Determination of molecular orientation in self-assembled monolayers using IR absorption intensities: The importance of grinding effects

Langmuir

Volumn 17, Issue 16, 2001, Pages 4980-4989

  Arnold, Ralf ^a   Terfort, Andreas ^b   Wöll, Christof ^a  

^a RUHR UNIVERSITY BOCHUM   (Germany)

^b UNIVERSITY OF HAMBURG   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

TRANSITION DIPOLE MOMENTS (TDM);

ABSORPTION SPECTROSCOPY; COMPLEXATION; INFRARED RADIATION; LIGHT REFLECTION; LIGHT SCATTERING; MOLECULAR ORIENTATION; PARTICLE SIZE ANALYSIS;

SELF ASSEMBLY;

EID: 0035822862     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la010202o     Document Type: Article

References (60)

1. Ulman, A. Self-Assembled Monolayers of Thiols; Academic Press: London, San Diego, 1998; Thin Films 24.
2. Bain, C.D.; Troughton, E.B.; Tao, Y.-T.; Evall, J.; Whitesides, G.M.; Nuzzo, R.G. J. Am. Chem. Soc. 1989, 111, 321-335.
3. Dubois, L.H.; Nuzzo, R.G. Annu. Rev. Phys. Chem. 1992, 43, 437-463.
4. Grundmeier, G.; Reinartz, C.; Rohwerder, M.; Stratmann, M. Electrochim. Acta 1998, 43, 165-174.
5. Xia, Y.; Whitesides, G.M. Angew. Chem., Int. Ed. Engl. 1998, 37, 550-575.
6. Xia, Y.; Qin, D.; Whitesides, G.M. Adv. Mater. 1996, 8, 1015-1017.
7. Xia, Y.; Whitesides, G.M. Langmuir 1997, 13, 2059-2067.
8. Kumar, A.; Biebuyck, H.A.; Whitesides, G.M. Langmuir 1994, 10, 1498-1511.
9. Sagiv, J. J. Am. Chem. Soc. 1980, 102, 92-98.
10. Hoffmann, H.; Mayer, U.; Krischanitz, A. Langmuir 1995, 11, 1304-1312.
11. Allara, D.L.; Nuzzo, R.G. Langmuir 1985, 1, 52-66.
12. Dannenberger, O.; Weiss, K.; Himmel, H.-J.; Jäger, B.; Buck, M.; Wöll, C. Thin Solid Films 1997, 307, 9885-9893.
13. Himmel, H.-J.; Terfort, A.; Arnold, R.; Wöll, C. Mater. Sci. Eng. C 2000, 8-9, 431-435.
14. Himmel, H.-J.; Terfort, A.; Wöll, C. J. Am. Chem. Soc. 1998, 120, 12069-12074.
15. Meldrum, F.C.; Flath, M.; Knoll, W. Langmuir 1997, 13, 2033-2049.
16. Meldrum, F.C.; Flath, M.; Knoll, W. Thin Solid Films 1999, 348, 188-195.
17. Hausch, M.; Beyer, D.; Knoll, W. Langmuir 1998, 14, 7213-7216.
18. Rothenhäusler, B.; Duschl, C.; Knoll, W. Thin Solid Films 1988, 159, 323-330.
19. Porter, M.D.; Bright, T.B.; Allara, D.L.; Chidsey, C.E.D. J. Am. Chem. Soc. 1987, 109, 3559-3568.
20. Nuzzo, R.G.; Fusco, F.A.; Allara, D.L. J. Am. Chem. Soc. 1987, 109, 2358-2368.
21. Hähner, G.; Wöll, C.; Grunze, M.; Kinzler, M.; Scheller, M.K.; Cederbaum, L.S. Phys. Rev. Lett. 1991, 67, 851-854, See also Erratum: Phys. Rev. Lett. 1992, 69, 694.
22. Debe, M.K. J. Appl. Phys. 1984, 55, 3354-3366.
23. Parikh, A.N.; Allara, D.L. J. Chem. Phys. 1992, 96, 927-944.
24. Born, M.; Wolf, E. Principles of Optics, 7th ed.; Cambridge University Press: Cambridge, 1999.
25. The light used for IR measurements actually does not come in at a single angle. In practice a light bundle with an aperture angle of 2.5° is focused onto the sample. Hence, the angle of incidence and the azimuth vary ±2.5°. The angle of 80° is referenced to the optical axis of the incident light bundle. The error bar resulting from the aperture in the present apparatus is less than 0.5°. See also ref 26.
26. Laibinis, P.E.; Whitesides, G.M.; Allara, D.L.; Tao, Y.T.; Parikh, A.N.; Nnzzo, R.G. J. Am. Chem. Soc. 1991, 113, 7152-7167.
27. Absorbance Units: 0 AU = 100% transmission, i AU = 10% transmission, 2 AU = 1% transmission (logarithm scale).
28. A ultra-high-precision balance (Sartorius 2104) with a resolution of 1 μg and a reproducibility of better than 5 μg was used.
29. Third-order polynoms were used.
30. Bio-Rad Laboratories, Package of Commercial Software: Win-IR-Pro, Cambridge, 1998.
