Self-aggregation of zinc chlorophylls possessing perfluoroalkyl chains in fluorous solvents: Selective extraction of the self-aggregates with fluorous phase and accelerated formation of the ordered supramolecules in this phase
摘要:
Zinc 3(1)-hydroxy-13(1)-oxo-chlorins possessing various perfluorooctyl groups in the 17-propionate were prepared by modifying naturally occurring chlorophyll-a. The synthetic compound having four perfluorooctyl groups readily self-assembled to form large J-aggregates, which were dissolved in fluorous phases with more ordered supramolecular structures than in a hydrocarbon solvent. (c) 2007 Elsevier Ltd. All rights reserved.
The present invention provides a process for efficiently obtaining polyethers having its high degree of polymerization by easily polymerizing substituted epoxides which could hardly or could not be made so far to provide a high degree of polymerization. That is, a polyether is obtained by a process which comprises ring-opening-polymerizing at least one substituted epoxide, except for propylene oxide and epihalohydrin, in the presence of a rare earth metal compound represented by the formula (I) and a reducing compound:
Wherein M represents a rare earth element selected from Sc, Y and lanthanide, and L
1
, L
2
and L
3
are same as or different from each other and each of them represents an oxygen-binding ligand.