Polyynes metal acetylide

The synthesis of several high molecular-weight platinum polyyne polymers carrying chiral (R)-l,l -bi-2-naphthol bridge, P17, was described.48 These represent the first examples of metal acetylide polymer with an optically active backbone. They display much larger specific negative optical rotations than both the metal-free alkyne precursors and their corresponding dinuclear model compounds. These results support the fact that the main chain of P17 adopts a one-handed helical conformation and induces the helical chirality of the polymers. 

Rigid-Rod Transition Metal Acetylide Polymers 1171 Table 5.4 Third-order nonlinear optical coefficients for some Pt-polyynes [84]... 

The electrical conductivity and photoconductivity of metal polyynes have been studied in some detail.For instance, it has been demonstrated that in the unoxidized state 166 (M = Gu) is an insulator (cr= 10 Scm ) and, upon doping with I2, the conductivity is increased to 10 S cm Polyynes such as 165 (M = Ni, Pd, Pt L = E Bus E = P or As) can either be oxidized with nitric acid or doped with Measurements on undoped films showed low conductivity values of ca. 10 Scm which improved to ca. 10 Scm in the l2-doped samples." The Pt-acetylide pyridine polymers 188 showed conductivities of 2.5 x 10 Scm upon doping with iodine. Quaternization followed by iodine doping gave a similar value (3.4 x 10 S cm ). These values appear to be the highest reported for soluble polymetallaynes. 

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