This document discusses polyacetylene, an organic polymer that can conduct electricity. It describes how polyacetylene was first synthesized in 1970 using a Ziegler-Natta catalyst. Polyacetylene exists in two forms, cis and trans. The document also explains how doping polyacetylene with oxidizing or reducing agents can increase its conductivity, and some applications of conductive polymers including rechargeable batteries, sensors, transistors, LEDs, solar cells, and electromagnetic shielding.

1. Polyacetylene

2.  Organic polymers that conduct electricity are
called conducting polymers.
 Such compounds may have metallic conductivity
or can be semiconductors.
 The biggest advantage of conductive polymers is
their processability, mainly by dispersion.

3.  In 1970 H.shirakawa reported high
molecular weight polyacetylene film by
passing dry acetylene gas over Ziegler-
Natta catalyst of titanium tetrabutoxide
triethyl aluminium in toluene at -78℃ .
 It was obtained on the surface of the
catalyst.
 And also in the two forms known as cis
and trans .

4. (1) Is cis polyacetylene.
(2) Is trans polyacetylene.

5. The role of a dopant is to either add or
remove electrons to the polymer.
 It is of two kinds:
 (1) Oxidative or p-doping.
(2) Reductive or n-doping.

6.  The oxidizing agents for P-doping are like iodine
vapours,I₂ dissolved in CCl₄ , HBF₄, HClO₄ ,
Br₂..etc.
 (CH)n → (CH)n ⁺ I₃⁻
 The conduction in this type of doping increases up
to 10⁵ s/cm.

7.  The reducing agents for n-doping are like Na
metal ,FeCl₂, lithium metal ,sodium
naphthalide..etc.
 (CH)n → (CH)⁻ Na⁺
 Negative charge resonates throughout the chain
and transferred to neighbouring chains through
Na⁺ during conduction.

8.  For making rechargeable batteries.
 Used as sensors for phenol , O₂..etc at low
concentrations.
 For manufacture of transistors ,LEDs, lasers and
solar cells.
 In telecommunication systems
 In the construction of photovoltaic cells.

9. Light-emitting diodes
Solar cell
Shield for computer screen
against electromagnetic
"smart" windows
radiation