Diyne monomers

Figure 50 Fluorescent organoboron polymers (81) obtained by Heck-Sonagashira coupling between diyne monomers and pyrazabole derivatives. (Adapted from ref. 115.)...

Conjugated organoboron polymers were prepared by haloboration-phenylboration polymerization between diyne monomers and bromodiphenylborane (scheme 29).54 The polymerization was carried out by adding a slight excess of bromodiphenylborane to a tetrachloroethane solution of diynes at room temperature... 

Polymerization in Bilayers. Upon irradiation with UV light the monomer vesicles are transferred to polymer vesicles (Figure 12.). In the case of the diyne monomers (2,5-9,12,13,14) the polyreaction can again be followed by the color change via blue to red except phospholipids (5,6), which turn red without going through the blue intermediate as observed in monolayers. The VIS spectra of these polymer vesicle dispersions are qualitatively identical to those of the polymer monolayers (Figure 13.). 

Figure 10-10 Polymerization of 1,6-diynes using a molybdenum alkylidene catalyst [Rp is (CFjljCHjC] [67]. The 1,6-diyne monomer is drawn in two different exaggerated conformations to illustrate that head-tail polymerization leads to six-membered rings, and tail-tail polymerization leads to five-membered rings. See Fig. 10-8 for a more mechanistic diagram of acetylene metathesis.

In both cases, the structure of the organometallic polymers can be designed by the diyne monomers. The regiochemistry of the mainchain connections at each met-allacycle imit is affected by the nature of the substituents on diynes and/or the Ug-ands on the low-valent transition metal complexes. It was also demonstrated that the regioselectivity of the mainchain connections reflects directly on the character of the functional polymers obtained by the polymer reactions. That is, the organotitanium polymers with regiospecific mainchain coimections obtained from titanimn... 

As shown in Scheme 3, diyne monomers 5a-f were designed to react with a series of commercially available amines and aldehydes. The polymerizatiOTi of diyne 5a, L-phenylalanine methyl ester hydrochloride 6, and formaldehyde 7 was first investigated and the effects of solvent, temperature, time, concentration. 

Recently, Tang and coworkers [246] reported a new method for the formation of conjugated hb polymers with diyne monomer [bis(4-ethynylphenyl)dimethylsilane] and benzene-1,3,5-tricarbonyl trichloride as branching unit using the A2-1- B3 polymerization approach (Table 5, entry 2) by the rhodium (Rh)-catalyzed decarbonylative reaction for the formation of hb poly(arylene chloro-vinylene)s. The molar ratio selected for polymerization of A2 B3 was 4 3 (A B = 8 9) so as to... 

Hyperbranched poly(silylenephenylenes) from polycyclotrimerization of A2-type diyne monomers synthesis, characterization, structural modeling, thermal stability, and fluorescent patterning. Macromolecules 40 7473-7486... 

---