A NOVEL LEWIS ACID-CATALYZED REACTION OF O-ALKYL-O-ACETONYL-PHOSPHORAMIDES

O-AIkyl-O-acetonyl-phosphoramides refhuxing in binzene in the presence of the Lewis acid BE_3 ·Ey_2O resulted in the formtion of new bicyclic crganophosphlorus compounds 2-alkoxy -5-methyl-6-oxa-7-(hydmxy-methyl)methylene-2-oxo-3,1,2- oxazaphosphabicyclo[3.2.0]heptanes The structure of the products was elucidated by IR,~1H,^(13)C,^(31)P-NMR and Mass specera.

Theoretical Studies on Mechanism and Rate Constant of Gas Phase Hydrolysis of Glyoxal Catalyzed by Sulfuric Acid

The gas phase hydration of glyoxal （HCOCHO） in the presence of sulfuric acid （H2SO4） were studied by the high-level quantum chemical calculations with M06-2X and CCSD（T） theoretical methods and the conventional transition state theory （CTST）. The mechanism and rate constant of the five different reaction paths are consid- ered corresponding to HCOCHO＋H2O, HCOCHO＋H2O… H2O, HCOCHO… H2O＋H2O, HCOCHO＋H2O… H2SO4 and HCOCHO… H2O＋H2SOa. Results show that H2SO4 has a strong catalytic ability, which can significantly reduce the energy barrier for the hydration reaction of glyoxal. The energy barrier of hydrolysis of glyoxal in gas phase is lowered to 7.08 kcal/mol from 37.15 kcal/mol relative to pre-reactive complexes at the CCSD（T）/6- 311＋＋G（3df, 3pd）//M06-2X/6-311＋＋G（3df, 3pd） level of theory. The rate constant of the H2SO4 catalyzed hydrolysis of glyoxal is 1.34×10-11 cm3/（molecule.s）, about 1013 higher than that involving catalysis by an equal number of water molecules, and is greater than the reaction rate of glyoxal reaction with OH radicals of 1.10×10-11 cm3/（molecule·s） at the room temperature, indicating that the gas phase hydrolysis of glyoxal of H2SO4 catalyst is feasible and could compete with the reaction glyoxal＋OH under certain atmospheric condi- tions. This study may provide useful information on understanding the mechanistic features of inorganic acid-catalyzed hydration of glyoxal for the formation of oligomer.

Synthesis,Characterization and Applications of MoO3-Fe3O4 Nanocomposite Material

In the present investigation,a series of nanocomposite material such as MoO3,Fe3O4 synthesized by co-precipitation method and Beta cyclodextrin(β-CD)doped MoO3-Fe3O4 and Graphite doped MoO3-Fe3O4 have been synthesized successfully by Sol-Gel method.Synthesized nanomaterials were characterized in detail by XRD,FT-IR,TEM-HRTEM,UV-Vis DRS techniques.The crystalline size was in the range of 10±2 nm.The activity of the prepared material as a heterogeneous catalyst was successfully tested on the organic reaction of synthesis of substituted m-Chloro-Nitrobenzene and it was found to give excellent yield.

Density functional theory study of the mechanism of the acid-catalyzed decarboxylation of pyrrole-2-carboxylic acid and mesitoic acid

The mechanisms of the acid-catalyzed decarboxylation of pyrrole-2-carboxylic acid and mesitoic acid have been investigated based on density functional theory calculations at the B3LYP/6-311G (d,p) level. A polarizable continuum model (PCM) has been established in order to evaluate the effects of solvents on these reactions. The results of the calculations indicate that the first step of the acid-catalyzed decarboxylation of the pyrrole-2-carboxylic acid has two possible pathways,that is,the proton of H3O+ attacks either the-carbon atom or the carboxyl oxygen atom. The subsequent process of forming a four-membered ring transition state is the rate-determining step. The activation energies of acid-catalyzed decarboxylation of pyrrole-2-carboxylic acid proceeding via attack at the-carbon atom and the carboxyl oxygen atom are determined to be 194.21 and 210.41 kJ/mol,respectively. The computational results show that both pathways are favored. However,for the reaction of mesitoic acid with H3O+,the reaction barrier for the former pathway is calculated to be 212.15 kJ/mol,whilst the latter pathway has a reaction barrier of 200.45 kJ/mol. Our computational results are consistent with the experimental observations of Mundle and Kluger.

