Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
ACS Nano. 2011 Jan 25;5(1):622-30. doi: 10.1021/nn102876j. Epub 2011 Jan 5.
We report the attachment of altitudinal light-driven molecular motors to surfaces using 1,3-dipolar cycloaddition reactions. Molecular motors were designed containing azide or alkyne groups for attachment to alkyne- or azide-modified surfaces. Surface attachment was characterized by UV-vis, IR, XPS, and ellipsometry measurements. Surface-bound motors were found to undergo photochemical and thermal isomerizations consistent with unidirectional rotation in solution. Confinement at a surface was found to reduce the rate of the thermal isomerization process. The rate of thermal isomerization was also dependent on the surface coverage of the motors. In solution, changes in the UV-vis signal that accompany thermal isomerization can be fit with a single monoexponential decay. In contrast, thermal isomerization of the surface-bound motors does not follow a single monoexponential decay and was found to fit a biexponential decay. Both one- and two-legged motors were attached to surfaces. The kinetics of thermal isomerization was not affected by the valency of attachment, indicating that the changes in kinetics from solution to surface systems are related to interactions between the surface-bound motors.
我们报告了使用 1,3-偶极环加成反应将高层度光驱动分子马达附着到表面上。为了附着到炔烃或叠氮化物修饰的表面上，分子马达被设计成含有叠氮化物或炔烃基团。通过 UV-vis、IR、XPS 和椭圆光度法测量来表征表面附着。发现表面结合的马达经历光化学和热异构化，与溶液中的单向旋转一致。在表面的限制被发现降低了热异构化过程的速率。热异构化的速率还取决于马达的表面覆盖率。在溶液中，伴随热异构化的 UV-vis 信号的变化可以用单个单指数衰减拟合。相比之下，表面结合的马达的热异构化不遵循单个单指数衰减，并且被发现适合双指数衰减。单腿和双腿马达都附着在表面上。热异构化的动力学不受附着价的影响，这表明从溶液到表面体系的动力学变化与表面结合的马达之间的相互作用有关。
