768-95-6Relevant articles and documents
Thermochemistry of Bridged-ring Substances. Enthalpies of Formation of Diamantan-1-, -3-, and -4-ol and of Diamantanone
Clark, Timothy,Knox, Trevor McO.,McKervey, M. Anthony,Mackle, Henry
, p. 1686 - 1689 (1980)
The enthalpies of combustion and of sublimation four mono-oxygenated diamantanes have been determined.The derived solid and gas-phase enthalpies of formation in kcal mol-1 at 298.15 K follow: diamantanone, -81.16+/-0.38, -56.53+/-0.41; diamantan-1-ol, -102.49+/-0.24, -74.30+/-0.28; diamantan-3-ol, -98.89+/-0.35, -71.14+/-1.10; diamantan-4-ol, -103.96+/-0.39, -75.80+/-0.39.Oxo and hydroxy group increments within the diamantane, adamantane, and cyclohexane series are discussed.Enthalpy differences betveen the isomeric diamantanols are compared with existing data from equilibration studies in solution.Comparisons are made between the experimental gas-phase enthalpies of formation and those obtained by molecular mechanics (empirical force field) calculations based on the Allinger MM1 force field model.
Regioselective intramolecular oxidation of unactivated C-H bonds by dioxiranes generated in situ
Yang,Wong,Wang,Tang
, p. 6611 - 6612 (1998)
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Site-isolated porphyrin catalysts in imprinted polymers
Burri, Estelle,Oehm, Margarita,Daguenet, Corinne,Severin, Kay
, p. 5055 - 5061 (2005)
A meso-tetraaryl ruthenium porphyrin complex having four polymerizable vinylbenzoxy groups (2) has been synthesized by reaction of pyrrole with 4-(vinylbenzoxy)benzaldehyde and subsequent metalation with [Ru 3(CO)12]. The porphyrin complex was immobilized by copolymerization with ethylene glycol dimethacrylate. The resulting polymer P2 was found to catalyze the oxidation of alcohols and alkanes with 2,6-dichloropyridine N-oxide without activation by mineral acids. Under similar conditions, the homogeneous catalyst 2 was completely inefficient. By using diphenylaminomethane and 1-aminoadamantane as coordinatively bound templates during the polymerization procedure, the molecularly imprinted polymers P3 and P4 have been synthesized. Compared with the polymer P2, the imprinted catalysts displayed a significantly increased activity with rate enhancements of up to a factor of 16.
Schleyer,Nicholas
, p. 2700,2706 (1961)
Schleyer et al.
, p. 4195 (1964)
Foiled conjugation in α-oximino carbocations
Creary, Xavier,Jiang, Ziqi
, p. 3482 - 3489 (1996)
The 4-CHNOCH3 group is a cation-stabilizing group when placed in the para-position of a cumyl cation. The effect of this group on cumyl cations when flanked by adjacent methyl groups has now been determined. Solvolysis rates of 3,5-(CH3)2-4-(CHNOCH3)cumyl trifluoroacetates are somewhat slower than that of 3,5-dimethylcumyl trifluoroacetate. This is attributed to steric inhibition of the cation-stabilizing resonance effect of the p-oximino group. In a 1-adamantyl system, where an α-oximino group has been placed directly adjacent to a developing cationic center, solvolysis rates relative to 1-adamantyl mesylate are slowed by a factor of 108. This is attributed a cation-destabilizing inductive effect where geometric constraints prevent stabilizing orbital overlap of the cationic center with the adjacent α-oximino group. This cation-destabilizing effect fades in the homoadamantyl and the bicyclo[3.3.1]nonyl systems, where rate-retarding effects are 1.6 × 104 and 1.5 × 102, respectively. The behavior of geometrically constrained α-oximino cations parallels that of analogously constrained allylic cations. Computational studies at the HF/6-31G* level indicate that twisting the α-oximino group out of planarity with a tertiary cationic center into a perpendicular arrangement decreases stabilization by 21 kcal/mol. These studies suggest that conjugative interactions, and not ground state destabilization, are the most important factors in controlling rates of formation of α-oximino cations from mesylates and trifluoroacetates.
