ackermann, Lutz
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supporting information
p. 765 - 768
(2018/01/17)
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- The synthesis of [phenyl-2H5]gluconasturtiin and its metabolites for metabolic studies
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The synthesis of a deuterium labelled glucosinolate, [2H 5]gluconasturtiin, is described starting from [2H 5]bromobenzene. The potential metabolites of the glucosinolate, namely the [phenyl-2H5/
- Morrison, John J.,Botting, Nigel P.
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p. 897 - 907
(2007/10/03)
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- On the Generation and Characterization of the Spirooctadienyl Anion in the Gas Phase
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Three routes have been explored in both a high-pressure chemical ionization (CI) source and a low-pressure Fourier transform ion cyclotron resonance (FT-ICR) cell to generate the spirooctadienyl anion in the gas phase: (i) proton abstraction from spiroocta-4,6-diene; (ii) expulsion of trimethylsilyl fluoride by phenyl ring participation following fluoride anion attack upon the silicon centre of 2-phenylethyl trimethylsilane; and (iii) collisionally induced dissociation (CID) of the carboxylate anion of 3-phenylpropanoic acid via carbon dioxide loss.From comparison of the CID spectra of various reference (1-) ions with those of the (1-) ions with those of the (1-) ions which could be generated via the routes (i) and (iii) in the CI source it can be concluded that only the third route yields a (1-) in whose CID spectrum is not inconsistent with the one expected for the spirooctadienyl anion.In the FT-ICR cell (1-) ions are generated along all three routes; their structures have been identified by specific ion-molecule reactions and appear to be different.Route (i) yields an α-methyl benzyl anion, probably due to isomerization within the ion-molecule complex formed.An ortho-ethylphenyl anions is formed along route (ii), presumably due to an intramolecular ortho proton abstraction in the generated trimethylsilyl fluoride solvated 2-phenylethyl primary carbanion.The (1-) ion formed along route (iii) shows reactions similar to those of the 1,1-dimethylcyclohexadienyl anion which is structurally related to the spirooctadienyl anion.Furthermore, the (1-) ion generated via route (iii) reacts with hexafluorobenzene under expulsion of only one hydrogen fluoride molecule which contains exclusively one of the original phenyl ring hydrogen atoms.On the basis of all these observations it is therefore quite likely that the spirooctadienyl anion is formed by collisionally induced decarboxylation of the 3-phenylpropanoic acid carboxylate anion and can be a long-lived and stable species in the gas phase.
- Maas, Wilfrid P. M.,Veelen, Peter A. van,Nibbering, Nico M. M.
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p. 546 - 558
(2007/10/02)
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- Preparation of deuterium labelled styrenes and divinylbenzenes
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Specifically deuteriated styrenes (1-d, 2,2'-d2, and ring labelled), perdeuteriostyrene, and specifically deuteriated divinylbenzenes (1,1'-d2 2,2,2',2'-d4, and ring labelled) have been prepared by transforming suitably labelled phenylacetic (hydride or d
- Werstiuk, Nick Henry,Timmins, George
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p. 1072 - 1076
(2007/10/02)
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- INTRAMOLECULAR RING-TO-RING PROTON TRANSFER IN GASEOUS ( omega -PHENYLALKYL)BENZENIUM IONS.
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Gaseous (2-phenylethyl)benzenium and (3-phenylpropyl)benzenium ions are generated easily by mass spectrometric loss of CO//2H from the positive molecular ions of the corresponding 1-( omega -phenylalkyl)-1,4-dihydrobenzoic acids. The major secondary fragm
- Kuck,Baether,Gruetzmacher
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p. 7154 - 7157
(2007/10/06)
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