Dormann JM, Ruoff A, Schatz J, Vysotsky MO, Böhmer V (2002)
Publication Type: Journal article, Original article
Publication year: 2002
Original Authors: Dormann J., Ruoff A., Schatz J., Vysotsky M.O., Böhmer V.
Publisher: Chemical Society
Book Volume: 2
Pages Range: 83-87
Journal Issue: 1
URI: https://www.scopus.com/record/display.uri?eid=2-s2.0-0036006973&origin=inward
Structural models for self-assembled dimers composed of two urea calix[4]arenes which entrap benzene or cyclohexane are developed using Fourier transform infrared (FTIR) spectroscopy. Based on the host-guest ratio determined by H NMR spectroscopy in solution, and confirmed for the solid state by a thermogravimetric analysis, it is possible to prove by a comparison of the FTIR data of host, guest, complex and model compounds, that the capsule is held together by a cyclic array of weak and strong hydrogen bonds between the urea units attached at the wide rim of the calixarenes. The dimerization of the two urea units leads to a loss of symmetry, and an averaged C symmetrical arrangement is probable. Guest molecules, such as benzene or cyclohexane, are enclosed inside the container rotating fast on the IR timescale around a longitudinal axis of the guest. From the observed splitting of absorption bands upon dimerization and inclusion it follows that either two crystallographically independent types of capsules exist in the crystal lattice or that the guests are occupying two major orientations in the capsule. As indicated by a higher complexation induced shift for cyclohexane, this guest exhibits a tighter interaction with the host molecules compared to benzene.
APA:
Dormann, J.M., Ruoff, A., Schatz, J., Vysotsky, M.O., & Böhmer, V. (2002). Vibrational spectroscopy of a tetraureidocalix[4]arene based molecular capsule. Journal of the Chemical Society, Perkin Transactions 2, 2(1), 83-87.
MLA:
Dormann, Jörg Martin, et al. "Vibrational spectroscopy of a tetraureidocalix[4]arene based molecular capsule." Journal of the Chemical Society, Perkin Transactions 2 2.1 (2002): 83-87.
BibTeX: Download