Tools and techniques for solution-phase structural understanding of SmI₂–additive complexes

SmI₂ is a versatile reducing agent for organic synthesis. Additive-induced tailoring of reaction mechanisms and products is one of the most promising aspects of this multifaceted reagent. In most instances, additives form a coordination complex with SmI₂. Insight on the solution-phase structure of SmI₂ in the presence of additives is significant to decipher possible reaction mechanisms and predict reactivity of SmI₂ in the presence of an entirely new additive. A series of experimental and computational tools are used to unravel the solution-phase structure of SmI₂–additive complex. This review aims to provide a comprehensive overview of how different analytic tools are employed, and data are analyzed to arrive at a possible solution-phase structure of SmI₂–additive complex. Understanding of SmI₂–additive solution-phase structure in predicting SmI₂ reactivity and plausible reaction mechanism is also discussed.