POLYMERIZATION OF 4-HYDROXY-N-PROPARGYLPIPERIDINE BY TRANSITION METAL CATALYSTS

The polymerization of 4-hydroxy-N-propargylpiperidine, having 4-hydroxypiperidine moiety, was carried out with various transition metal catalysts. The polymerizations proceeded well to give a relatively high yield of polymer (maximum polymer yield: 93%). Palladium, platinum, and ruthenum chlorides were found to be generally effective for this polymerization. On the other hand, the group 5 and 6 transition metal catalysts such as WCl 6 , MoCl 5 , WCl 6 -organoaluminum compounds etc. fail to polymerize this monomer. The molecular structure of the resulting poly(4-hydroxy-N-propargylpiperidine) was characterized by the various instrumental analysis methods such as NMR ( 1 H-and 13 C-)IR, and UV-visible spectroscopies. The IR spectrum of polymer shows neither the acetylenic hydrogen stretching (3197 cm −1 ) nor the carbon-carbon triple bond stretching (2113 cm −1 ) frequencies presented in the IR spectrum of monomer. Instead, the carbon-carbon double bond stretching frequency at 1611 cm −1 was newly observed. These polymers were mostly brown and black powders and were completely soluble in such polar solvents as formic acid, DMF, DMSO, and tetrahydrofuran. X-ray diffraction analysis of the resulting poly(4-hydroxy-N-propargylpiperidine) revealed that this polymer is mostly amorphous.