Photooxygenations in aqueous solution with a hydrophilic polymer-immobilized photosensitizer

Abstract

of 2.10 A as being typical of neutral sp3-hybridized nitrogen atoms in macrocyclic high-spin nickel complexes (see ref 7 and 1 I), then an optimum hole size of -4.25 A is predicted for nickel(l1). This is larger than that of 4.13 A determined by X-ray for free 15-02N2 in a flat conformation (McPartlin, M.; Tasker, P. A.; Trotter, J., unpublished results) and supports the postulate that the hole size of 16-02N2 is the one of best fit for the present series of ligands.

Tryptophan Photo-Oxidation by Clay-Adsorbed Sensitizers

“…Problems with solvent incompatibilities of sensitizer and 10 2 acceptor can be overcome (Buell & Demas, 1983). Some well known examples are RB chemically bound to silica gel (Blossey et al, 1973 ;Tamagaki et al, 1980) or the commercially available RB-polymer complexes (Schaap et al, 1979), and resin-bound tris(2,2'-bipyridine)ruthenium(II) (Buell & Demas, 1983).…”

Solid Materials as Sources for Synthetically Useful Singlet Oxygen

“…[67] For example, 9,10-dicyanoanthracene, dissolved in isooctane, is size-excluded from the ZSM-5 channels and produces 1 O 2 which reacts with trans,trans-1,4-diphenylbutadiene to form an endoperoxide, Eq. (19). The product is not extracted by the isooctane during reaction, and must be washed out in a separate work-up procedure, e.g., with dichloromethane.…”

“…[19] After functionalization with RB, the hydrophilic polymer (HP) is a suitable sensitizer for reactions in water or in methanol. A typical reaction is the oxidation of Nmethylpyrrole, Eq.…”

Polymeric Photosensitizers, 5. Synthesis and Photochemical Properties of Poly[(N-isopropylacrylamide)-co-(vinylbenzyl chloride)] Containing Covalently Bound Rose Bengal Chromophores

“…Heterogeneous -beads suspended in methanol 0.48 [38] Styrene-vinylbenzyl chloride copolymer Heterogeneous -polymer film 0.05 [39] Heterogeneous -powder dispersed in methanol 0.41 a) [39] Homogeneous -solution in CH 2 Cl 2 0.38 a) [2] Poly(sodium styrenesulfonate-styrene-vinylbenzyl chloride) Microheterogeneous system in methanol 0.75 a) [13] Sodium styrenesulfonate-vinylbenzyl chloride copolymer Homogeneous -solution in methanol 0.73 [14] a) The highest value for a series of polymers with different numbers of RB units attached to the chain. The separation of the RB chromophores resulted in an increase of the quantum yield of singlet oxygen formation.…”