By Noyes W. A.
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Additional resources for A Kinetic Hypothesis to Explain the Function of Electrons in the Chemical Combination of Atoms(en)(5
This reaction is highly selective for organic cyanates; isocyanates, inorganic cyanates and thiocyanates are notably unreactive . 14 to 6 X 10-8 g has been determined. Measurements may be made on pulverized insoluble samples . These two characteristics appear to make this method very attractive for high conversion polymer samples. 15). This is a reflection of the cyanate group's pseudohalogen character where potential dissociation into an alkyl-cyanate ion pair may lead to substitution (SNI or SN2) or elimination reactions that are well known for alkyl halides .
Also, the 14N chemical shift for ethyl cyanate (222 ppm) is upfield of that for phenyl cyanate (208 ppm) indicating a difference in nitrogen electron density between alkyl and aryl cyanates . These effects should be observed in cyanate monomers and may bear some relation to reactivity. 3 Infrared spectroscopy Infrared spectroscopy has been a very important tool for cyanate monomer identification, measurement of conversion to polymer and identification of hydrolysis products and impurities. The cyanate functional group is identified by a strong C=N stretching band at 2200-2300 cm- I and a strong C-O-C stretch at 1160-1240 cm- I .
After completion of the addition, the agitation is stopped and the phases separate. The organic phase is separated and washed with water. The solvent is separated at reduced pressure. Yields and purities up to 99+% are claimed. In addition to the advantages cited above, this procedure may be employed on a large scale with rapid throughput. It is claimed that the organic solvent is necessary in that without it, hydrolysis of the cyanate ester occurs. Hydrolysis of the cyanogen chloride is also a concern but was not found to occur.
A Kinetic Hypothesis to Explain the Function of Electrons in the Chemical Combination of Atoms(en)(5 by Noyes W. A.