A Stable Iridabenzene Formed from an Iridacyclopentadiene Where the Additional Ring-Carbon Atom Is Derived from a Thiocarbonyl Ligand

2008 ◽  
Vol 27 (3) ◽  
pp. 451-454 ◽  
Author(s):  
George R. Clark ◽  
Paul M. Johns ◽  
Warren R. Roper ◽  
L. James Wright
Keyword(s):  
Carbon Atom ◽  
Ring Carbon ◽  
Ring Carbon Atom

At a Ring Carbon Atom

2004 ◽  
pp. 1
Author(s):  
N. Haider ◽  
W. Holzer
Keyword(s):  
Carbon Atom ◽  
Ring Carbon ◽  
Ring Carbon Atom

scholarly journals Rhenium(I) Carbonyl Complexes of 2,4,6-Tris(2-pyridyl)-1,3,5-triazine (TPT). Rhenium(I)-Promoted Methoxylation of the Triazine Ring Carbon Atom in Dinuclear Rhenium Complexes

2001 ◽  
Vol 40 (12) ◽  
pp. 2769-2777 ◽  
Author(s):  
Xiaoyuan Chen ◽  
Frank J. Femia ◽  
John W. Babich ◽  
Jon A. Zubieta
Keyword(s):  
Carbon Atom ◽  
Carbonyl Complexes ◽  
Triazine Ring ◽  
Rhenium Complexes ◽  
Ring Carbon ◽  
Ring Carbon Atom

scholarly journals Catabolism of Arylboronic Acids by Arthrobacter nicotinovorans Strain PBA

2003 ◽  
Vol 69 (7) ◽  
pp. 4263-4267 ◽  
Author(s):  
Ana C. Negrete-Raymond ◽  
Barbara Weder ◽  
Lawrence P. Wackett
Keyword(s):  
Carbon Atom ◽  
Oxygen Atom ◽  
Boronic Acid ◽  
Phenylboronic Acid ◽  
Boronic Acids ◽  
Ring Carbon ◽  
Arylboronic Acids ◽  
Arthrobacter Nicotinovorans ◽  
Ring Carbon Atom

ABSTRACT Arthrobacter sp. strain PBA metabolized phenylboronic acid to phenol. The oxygen atom in phenol was shown to be derived from the atmosphere using 18O2. 1-Naphthalene-, 2-naphthalene-, 3-cyanophenyl-, 2,5-fluorophenyl-, and 3-thiophene-boronic acids were also transformed to monooxygenated products. The oxygen atom in the product was bonded to the ring carbon atom originally bearing the boronic acid substituent with all the substrates tested.

NUCLEAR MAGNETIC RESONANCE STUDIES OF THE PROTONATION OF WEAK BASES IN FLUOROSULPHURIC ACID: III. METHYLBENZENES AND ANISOLE

1964 ◽  
Vol 42 (3) ◽  
pp. 502-513 ◽  
Author(s):  
T. Birchall ◽  
R. J. Gillespie
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Carbon Atom ◽  
Proton Magnetic Resonance ◽  
Exchange Process ◽  
Proton Exchange ◽  
Magnetic Resonance Studies ◽  
Ring Carbon ◽  
Weak Bases ◽  
Ring Carbon Atom

The proton magnetic resonance spectra of solutions of mesitylene, durene, pentamethylbenzene, hexamethylbenzene, m- and p-xylenes, and anisole have been studied in fluorosulphuric acid and protonation on the ring carbon atom established. Rates of proton exchange have been measured and activation energies calculated for the proton exchange process. Intermolecular exchange with the solvent is suggested as the most probable exchange process in all cases.

Functionalisation of Cycloheptatrienones at the C-3 Ring Carbon Atom

Synthesis ◽  
1975 ◽  
Vol 1975 (03) ◽  
pp. 189-191 ◽  
Author(s):  
Bruno RICCIARELLI ◽  
Gino BIGGI ◽  
Renzo CABRINO ◽  
Francesco PIETRA
Keyword(s):  
Carbon Atom ◽  
Ring Carbon ◽  
Ring Carbon Atom

ChemInform Abstract: FUNCTIONALISATION OF CYCLOHEPTATRIENONES AT THE C-3 RING CARBON ATOM

1975 ◽  
Vol 6 (24) ◽  
pp. no-no
Author(s):  
B. RICCIARELLI ◽  
G. BIGGI ◽  
R. CABRINO ◽  
F. PIETRA
Keyword(s):  
Carbon Atom ◽  
Ring Carbon ◽  
Ring Carbon Atom

