A series of single component FLPs has been investigated for small molecule capture, with the finding that through tuning of both the thermodynamics of binding/activation and the degree of preorganization (i.e., ΔS^⧧) reversibility can be brought about at (or close to) room temperature. Thus, the dimethylxanthene system {(C₆H₄)₂(O)CMe₂}(PMes₂)(B(C₆F₅)₂): (i) heterolytically cleaves dihydrogen to give an equilibrium mixture of FLP and H₂ activation product in solution at room temperature and (ii) reversibly captures nitrous oxide (uptake at room temperature, 1 atm; release at 323 K).