resorcinarene and anthracene

Herein we present the synthesis and the photochemical behavior of several new hemicarcerands containing anthracene units as photoactive species. By means of NMR investigations of compounds 9 and 11 the dimerization mode was revealed as a 9,10-9',10'-dimerization, classically known from anthracene. Nevertheless only compound 11 could be converted to the opened form upon irradiation with 300 nm. Reopening of compounds 9 and 10 could not be achieved so far either by heating or by irradiation.

Topics: Anthracenes; Calixarenes; Capsules; Dimerization; Molecular Structure; Phenylalanine; Photochemical Processes; Stereoisomerism

A novel silica-bonded stationary phase containing a functionalized resorcinarene selector was prepared by a straightforward synthesis. The complete modification of all resorcinic hydroxyl groups was achieved by reaction with isopropyl isocyanate. The derivatized resorcinarene selector was subsequently immobilized via the four alkenyl chains containing a terminal double bond by a free radical-induced reaction on mercaptopropyl-functionalized silica. A comprehensive characterization of the resulting bonded stationary phase was carried out by solid state NMR, IR and elemental analysis. The resulting selector is defined as a "polar headed" reversed phase since the highly ordered polar carbamate groups of the new stationary phase are located, compared to conventional polar embedded stationary phases, at a greater distance from the silica surface. Thus a new concept is introduced in the field of polar modified reversed-phase HPLC. The properties of the novel stationary phase are demonstrated by comparison with commercially available reversed phases.

Topics: Anthracenes; Calixarenes; Chromatography, High Pressure Liquid; Isotopes; Naphthalenes; Nuclear Magnetic Resonance, Biomolecular; Phenol; Phenylalanine; Silicon; Silicon Dioxide; Spectrophotometry, Infrared; Spectroscopy, Fourier Transform Infrared