Single‐Crystalline Organoiridium Complex for Gas‐Triggered Chromogenic Switches and Its Applications on CO Detection and Reversible Scavenging

Abstract

Summary of main observation and conclusionNonporous molecular single crystals of coordinatively unsaturated 16‐electron metallacycle are found to undergo highly selective – yet reversible – binding of CO over CH4, H2, N2, CO2, various volatile organic compounds and water, through binding of the molecule to its metal centers. Carbon monoxide is taken up by black crystals and subsequently liberated from the corresponding orange CO adduct by reversible metal coordination, the structural evidence obtained from in situ X‐ray diffraction. The single‐crystallinity of the metallacycle is retained even after several cycles. The material, when adsorbed on silica, shows remarkable sensitivity and selectivity for CO, allowing visual CO sensing in the solid state. The metallacycle offer the possibility of serving as readily regenerable scavenger for removing trace CO from gas mixtures with N2.