Toward a light-driven motorized nanocar: synthesis and initial imaging of single molecules.

A second generation motorized nanocar was designed, synthesized, and imaged. To verify structural integrity, NMR-based COSY, NOESY, DEPT, HSQC, and HMBC experiments were conducted on the intermediate motor. All signals in (1)H NMR were unambiguously assigned, and the results were consistent with the helical structure of the motor.

Toward chemical propulsion: synthesis of ROMP-propelled nanocars.

The synthesis and ring-opening metathesis polymerization (ROMP) activity of two nanocars functionalized with an olefin metathesis catalyst is reported. The nanocars were attached to a Hoveyda-Grubbs first- or second-generation metathesis catalyst via a benzylidene moiety. The catalytic activity of these nanocars toward ROMP of 1,5-cyclooctadiene was similar to that of their parent catalysts.

Synthesis of fluorescent dye-tagged nanomachines for single-molecule fluorescence spectroscopy.

In an effort to elucidate the mechanism of movement of nanovehicles on nonconducting surfaces, the synthesis and optical properties of five fluorescently tagged nanocars are reported. The nanocars were specifically designed for studies by single-molecule fluorescence spectroscopy and bear a tetramethylrhodamine isothiocyanate fluorescent tag for excitation at 532 nm. The molecules were designed such that the arrangement of their molecular axles and p-carborane wheels relative to the chassis would be conducive to the control of directionality in the motion of these nanovehicles.

Synthesis of highly fluorescent BODIPY-based nanocars.

The convergent synthesis of inherently highly fluorescent nanocars incorporating 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-containing axles and p-carborane wheels is reported. These nanocars are expected to exhibit rolling motion with predetermined patterns over smooth surfaces, depending on their chassis. Their quantum yields of fluorescence (Phi(F) > 0.