Answer: Polar covalent C-Mg bond with C acting as nucleophile.
- A Polar covalent C-Mg bond with C acting as nucleophile
- B A largely ionic bond between a carbanion and the magnesium cation
- C A non-polar covalent bond identical to a C-C bond in alkanes
- D A mainly dative bond donated from magnesium toward the carbon atom
Correct answer: A. Polar covalent C-Mg bond with C acting as nucleophile
Explanation: The C-Mg bond in a Grignard reagent is strongly polarised (Mg is more electropositive), making the carbon nucleophilic (carbanion character).
SN2 proceeds in a single step with backside attack and inversion of configuration, while SN1 forms a planar carbocation intermediate first, leading to racemisation.
Concept context
Study carbon-halogen compounds: how they are made, how they react via SN1/SN2 and elimination, their stereochemistry, and their environmental impact.