700-58-3Relevant articles and documents
Temperature deactivation of excited Tb3+ in the presence of 1,2-dioxetane in acetonitrile
Ableeva, N. Sh.,Voloshin, A. I.,Ostakhov, S. S.,Kukovinets, A. G.,Korobeinikova, V. N.,et al.
, p. 1667 - 1671 (1994)
Quenching the fluorescence (FL) of terbium perchlorate by 2,2'-adamantane-2,2'-dioxide (1) was shown to have a chemical character and was caused by the formation of the 3+> complex.The dependence of the lifetime (τ) of FL of Tb.3+ in acetonitrile on the temperature and concentration of 1 has been studied.The temperature dependence of τ is caused by rearrangement of the inner sphere of the aquasolvate complexes of Tb3+, which leads to the replacement of H2O with MeCN and 1.The energy of replacing the H2O molecule in the inner sphere of complexes with a solvent molecule has been calculated. - Key words: chemiluminiscence, fluorescence, Tb(ClO4)3*6H2O, 2,2'-adamantane-2,2'-dioxide, lifetime, quenching.
Contrasting reactions of ketones and thioketones with alkyllithiums: A coordinated experimental and computational investigation
Bailey, William F.,Bartelson, Ashley L.,Wiberg, Kenneth B.
, p. 3199 - 3207 (2012)
The reaction of ketones with organolithium reagents generally proceeds by addition of the organometallic to the electrophilic carbon of the C=O group to give the lithium salt of a tertiary alcohol. The seemingly analogous reaction of thioketones with organolithiums is a fundamentally different process: such reactions typically afford a variety of products, and addition of the organolithium to carbon of the C=S group to give a thiol is a relatively unimportant component. Reactions of the stable thioketone, adamantantanethione (1), with several alkyllithiums (MeLi, n-BuLi and t-BuLi) in a variety of solvents have been studied in the first comprehensive investigation of the reactions of organolithiums with a representative alkyl-substituted thione. Reactions of 1 with n-BuLi or t-BuLi afforded 2-adamantanethiol (2) as the major product. In an effort to explain the marked difference in behavior of ketones and thioketones in reactions with organolithiums, transition states for both the addition and reduction reactions have been located at the B3LYP/6-311+G* level using acetone and thioacetone as model substrates. The transition states for the addition of dimeric MeLi to the C=O and C=S carbons of acetone and thioacetone were significantly different as a result of the small bond angles preferred by divalent sulfur, and this accounts for the much slower addition to a C=S carbon vis-a-vis a C=O group. Transition states for reduction of acetone and thioacetone by EtLi were similar, but the greater exothermicity of the reduction of the thioketone results in an earlier transition state and lower activation energy for this process than that for the reduction of a ketone. The possible role of radical-mediated processes in this chemistry is also discussed.
Solvent-cage effect (viscosity dependence) as a diagnostic probe for the mechanism of the intramolecular chemically initiated electron-exchange luminescence (CIEEL) triggered from a spiroadamantyl-substituted dioxetane
Adam, Waldemar,Bronstein, Irena,Trofimov, Alexei V.,Vasil'ev, Rostislav F.
, p. 958 - 961 (1999)
The excitation step of the intramolecular CIEEL generation in the triggered cleavage of spiroadamantyl-substituted dioxetane has been studied. The electron back-transfer (BET) process versus the direct chemiexcitation of the phenolate-anion emitter have been considered as mechanistic alternatives. The observed solvent-cage effect on the CIEEL generation, manifested by the increase of the singlet chemiexcitation yield at increased viscosity, provides evidence that the BET process operates in the intramolecular CIEEL mechanism.
In Vivo Chemiluminescent Imaging Agents for Nitroreductase and Tissue Oxygenation
Cao, Jian,Campbell, James,Liu, Li,Mason, Ralph P.,Lippert, Alexander R.
