In industrial chemistry, which of the following substances is an organometallic compound (i.e., an organic molecule containing a direct carbon–metal bond)?

Introduction:
Organometallic chemistry focuses on compounds with at least one direct bond between a metal and a carbon atom of an organic group. Identifying such compounds is foundational for catalysis, fuel additives history, and materials synthesis. This question tests recognition of a classic organometallic: tetraethyl lead.

Given Data / Assumptions:

• We compare four choices spanning hydrocarbons, alcohols, minerals, and a lead compound.
• Definition: organometallic = compound with metal–carbon sigma bond(s).
• No advanced spectroscopy is required; structural knowledge suffices.

Concept / Approach:
Tetraethyl lead, Pb(C2H5)4, contains lead–carbon bonds. Cumene (isopropylbenzene) and isopropyl alcohol are purely organic with no metal atom. Zeolite is an inorganic aluminosilicate solid without C–metal bonds; it is a catalyst/adsorbent, not an organometallic molecule.

Step-by-Step Solution:
Identify the metal presence: lead in tetraethyl lead.Check for C–metal bonds: ethyl groups bonded to Pb confirm organometallic nature.Eliminate purely organic (cumene, isopropyl alcohol) and inorganic framework (zeolite).

Verification / Alternative check:
Historical use of tetraethyl lead as an antiknock gasoline additive relied on its decomposition pathway, characteristic of organometallics undergoing homolysis and delivering lead species to quench radicals.

Why Other Options Are Wrong:

• Cumene: hydrocarbon, no metal.
• Zeolite: inorganic aluminosilicate lattice, no C–metal bonds.
• Isopropyl alcohol: oxygenated organic, no metal atom.

Common Pitfalls:
Confusing “contains a metal” with “organometallic.” Many catalysts (zeolites) contain metals or metal-like centers but lack direct metal–carbon bonds and thus are not organometallics.

Final Answer:
Tetraethyl lead