1. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 1 of 21 Spectroelectrochemistry of Self Assembled Monolayers of Biphenyl Ethynyl Thiols on Gold Electrodes Abdel Aziz Jbarah, Katrin Rößler, Heinrich Lang and Rudolf Holze Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz

2. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 2 of 21

3. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 3 of 21

4. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 4 of 21

5. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 5 of 21 Nyquist-plots of a gold electrode, 1: 3a/Au, 3: 3b/Au, 2: 4/Au und 21/Au, 0.01 M (NH 4 ) 2 Fe(SO 4 ) 2 /0.01 M (NH 4 )Fe(SO 4 ) 2 in 1 M HClO 4

6. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 6 of 21 0.01 M (NH 4 ) 2 Fe(SO 4 ) 2 /0.01 M (NH 4 )Fe(SO 4 ) 2 in 1 M HClO 4 Assumption: 2 and 3 should yield the same SAM after S-R-cleavage

7. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 7 of 21 Assuming: 3 stands upright and 1 is tilted → α ≈ 60°

8. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 8 of 21

9. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 9 of 21 UV-Vis spectra of 10 -5 mM of 1 in THF (a), 10 -5 mM of 2 in THF (b) and 10 -5 mM of 3 in THF (c), 5.0 mm cell, resolution 0.1 nm.

10. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 10 of 21

11. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 11 of 21

12. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 12 of 21

13. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 13 of 21 3

14. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 14 of 21

15. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 15 of 21 Tilted orientation, weaker Au-S interaction than with 3 1

16. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 16 of 21

17. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 17 of 21 More tilted or even flat orientation – fits with C DL, very weak Au-S interaction, presum- ably R-S-R intact with corresponding orienta- tion 2

18. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 18 of 21

19. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 19 of 21 Au-S-mode typical of thiolate 3

20. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 20 of 21 Take home: SAMs are formed different compactness/thickness Some are tilted with respect to surface normal Various strengths of Au-S-interaction

21. SERS Roundtable 2007 Ellenz-Poltersdorf, October 03 – 05, 2007 21 of 21