Scanning tunneling thiol

Yu et al. prepared 48, bound to an Au(lll) surface by a thiol on the biphenyl end, then deprotected on the bipyrimidine end to expose a thiol to bind an Au nanoparticle. Rectification was measured by scanning tunneling spectroscopy (STS), and it could be reversed by the addition of acid, which protonated the pyrimidine rings, converting them from donor to acceptor [121]. Yu s group has also inverted the attachment of a rectifier, as shown with 49 and 50, and confirmed that the rectification direction reversed [122]. This was recently verified by STM-BJ measurements [123]. 

Figure 9 Scanning tunneling microscopy (STM) image of a SAM of dodecanethiolate on Au(l 11) that shows a gold step, a screw dislocation, and depressed lines in the monolayer due to the accommodation of missing lines of thiols by vicinal molecules. The inset shows five pits in gold that were 0.24 nm deep and linked by domain boundaries. The monolayer packing corresponds to a phase of the c(4 2) rectangular superlattice. These images were provided by Biebuyck and coworkers [62]...

Reimers, J.R., Zhang, J.D., and Ulstrup, J. (2009) Scanning tunneling microscopic observation of adatom-mediated motifs on gold-thiol self-assembled monolayers at high coverage. Journal of Physical Chemistry C, 113, 19601-19608. 

There exists a large number of literature on SAM formation and characterization in general [1,3-5] and on functionalized alkane thiols in particular [6-8], The most frequently used methods to analyze the SAMs are Scanning Tunneling Microscopy (STM), Infra-red spectroscopy (IRS), X-ray absorption spectroscopy (NEXAFS) and Low Energy Electron Diffraction (LEED). In this contribution we will focus on the application of Thermal Desorption Spectroscopy (TDS). This method allows... 

Yasuda, S. Futaba, D.N. Takeuchi, O. Suzuki, L Yase. K. Sumaoka. J. Komiyama. M. Shigeliawa, H. Mono-layer formation of 6-deoxy-6-thiol-P-cyclodextrin on a Au(lll) surface studied by scanning tunneling microscopy. J. Vac. Sci. Technol.. A 2001. 19. 1266-1269. Yasuda. S. Shigekawa, H. Suzuki, L Nakamura. T. Matsumoto. M. Komiyama, M. Scanning tunneling microscopy on the formation of lipoamide-cyclodextrin monolayer on Audi 1). Appl. Phys. Lett. 2000. 76, 643-645. 

Using scanning tunneling specboscopy (STS), Paul Weiss and coworkers showed that the currents across alkanethiols and aromatic thiols bonded to Au are larger when the molecules have aromatic, rather than aliphatic, moieties. ... 

---