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