In Zeigler-Natta polymerisation of ethylene, the active species is

Question

In Zeigler-Natta polymerisation of ethylene, the active species is (A)  AlCl3  (B) Et3Al (C) CH2CH2 (D) TiIII

Tardigrade Admin · Accepted Answer

Ziegler Natta catalysts are used to polymerize terminal 1-alkenes (ethylene and alkenes with the vinyl double bond) as follows:

n C H_{2} = C H R \to [C H_{2} C H R]_{n} .

Zeigler-Natta catalyst is formed by the action of

(C_{2} H_{5})_{3} A l

and

T i C l_{4}

.
Active species is

T i^{III}

as

(C_{2} H_{5})_{3} A l

can reduce

T i C l_{4}

to

T i C l_{3} . T i^{III}

has active site vacant and thus, can accommodate one alkyl group.

Q. In Zeigler-Natta polymerisation of ethylene, the active species is