Oxidation of organic compounds by ozone on a surface: 1. Ozonization of adamantane on silica gel
Avzyanova,Kabal'nova,Shereshovets
, p. 360 - 362 (1996)
Adamantanol was obtained by the ozonization of adamantane, at -78°C, adsorbed on silica gel. Ozone does not decompose on silica gel in the absence of a substrate. Ozonization of adamantane on silica gel is accompanied by chemiluminescence in the IR region. The chemiluminescence quenching is of first-order with the effective rate constant k′. In the range from 0.4 to 5 mmol, k′ depends linearly on the amount of adamantane adsorbed on the silica gel. The activation energy Ea = 9.97±1.89 kcal mol-1 and the pre-exponential factor A = (2.76±0.52)·106 were calculated from the temperature dependence of k′.
Dissociative electron transfer to dihaloalkanes. electrochemical reduction of 1,3-dihaloadamantanes, 1,4-dihalobicyclo[2.2.2]octanes, and 1,3-dihalobicyclo[1.1.1]pentanes
Adcock, William,Clark, Christopher I.,Houmam, Abdelaziz,Krstic, Alexander R.,Pinson, Jean,Savéant, Jean-Michel,Taylor, Dennis K.,Taylor, Julian F.
, p. 4653 - 4659 (1994)
The electrochemical reductive cleavage of the title compounds was investigated by means of cyclic voltammetry and electrolysis. The reaction is a two-electron process that yields competitively ring closure (or fragmentation) products and the monohalide resulting from the expulsion of the best leaving halide ion. Product selection occurs at the level of the carbanion resulting from the reduction of the one-electron reductive cleavage radical. In the formation of the latter, electron transfer and bond breaking are concerted; thus, the anion radical is not involved as an intermediate. The variations in the reduction potential observed in the three series of compounds can be rationalized, by application of the dissociative electron-transfer theory, as related variations of the bond dissociation energy of the first carbon-halogen bond to be cleaved. In the adamantane and bicyclopentane series, these are mainly the result of through-space-bonded interactions in the one-electron reductive cleavage radical and, to a lesser extent, in the starting dihalide itself, while through-bond interactions appear to prevail in the bicyclooctane series.
Hydrogen-atom and oxygen-atom transfer reactivities of iron(
Banerjee, Sridhar,Haukka, Matti,Hossain, Md. Kamal,Huelsmann, Ricardo Dagnoni,Martendal, Edmar,Munshi, Sandip,Nordlander, Ebbe,Paine, Tapan K.,Peralta, Rosely,Singh, Reena,Sinha, Arup,Valiati, Andrei Felipe,Wendt, Ola F.,Xavier, Fernando,Yiga, Solomon
supporting information, p. 870 - 884 (2022/02/01)
A series of iron(ii) complexes with the general formula [FeII(L2-Qn)(L)]n+ (n = 1, L = F?, Cl?; n = 2, L = NCMe, H2O) have been isolated and characterized. The X-ray crystallographic data reveals that
Aqueous Microdroplets Capture Elusive Carbocations
Kumar, Anubhav,Mondal, Supratim,Banerjee, Shibdas
supporting information, p. 2459 - 2463 (2021/02/16)
Carbocations are short-lived reactive intermediates in many organic and biological reactions that are difficult to observe. This field sprung to life with the discovery by Olah that a superacidic solution allowed the successful capture and nuclear magnetic resonance characterization of transient carbocations. We report here that water microdroplets can directly capture the fleeting carbocation from a reaction aliquot followed by its desorption to the gas phase for mass spectrometric detection. This was accomplished by employing desorption electrospray ionization mass spectrometry to detect a variety of short-lived carbocations (average lifetime ranges from nanoseconds to picoseconds) obtained from different reactions (e.g., elimination, substitution, and oxidation). Solvent-dependent studies revealed that aqueous microdroplets outperform organic microdroplets in the capture of carbocations. We provide a mechanistic insight demonstrating the survival of the reactive carbocation in a positively charged aqueous microdroplet and its subsequent ejection to the gas phase for mass spectrometric analysis.
KF-Promoted copper-catalyzed highly efficient and selective oxidation of methane and other alkanes with a dramatic additive effect
Chen, Wei,Chen, Xiaoyan,Fan, Wu,Li, Suhua,Liu, Luyao
, p. 4962 - 4968 (2021/07/26)
Highly efficient oxidation of methane to methyl trifluoroacetate mediated by CuCl/KF/K2S2O8in trifluoroacetic acid (TFA) and trifluoroacetic anhydride (TFAA) is described. The additive effect has been systematically evaluated and potassium fluoride (KF) was identified as the most effective promoter among the salts screened. KF is conjectured to exhibit the salt effect to promote the [SO4˙]?radical to escape the solvent cage based on control experiments. Cyclohexane and adamantane could also be efficiently oxidized into benzene or corresponding trifluoroacetates.