Loosely packed self-assembled monolayers on gold generated from 2-alkyl-2-methylpropane-1,3-dithiols

Joon-Seo Park; Aaron C Smith; T Randall Lee

doi:10.1021/la036424z

Loosely packed self-assembled monolayers on gold generated from 2-alkyl-2-methylpropane-1,3-dithiols

Langmuir. 2004 Jul 6;20(14):5829-36. doi: 10.1021/la036424z.

Authors

Joon-Seo Park¹, Aaron C Smith, T Randall Lee

Affiliation

¹ Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77204-5003, USA.

PMID: 16459597
DOI: 10.1021/la036424z

Abstract

A series of 2-alkyl-2-methylpropane-1,3-dithiol derivatives with increasing alkyl chain lengths (i.e., CH3(CH2)mC(CH3)[CH2SH]2, where m = 7, 9, 11, 13, 15) were synthesized and used to generate self-assembled monolayers (SAMs) on gold. The resulting monolayers were analyzed by ellipsometry, contact angle goniometry, polarization modulation infrared reflection-absorption spectroscopy, and X-ray photoelectron spectroscopy. These data were compared with those obtained on SAMs on gold derived from normal alkanethiols (CH3(CH2)(m+2)SH) and 2-monoalkylpropane-1,3-dithiols (CH3(CH2)(m)CH[CH2SH]2) having the same number of carbon atoms in the primary chain. The results demonstrate that the 2-alkyl-2-methylpropane-1,3-dithiols generate conformationally disordered monolayer films in which the density of alkyl chains is less than those generated from normal alkanethiols and the 2-monoalkylpropane-1,3-dithiols.