Enthalpies Estimation of Formation of Monosubstituted Alkanes by Interaction Potential Index

The interaction potential index IPI（X） of 16 Br, C1, I, NO2, CN, CHO, COOH, CH3, CH： kinds of substituents X （X---OH, SH, NH2, ：CH2, C-CH, Ph, COCH3, COOCH3） were proposed, which are derived from the experimental enthalpies of formation △fHФ （g） values of monosubstituted straight-chain alkanes. Based on the IPI（X） and polarizability effect index, a simple and effective model was constructed to estimate the △fHФ （g） values of monosubstituted alkanes RX （including the branched derivatives）. The present model takes into account not only the contributions of the alkyl R and the substituent X, but also the contribution of the interaction between R and X. Its stability and prediction ability was confirmed by the results of leave-one-out method. Compared with previous reported studies, the obtained equation can be used to estimate enthalpies of formation for much more kinds of monosubstituted alkanes with less parameters. Thus, it is recommended for the calculation of the △fHФ（g） for the RX.

The Effect of the Monosubstituted Benzenes Functional Groups on the Inhibition of Methane Gas Biosynthesis

Aromatic compounds are inhibitors of methane biosynthesis in anaerobic treatment of solid wastes and industrial effluents. Anaerobic treatment of solid wastes and industrial effluents may be limited by the methanogenic bacteria inhibition exerted by these types of compounds, the production of biogas is not possible and the organic matter contained in the effluent is not reduced. These effluents poured in the nature can be the basis of the pollution. The objective of this study is to evaluate the effect of monosubstituted aromatic compounds functional groups on the methanogenic inhibition. The toxicity to acetoclastic methanogenic bacteria has performed in serum flasks, utilizing digested pig manure as inoculums, by measuring methane production. The nature of aromatic functional groups was observed to have a profound effect on the toxicity of the monosubstituted aromatics. Among the monosubstituted aromatic, the chlorobenzene was the most toxic with 50% of inhibition occurring at the concentration of 30.08 mg/l. In contrast, benzoic acid is the least inhibitory with IC50 of 2515.20 mg/l. The partition coefficient octanol/water (logPoct), an indicator of hydrophobicity, had a significant correlation with the methanogenic toxicity.

Para-selective borylation of monosubstituted benzenes using a transient mediator

Herein,we conceptualized a transient mediator approach that has the capability of para-selective C–H functionalization of monosubstituted aromatics.This approach is enabled by in situ generation of a versatile sulfonium salt via highly electrophilic phenoxathiine or thianthrene dication intermediate which can be readily generated from its sulfoxide with trifluoromethanesulfonic anhydride.Preliminary mechanistic study implied that the remarkable para selectivity might be related to the incredible electrophilicity of thianthrene dication intermediate.The versatility of this approach was demonstrated via paraborylation of various monosubstituted simple aromatics combining the sulfonium salt formation with further photocatalyzed transformation.

Syntheses and Characterization of Two Diiron Dithiolate Complexes Containing 4-Dimethylaminopyridine

Two diiron dithiolate complexes, （μ-pdt）Fe2（CO）5（C7H10N2） 3 and （μ-edt）-Fe2（CO）5（C7H10N2） 4 （pdt = -S（CH2）3S-, edt = -S（CH2）2S-）, have been synthesized and characterized by single-crystal X-ray diffraction. Complex 3 crystallizes in the monoclinic system, space group P21/c with a = 10.168（4）, b = 11.816（4）, c = 16.595（7） and β = 95.195（6）o; and complex 4 crystallizes in the orthorhombic system, space group P212121 with a = 9.317（3）, b = 11.898（4）, c = 34.006（10） .The distances of Fe（1）–Fe（2） are 2.5058（9） in 3 and 2.4942（10） in 4, falling in the normal range of Fe–Fe bond length （2.49～2.57 ）. The cyclic voltammograms show that 3 and 4 display irreversible reduction peaks （FeIFeI/ FeIFe0） at –1.717 V and –1.673 V vs. Ag/AgCl, respectively. With different acids, complex 3 has distinguishable behavior, two protonations in addition of HBF4-Et2O and single protonation besides HOAc-CH3CN, and complex 4 has a similar action to 3 with HOAc-CH3CN for a semblable structure.