Poly l-pentenylene

In 1974 it seemed likely that fra 5-poly(l-pentenylene), sometimes termed trans-polypentenamer, was about to make its debut as the new all-purpose synthetic 

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In poly(l-pentenylene) the chemical shifts of the -carbons are about 0.5 ppm upfield from those in the polymers of the other cycloalkenes, an effect which is attributed to a higher proportion of gauche conformations about the CH2—CH2 bonds arising from the influence of the y-olefinic carbons347. 

The formation of polymers containing [=CH(CH2)4CH=], units is possible through the ROMP of an appropriate cyclic diene, such as cycloocta-1,3-diene, or by a double-bond shift reaction of a polymer such as poly(l-pentenylene). Such units can be eliminated as cyclohexene so long as metathesis activity is present in the system360. The ROMP of 2,3-dihydropyran, initiated by Mo(CO)6/CBr4// v, has been reported361. 

Subsequently, Eleuterio [41] filed a patent concerning the ring-opening polymerisation of cyclopentene leading to poly(l-pentenylene) ... 

Fig. 11.6 22.63 MHz C NMR spectrum of a sample of poly(l-pentenylene) containing 47% cis double bonds (Ivin 1979a).

Fig. 15.1 C NMR spectrum of poly(l-pentenylene) oil prepared from cyclopentene in the...

Poly(l-pentenylene) can be readily degraded with hex-2-ene to yield the expected C9, Cn, and Co products derived from single monomer units, together with C]4, C16, and Cjg products derived from pairs of monomer units (Ast 1970). 

Example 3.33 Poly(l-Pentenylene) by Metathesis Polymerization of Cyclopentene with a Ziegler-Natta-Catalyst in Solution... 

Catalytic quantities of WCI3(DME)(CBu ) cause the polymerisation of cyclopentene to poly-l-pentenylene which has predominantly (75%) trans C=C bonds but metathesises oct-l-ene to ethene and predominantly trans-7-tetradecene.206 Addition of CyNCO to WCl3(DME) (CBu ) gives WCl3(NCy) [N(Cy)C C(But)=C=0 0] The... 

Phosphorous groups may be linked to alkenic compounds by radical-induced addition of organic phosphites Azuma and MacKnight prepared phosphonylated derivatives of a polypentenamer poly(l-pentenylene) (PP) using dimethyl phosphite (DMP) as reactant and dibenzoyl peroxide as the free radical source (reaction 8). 

More recently the addition of a,j -unsaturated carboxylic acids to polydienes such as cis-1,4-polybutadiene (1,4-P), 1,2-polybutadiene (1,2-PB) and polypentenamer poly(l-pentenylene) (PP) was investigated in the presence of acid catalysts the products are cyclized rubbers with pendent a,j -unsaturated carboxylate groups. It was shown that acid adds only to the original double bonds of the polydienes and not to those of cyclized structure, with cyclization taking place in the following order 1,2-PB > 1,4-PB > PP. 

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