{"title":"The Study of Photosensitized Reactions of Nitrobenzene and m-Dinitro Benzene Using Benzophenone As a Sensitizer under Visible Light Irradiation","authors":"Pranav Trivedi, Chandramauly Sharma, Kuldeep Sharma, Umeshchandra Pande","doi":"10.1134/s0036024424701280","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The photosensitized reaction of nitrobenzene and its derivatives, including dinitrobenzene, has been extensively investigated in an aqueous alkaline medium using Benzophenone as a sensitizer under visible light irradiation. A 100 W tungsten lamp was employed for the purpose of irradiation. The presence of the strongly electron-withdrawing NO<sub>2</sub> group leads to polarization of the C–H bond. In this process, the triplet excited state of benzophenone initiates H<sup>+</sup> abstraction from the polarized C–H bond of nitrobenzene (NB) and meta-dinitrobenzene (<i>m</i>-DNB) through exciplex formation. Proton abstraction results in the formation of free radicals for both NB and <i>m</i>-DNB, followed by dimerization of the free radicals. The observed rate of the reaction follows the order <i>m</i>-DNB > NB. However, no photochemical reaction was observed for <i>p</i>-dinitrobenzene (<i>p</i>-DNB). Various parameters such as pH, substrate concentration, sensitizer concentration, light intensity, solvent effect, and the rate of the photochemical reaction were investigated. The quantum efficiency of the product was determined using a potassium ferrioxalate actinometer. The formation of the product occurs through exciplex formation from the triplet excited state. The possible products, namely 2,2'-dinitro biphenyl and 2,2'-4,4'-tetranitro biphenyl, were confirmed using UV–visible spectrophotometry and mass spectrometry. Finally, a proposed reaction mechanism was suggested based on the experimental findings.</p>","PeriodicalId":767,"journal":{"name":"Russian Journal of Physical Chemistry A","volume":null,"pages":null},"PeriodicalIF":0.7000,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Russian Journal of Physical Chemistry A","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1134/s0036024424701280","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The photosensitized reaction of nitrobenzene and its derivatives, including dinitrobenzene, has been extensively investigated in an aqueous alkaline medium using Benzophenone as a sensitizer under visible light irradiation. A 100 W tungsten lamp was employed for the purpose of irradiation. The presence of the strongly electron-withdrawing NO2 group leads to polarization of the C–H bond. In this process, the triplet excited state of benzophenone initiates H+ abstraction from the polarized C–H bond of nitrobenzene (NB) and meta-dinitrobenzene (m-DNB) through exciplex formation. Proton abstraction results in the formation of free radicals for both NB and m-DNB, followed by dimerization of the free radicals. The observed rate of the reaction follows the order m-DNB > NB. However, no photochemical reaction was observed for p-dinitrobenzene (p-DNB). Various parameters such as pH, substrate concentration, sensitizer concentration, light intensity, solvent effect, and the rate of the photochemical reaction were investigated. The quantum efficiency of the product was determined using a potassium ferrioxalate actinometer. The formation of the product occurs through exciplex formation from the triplet excited state. The possible products, namely 2,2'-dinitro biphenyl and 2,2'-4,4'-tetranitro biphenyl, were confirmed using UV–visible spectrophotometry and mass spectrometry. Finally, a proposed reaction mechanism was suggested based on the experimental findings.
期刊介绍：
Russian Journal of Physical Chemistry A. Focus on Chemistry (Zhurnal Fizicheskoi Khimii), founded in 1930, offers a comprehensive review of theoretical and experimental research from the Russian Academy of Sciences, leading research and academic centers from Russia and from all over the world.
Articles are devoted to chemical thermodynamics and thermochemistry, biophysical chemistry, photochemistry and magnetochemistry, materials structure, quantum chemistry, physical chemistry of nanomaterials and solutions, surface phenomena and adsorption, and methods and techniques of physicochemical studies.
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