On the interaction of triphenylmethyl salts with α‐methylstyrene

Abstract

The interaction of triphenylmethyl salts with α‐methylstyrene and 1,1‐diphenylethylene was investigated. With 1,1‐diphenylethylene at a monomer‐initiator ratio of 2 (room temperature), mainly 1,1,3‐triphenyl‐3‐methyl‐indane was isolated, whereas at a ratio of 100 (−10°C), the dimer 1,1,3,3‐tetraphenylbutene‐1 mainly formed. In both cases no addition of the trityl group was registered. In the interaction of α‐methylstyrene with Ph3C+SbCl 6− at a monomer‐initiator ratio of 2(room temperature) a pure 1,3,3‐trimethyl‐1‐phenylindane was isolated and no addition of the trityl group to the double bond was recorded. The initiation reaction of α‐methylstyrene polymerization by trityl and chlorinated trityl salts was studied at temperatures from −20 to 0°C and different concentrations. The oligomers obtained with (pCI‐C6H4)3C+ were investigated by elemental analysis and fluorescence spectroscopy. The presence of Ph3CH in the reaction mixture was demonstrated by GLC and NMR spectra. The results obtained give evidence that the initiation of α‐methylstyrene polymerization involves hydride abstraction from the monomer.

Polymerization of cyclic acetals. II. Synthesis of amphiphilic block copolymers

“…This behavior confirms that the lower the temperature, the smaller is the contribution of the alkoxycarbenium ions, which are the active species in cross-propagation reaction. 8 The polymerization ofp-MeOSt, a-MeSt, and IBVE (Stage 11) was initiated by living polyacetals formed in the first stage. The reaction mixtures and the precipitated polymers obtained in the both stages were analyzed by GPC (RI and UV detection), NMR, IR, and solubility.…”

“…In the course of our investigations on the cationic polymerization of macrocyclic acetals under properly adjusted conditions, block copolymers ( polyacetal-polymethoxystyrene ) were synthesized. 8 Besides improving the properties of the polymers, the matter of interest was to elucidate the possibility of block copolymerization with inherent different mechanisms of polymerization. The cyclic acetals propagate by scission of u bond through oxonium or alkoxycarbenium The vinyl monomers polymerize by opening of 7~ bond via carbenium ions.…”

Heterograft copolymers via double click reactions using one‐pot technique

“…1,2 Graft copolymers can be obtained with three general methods: (i) graftingonto, in which side chains are preformed, and then attached to the backbone; (ii) grafting-from, in which the monomer is grafted from the backbone; and (iii) grafting-through, in which the macromonomers are copolymerized. 3,4 The grafting reaction provides an opportunity to vary physical and chemical properties of resulting polymers.…”

Heterograft brush copolymers via romp and triple click reaction strategies involving CuAAC, diels–alder, and nitroxide radical coupling reactions

“…1 Brush copolymers can be obtained with three general strategies: (i) grafting-onto, in which side chains are preformed, and then attached to the main polymer backbone; (ii) grafting-from, in which the monomer is grafted from the main backbone; and (iii) grafting-through, in which the macromonomers are copolymerized in order to give the resultant graft copolymer. 2,3 A combination of the living polymerizations involving ionic polymerizations, living/controlled radical polymerizations, ring opening polymerization (ROP) and ring opening metathesis polymerization (ROMP), and their compatible partner click reactions 4 such as primarily copper-catalyzed azide-alkyne cycloaddition (CuAAC), and Diels-Alder cycloaddition, affords increasingly the synthesis of well-defined graft (or brush) copolymers with desired molecular weight, topology, composition, and functional groups, thus offering a broad range of applications from biology to nanoscience. 1, [5][6][7][8][9][10][11][12][13][14][15][16] The ROMP is a versatile and an efficient synthetic strategy for the polymerization of cyclic olefins (norbornene, oxanorbornene, norbornadiene, and dicyclopentadiene) by using metal alkylidene initiators (e.g., molybdenum and ruthenium complex catalysis).…”