摘要 |
PCT No. PCT/GB95/02376 Sec. 371 Date Jul. 15, 1997 Sec. 102(e) Date Jul. 15, 1997 PCT Filed Oct. 9, 1995 PCT Pub. No. WO96/13527 PCT Pub. Date May 9, 1996Process for the free-radical polymerisation of olefinically unsaturated monomer(s) using a free-radical initiator, the polymerisation being performed in the presence of a compound for effecting molecular weight control, wherein the molecular weight control compound is a Co Il chelate of the following formula I wherein each group X, independently in each ring and in different rings, is a substituent selected from alkyl of 1 to 14 carbon atoms and cycloalkyl of 6 to 14 carbon atoms; n, independently in each ring, is 0 to 5 provided that in at least one ring, n is 1 to 5; Z, independently on each boron atom, is selected from F, Cl, Br, OH, alkoxy of 1 to 12 carbon atoms, aryloxy of 6 to 12 carbon atoms, alkyl of 1 to 12 carbon atoms, and aryl of 6 to 12 carbon atoms; or two Z groups taken together provide on one or both boron atoms a group -O-(Q)-O- where Q is a divalent aryl or alicyclic linking group or an alkylene linking group, or two Z groups taken together on one or both boron atoms provide a 1,5-cyclooctanediyl linking group; or being a Co III analogue of said Co II chelate of formula I in which the Co atom is additionally covalently bonded, in a direction at right angles to the macrocyclic chelate ring system, to H, halide or other anion, or a homolytically dissociable organic group; and wherein optionally at least one further ligand is coordinated to the CoII or CoIII atom, being a ligand which does not alter the Co valency state. Also the Co chelates used in the polymerisation process, a process for their production, and the use in various applications of oligomers made using the polymerisation process.
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