Self-Assembled Monolayers of ω-Biphenylalkanethiols on Au(111): Influence of Spacer Chain on Molecular Packing

P Cyganik, Manfred Buck, W Azzam, C Wöll

Research output: Contribution to journalArticlepeer-review

153 Citations (Scopus)

Abstract

Self-assembled monolayers (SAM) of omega-(4'-methylbiphenyl-4-yl)alkanethiols CH3(C6H4)(2)(CH2)nSH (BPn, n = 1-6) on Au(1 1 1) substrates, prepared at room and elevated temperatures, were studied using scanning tunneling microscopy (STM). Molecularly resolved images reveal that all BPn SAMs form well-ordered layers over areas easily exceeding 50 x 50 nm(2). Only two basic structures are alternatingly adopted with n changing between odd and even. The unit cell of odd-numbered SAMs is described by an oblique (2root3 x root3)R30degrees structure and contains two molecules. In contrast, the even-numbered SAMs are described by a much larger, rectangular (5root3 x 3) structure with eight molecules per unit cell and occupying an area per molecule larger by about 25% compared to n = odd. With the exception of BP1 and BP6 the preparation at elevated temperatures resulted in a significant improvement in structural quality, yielding very large domains. For BP6 prepared at 343 K a strong domain anisotropy is observed, which is explained by the influence of the alkane spacer chain. For BP1 prepared at 343 K formation of gold islands is concluded.

Original languageEnglish
Pages (from-to)4989-4996
Number of pages8
JournalJournal of Physical Chemistry B
Volume108
Issue number16
DOIs
Publication statusPublished - 22 Apr 2004

Keywords

  • SCANNING-TUNNELING-MICROSCOPY
  • BIPHENYL-BASED THIOLS
  • ATOMIC-FORCE MICROSCOPY
  • ELECTRICAL-CONDUCTION
  • STRUCTURAL CHARACTERIZATION
  • ALKANETHIOLATE MONOLAYERS
  • AROMATIC THIOLS
  • VACANCY ISLANDS
  • BAND-STRUCTURE
  • GOLD

Fingerprint

Dive into the research topics of 'Self-Assembled Monolayers of ω-Biphenylalkanethiols on Au(111): Influence of Spacer Chain on Molecular Packing'. Together they form a unique fingerprint.

Cite this