Oxidation of organic compounds by ozone on a surface

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 chemiluntinescence in the IR region. The chemiluminescence quenching is of first-order with the effective rate constantk'. 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 E_a = 9.97±1.89 kcal mol^–1 and the pre-exponential factorA = (2.76±0.52) - 10⁶ were calculated from the temperature dependence ofk'.Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 375–378, February, 1996.     

New Synthesis of Mono-Halogenated Adamantanes

A variety of direct halogenations on the adamantane skeleton have been reported. For example, bromination of adamantane with bromine, which is considered to proceed through an ionic mechanism, gives high yield of 1-broinoadamsntane. In contrast to the ionic bromination of adamantane, chlorinations are much less selective^2,3,4,5. Photochloroadamantane of adamantane gives l-chloroadamntane and 2-chloroadamantane. Chlorination with t-butyl chloride in the presence of A1C1₃ gives rise to a mixture of 1-chloroadamantane and 1,3-dichloroadamantane.     

The electron spin resonance spectrum of the lithium trimer in hydrocarbon matrices

The lithium metal trimer, Li₃, has been prepared in adamantane using a rotating cryostat and its electron spin resonance spectrum recorded from 4 to 298 K. It has three magnetically equivalent Li nuclei with parameters a₇(3) = 33.1 G and g = 2.001. Consequently a change of matrix from argon to adamantane has no effect on the spin distribution and structure of Li₃ which appears to be a pseudorotating dynamic Jahn-Teller molecule at all temperatures. In adamantane it is stable for several hours even at room temperature.     

Carbon-13 nuclear magnetic resonance spectra: III—2-heteroadamantanes

The ¹³C n.m.r. spectra of some 2-heteroadamantanes and 1-substituted 2-heteroadamantanes are reported. The influences of the heteroatoms in the adamantane framework, and those of the substituents attached to it, on the ¹³C chemical shifts of the adamantane carbons are investigated and compared with related compounds such as the corresponding heterocyclohexane derivatives and 2-mono- and 2,2-disubstituted adamantanes. The nonadditivity of the substituent effects for 1-substituted 2-heteroadamantanes, especially for the geminally substituted carbons, is substantially confirmed. In addition, the influences of a missing CH₂ group and of NCH₃ carbons upon the ¹³C chemical shifts of the carbons in the adamantane system are described.     

An AIE singlet oxygen generation system based on supramolecular strategy

The design of supramolecular system s with efficient singlet oxygen generation has attracted considerable interests.Herein,an AIE-based singlet oxygen generation system with chemiluminescence properties is reported in aqueous media based on supramolecular host-guest assembly between a water-soluble pillar[5]arene(WP5) and an AIE photosensitizer(TPEDM).The formed supramolecular nanoparticles exhibit significant singlet oxygen generation ability as well as enhanced fluorescence.In addition,by introducing catalase,this H_2 O_2-responsive supramolecular system shows increased ~1 O_2 generation efficiency compared with the blank nanoparticles.An efficient chemiluminescence system can also be achieved by entrapping an energy donor adamantane derivative(AMPPD).Moreover,the present system can function as nanoreactors to perform the photooxidation of dopamine to form polydopamine with visible light irradiation.This wo rk provides a new strategy for the construction of ~1 O_2 generation system based on supramolecular nanomaterials,which has potential applications in the fields such as chemiluminescence imaging and controlled photocatalysis.     

Stereospecific Bromine Replacement in the Synthesis of 4(e) and 4(a)-Deuterioadamantan-2-ones

Stereospecific introduction of deuterium on the adamantane skeleton has been accomplished with LiAID(OCH₃)₃-CuI.     

Activities of polyhedral vanadium-containing silsequioxane-based catalysts for photo-assisted oxidation of hydrocarbons

The catalytic activity of a polyhedral vanadium-containing silsesquioxane ((c-C₅H₉)₇Si₇O₁₂VO, 1b) with a cubic core structure towards the selective photooxidation of benzene, cyclohexane, and adamantane was examined under O₂ (1 atm) at around 300 K. The reaction of benzene in the presence of 1b afforded phenol selectively, but the TON was low (≈1.4). Complex 1b showed high activity towards the reaction of cyclohexane (TON ≈16) and adamantane (TON≈7.0). The order of the reactivity of the C−H bonds in adamantane was tertiary C−H> secondary C−H. In addition to 1b, the mixtures of vanadyl bisacetylacetonate and incompletely-condensed silsesquioxanes with silanol functionality showed relatively high activities, although vanadyl bisacetylacetonate itself was not effective. The degradation of the catalysts in the course of the reaction was partly suppressed in the presence of molecular sieves-4A.     

