3328-57-2Relevant articles and documents
REACTIONS OF PENTAFLUOROSULFANYLIMINODIHALOSULFANES, SF5N=SX2, WITH NUCLEOPHILES. PREPARATION AND CHARACTERIZATION OF PENTAFLUOROSULFANYLSULFINYLAMINE, SF5N=S=O
Thrasher, Joseph S.,Iannaccone, Gennaro A.,Hosmane, Narayan S.,Maurer, Donald E.,Clifford, Alan F.
, p. 537 - 552 (1981)
Reactions of SF5N=SF2 with sodium alkoxides and aryloxides have produced both the mono- and disubstituted derivatives SF5N=S(F)OR and SF5N=S(OR)2, where R=CH3, CH2CH=CH2, C6H5, p-C6H4NO2, p-C6H4Br, p-C6H4CN.The reaction of SF5N=SCl2 with AgNCO produced SF
Tyrosinase-like reactivity in a CuIII2(??-O) 2 species
Company, Anna,Palavicini, Sara,Garcia-Bosch, Isaac,Mas-Ballesteì?, Ruben,Que Jr., Lawrence,Rybak-Akimova, Elena V.,Casella, Luigi,Ribas, Xavi,Costas, Miquel
supporting information; experimental part, p. 3535 - 3538 (2009/05/07)
A study was conducted to demonstrate a bis(??-oxo)dicopper(III) species that binds and ortho-hydroxylates phenolates for reactivity of tyrosinase. The study characterized a metastable species from the low-temperature reaction of sodium p-chloro-phenolate (p-Cl-C6H4ONa) with a bis(??-oxo)dicopper(III) species. The study found that the addition of 10 equivalents of the sodium salt of p-chlorophenol at -90?°C can cause bleaching of the spectral features. High performance liquid chromatography (HPLC) analysis showed that 4-chlorocatechol was formed in 76% yield. The study used UV/UVis monitoring for reaction in acetone to determine the initial features to the bis(??-oxo) species and found that these features disappear after phenolate addition. The study observed that the activation parameters for the monophenolase reaction catalyzed by tyrosinase.
Do electrostatic interactions with positively charged active site groups tighten the transition state for enzymatic phosphoryl transfer?
Nikolic-Hughes, Ivana,Rees, Douglas C.,Herschlag, Daniel
, p. 11814 - 11819 (2007/10/03)
The effect of electrostatic interactions on the transition-state character for enzymatic phosphoryl transfer has been a subject of much debate. In this work, we investigate the transition state for alkaline phosphatase (AP) using linear free-energy relationships (LFERs). We determined fcat/K M for a series of aryl sulfate ester monoanions to obtain the Bronsted coefficient, βIg, and compared the value to that obtained previously for a series of aryl phosphorothioate ester dianion substrates. Despite the difference in substrate charge, the observed Bronsted coefficients for AP-catalyzed aryl sulfate and aryl phosphorothioate hydrolysis (-0.76 ± 0.14 and -0.77 ± 0.10, respectively) are strikingly similar, with steric effects being responsible for the uncertainties in these values. Aryl sulfates and aryl phosphates react via similar loose transition states in solution. These observations suggest an apparent equivalency of the transition states for phosphorothioate and sulfate hydrolysis reactions at the AP active site and, thus, negligible effects of active site electrostatic interactions on charge distribution in the transition state.
Free Radical Combination Reactions Involving Phenoxyl Radicals
Jonsson, M.,Lind, J.,Reitberger, T.,Eriksen, T. E.,Merenyi, G.
, p. 8229 - 8233 (2007/10/02)
The rates of phenoxyl radical reactions with the superoxide anion radical, O2.-, a peroxyl radical, HOC(CH3)2CH2OO., and an alkyl radical, HOC(CH3)2CH2., in aqueous solution have been measured for 15 different phenoxyl radicals by means of pulse radiolysis.In addition, the one-electron reduction potentials of 10 phenoxyl radicals have been determined.The fraction of electron transfer in the reaction of phenoxyl radicals with O2.- was determined by analysis of γ-irradiated samples.The experimental data can be accommodated by the Marcus theory for electron transfer, with the reorganization energy λ0 = 155 kJ/mol for the reaction between O2.- and phenoxyl radicals.
