Question

Among the options given, identify the correct pair(s) of catalyst and co-catalyst that form a Ziegler–Natta catalyst.

• A. TiCl\textsubscript{3} and Al(CH\textsubscript{3}CH\textsubscript{2})\textsubscript{2}Cl
• B. ZnCl\textsubscript{2} and Al(CH\textsubscript{3})\textsubscript{3}
• C. TiO\textsubscript{2} and Al(CH\textsubscript{3})\textsubscript{3}
• D. VCl\textsubscript{4} and Al(CH\textsubscript{3}CH\textsubscript{2})\textsubscript{2}Cl

Hint:

Ziegler–Natta catalysts always involve a \textbf{transition metal halide} (TiCl\textsubscript{3}, TiCl\textsubscript{4}, VCl\textsubscript{4}) and an \textbf{organoaluminium compound}.

Answer 1

The Correct Option is A, D

Step 1: Recall composition of Ziegler–Natta catalysts.
They consist of a transition metal compound (usually Ti or V halide) and an organoaluminium compound (trialkyl aluminium or dialkyl aluminium halide).
Step 2: Check each option.
- (A) TiCl\textsubscript{3} + Al(C\textsubscript{2}H\textsubscript{5})\textsubscript{2}Cl $\Rightarrow$ classic Ziegler–Natta system.
- (B) ZnCl\textsubscript{2} + Al(CH\textsubscript{3})\textsubscript{3} $\Rightarrow$ zinc halide is not an active transition metal center for Ziegler–Natta polymerization.
- (C) TiO\textsubscript{2} + Al(CH\textsubscript{3})\textsubscript{3} $\Rightarrow$ TiO\textsubscript{2} is inert and not a halide catalyst.
- (D) VCl\textsubscript{4} + Al(C\textsubscript{2}H\textsubscript{5})\textsubscript{2}Cl $\Rightarrow$ another valid Ziegler–Natta catalyst system.
Step 3: Conclude.
Valid Ziegler–Natta catalysts are given in options (A) and (D). Final Answer: \[ \boxed{\text{(A) and (D)}} \]