Compartmentalization of Zinqii) Tetraphenylporphyrin in a Hydrophobic Microdomain of an Amphiphilic Polyelectrolyte: A Physicochemical Model of Biological Metalloporphyrin Systems

Abstract

Small mole fractions of zinc(I1) tetraphenylporphyrin (ZnTPP) moieties were covalently incorporated into amphiphilic polysulfonates having bulky hydrophobic groups such as lauryl, cyclododecyl, and (2-naphthy1)methyl (Np) groups in their side chains. The ZnTPP moieties are "compartmentalized" in the hydrophobic domains of these amphiphilic polyelectrolytes in aqueous solution. For comparison, the ZnTPP moieties were covalently incorporated into a polysulfonate without hydrophobic groups. The ZnTPP moieties in this reference poiymer are exposed to water in aqueous solution. The compartmentalized ZnTPP systems in aqueous fluid solution emitted phosphorescence and thermally activated delayed fluorescence at room temperature. This is due to an extremely long-lived triplet excited state in the compartmentalized systems at room temperature in aqueous solution, e.g. 19 ms for ZnTPP compartmentalized in Np domains, compared with 3 ms for ZnTPP in the reference polymer. These remarkable compartmentalization effects may be attributed to a restriction of motional freedom of the ZnTPP moiety isolated in a rigid and hydrophobic microenvironment provided by the amphiphilic polyelectrolytes in aqueous solution.

Fluorescence Studies of Pyrene-Labeled Cholesterol-Bearing Polymer Films

“…[4] Previously, we reported the spectroscopic and photochemical behavior of zinc (II) tetraphenylporphynate (ZnTPP) moieties incorporated into unimolecular micelles (unimer micelles) formed from hydrophobically modified polyelectrolytes in aqueous solution. [5,6] An example of a ZnTPP-functionalized hydrophobically modified polyelectrolytes is the terpolymer of sodium 2-(acrylamido)-2-methylpropanesulfonate, N-cyclododecylmethacrylamide, and a small amount (0.1 mol-%) of zinc (II) 5-(4-acrylamidophenyl)-10,15,20-triphenylporphynate.…”

Nanoscopic Aggregation in Amphiphilic Random Copolymer Bulk Films Studied with Photochemical Hole Burning

“…[11] Three terpolymers of AMPS with 49 mol-% CDMAm and 1 mol-% AATPP, poly(A/CD/TPP) (M -w = 3.2 6 10 5 , 3.2 6 10 4 , 2.4 6 10 4 g/mol respectively), were prepared by free radical terpolymerization according to the procedures reported previously. [21] The copolymers of AMPS with 25, 50, 75 mol-% CDMAm or LAMAm were prepared by free radical copolymerization. [21] These copolymers are denoted as poly .…”

“…[21] The copolymers of AMPS with 25, 50, 75 mol-% CDMAm or LAMAm were prepared by free radical copolymerization. [21] These copolymers are denoted as poly . Chemical structures of the amphiphilic random copolymers, terpolymers, homopolymers and chromophores.…”

Photochemical hole burning study of unimacromolecular micelles with controlled radii embedded in poly(vinyl alcohol)

“…The terpolymers of AMPS with 49 mol-% CDMAm and 1 mol-% H 2 AATPP, poly(A/CD/TPP) (M w = 3.2610 5 , 3.2610 4 , 2.4610 4 , respectively) were prepared by free radical terpolymerization according to the procedures reported previously 23) . Homopolymers of CDMAm and AMPS (M w = 4.4610 3 , 1.3610 5 , respectively) were prepared by radical polymerization initiated by 2,29-azobis(isobutyronitrile) (AIBN) in N,N-dimethylformamide solution, then purified by reprecipitation.…”