Synthesis and Characterization of Poly(N-propargylsulfamides)

Abstract

A variety of novel N-propargylsulfamide monomers (HC≡CCH 2NHSO2R) with alkyl (1-4) or aryl groups (5-10) were polymerized with a Rh catalyst, (nbd)Rh + B -(C6H5)4 (nbd ) 2,5-norbornadiene), to provide polymers with moderate molecular weights (3000-15 000) in good yields (above 80%). Polymerization of monomer 4 (R ) -(CH2)7CH3) at -15 °C yielded a stereoregular polymer whose cis content was nearly 100%, while the cis content remained 79% at 30 °C. Thus, the stereoregularity of the polymer largely depended on polymerization temperature. On the other hand, polymerization solvents hardly affected stereoregularity. Copolymerization of monomer 4 and N-propargylamide monomer 11 afforded copolymers with various compositions in high yields (above 87%), and the cis contents of the resultant copolymers were located between those of the corresponding homopolymers. The presence of intramolecular hydrogen bonding between the neighboring sulfamide groups was confirmed by IR spectroscopy measured in chloroform, suggesting that these types of polymers with appropriate substitutents also have the potential to form helices under suitable conditions like poly(N-propargylamides).

Synthesis of novel mono-substituted polyacetylenes bearing functional urea groups in side chains

“…Enhancing temperature caused this isomerization to occur more rapidly, reflecting that the trans isomers were more stable compared with the cis isomers. This is in well agreement with other substituted polyacetylenes [19].…”

“…g When DMF was used as the solvent, a slight of THF was added into the solution after polymerization; the mixture solution was mixed thoroughly and then poured into a large amount of hexane to precipitate the polymer. observed in the polymerization of N-propargylsulfamide monomers [19]. Fig.…”

“…In detail, it decreased from 100% to 88% with the polymerization time being 24 h. At 0°C, cis content reached 89% even after 48 h; at À15°C, it remained at 93%. These results demonstrated that cis-trans isomerization took place even during the polymerization [19,27]. Enhancing temperature caused this isomerization to occur more rapidly, reflecting that the trans isomers were more stable compared with the cis isomers.…”

“…In previous studies, we had synthesized a series of mono-substituted polyacetylenes bearing either amide [18] or sulfamide pendent groups [19]. In view of the interesting properties of conjugated polyacetylenes [20] and versatile functional urea groups described above, novel macromolecules containing conjugated polyene backbones and functional urea moieties are assumed to possess the integrated superior properties from the conjugated polymers and the functional urea groups.…”

A Novel Type of Mono-Substituted Polyacetylene: Synthesis and Characterization of Poly(N-Propargylthiourea)s

“…In the spectrum of poly(4), besides the absorption peak around 265 nm, we can see a moderate absorption at about 310 nm, supporting the fact that poly(4) possess conjugated polyacetylene backbones [33]. The results with respect to UV-Vis absorption spectra are similar to some mono-substituted polyacetylenes studied by us earlier, e.g., poly(N -propargylsulfamide)s [34] and poly(N -propargylurea)s [26]. However, under the investigated conditions, the present poly(N -propargylthiourea)s failed to form helical conformations, which were frequently observed in mono-substituted polyacetylenes [23][24][25]35].…”