Orthogonal Initiation of Molecular Motion Devices by Two Chemical Fuels.

Herein, we demonstrate the selective dissipative and orthogonal actuation of two distinct molecular devices controlled by alternate fuel use. When the multicomponent ensemble of [2]rotaxane 1 and turnstile [Cu( 2 )( 3 )] + was charged with AgBF 4 as chemical fuel ( Fuel 1 ) together with NEt 3 /PhCH 2 Br (cofuels), the transiently formed [Ag( 1 )] + showed a stochastic shuttling of the silver macrocycle between two degenerate triazole stations on the thread ( k 298 = 1.2 × 10 5 s -1 ), whereas [Cu( 2 )( 3 )] + was unperturbed. Instead, treatment of the mixture with PPh 3 as an alternative fuel ( Fuel 2 ) in the presence of oxidant 4 (cofuel) generated the complex [Cu( 3 )(PPh 3 ) 2 ] + and transient thermal motion in rotor 2 ( k 298 = 4.9 × 10 4 s -1 ), whereas rotaxane 1 stayed dormant. Thus, two distinct chemical fuels selectively and orthogonally activated two distinct transient motion devices from a multicomponent mixture. In total, four interference-free dissipative cycles were demonstrated by using alternating fuel additions.