Fluorescence Studies of the Effects of t-Butyl Functionalities on the Formation of Ternary β-Cyclodextrin Complexes with Pyrene
Abstract:The effects of t-butyl (TB) compounds on the formation of β-cyclodextrin (CD)/pyrene complexes have been examined by monitoring changes in the fluorescence I/III band ratio of 1.0 x 10-7 M pyrene in 0.075 M of the t-butyl compounds and in various concentrations of β-CD in a solvent mixture consisting of 60% v/v methanol/40% water solution. For the compounds tested, the strongest effects were observed in the presence of the following (in decreasing order): TB-carbamate, TB-carbazate, TB-(N-hydroxy) carbamate, TB-(N-butoxy carbonyl) glycine, and TB-formate. In terms of enhancement of the pyrene/β-CD binding constant, all exhibited effects stronger than those previously reported for t-butyl alcohol. In contrast, TB-amine, TB-acetic acid, and TB-acetoacetate exhibited very little effect. There appears to be a relationship between the chemical structure of the modifier molecules and the magnitude of their concomitant effects on the I/III ratio. In fact, the t-butyl modifiers which exhibited moderate, to strong effects have a common caboxy, -C-O-, skeleton attached to the t-butyl moiety in their general structure: (CH3)3C-O-R. The modifier effect was also found to be independent of the pH of the solutions. A detailed explanation has been offered for the observed changes in the I/III ratio relative to t-butyl functionalities.
Document Type: Research Article
Publication date: August 1, 1996
More about this publication?
- The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Request copyrighted SAS materials
- Spectroscopic Nomenclature
- Focal Point (Open Access)
- ingentaconnect is not responsible for the content or availability of external websites