Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state
In this work we study the product distribution in the steady state photolysis of a diazene, (1-biphenyl-4-yl-1-methyl-ethyl)-tert-butyl diazene, and a ketone, 2,4-bis(biphenyl-4-yl)-2,4-dimethyl-pentan-3-one, in the solid state and in solution. The two compounds yield 1-biphenyl-4-yl-1-methyl-ethyl...
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2009
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1474905X_v8_n7_p961_Hoijemberg http://hdl.handle.net/20.500.12110/paper_1474905X_v8_n7_p961_Hoijemberg |
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paper:paper_1474905X_v8_n7_p961_Hoijemberg2023-06-08T16:17:49Z Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state Hoijemberg, Pablo Ariel Aramendía, Pedro Francisco biphenyl diamide ketone derivative radical article chemical reaction kinetics controlled study crystal structure energy entropy liquid photochemistry photolysis priority journal solid state substitution reaction temperature In this work we study the product distribution in the steady state photolysis of a diazene, (1-biphenyl-4-yl-1-methyl-ethyl)-tert-butyl diazene, and a ketone, 2,4-bis(biphenyl-4-yl)-2,4-dimethyl-pentan-3-one, in the solid state and in solution. The two compounds yield 1-biphenyl-4-yl-1-methyl-ethyl (BME) radicals upon photolysis. The ketone yields two units of this radical, whereas the diazene yields one BME and one tert-butyl radical. Product analysis of the two compounds in solution makes it possible to differentiate their origin from their corresponding geminate cages, and from the different encounter pairs in the case of the asymmetrically substituted diazene photolysis. In this way we obtain a complete reaction scenery for the diazene, a compound with interesting features as a radical photoinitiator and as a cage effect probe in fluid media. The reaction in cages containing two BME radicals shows a decrease by a factor of 4 in the ratio of combination to disproportionation products upon going from the solid to the liquid phase. On the contrary, the reaction in cages containing a BME and a tert-butyl radical shows a 30-fold increase in combination to disproportionation ratio in liquid compared to the crystal. We analyze the reasons for these differences considering the differences in the reactivity of the radicals and in cage rigidity. © The Royal Society of Chemistry and Owner Societies 2009. Fil:Hoijemberg, P.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Aramendía, P.F. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1474905X_v8_n7_p961_Hoijemberg http://hdl.handle.net/20.500.12110/paper_1474905X_v8_n7_p961_Hoijemberg |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
biphenyl diamide ketone derivative radical article chemical reaction kinetics controlled study crystal structure energy entropy liquid photochemistry photolysis priority journal solid state substitution reaction temperature |
| spellingShingle |
biphenyl diamide ketone derivative radical article chemical reaction kinetics controlled study crystal structure energy entropy liquid photochemistry photolysis priority journal solid state substitution reaction temperature Hoijemberg, Pablo Ariel Aramendía, Pedro Francisco Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| topic_facet |
biphenyl diamide ketone derivative radical article chemical reaction kinetics controlled study crystal structure energy entropy liquid photochemistry photolysis priority journal solid state substitution reaction temperature |
| description |
In this work we study the product distribution in the steady state photolysis of a diazene, (1-biphenyl-4-yl-1-methyl-ethyl)-tert-butyl diazene, and a ketone, 2,4-bis(biphenyl-4-yl)-2,4-dimethyl-pentan-3-one, in the solid state and in solution. The two compounds yield 1-biphenyl-4-yl-1-methyl-ethyl (BME) radicals upon photolysis. The ketone yields two units of this radical, whereas the diazene yields one BME and one tert-butyl radical. Product analysis of the two compounds in solution makes it possible to differentiate their origin from their corresponding geminate cages, and from the different encounter pairs in the case of the asymmetrically substituted diazene photolysis. In this way we obtain a complete reaction scenery for the diazene, a compound with interesting features as a radical photoinitiator and as a cage effect probe in fluid media. The reaction in cages containing two BME radicals shows a decrease by a factor of 4 in the ratio of combination to disproportionation products upon going from the solid to the liquid phase. On the contrary, the reaction in cages containing a BME and a tert-butyl radical shows a 30-fold increase in combination to disproportionation ratio in liquid compared to the crystal. We analyze the reasons for these differences considering the differences in the reactivity of the radicals and in cage rigidity. © The Royal Society of Chemistry and Owner Societies 2009. |
| author |
Hoijemberg, Pablo Ariel Aramendía, Pedro Francisco |
| author_facet |
Hoijemberg, Pablo Ariel Aramendía, Pedro Francisco |
| author_sort |
Hoijemberg, Pablo Ariel |
| title |
Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| title_short |
Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| title_full |
Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| title_fullStr |
Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| title_full_unstemmed |
Photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| title_sort |
photolysis of an asymmetrically substituted diazene in solution and in the crystalline state |
| publishDate |
2009 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_1474905X_v8_n7_p961_Hoijemberg http://hdl.handle.net/20.500.12110/paper_1474905X_v8_n7_p961_Hoijemberg |
| work_keys_str_mv |
AT hoijembergpabloariel photolysisofanasymmetricallysubstituteddiazeneinsolutionandinthecrystallinestate AT aramendiapedrofrancisco photolysisofanasymmetricallysubstituteddiazeneinsolutionandinthecrystallinestate |
| _version_ |
1768544054984835072 |