Acta Phys. -Chim. Sin. ›› 1997, Vol. 13 ›› Issue (06): 515-524.doi: 10.3866/PKU.WHXB19970608

• ARTICLE • Previous Articles     Next Articles

New Approach on the Synthesis of Functionalized Alkanethiols and the Structural Characterization of Their Self-Assembled Monolayers

Zhang Hao-Li,Zhang Jin,Zhao Jiang,Wang Yong-Qiang,She Jin,Yu Hua-Zhong,Li Hu-Lin,Liu Zhong-Fan   

  1. Center for Intelligent Materials Research(CIMR),College of Chemistry and Molecular Engineering,Peking University,Beijing 100871|Chemistry Department of Lanzhou University,Lanzhou 730000
  • Received:1996-10-22 Revised:1996-12-30 Published:1997-06-15
  • Contact: Liu Zhong-Fan

Abstract:

A simple and general method for synthesizing functionalized alkanethiols is reported. The synthesis started from carboxylic acid, RCOOH, which was selectively condensed with the amino group of 2-aminoethanethiol, thus giving the targetting thiol compounds. A series of thiol compounds having a structure of RC(O)NHCH2CH2SH, where R was azobenzene derivatives, dicetylene derivatives and n-akanes, respectively, have been synthesized using this method. The self-assembled monolayers(SAMs) of these species were characterized by wettability measurement, electrochemistry and grazing incidence refletance infrared spectroscopy(GIR-IR). The SAM from 4((N-(2’-mercaptrvethyl)amino)carbonyl) azobenzene showed clearcut electrochemical reactivity in aqueous solution, in which the surface coverage was evaluated to be 4.21×10-10mol•cm-2. On the other hand, for the thiols of R being n-alkanes, the packing structures became gradually improved with increasing the alkyl chain length. For CH3(CH2)6C(O)NHCH2CH2SH SAM, GIR-IR data indicate that the C=O and N-H groups are parallel with the substrate surface while the whole molecular axis is perpendicular to the surface.

Key words: Self-assembled monolayers(SAMs), Thiols, Azobenzene derivative, Diacetylene derivative, Contact angle measurement;Electrochemistry, Grazing incidence reflectance infrared spectroscopy(GIR-IR)