Electrochimica Acta, Vol.53, No.14, 4900-4906, 2008
Artificially phase-separated binary self-assembled monolayers composed of 11-amino-1-undecanethiolate and 10-carboxy-1-decanethiolate on Au(111): A comparative study of two preparing methods
Two methods have been compared for preparing artificially phase-separated two-component SAMs on Au(111) composed of 11-amino-1-undecanethiolates (AUTe) and 10-carboxyl-1-decanethiolates (CDTe), which would form, thermodynamically, a homogeneously mixed binary SAMs. The first method starts with the formation of a phase-separated binary SAM of AUTe and 2-hydroxy-1-ethanethiolate (HETe) as a template of the artificially phase-separated SAM, followed by the selective desorption of HER domains and succeeding filling of the vacancy with CDTe. The second method utilizes fluoren-9-ylmethyl N-(11-mercaptoundecyl) carbamate (FMUCe) instead of 11-amino-1-undecanethiol in preparing the template. After the filling with CDR, the 9-fluorenylmethyloxycarbonyl (Fmoc) group is removed to obtain AUTe domains. Both methods yield artificially phase-separated binary SAMs having AUTe domains of tens nanometer across. The molecularly flat SAM surface with nanometer-scale domains of different acid-base and electrostatic properties are thus created. For preparing binary SAMs with a higher degree of phase separation, the second method is a better choice; a more clear-cut phase separation is achieved. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords:self-assembled monolayer;SAM;binary self-assembled monolayer;phase separation;artificial phase separation;11-amino-1-undecanethiol;10-carboxyl-1-decanethiol Fmoc;fluoren-9-ylmethyl N-(11-mercaptoundecyl)carbamate