31. Wilson, G.; Bloor, J.E. Phys. Rev. 1934, 45, 706-714.
32. The relative method neglects the effect of anomalous dispersion. The real part of the refractive index is assumed to be constant.
33. 3 sym mode has to be considered.
34. The constant azimuthal factor can be taken into the relative concentration factor and further be ignored.
35. If the packing densities of the crystallites in the pellet and in the SAM are equal, it is possible to consider the thickness of the substance instead of the concentration. In the pellet, the thickness of the sample is given by the product of the concentration of the substance and the thickness of the pellet. The thickness of the SAM on the substrate can be determined experimentally by XPS or ellipsometry. Alternatively, the known length of a molecule chain can be used to calculate the thickness of the SAM depending on the set tilt angle. In the present work the experimentally determined thickness of 24 Å was used for ODT SAMs.
36. The fit results of the IR bands obtained from the bulk were shifted to the appropriate band positions of the SAM before executing the calculation.
37. The apparent absorbance depends on the particular type of mortar (laboratory mortars or micromortars). Different persons using the same hand mortar typically also yield different results.
38. Bohren, C.F.; Huffman, D.R. Absorption and Scattering of Light by Small Particles; John Wiley & Sons: New York, Chichester, Brisbane, Toronto, Singapore, 1983.
39. As described in this work, the Mie theory is the exact solution of the scattering problem for spherical particles. The use of other particle shapes requires a more refined theoretical treatment and will result in different band shapes and intensities.
40. Sharpless, N.E. Appl. Spectrosc. 1963, 17, 47-50.
41. Duyckaerts, G. Spectrochim. Acta 1955, 7, 25-31.
42. Duyckaerts, G. Analyst 1959, 84, 201-214.
43. Hlavay, J.; Jonas, K.; Elek, S.; Inczedy, J. Clays Clay Miner. 1977, 25, 451-6.
44. Hlavay, J.; Inczedy, J. Spectrochim. Acta, Part A 1985, 41A, 783-7.
45. Lunige, H.J.; de Koeijer, J.A.; van der Maas, J.H.; Chalmers, J.M.; Tayler, P.J. Vib. Spectrosc. 1993, 4, 301-308.
46. Charbonneau, G.P.; Delugeard, Y. Acta Crystallogr. 1976, 32, 1420.
47. Günzler, H.; Heise, H.M. IR-Spektroskopie, 3rd ed.; VCH: Weinheim, Germany, 1996.
48. Badia, A.; Demers, L.; Dickinson, L.; Lennox, F.G.M.B.; Reven, L. J. Am. Chem. Soc. 1997, 119, 11104-11105.
49. Badia, A.; Gao, W.; Singh, S.; Demers, L.; Cucia, L.; Reven, L. Langmuir 1996, 12, 1262-1269.
50. Arnold, R.; Wühn, M.; Terfort, A.; Allara, D.L.; Wöll, C. To be published.
51. Hautman, J.; Klein, M.L. J. Chem. Phys. 1990, 93, 7483-7492.
52. Pertsin, A.J.; Grunze, M. Langmuir 1994, 10, 3668-3674.
53. Fenter, P.; Eisenberger, P.; Liang, K.S. Phys. Rev. Lett. 1993, 70, 2447-2450.
54. Bain, C.D.; Evall, J.; Whitesides, G.M. J. Am. Chem. Soc. 1989, 111, 7155-7164.
55. 2 bands are not proportional to the number of the methylene groups in the n-alkane chains. Empirically it has been found that the experimental intensities can be reproduced by a linear function for alkanethiols containing n = 15 to n = 19 methylene groups by decreasing the number of methylene groups to n - 8. See the Supporting Information of ref 26.
56. Harder, P.; Grunze, M.; Dahint, R.; Whitesides, G.M.; Laibinis, P.E. J. Phys. Chem. B 1998, 102, 426-436.
57. Data were taken from 360 s ground pellet of Figure 3.
58. Dale, J. Acta Chem. Scand. 1957, 11, 640-649.
59. Akiyama, M. Spectrochim. Acta 1984, 40A, 367-371.
60. Varsanyi, G. Vibrational Spectra of Benzene Derivates; Academic Press: New York, London, Budapest, 1969.