Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• spectroscopy; dipolar relaxation; entropy; gauche defect; organic monolayer; Introduction Self-assembled monolayers (SAM) and organic molecular layers (OML) have attracted great interest over the past two decades because surface functionalization offers great flexibility for a molecular-level control of

• relaxation peak intensities, relaxation mechanisms B1 and B2 will be, respectively, attributed to acid end-group dipoles and to gauche defect configurations. Results As reported previously [32], several techniques were used to obtain complementary information on the conformal coverage (STM, AFM), OML

• disordered while they simultaneously experience larger motional constraints (smaller frequency, larger activation energy) than the gauche defects (B2). Assuming a constant dipolar strength for all gauche defects, the dependence of the gauche defect response on temperature (range 220–280 K) provides a value

When “small” terms matter: Coupled interference features in the transport properties of cross-conjugated molecules

• Gemma C. Solomon,
• Justin P. Bergfield,
• Charles A. Stafford and
• Mark A. Ratner

Beilstein J. Nanotechnol. 2011, 2, 862–871, doi:10.3762/bjnano.2.95

• , the third-nearest-neighbor terms also show significant contribution to this system. Similar terms were observed in the local transmission through an alkane with a gauche defect [45]. All of these non-nearest-neighbor terms are quite small compared with their nearest-neighbor counterparts