Monoradically luminescent polymers by a super acid-catalyzed polymerization and deep-red electroluminescence

Luminescent radicals have received great attention recently due to their idiographic luminescent properties and potential 100%utilization efficiency of doublets under electrical excitation.However,luminescent radical polymers are rarely explored owing to their challenging molecular design and synthesis.Herein,we report an efficient approach to construct luminescent radical polymers by a super acid-catalyzed polymerization reaction proceeded at room temperature,which intrinsically avoid the heavy metal catalyst.The obtained polymers exhibit the unique paramagnetic signals,good thermal properties,and excellent photostability.Moreover,the quantifiable electroluminescence of such radical polymers was demonstrated for the first time.

Effects of seed particles Al2O3, Al2（SO4）3 and H2SO4 on secondary organic aerosol

Seed particles Al2O3, Al2（SO4）3 and H2SO4 were selected to investigate their effects on secondary aerosol （SA） formation in toluene/NOx photooxidation under sulfur dioxide （SO2） and ammonia （NH3）. Effect of seed particles on SA formation was related to their acid-base properties and the presence of acid or alkaline gases. Under NH3-poor condition, SA formation increased with increasing SO2 concentration due to the acid-catalyzing effect of the oxidation products of SO2 （i.e. H2SO4）, The enhancing effect of SO2 became unobvious under NH3-rieh condition, because NH3 would eliminate the acid-catalyzing effect by neutralizing the acid products. Acidic seeds H2SO4 accelerated SA formation under either SO2 or NH3 condition. Weak acidic Al2（SO4）3 seeds didn＇t affect obviously on SA formation. The inhibiting effect of amphoteric seeds Al2O3 on SA formation was related to the presence of SO2 / NH3 due to their acid-base property. Under NH3-poor condition, the inhibiting effect of Al2O3 on SA formation decreased with increasing concentration of SO2, while under NH3-rich condition, the inhibiting effect wasn＇t remarkable.

Uptake of isoprene, methacrylic acid and methyl methacrylate into aqueous solutions of sulfuric acid and hydrogen peroxide

Multiphase acid-catalyzed oxidation by hydrogen peroxide has been suggested to be a potential route to secondary organic aerosol formation from isoprene and its gas-phase oxidation products, but the lack of kinetics data significantly limited the evaluation of this process in the atmosphere. Here we report the first measurement of the uptake of isoprene, methacrylic acid and methyl methacrylate into aqueous solutions of sulfuric acid and hydrogen peroxide. Isoprene cannot readily partition into the solution because of its high volatility and low solubility, which hinders its further liquid-phase oxidation. Both methacrylic acid and methyl methacrylate can enter the solutions and be oxidized by hydrogen peroxide, and steady-state uptake was observed with the acidity of solution above 30 wt.% and 70 wt.%, respectively. The steady-state uptake coefficient of methacrylic acid is much larger than that of methyl methacrylate for a solution with same acidity. These observations can be explained by the different reactivity of these two compounds caused by the different electron-withdrawing conjugation between carboxyl and ester groups. The atmospheric lifetimes were estimated based on the calculated steady-state uptake coefficients. These results demonstrate that the multiphase acid-catalyzed oxidation of methacrylic acid plays a role in secondary organic aerosol formation, but for isoprene and methyl methacrylate, this process is not important in the troposphere.

Synthesis of Amino Silicone Resins by Three-Step Method and Characterization

Amino silicone resins were synthesized through a three-step method using （3-aminopropyl） triethoxysilane （APTES）, methyltrimethoxysilane （MTMS） and end-capping agents, The products were characterized by Fourier transformed infrared spec- troscopy （FT-IR）, nuclear magnetic resonance （ 1 H NMR）, element analysis and gel permeation chromatography （GPC）. The results of 1 H NMR indicate that the chemical shift signal of acid-catalyzed products is weak at δ3.4 （attributing to alkoxy）. FT-IR shows that there is a vibration peak of Si-OH at 3 100-3 600 cm 1 and the intensity of the peaks is most weak at 6h. The results show that this method cannot only effectively reduce the residue of alkoxy groups and Si-OH groups, but also obtain the products with sufficient amino group. It concludes that this resin is suitable as modifier in the silicone rubber.