Synthesis and Characterization of Tris(2,2‘-bipyridine)ruthenium(II)-Centered Polystyrenes via Reversible Addition−Fragmentation Chain Transfer (RAFT) Polymerization

Abstract

A novel bipyridine-functionalized dithioester, 5,5′-bis(thiobenzoylthiomethyl)-2,2′-bipyridine (3), was first synthesized through a simple ester exchange reaction with the commercially available dithioester, carboxymethyl dithiobenzoate (CMDB), and further used as a RAFT agent in bulk polymerization of styrene for the synthesis of well-defined bipyridine-centered polystyrene polymers. The molecular weight is well-controlled, and also the molecular weight distribution remains quite narrow. This shows that the novel bipyridine-functionalized dithioester 3 is an efficient RAFT agent. More importantly, the good agreement between theoretical and 1 H NMR-determined molecular weights indirectly indicates that almost all of the polymer chains are centered by the bipyridine functional groups derived from the new RAFT agent. Two of the bipyridine-centered polystyrene polymers were further complexed with ruthenium(II) ions to produce tris(bipyridine)ruthenium(II)-centered polystyrene metallopolymers. The metallopolymers were characterized by UV-vis, fluorescence, size exclusion chromatography (SEC), and differential scanning calorimetry (DSC) techniques. The characterization data show that tris(bipypridine)ruthenium(II) ions have been successfully incorporated into the center of polymer chains.

Electron tomographic analysis of synaptic ultrastructure

“…The probable reason is that the ion‐bonded star copolymer adsorbs more strongly onto the stationary phase than the PSt precursor. The similar GPC problem was also found in the metallo‐supramolecular block copolymers 62–64. All the evidence suggests that ion‐bonded (PSt) 2 OPE was successfully synthesized from the polystyrene carrying tertiary amino group and carboxy‐terminated OPE.…”

Left ventricular puncture: No frontier is risk free

“…The probable reason is that the ion‐bonded star copolymer adsorbs more strongly onto the stationary phase than the diester PSt. Similar GPC problem was also observed in the investigation of the metallo‐supramolecular block copolymers 43–46…”

Experimental Requirements for an Efficient Control of Free‐Radical Polymerizations via the Reversible Addition‐Fragmentation Chain Transfer (RAFT) Process

“…[30] Many [199,223] NIPAm [199,223] NIPAm [279] -CH 2 CN VAc [67] -CH 2 CO 2 H MMA [115] Sty [115,144,215] AA [248] VAc b) [144] b) [144] StySO 3 Na [235] BA [115] a) [215] StyOCOMe [240] DMAm [286] NAM [43,286] -CH 2 CO 2 Me VAc [313,328,329,333] b) [330] -CH 2 CO 2 Et MMA [115] Sty [115] BA [115] -CH 2 CO 2 CH 2 CH 2 C 6 F 13 MMA [113] Sty [113] B [113] -CH 2 CON(Me) 2 DMAm [285] -CH 2 CH 2 Ph VAc [327] VPr [327] -CH 2 CH 2 C 8 F 17 MMA [113] Sty [113] Sty [338,339] BA [338] -H MMA [116] Sty [116,192] MA [116,192] -SC(Me) 3 MMA …”