, p. 4995 - 5002 (2016)
Tissue oxygenation is a driving parameter of the tumor microenvironment, and hypoxia can be a prognostic indicator of aggressiveness, metastasis, and poor response to therapy. Here, we report a chemiluminescence imaging (CLI) agent based on the oxygen-dependent reduction of a nitroaromatic spiroadamantane 1,2-dioxetane scaffold. Hypoxia ChemiLuminescent Probe 2 (HyCL-2) responds to nitroreductase with ～170-fold increase in luminescence intensity and high selectivity for enzymatic reductase versus other small molecule reductants. HyCL-2 can image exogenous nitroreductase in vitro and in vivo in living mice, and total luminescent intensity is increased by ～5-fold under low oxygen conditions. HyCL-2 is demonstrated to report on tumor oxygenation during an oxygen challenge in H1299 lung tumor xenografts grown in a murine model as independently confirmed using multispectral optoacoustic tomography (MSOT) imaging of hemoglobin oxygenation.
Bimodal Evans-Polanyi Relationships in Hydrogen Atom Transfer from C(sp3)-H Bonds to the Cumyloxyl Radical. A Combined Time-Resolved Kinetic and Computational Study
Bietti, Massimo,Dilabio, Gino A.,Galeotti, Marco,Groff, Benjamin D.,Mayer, James M.,Romero-Montalvo, Eduardo,Salamone, Michela,Van Santen, Jeffrey A.
, p. 11759 - 11776 (2021)
The applicability of the Evans-Polanyi (EP) relationship to HAT reactions from C(sp3)-H bonds to the cumyloxyl radical (CumO?) has been investigated. A consistent set of rate constants, kH, for HAT from the C-H bonds of 56 substrates to CumO?, spanning a range of more than 4 orders of magnitude, has been measured under identical experimental conditions. A corresponding set of consistent gas-phase C-H bond dissociation enthalpies (BDEs) spanning 27 kcal mol-1 has been calculated using the (RO)CBS-QB3 method. The log kH′ vs C-H BDE plot shows two distinct EP relationships, one for substrates bearing benzylic and allylic C-H bonds (unsaturated group) and the other one, with a steeper slope, for saturated hydrocarbons, alcohols, ethers, diols, amines, and carbamates (saturated group), in line with the bimodal behavior observed previously in theoretical studies of reactions promoted by other HAT reagents. The parallel use of BDFEs instead of BDEs allows the transformation of this correlation into a linear free energy relationship, analyzed within the framework of the Marcus theory. The ΔG?HAT vs ΔG°HAT plot shows again distinct behaviors for the two groups. A good fit to the Marcus equation is observed only for the saturated group, with λ = 58 kcal mol-1, indicating that with the unsaturated group λ must increase with increasing driving force. Taken together these results provide a qualitative connection between Bernasconi's principle of nonperfect synchronization and Marcus theory and suggest that the observed bimodal behavior is a general feature in the reactions of oxygen-based HAT reagents with C(sp3)-H donors.
Highly selective production of 2-adamantanone by photocatalytic oxidation of adamantane
Song, Sun-Jung,Kim, Kyoung Seok,Kim, Kyung Hwan,Kim, Jong Beom,Kim, Jong-Ho,Kim, Keun-Sik,Shin, Honghyun,Cho, Dong Lyun
, p. 1052 - 1053 (2008)
2-Adamantanone was selectively produced by photocatalytic oxidation of adamantane in acetic acid using TiO2 powders. The reactions were carried out at ambient and acetic acid reflux temperatures with and without an oxidant. Adding oxidant in refluxing acetic acid under irradiation remarkably increased conversion and selectivity. Rutile TiO2 powders showed better conversion and selectivity in the presence of H2O2. The total conversion was 67% and the highest selectivity of 2-adamanta-none was 89%. Copyright
MECHANISM OF ACTIVATION AND CATALYSIS OF CHEMILUMINESCENCE BY Eu(fod)3 CHELATE IN THERMAL DECOMPOSITION OF ADAMANTYLIDENEADAMANTANE-1,2-DIOXETANE
Voloshin, A. I.,Sharipov, G. L.,Kazakov, V. P.,Tolstikov, G. A.