Hydrogen storage in porous structures of adamantane‐based nitrogen‐heterocyclic ring with diamond‐like structure

Using the density functional theory and molecular mechanics methods, we calculated the binding energy and parameters about the primitive cell designed by us with the adamantane and the nitrogen heterocyclic ring, the vibrational frequencies about the small complexes. Grand canonical Monte Carlo simulations were performed to predict the capacities for the hydrogen storage and adsorption isotherms. The results show the positive effects of bigger specific surface area and pore volume on hydrogen storage and isosteric heat. The gravimetric hydrogen uptake of adamantane‐based nitrogen‐heterocyclic ring of quaterpyridyl can reach 9.02 wt % at room temperature and 100 bar. But the volumetric H₂ capacities of the four materials are low at T = 298 K because of weak interaction between the materials and H₂ molecule. © 2014 Wiley Periodicals, Inc.     

A short-cut from 1-acetyl adamantane to 2-(1-adamantyl)pyrroles

The oxime of 1-acetyl adamantane 2 is added to acetylene (KOH/DMSO, 70 °C, initial acetylene pressure 13 atm, 30 min) to afford the corresponding O-vinyl oxime 5 in 80% yield. The latter upon heating (DMSO, 120 °C, 1 h) gives 2-(1-adamantyl)pyrrole 3, 1-acetyl adamantane 1, and adamantane (6:3:1 mass ratio), the yield of the pyrrole 3 being 83% (based on 1-acetyl adamantane 1 consumed). Under harsher conditions (NaOH/DMSO, 130 °C, atmospheric pressure of acetylene, 4 h) oxime 2 reacts with acetylene to furnish pyrrole 3, 1-acetyl adamantane 1, 1-vinyl adamantane 9, and adamantane (6:7:3:1 mass ratio), with the isolated yield of pyrrole 3 reaching 34%. Under pressure (NaOH/DMSO, 120 °C, initial acetylene pressure 14 atm, 1 h) the same reaction leads to 2-(1-adamantyl)-1-vinylpyrrole 4 and ketone 1 in 48% (based on consumed ketone 1) and 24% yields, respectively. The pyrrole 4 is easily deprotected to the corresponding 1H-pyrrole 3 in 77% yield by treatment (aqueous MeCN) with Hg(OAc)₂ and NaBH₄.     

1,7-Trimethylenenorbornane. A novel member of the ‘adamantaneland’. Preliminary communication

A synthesis of the novel C₁₀H₁₆ hydrocarbon 1,7-trimethylenenorbornane ( 13 ), one of the 19 members of the adamantane family, is described.     

The EPR spectrum and structure of Cu(CO)3

Cu(CO)₃ is formed when Cu atoms and CO are allowed to react on adamantane at 77 K in a rotating cryostat. This carbonyl has most of the unpaired spin in a 4p_z orbital on Cu and is a trigonal planar π radical.     

The mild bromination of adamantane and (trimethylsilyl) adamantanes

Small amounts of H₂O or MeOH catalyze the reaction of Br₂ with adamantane and its 1-(trimethylsilyl) and 1,3-bis(trimethylsilyl) derivatives.     

Mechanism of the oscillating chemiluminescence reaction in the luminol-H2O2-KSCN-CuSO4-NaOH system

We conducted a simultaneous measurement of the potential of Cu²⁺, oxidation-reduction potential (ORP), and the chemiluminescence intensity in the luminol-H₂O₂-KSCN-CuSO₄-NaOH system. Two types of chemiluminescence were identified: a very faint continuous chemiluminescence and a strong oscillating chemiluminescence. The correlation between the potential of Cu²⁺ and ORP was measured experimentally for the first time. The effect of the initial concentrations of Cu²⁺ and H₂O₂ on the overall chemiluminescence intensity and the oscillation frequency was investigated in detail. Time-dependent concentration variation of the chemical species existing in the reaction system was calculated using a Runge-Kutta method. Two elementary chemical reactions not considered previously were taken into consideration. The overall experimental behavior was well explainable with our simulation. Based upon the comparison of our simulation with the experiment, we proposed that the strong oscillating chemiluminescence was induced by the reaction of luminol with ·OS(O)CN.     

