Which of the following is not considered as an organometallic compound?

• A. Ferrocene
• B. Cis-platin
• C. Ziese’s salt
• D. Grignard reagent

To determine which option is not an organometallic compound, let's briefly define what organometallic compounds are. These are compounds that contain at least one bond between a carbon atom of an organic molecule and a metal.

Options Analysis

• Ferrocene: This is an organometallic compound consisting of iron sandwiched between two cyclopentadienyl anions.
• Cis-platin: This is a coordination complex of platinum and is not classified as organometallic because it does not have a direct carbon-metal bond.
• Ziese’s salt: This compound contains a metal (aluminum) bonded to an organic group, making it organometallic.
• Grignard reagent: These are organometallic compounds formed by the reaction of alkyl or aryl halides with magnesium.

Based on this analysis, the answer is Cis-platin, as it does not fit the definition of an organometallic compound.