N-Picrylethylenediamine – methoxide ion interactions: N-deprotonation and σ-complex formation reactions

1981 ◽  
Vol 59 (5) ◽  
pp. 795-801 ◽  
Author(s):  
Erwin Buncel ◽  
Masashi Hamaguchi ◽  
Albert R. Norris
Keyword(s):  
Carbon Atom ◽  
Dimethyl Sulfoxide ◽  
Solvent Mixtures ◽  
Absorption Properties ◽  
Visible Absorption ◽  
Ring Carbon ◽  
Ion Interactions ◽  
Uv Visible ◽  
Methoxide Ion ◽  
Ring Carbon Atom

The interactions of N-picrylethylenediamine as the HCl salt (PED) with methoxide ion in dimethyl sulfoxide – methanol (DMSO/MeOH) media and with 1,4-diazabicyclooctane in dimethyl sulfoxide have been investigated spectrophotometrically at 25.0 °C. Evidence is presented to show that, in solvent mixtures rich in dimethyl sulfoxide (e.g. 95/5, V/V, DMSO/MeOH), deprotonation reactions at the nitrogen centres on the ethylenediamine occur in preference to reactions in which σ-complexes are formed via addition of CH3O− to one or more ring carbon atoms. The initial 1:1 interaction of CH3O− and PED results in the rapid, reversible deprotonation of the NH centre while the 2:1 interaction is associated with rapid, reversible abstraction of H+ from the NH3+ centre. At mole ratios of CH3O− to PED > 3 a σ-complex is formed as a result of the addition of CH3O− ion to a C-3 ring carbon atom of the di-deprotonated PED. The uv–visible absorption properties of these various species are reported and compared to the properties of corresponding species formed in related systems.

A theoretical study of the nitration of eugenol with the nitronium ion

2011 ◽  
Vol 76 (12) ◽  
pp. 1529-1548
Author(s):  
Ricardo Ugarte ◽  
Guillermo Salgado ◽  
Luis Basáez
Keyword(s):  
Carbon Atom ◽  
Gas Phase ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Reaction Pathway ◽  
Minimum Energy ◽  
Stationary Points ◽  
Functional Theory ◽  
Π Complex ◽  
Ring Carbon Atom

The nitration of eugenol was investigated by using density functional theory (DFT) calculations. Potential energy surface and molecular electrostatic potential of eugenol was constructed in order to find, respectively, the minimum energy conformers and the possible sites for electrophilic attack. Stationary points were located and characterized at the B3LYP/6-311++G(2d,2p) level of theory. A strongly bound π-complex was found, in which the distance between the nitrogen atom of the NO2 moiety and the C1 carbon atom of the aromatic ring is 2.15 Å in the gas phase and 2.06 Å in dichloromethane. The most favorable σ-complex or Wheland intermediate is the result from the interaction between the nitrogen and the C6 ring carbon atom. The transition state that connects both complexes is more resembling the σ-complex. The nitronium ion exothermically reacts with eugenol to give the π-complex without an energy barrier. The next stage of the reaction pathway, π-complex → σ-complex, is endothermic and involves a Gibbs energy of activation of 7.9–8.0 kcal mol–1 (gas phase) and 8.3–8.9 kcal mol–1 (CH2Cl2).

An atomic resolution study of a carbide phase in platinum

1992 ◽  
Vol 50 (1) ◽  
pp. 20-21
Author(s):  
M.J. Witcomb ◽  
M.A. O'Keefe ◽  
CJ. Echer ◽  
C. Nelson ◽  
J.H. Turner ◽  
...  
Keyword(s):  
Solid Solution ◽  
Carbon Atom ◽  
Carbide Phase ◽  
Structural Changes ◽  
Critical Role ◽  
Alloy System ◽  
Atomic Resolution ◽  
Excess Carbon ◽  
Interstitial Carbon ◽  
Resolution Study

Under normal circumstances, Pt dissolves only a very small amount of interstitial carbon in solid solution. Even so, an appropriate quench/age treatment leads to the formation of stable Pt2C {100} plate precipitates. Excess (quenched-in) vacancies play a critical role in the process by accommodating the volume and structural changes that accompany the transformation. This alloy system exhibits other interesting properties. Due to a large vacancy/carbon atom binding energy, Pt can absorb excess carbon at high temperatures in a carburizing atmosphere. In regions rich in carbon and vacancies, another carbide phase, Pt7C which undergoes an order-disorder reaction was formed. The present study of Pt carburized at 1160°C and aged at 515°C shows that other carbides in the PtxC series can be produced.

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