5711-69-3Relevant academic research and scientific papers
Fluorescent monitoring of the reaction kinetics of nonfluorescent molecules enabled by a fluorescent receptor
Bai, Lin-Ming,Zhou, Hang,Liu, Wei-Er,Chai, Hongxin,Yang, Liu-Pan,Yan, Wei,Zhang, Wen,Yang, Hong-Hui,Jiang, Wei
supporting information, p. 3128 - 3131 (2019/04/02)
A facile fluorescent method was developed to quantitatively monitor the hydrolysis kinetics of nonfluorescent esters by using a fluorecent endo-functionalized molecular tube and its recognition ability towards small polar molecules in water. It is possible to determine the apparent rate constants and study the structure-activity relationship.
Solvolytic Behavior of Aliphatic Carboxylates
Matic, Mirela,Denegri, Bernard,Kronja, Olga
supporting information, p. 1477 - 1486 (2015/10/05)
The leaving group abilities (nucleofugalities) of a series of aliphatic carboxylates have been obtained by determining the nucleofuge-specific parameters (Nf and sf) from solvolysis rate constants of X,Y-substituted benzhydryl carboxylates in a series of aqueous ethanol mixtures by applyication of the linear free energy relationship (LFER) equation: log k = sf (Ef + Nf). These values can be employed to compare reactivities of carboxylates with those of other leaving groups previously included in the nucleofugality scale, and also to estimate the solvolysis rates of various carboxylates. It is confirmed that the inductive effect is the most important variable governing the reactivities of halogenated carboxylates in solution. Moreover, both the Hammett correlation and the solvolytic activation parameters have revealed a strong influence of the inductive effect on the nucleofugality of alkyl-substituted carboxylates. The reaction constants (sf) indicate that carboxylate substrates with weaker leaving groups solvolyze via later, more carbocation-like, transition states, which is in accord with the Hammond postulate. In addition, due to the weaker demand for solvation of transition states that produce more strongly stabilized benzhydrylium ions, in which more efficient charge delocalization occurs, the reaction constants (sf) obtained with most of the leaving groups investigated here increase as the polarity of the solvent decreases.
The Ever-surprising chemistry of boron: Enhanced acidity of phosphine·boranes
Hurtado, Marcela,Yanez, Manuel,Herrero, Rebeca,Guerrero, Andres,Juan Z. Davalos,Jose-Luis, M. Abboud,Khater, Brahim,Guillemin, Jean-Claude
supporting information; experimental part, p. 4622 - 4629 (2009/12/29)
The gas-phase acidity of a series of phosphines and their corresponding phosphine·borane derivatives was measured by FT-ICR techniques. BH 3 attachment leads to a substantial increase of the intrinsic acidity of the system (from 80 to 110 kJ mol-1). This acidity-enhancing effect of BH3 is enormous, between 13 and 18 orders of magnitude in terms of ionization constants. This indicates that the enhancement of the acidity of protic acids by Lewis acids usually observed in solution also occurs in the gas phase. High- level DFT calculations reveal that this acidity enhancement is essentially due to stronger stabilization of the anion with respect to the neutral species on BH3 association, due to a stronger electron donor ability of P in the anion and better dispersion of the negative charge in the system when the BH3 group is present. Our study also shows that deprotonation of ClCH2PH2 and ClCH 2PH2·BH3 is followed by chloride departure. For the latter compound deprotonation at the BH3 group is found to be more favorable than PH2 deprotonation, and the subsequent loss of Cl- is kinetically favored with respect to loss of Cl - in a typical SN2 process. Hence, ClCH2PH 2·BH3 is the only phosphine·borane adduct included in this study which behaves as a boron acid rather than as a phosphorus acid.
Formation of interim by-products in methanogenic degradation of butyrate
Fang, Herbert H. P.,Jia, Xiao-Shan
, p. 1791 - 1798 (2007/10/03)
The formation of interim by-products during the methanogenic degradation of butyrate was monitored and analyzed in this study. Two series of experiments were conducted at various butyrate concentrations and under the influence of increased partial pressur
Tin Oxide Surfaces. Part 11.-Infrared Study of the Chemisorption of Ketones on Tin(IV) Oxide
Harrison, Phillip G.,Maunders, Barry M.
, p. 1329 - 1340 (2007/10/02)
Infrared spectroscopy has been employed to study the chemisorption of a number of unsymmetrical ketones, RCOMe, onto tin(IV) oxide.In every case, the final product was the surface carboxylate, RCO2-(ads).The data suggested a mechanism involving initial coordination of the ketone to a surface tin site, followed by nucleophilic attack of a neighbouring hydroxyl group at the carbonyl carbon atom.