, p. 828 - 834 (1992)
Complexation of the chelate both with dioxetane and with adamantanone (2), the product of decomposition of dioxetane, have an important effect on chemiluminescence (CL) in thermal decomposition of adamantylideneadamantane-1,2-dioxetane (1) in the presence of Eu(fod)3 chelate.The stability constants of Eu(fod)3*1 and Eu(fod)3*2 complexes were obtained.It was found that Eu(fod)3 catalyzes and activates chemiluminescent decomposition of 1.The rate constant (k2) of decomposition of the Eu(III)*1 complex was determined from the kinetics of quenching of CL, and the activation parameters were determined from the temperature curve.Luminescence from the 5D1- level of the Eu(III) ion was detected in the CL spectrum and was correlated with direct (bypassing the triplet of the ligand) transfer of excitation energy from 2t* to the luminescent levels of Eu(III) in the geometrically distorted complex Eu(fod)3*2. Keywords: chemiluminescence, adamantylideneadamantane-1,2-dioxetane, Eu(fod)3, catalysis.
Chemiluminescence and catalysis of decomposition of dispiro(diadamantane-1,2-dioxetane) in the presence of EuIII and TbIII tris(benzoyltrifluoroacetonate) complexes
Kazakov,Voloshin,Ostakhov,Zharinova
, p. 386 - 393 (1998)
Catalysis of decomposition of dispiro(diadamantane-1,2-dioxetane) (1) in the presence of EuIII and TbIII tris(benzoyltrifluoroacetonate) complexes (Ln(btfa)3) accompanied by the formation of adamantanone (2) and chemiluminescence (CL) was studied. The rate constants (k2) of decomposition of compound 1 in the 1 · Ln(btfa)3 complexes and their stability constants (K1) have been determined. The Arrhenius parameters of decomposition of 1 (Ea = 22.4±0.7 kcal mol-1, logA = 10.2±0.8 for 1 · Tb(btfa)3 and Ea = 23.4±0.6 kcal mol-1, logA = 10.6±0.8 for 1 · Eu(btfa)3) and thermodynamic parameters of complex formation (ΔH = -5.5±0.5 kcal mol-1, ΔS = -10.4±0.7 e.u. for 1 · Tb(btfa)3 and ΔH = -5.8±0.5 kcal mol-1, ΔS = -10.9+0.7 e.u. for 1 · Eu(btfa)3) have been calculated from the temperature dependences of k2 and K1. The yields of excitation of the Ln(btfa)3 chelates φ*Eu = 0.021±0.006 and φ*Tb = 0.12±0.04 have been determined. A higher efficiency of the occupation of the 5D4-level of Tb3+ compared to those of the 5D1- and 5D0-levels of Eu3+ is caused by different efficiencies of the non-radiative energy dissipation in the Ln3+ ion after the intracomplex energy transfer from the 3n,π*-state of 2 to the resonance excited levels of lanthanides.
Selective and mild oxyfunctionalization of model polyolefins
Boaen, Nicole K.,Hillmyer, Marc A.
, p. 7027 - 7034 (2003)
The direct oxyfunctionalization of a model polyolefin, polyethylene-alt-propylene (PEP), was achieved utilizing a straightforward, mild process. In the presence of a manganese complex, manganese meso-tetra-2,6-dichlorophenylporphyrin acetate (Mn(TDCPP)OAc), imidazole, a phase transfer agent, and potassium peroxymonosulfate (Oxone), PEP was functionalized under ambient conditions without chain degradation. The primary oxidation products contained tertiary alcohols and ketones based on IR, 1H NMR, 13C NMR, and DEPT 13C NMR spectroscopy of the oxyfunctionalized products. The oxyfunctionalization of squalane, a small molecule, structural analogue of PEP, was also demonstrated. Spectroscopic analyses of the main products from the squalane oxidation were nearly identical with the functional groups identified in the PEP oxidation products. The degree of functionalization was modulated by changing the relative concentration of the oxidant, Oxone. The degree of functionalization and the thermal properties are reported for these new polymeric materials.
Enolates in 3-D: An experimental and computational study of deprotonated 2-adamantanone
Meyer, Matthew M.,Kass, Steven R.
, p. 4274 - 4279 (2010)
Deprotonation of 2-adamantanone (1) in the gas phase affords the corresponding β-enolate anion. This ion was independently prepared by the fluoride-induced desilylation of 4-trimethylsilyl-2-adamantanone, and its reactivity and thermodynamic properties we
