Synthesis, conformational studies, and inclusion properties of tris((2-pyridylmethyl)oxy)hexahomotrioxacalix(3)arenes
Article Abstract:
O-Alkylation of a flexible macrocycle with 2-(chloromethyl)pyridine in the presence of Cs2CO3 has yielded a partial cone, preferentially. With K2CO3, cone-to-partial-cone ratio increased. The alkali metal cations act as a template, which has an important part in this O-alkylation reaction. Synergism of cyclophane moiety and 2-3 lower-rim side chains with pyridyl groups has a plays a significant part in complexation of tris((2-pyridylmethyl)oxy) derivatives, the cone and the partial cone with n-butylammonium ion and Ag+ ion. Calixarene and related macrocycles have been of interest because of their host-guest chemistry when they are ionophoric receptors. In biology they can potentially be enzyme mimics
Publication Name: Canadian Journal of Chemistry
Subject: Chemistry
ISSN: 0008-4042
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
Precise measurement of fluorescence from uranium taken up in sodium fluoride
Article Abstract:
Fluorescence signals from multiple samples of uranium in fused sodium fluoride beads, read in the customary way, do not display normal distribution. The signal from one bead shows considerable sinusoidal variation as the bead is rotated. The superposition of this sinusoidal variation on the normal variation between beads that leads to widened or even bimodal distribution among replicates. If each bead is read again after a half rotation, the average of the two readings gives the actual signal underlying the sinusoidal variation.
Publication Name: Canadian Journal of Chemistry
Subject: Chemistry
ISSN: 0008-4042
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
Escherichia coli beta-galactosidase is hetrogeneous with respect to the activity of individual molecules
Article Abstract:
Escherichia coli beta-galactosidase molecules have been placed in a fluorogenic substrate in a capillary and incubated. Activities of individual enzyme molecules were detected using laser-induced fluorescence detection. The molecules differed in activity and showed a 23-fold distribution of activities. The majority were within a 4-fold distribution.
Publication Name: Canadian Journal of Chemistry
Subject: Chemistry
ISSN: 0008-4042
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Synthesis, structure, and bonding in polyiodide and metal iodide-iodine systems. The hydrothermal synthesis of zeolites: history and development from the earliest days to the present time
- Abstracts: Structural and chemical properties of silyl radicals. Silsesquioxanes
- Abstracts: Selective hydroboration of alkenes and alkynes in the presence of aldehydes and ketones. The reactivity of the high-energy intermediates formed in the reactions of Group 13 metal atoms and aromatic alkenes
- Abstracts: Spectroscopic and differential scanning calorimetric studies of the phase transitions in oxanorbornane. Pressure-tuning infrared and Raman spectroscopic study of (2,2'-bypyridine)tetracarbonylchromium(0)
- Abstracts: Uniaxial deformation of nylon-6 and nylon-11: changes in orientation and crystal phase. The crystal structure of 3,4,7,8-tetramethylglycoluril