1415692-75-9Relevant academic research and scientific papers
Understanding the relationship between photolysis efficiency and metal binding using argencast photocages
Mbatia, Hannah W.,Kennedy, Daniel P.,Burdette, Shawn C.
, p. 844 - 850 (2012/09/05)
ArgenCast-1 (1), a photocage for silver utilizing acyclic polythioether 3,6,12,15-tetrathia-9-azaheptadecane receptor and 4,5-dimethoxy-2-nitrobenzyl (DMNB) chromophore has been prepared using trimethylsilyl trifluoromethanesulfonate-assisted electrophilic aromatic substitution. Metal binding studies with ArgenCast-1 reveal interactions with Ag+, Hg2+ and Cu+, but only Ag+ coordinates in both aqueous and organic solvents. The uncaging mechanism of ArgenCast-1 metal complex involves a photoreaction that converts the nitrobenzydrol into the electron withdrawing nitrosobenzophenone that participates in a resonance interaction with a metal-bound aniline nitrogen atom. The structural change following photolysis decreases availability of the nitrogen lone pair for Ag+ coordination, but strong interactions between Ag+ and the thioether ligands mitigates metal ion release. A resonance interaction with a key aci-nitro intermediate reduces the photolysis quantum yield of ArgenCast-1, so several naphthyl-based nitrobenzyl groups were screened as alternatives to DMNB. The naphthyl Ag+ photocages, ArgenCast-2 and -3, exhibit nearly identical quantum yield to ArgenCast-1 owing to the dominance of resonance between aci-nitro intermediate and the aniline nitrogen atom.
