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Abstract

The studies of our group on the catalytic activities of rare earth calixarene complexes in polymer syntheses are reviewed. Rare earth calixarene complexes are effect catalysts for the polymerizations of butadiene, isoprene, ethylene, styrene, propylene oxide, styrene oxide, trimethylene carbonate and 2,2-dimethyl-trimethylene carbonate.

Numerical Solution of an Integro-Differential Equation Arising in Oscillating Magnetic Fields

“…The test functions are used to ensure that the differential equation and perhaps some boundary conditions are satisfied as closely as possible by the truncated series expansion. This is achieved by minimizing the residual function that is produced by using the truncated expansion instead of the exact solution with respect to a suitable norm [1,2,3,4,5,6,7,8,9, 10].…”

Applications of Calixarenes in Polymer Synthesis

“…An EDTA complex-titration of C6Sc revealed that the content of scandium in the calixarene complex was 2.75%, which indicates that every six phenol units of the p-tert-butylcalix [6]arene have 2.0 OH groups that coordinate to the scandium atom (Scheme 6), which differs from other rare earth p-tert-butyl calix [6]arene complexes. This is probably due to the weaker coordination capacity of the scandium atom.…”

“…A scandium p-tert-butylcalix [6]arene complex (C6Sc) has been synthesized from scandium isopropoxide and p-tert-butylcalix [6]arene. An EDTA complex-titration of C6Sc revealed that the content of scandium in the calixarene complex was 2.75%, which indicates that every six phenol units of the p-tert-butylcalix [6]arene have 2.0 OH groups that coordinate to the scandium atom (Scheme 6), which differs from other rare earth p-tert-butyl calix [6]arene complexes.…”

“…Rare Earth Calixarene Complexes as Polymerization Catalysts [6] Ethylene Polymerization Polyethylene is one of the most important synthetic resins. There is an intensive interest in exploring new and active catalysts for ethylene polymerization.…”

“…For this purpose, rare eath calixarene complexes have been synthesized. As an example, a neodymium p-tert-butylcalix [6]arene complex has been synthesized by the following procedure: 2.469 g (2.54 mmol) of p-tert-butylcalix [6]arene and 0.816 g (2.54 mmol) of neodymium isopropoxide were mixed in 50 mL of toluene. The mixture became dark green after stirring for 2 h at room temperature.…”