The given zirconocene compound, $(\eta^5-\text{Cp})_2\text{ZrEt}_2$, when heated in the presence of an equimolar amount of $\text{PMe}_3$ results in the formation of a compound $X$ which obeys the 18 electron rule. The reaction also resulted in the release of a saturated hydrocarbon. [Given: Atomic number of $\text{Zr} = 40$] The structure of compound $X$ is ________
To determine the structure of compound \( X \), we need to consider the given zirconocene compound \((\eta^5-\text{Cp})_2\text{ZrEt}_2\) and its reaction with \(\text{PMe}_3\).
- The starting compound is \((\eta^5-\text{Cp})_2\text{ZrEt}_2\), where:
- \((\eta^5-\text{Cp})\) is the cyclopentadienyl ligand, contributing \(5 \times 2 = 10\) electrons.
- Each ethyl group (\(\text{Et}\)) is considered a 1-electron donor, contributing \(2\) electrons.
- The zirconium (\(\text{Zr}\)) contributes its own \(4\) valence electrons.
- The total electron count of the starting complex is \(10 + 2 + 4 = 16\) electrons.
- The reaction involves an equimolar amount of \(\text{PMe}_3\), a 2-electron donor, leading to the replacement of one ethyl group.
- The description of compound \(X\) mentions it following the 18-electron rule. This means that after the reaction, the compound should have a total of \(18\) electrons.
- When one ethyl group is replaced by \(\text{PMe}_3\), it adds \(2\) electrons, and the remaining ethyl is transformed to ethylene \((\text{C}_2\text{H}_4)\), which does not change the electron count as it releases ethane (\(\text{C}_2\text{H}_6\)), a saturated hydrocarbon.
- This transformation results in a zirconocene complex with \(\text{PMe}_3\) and ethylene, satisfying the 18-electron rule.
Therefore, the correct answer is: A zirconocene complex with one \(PMe_3\) ligand and one ethylene ligand.
Important Questions from 18 Electron Rule
The number of metal-metal bond(s) in the complex $[(\eta^5-Cp)Mo(CO)_2]_2$ is $x$ and in $[(\eta^5-Cp)_2Fe_2(CO)_3]$ is $y$. The value of $x + y$ is ___________.
(Assume 18 electron rule is followed.)
(Answer in integer)The total number of valence electrons in $W(\eta^3-Cp)(\eta^5-Cp)(CO)_2$ is ______________.(Atomic number of W = 74)
$[CpMoCl_2]_2$ obeys the 18 electron rule. The correct structure of this compound is
(atomic number of Mo = 42)
- The species which follows 18-electron rule is
(en = ethylenediamine)
