50995-90-9Relevant academic research and scientific papers
The Photodynamic Covalent Bond: Sensitized Alkoxyamines as a Tool to Shift Reaction Networks Out-of-Equilibrium Using Light Energy
Herder, Martin,Lehn, Jean-Marie
, p. 7647 - 7657 (2018)
We implement sensitized alkoxyamines as "photodynamic covalent bonds" - bonds that, while being stable in the dark at ambient temperatures, upon photoexcitation efficiently dissociate and recombine to the bound state in a fast thermal reaction. This type of bond allows for the photochemically induced exchange of molecular building blocks and resulting constitutional variation within dynamic reaction networks. To this end, alkoxyamines are coupled to a xanthone unit as triplet sensitizer enabling their reversible photodissociation into two radical species. By studying the photochemical properties of three generations of sensitized alkoxyamines it became clear that the nature and efficiency of triplet energy transfer from the sensitizer to the alkoxyamine bond as well as the reversibility of photodissociation crucially depends on the structure of the nitroxide terminus. By employing the thus designed photodynamic covalent bonding motif, we demonstrate how to use light energy to shift a dynamic covalent reaction network away from its thermodynamic minimum into a photostationary state. The network could be repeatedly switched between its minimum and kinetically trapped out-of-equilibrium state by thermal scrambling and selective photoactivation of sensitized alkoxyamines, respectively.
AMELIORATION OF CATARACTS, MACULAR DEGENERATION AND OTHER OPHTHALMIC DISEASES
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Page/Page column 42-44, (2008/06/13)
Ophthalmically acceptable compositions used in arresting the development of cataract, presbyopia, macular degeneration and other retinopathies, glaucoma, uveitis and various corneal disorders are disclosed. The compositions are also useful as a prophylactic treatment to prevent or delay development of age-related ocular disorders, which include cataracts, presbyopia, glaucoma and macular degeneration. The compositions comprise a pharmaceutically acceptable carrier or diluent and at least one compound having the formula where R1 and R2 are, independently, H or C1 to C3 alkyl ; R3 and R4 are, independently C1 to C3 alkyl; and where R1 and R2, taken together, or R3 and R4, taken together, or both may be cycloalkyl; R5 is H, OH, or C1 to C6 alkyl ; R6 is or C1 to C6 alkyl, alkenyl, alkynyl, or substituted alkyl or alkenyl ; R7 is C1 to C6 alkyl, alkenyl, alkynyl, or substituted alkyl or alkenyl or where R6 and R7, or R5, R6 and R7, taken together, form a carbocycle or heterocycle having from 3 to 7 atoms in the ring.
