Abstract
Molecular clips are able to selectively bind electron deficient aromatic and aliphatic substrates, and these processes are usually investigated in dilute solutions of organic solvents. Caused by discrepancies between polar and hydrophobic groups, molecular clips are surface-active compounds and, in analogy to surfactants, they can form monomolecular films at the water surface. In this publication, we systematically investigated the self-association process and the phase-behaviour of three different molecular clips with the polar head groups -OCH2COOH (a), -OCH2COOEt (b), and -OCONHPh (c) by means of surface-pressure-area-isotherms and Brewster-angle-microscopy (BAM). We observed marked differences for all investigated surface-active compounds. The molecular surface areas of the three clips, determined from pressure-area-isotherms, could be traced back to the molecular diameters of the amphiphilic compounds. In several experiments we investigated the influence of diverse film compression and expansion steps. Hysteresis effects could be explained by different film morphologies. In a series of experiments we could show that the aromatic guest molecule 1,2,4,5-tetracyanobenzene (TCNB), which strongly binds to molecular clips, did not influence the phase diagrams and film structures.
Similar content being viewed by others
References
McConnell HM (1991) Annu Rev Phys Chem 42:171
Möhwald H (1988) Thin Solid Films 159:1
Knobler CM, Desai RC (1992) Annu Rev Phys Chem 43:207
Vollhardt D (1993) Adv Colloid Interface Sci 47:1
Lavigne P, Tancrede P, La marche F, Max JJ (1992) Langmuir 8:1988
Vollhardt D (1996) Adv Colloid Interface Sci 64:143
Reda T, Hermel H, Höltje H-D (1996) Langmuir 12:6452
Vollhardt D, Fainerman VB (2002) J Phys Chem 106:345
Hönig D, Möbius D (1991) J Phys Chem 95:4590
Hénon S, Meunier J (1991) Rev Sci Instrum 62:936
Kaerchert T, Möbius D, Welt R (1995) Vis Res 35:2231
Vollhardt D (1999) Adv Colloid Interface Sci 79(1):19–57
Klärner F-G, Panitzky J, Bläser D, Boese R (2001) Tetrahedron 3673
Atwood JL, Davies JED, MacNicol DD, Vögtle F, Suslick KS (1996) Comprehensive supramolecular chemistry. Elsevier, Oxford
Jasper C, Schrader T, Panitzky J, Klärner F-G (2002) Angew Chem Int Ed 41:1355–1358
Klärner F-G, Kahlert B (2003) Acc Chem Res 36:919–932
Acknowledgements
Financial support for this work through grants from the “Deutsche Forschungsgemeinschaft” SFB 452 and the “Fonds der Chemischen Industrie” is gratefully acknowledged.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Degen, P., Rehage, H., Klärner, F.G. et al. Characterization of Langmuir-monolayers of molecular clips by means of Brewster-angle-microscopy. Colloid Polym Sci 284, 44–50 (2005). https://doi.org/10.1007/s00396-005-1329-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00396-005-1329-y