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Physical Sciences and Mathematics Commons

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Chemistry

University of Louisville

Theses/Dissertations

Photochemistry

Publication Year

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Computational Investigations Of The Photochemical Properties Of B12-Dependent Systems: From Solution To Enzymes., Megan Toda Mackintosh Dec 2021

Computational Investigations Of The Photochemical Properties Of B12-Dependent Systems: From Solution To Enzymes., Megan Toda Mackintosh

Electronic Theses and Dissertations

The photochemical properties of the B12 family of molecules (cobalamins = Cbls) have been known for many years yet only until the 21st century have applications for the light-sensitivity of Cbls come to the surface. Photolabile Cbls can be used for the delivery of therapeutics with spatial and temporal control, in the generation of hydroxyl radicals, and in nature, as demonstrated in the catalytic cycle of coenzyme B12-dependent photoreceptors. This dissertation describes the use of computational methods to explore the photochemical properties of Cbl systems including antivitamins B12, a thiolato-cobalamin, and the coenzyme B …


Computational Modeling Of Electronically Excited States In Cobalamin-Dependent Reactions., Brady D. Garabato May 2018

Computational Modeling Of Electronically Excited States In Cobalamin-Dependent Reactions., Brady D. Garabato

Electronic Theses and Dissertations

The current understanding of the photolytic properties of Vitamin B12 derivatives or cobalamins are summarized from a computational point of view. The focus is on two non-alkylcobalamins, cyanocobalamin (CNCbl) and hydroxocobalamin (HOCbl), two alkylcobalamins, methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), as well as the stable cob(II)alamin radical. Photolysis of alkylcobalamins involves low-lying singlet excited states where photo-dissociation of the Co-C bond forms singlet-born alkyl/cob(II)alamin radical pairs (RPs). Potential energy surfaces (PESs) of low-lying excited states as functions of both axial bonds provide the most reliable tool for analysis of photochemical and photophysical properties. Due to the size limitations associated with the …