Question

The structure of \[K[PtC{l_3}({C_2}{H_4})]\] and the hybridization of Pt respectively are:
A.square planar, \[s{p^2}{d^2}\]
B.Square planar, \[ds{p^2}\]
C.Tetrahedral, \[s{p^3}\]
D.Octahedral, \[{d^2}s{p^3}\]

Answer 1

Hint: This given compound is more commonly known as Zeise’s Salt and is chemically named as potassium trichloro(ethylene)platinate (II). Potassium is the cationic part of this salt, while \[{[PtC{l_3}({C_2}{H_4})]^ - }\] is the anionic part.

Complete step by step answer:
The given compound is a salt made of an anion and a cation. This salt is of historic significance in organometallic chemistry because it is one of the first known examples of transition metal alkene complexes. The anionic part of the salt is a coordination complex which is yellow in colour, stable in air and contains a \[{\eta ^2} - ethylene\] ligand. The \[{\eta ^2}\] structure corresponds to the metal alkene system.
Pi ligands are basically a type of organometallic ligands which have extended \[\pi \] systems, which include linear molecules like ethylene, allyl and cyclic molecules. Because of this, we can say that the given compound is a \[\pi \] complex.
Potassium is the central atom here and has 4 different ligands that are attached to it. This gives the entire compound a square planar geometry and thus the platinum in this salt undergoes hybridization\[ds{p^2}\].

Hence, Option B is the correct option.

Note:
The ‘σ-bond’ produced from donation of ‘π-electron’ clouds of alkene to the metal centre is called ‘μ-bond’. Bonding takes place as—
\[{C_2}{H_4}\] (π)→Pt (\[ds{p^2}\]) μ type σ-bond
Pt (‘dxz’ or ‘dp’ hybrid) →\[{C_2}{H_4}\] (π*) π bond