Theoretical Studies on Thermal Decomposition of Benzoyl Peroxide in Ground State

Systematic studies of the thermal decomposition mechanism of benzoyl peroxide(BPO) in ground state, leading to various intermediates, products and the potential energy surface(PES) of possible dissociation reactions were made computationally. The structures of the transition states and the activation energies for all the paths causing the formation of the reaction products mentioned above were calculated by the AM1 semi-empirical method. This method is shown to to be one predict correctly the preferred pathway for the title reaction. It has been found that in ground state, the thermal decomposition of benzoyl peroxide has two kinds of paths. The first pathway PhC(O)O-OC(O)Ph→PhC(O)O · →Ph · +CO 2 produces finally phenyl radicals and carbon dioxide. And the second pathway PhC(O)OO-C(O)Ph→PhC(O)OO · +PhC(O) · → PhC(O) · +O 2 →Ph · +CO+O 2, via which the reaction takes place only in two steps, produces oxygen and PhC(O) · radicals, and the further thermal dissociation of PhC(O) · is quite difficult because of the high activation energy in ground state. The calculated activation energies and reaction enthalpies are in good agreement with the experimental values. The research results also show that also the thermal dissociation process of the two bonds or the three bonds for the benzoyl peroxide doesn′t take place in ground state.

In situ Preparation of Tri-Fe(Ⅲ) and Bi-Cu(Ⅱ) Clusters from Benzoyl Peroxide Reacting with Metal Powders

Three crystal architectures, including one organic compound of benzoyl peroxide（Ⅰ） and two clusters of tri-iron（Ⅲ） and bi-cupper（Ⅱ） with benzoic ligands（2 and 3）, were self-assembled by an in situ redox way of benzoyl peroxide oxidants reacting with Mo, Fe and Cu powders, respectively. X-ray crystallographic results show that both the asymmetry tri-iron（Ⅲ） cluster and the benzoylperoxide crystal architecture（2 and 1） with complicated 3D networks were constructed by intermolecular hydrogen-bonding interactions. Contrarily, the symmetrical bi-copper（Ⅱ） cluster crystal architecture（3）, only with π-π stacking between paralleled phenyl groups and without any intermolecular hydrogen-bonding interactions, only presented an 1D zigzag chain along the a-axis.

Efficacy and Tolerability of 0.1%Adapalene With 1%Clindamycin Versus 0.1%Adapalene With 2.5%Benzoyl Peroxide on Acne Vulgaris:A Case Control Study

Objective:Combination therapy is currently the preferred acne treatment.We conducted this study to compare the efficacy and tolerability of 0.1%adapalene with 1%clindamycin versus 0.1%adapalene with 2.5%benzoyl peroxide(BPO)in the treatment of acne vulgaris.Methods:This study was conducted over a period of 1 year from September 2014 to September 2015.One-hundred patients aged 14 to 30 years with mild to moderate acne vulgaris were included.The patients were randomly allocated to 2 equal groups(n=50 in each group),and received a topical combination of 0.1%adapalene with 1%clindamycin andtopical combination of 0.1%adapalene with 2.5%BPO,respectively).The efficacy and tolerability of two treatments were compared.The unpaired studentt test was used to compare the difference in continuous variables between 2 groups,while the chi-square test or Fisher exact test was used for categorical variables.Results:One-hundred patients with mild to moderate acne vulgaris were randomly allocated to 2 equal groups(n=50 in each group).After 12 weeks of treatment,there were no significant differences between the adapalene-clindamycin and adapalene-BPO in the mean reductions in the numbers of non-inflammatory lesions(11.16±8.01 and 11.12±8.62,respectively),inflammatory papules(49.78±37.57 and 50.48±36.57,respectively),and total lesions(67.50±44.59 and 70.12±46.83,respectively).The incidence of a burning sensation was significantly greater in the adapalene-BPO group than the adapalene-clindamycin group(32%vs.6%;P=0.002).Conclusion:Topical adapalene plus clindamycin and adapalene plus BPO had similar efficacies in the treatment of acne.Adapalene with clindamycin was better tolerated than adapalene with BPO.

Carbon dot-based fluorescent and colorimetric sensor for sensitive and selective visual detection of benzoyl peroxide

Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot(CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response.Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.

Electrochemiluminescence of Bare Glassy Carbon with Benzoyl Peroxide as the Coreactant in N,N-Dimethylformamide

The electrochemiluminescence(ECL)properties of many carbon materials have been reported with glassy carbon(GC),Pt,Au or indium tin oxide(ITO)as the working electrode(WE).As one type of carbon materials,GC itself can generate ECL signal.Some research groups have already noticed the ECL signal from GC WE and reported the results of GC WE with respect to their luminophores.However,comprehensive analyses of ECL properties of GC WE are rare.Herein,the ECL properties of GC WE in organic electrolyte with benzoyl peroxide as the coreactant are reported.Our results are of great importance to distinguish the true ECL data of luminophores from that of GC.

Preparation of Polystyrenylphosphonous Acid of Low Polymerization Degree and Influence of Initiators upon the Free Radical Reaction Mechanism

The polystyrenylphosphonous acid (PSPA) of low polymerization degree was prepared with one step reaction. The reaction mechanism was changed with different initiators. For the reaction with AIBN or BPO as the initiator, there are 2 or 3 series of radical reaction chains and 5 or 9 series of polystyrenyl products. The main products are PSPA without or with the fragment of the initiator H[CH(C6H5)-CH2]n-PO2H2 and C6H5CO2-[CH2CH (C6H5)]n-PO2H2 respectively.