Studies of two interrelated series of triiridatrithia-cyclohexane and trimetallatrithia (or trioxo)-adamantane rhodium and iridium complexes

From a comparativereview on the two title series of compounds, the first part of the paper describes the most salient structural and reactivity properties of these trimetallic complexes, including metal-metal bond formation, conformational changes, enantio, and diastereomorphism. The second part presentsnew results which extend the comparison to a series of trimetallatrioxo adamantane complexes. The single crystal X-ray diffraction of the parent compound [Rh₃{μ ₃−(OCH₂)₃CCH₃}(CO)₆]—a derivative of the commercially available tripod ligand 1,1,1tris (oxomethyl)ethane—is reported together with its crystal packing which is compared to that of its sulfido analog. The paper includes a discussion of the nucleophilic and electrophilic properties of the trimetalla trioxo adamantane rhodium complexes, based on semi-empirical extended Hückel calculations Dedicated to Professor Yves Jeannin on the occasion of his 65 th birthday.     

Inclusion complexes naphthalene-γ-cyclodextrin-adamantane and naphthalene-γ-cyclodextrin-o-carborane: the structure and luminescence properties

The luminescence properties of inclusion complexes of naphthalene-d₈ with γ-cyclodextrin (γ-CD) in the presence of adamantane or o-carborane added as third parties were studied in aqueous solutions. It was found that the structure of the cage compound added to the aqueous solution of the naphthalene-d₈@γ-CD complex completely determines the luminescence type of the ternary complex. For instance, the intensity of excimer fluorescence (EF) band increases considerably at the expense of reduction of the intensity of monomer fluorescence (MF) band on adding adamantane. On the contrary, adding o-carborane causes a decrease in the intensity of the EF band of naphthalene-d₈ and simultaneous appearance of MF in addition to long-lived room-temperature phosphorescence (RTP) whose lifetime increases from 1.5 s to 9.1 s after deoxygenation of the solution. Structural differences between the complexes affecting their behavior under the action of the third parties were explained using the results of semiempirical quantum chemical calculations.     

Arylation of adamantanamines: VI. Palladium-catalyzed arylation of amines and diamines of the adamantane series with 3-bromopyridine

Palladium-catalyzed amination of 3-bromopyridine with amines of the adamantane series in the presence of Pd(dba)₂/L [L = 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl or 2-dimethylamino-2′-dicyclohexylphosphinobiphenyl] gave the desired N-(pyridin-3-yl)-substituted amines in 74–97% yields. Diamines of the adamantane series reacted with 2 equiv of 3-bromopyridine in a complicated fashion to produce mono- and triaryl-substituted derivatives as by-products, while the yields of N,N′-diarylation products were 18–56%.     

The first selective one-pot synthesis of 1,3-dicarbonyl adamantanes from adamantane and 1,3-dimethyladamantane

A new approach to a simple one-pot functionalization of adamantane and 1,3-dimethyladamantane with CO and various nucleophiles in the presence of the superelectrophilic complex, CBr₄·2AlBr₃ provides access to important 1,3-dicarbonyl adamantanes with two new functional groups at the bridge-head positions.     

Application of NO2/supercritical CO2 system for safe and selective nitration of adamantanes and tertiary alkyl bromides

A concise safe approach for selective nitration and nitroxylation of tert-alkanes, in particular adamantane, and tert-alkyl bromides utilizing NO₂ in supercritical CO₂ medium has been established. Major reaction products were tert-alkyl nitro compounds and tert-alkyl nitrates depending on the reaction conditions.     

Chirality and spin density: Ab initio and density functional approaches

The spin distribution in a stable nitroxide biradical that shows ferromagnetic interactions in the solid phase has been studied at three levels of theory: First, at the UHF level; then, including correlation effects in UMP 2 calculations; and finally, the results are compared with the spin density obtained using the local density functional (LDF ) approximation. It is shown that LDF spin densities are closer to UMP 2 than to UHF predictions; the difference between the UHF and the (UMP 2, LDF ) results points to a redistribution of the spin repartition between N and O due to electronic correlation. For planar conformations of the NO group, there is symmetric distribution (D_2d) of the spin density on the adamantane skeleton. For nonplanar nitroxides, the molecule is chiral (C₂), which results in a breakdown of the spin transmission on part of the adamantane cage. © 1993 John Wiley & Sons, Inc.     

Ab-initio heats of formation of medium-sized hydrocarbons. 4. Perhydrotriquinacene

The ΔH_f of perhydrotriquinacene is obtained from that of adamantane and their enthalpy of isomerization computed by ab initio SCF methods, with corrections for zero-point and thermal effects.