TY - JOUR
T1 - Polyethers containing coumarin dimer components in the main chain. I. Synthesis by photopolymerization of 7,7′-(polymethylenedioxy) dicoumarins
AU - Chen, Yun
AU - Jean, Chuen Sheng
PY - 1997/5/31
Y1 - 1997/5/31
N2 - Eight 7,7′-(polymethylenedioxy)dicoumarins were successfully synthesized by solution condensation of 7-hydroxycoumarin (umbelliferone) or 7-hydroxy-4-methylcoumarin (4-methylumbelliferone) with various dibromoalkanes. Upon benzophenone-sensitized irradiation with 350 nm light in dichloromethane, the terminal coumarin chromophores dimerize to form polyethers containing coumarin dimer components in the main chain. The configurations of the coumarin dimer linkages were characterized by 1H-NMR spectra. For unsubstituted dicoumarins, the resulting polyethers consist mainly of syn and anti head-to-head coumarin dimer linkages. However, the configurations are syn and anti head-to-tail for those from 4-methyl-substituted dicoumarins. The highest reduced viscosity is 0.23 dL/g obtained with polyether from 7,7′-(decamethylenedioxy)dicoumarin. The photopolymerization in dichloromethane obeys zero order and first order with respect to coumarin chromophore and benzophenone, respectively.
AB - Eight 7,7′-(polymethylenedioxy)dicoumarins were successfully synthesized by solution condensation of 7-hydroxycoumarin (umbelliferone) or 7-hydroxy-4-methylcoumarin (4-methylumbelliferone) with various dibromoalkanes. Upon benzophenone-sensitized irradiation with 350 nm light in dichloromethane, the terminal coumarin chromophores dimerize to form polyethers containing coumarin dimer components in the main chain. The configurations of the coumarin dimer linkages were characterized by 1H-NMR spectra. For unsubstituted dicoumarins, the resulting polyethers consist mainly of syn and anti head-to-head coumarin dimer linkages. However, the configurations are syn and anti head-to-tail for those from 4-methyl-substituted dicoumarins. The highest reduced viscosity is 0.23 dL/g obtained with polyether from 7,7′-(decamethylenedioxy)dicoumarin. The photopolymerization in dichloromethane obeys zero order and first order with respect to coumarin chromophore and benzophenone, respectively.
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U2 - 10.1002/(sici)1097-4628(19970531)64:9<1749::aid-app11>3.0.co;2-t
DO - 10.1002/(sici)1097-4628(19970531)64:9<1749::aid-app11>3.0.co;2-t
M3 - Article
AN - SCOPUS:4043055862
VL - 64
SP - 1749
EP - 1758
JO - Journal of Applied Polymer Science
JF - Journal of Applied Polymer Science
SN - 0021-8995
IS - 9
ER -