Soluble polymers of monosubstituted acetylenes with quaternary ammonium pendant groups. Structure and morphology

Soluble conjugatedpolymerswereobtained inthe presence ofPd(II),Pt(II)andRh(I) complexes frommonosubstituted acetylene 3-dimethylamino-1-propyne (H–C CCH2N(CH3)2, 1) and the corresponding hydrochloride (H–C CCH2N(CH3)2·HCl, 2) and hydrobromide (H–C CCH2N(CH3)2·HBr, 3) derivatives. A series of reactionswere performed to achieve the optimization of the polymerization conditions.Thehighest yieldswere foundforpolymers synthesized usingPd(II)bisacetylides specially prepared, i.e. trans-[Pd(PPh3)2(C CCH2N(CH3)2)2], trans-[Pd(PPh3)2(C CCH2N(CH3)2)2HCl] and trans-[Pd(PPh3)2(C CCH2N(CH3)2)2HBr], respectively. The dimension and size distribution of the polymers were investigated using dynamic light scattering. Polymers containing quaternary ammonium groups showed evidence of a hydrodynamic radius of about 300 nm if prepared with the Rh(I) catalyst and of 160 nm if prepared with the Pd(II) catalysts. Polymers obtained from 1 showed smaller hydrodynamic radius compared to polymers obtained from 2 and 3, regardless the polymerization catalyst. The ionic polymericmaterials were soluble in organic solvents and, more interestingly, in water. The formation of nanoparticles with pearl-like morphology was achieved using a recently developed osmosis-based method, with dimensions varying from 60 nm up to micrometres. c 2011 Society of Chemical Industry