On the stability of carbocation in water microdroplets

Air-water system represents a ubiquitous interface that appears with a unique polar environment. Performing and studying chemistry at this interface is of growing importance for a sustainable future. Current advances in microdroplet chemistry hinted at the mysterious nature of water microdroplets, which is strikingly different from the corresponding bulk phase. Recently, we have revealed that reactive carbocation species can be captured and stabilized in water microdroplets by enhancing their lifetime up to 109 times at or nearer to the air-water interface. This result is in contrast to the expectation as car-bocations are conventionally known to be rapidly annihilated by the nucleophilic attack of water. This article aims to offer some critical insights on the possible surface/interface factors, based on experiments and literature precedence, that could primarily contribute to stabilizing carbocations. How the super -acidic microdroplet surface with low water density and high electric field might allow carbocation dangling at the air-water interface is discussed.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Air-water system is an important interface for studying chemistry and achieving sustainability. Recent research shows that reactive carbocation species can be stabilized and captured in water microdroplets, contrary to previous expectations. This article provides insights on the factors that contribute to stabilizing carbocations at the air-water interface.