}

Research output:Contribution to journal ›Article ›Academic ›peer-review

TY - JOUR

T1 - Unidirectional molecular motor on a gold surface

AU - van Delden, RA

AU - ter Wiel, MKJ

AU - Pollard, MM

AU - Vicario, J

AU - Koumura, N

AU - Feringa, BL

AU - Delden, Richard A. van

PY - 2005/10/27

Y1 - 2005/10/27

N2 - Molecules capable of mimicking the function of a wide range of mechanical devices have been fabricated, with motors that can induce mechanical movement attracting particular attention(1,2). Such molecular motors convert light or chemical energy into directional rotary or linear motion(2-10), and are usually prepared and operated in solution. But if they are to be used as nanomachines that can do useful work, it seems essential to construct systems that can function on a surface, like a recently reported linear artificial muscle(11). Surface-mounted rotors have been realized and limited directionality in their motion predicted(12,13). Here we demonstrate that a light-driven molecular motor capable of repetitive unidirectional rotation(14) can be mounted on the surface of gold nanoparticles. The motor design(14) uses a chiral helical alkene with an upper half that serves as a propeller and is connected through a carbon - carbon double bond ( the rotation axis) to a lower half that serves as a stator. The stator carries two thiol-functionalized 'legs', which then bind the entire motor molecule to a gold surface. NMR spectroscopy reveals that two photo-induced cis-trans isomerizations of the central double bond, each followed by a thermal helix inversion to prevent reverse rotation, induce a full and unidirectional 3608 rotation of the propeller with respect to the surface-mounted lower half of the system.

AB - Molecules capable of mimicking the function of a wide range of mechanical devices have been fabricated, with motors that can induce mechanical movement attracting particular attention(1,2). Such molecular motors convert light or chemical energy into directional rotary or linear motion(2-10), and are usually prepared and operated in solution. But if they are to be used as nanomachines that can do useful work, it seems essential to construct systems that can function on a surface, like a recently reported linear artificial muscle(11). Surface-mounted rotors have been realized and limited directionality in their motion predicted(12,13). Here we demonstrate that a light-driven molecular motor capable of repetitive unidirectional rotation(14) can be mounted on the surface of gold nanoparticles. The motor design(14) uses a chiral helical alkene with an upper half that serves as a propeller and is connected through a carbon - carbon double bond ( the rotation axis) to a lower half that serves as a stator. The stator carries two thiol-functionalized 'legs', which then bind the entire motor molecule to a gold surface. NMR spectroscopy reveals that two photo-induced cis-trans isomerizations of the central double bond, each followed by a thermal helix inversion to prevent reverse rotation, induce a full and unidirectional 3608 rotation of the propeller with respect to the surface-mounted lower half of the system.

KW - SINGLE STEREOGENIC CENTER

KW - ROTARY MOTION

KW - ROTATION

KW - NANOPARTICLES

KW - ROTOR

KW - SYSTEM

U2 - 10.1038/nature04127

DO - 10.1038/nature04127

M3 - Article

SN - 0028-0836

VL - 437

SP - 1337

EP - 1340

JO - Nature

JF - Nature

IS - 7063

ER -