Synthesis and characterization of novel fluorophosphazene-derived cobaltacyclopentadienyl metallacycles: Reagents for assembly of aryl-bridged fluorophosphazenes

摘要

Reaction of (beta-phenylethynyl) pentafluorocyclotriphosphazene, F5P3N3C CPh, with in situ generated eta(5)-(MeOC-(O)C5H4)Co(PPh3) 2 resulted in the formation of two isomers of cobaltacyclopentadienylmetallacycles, (eta(5)-carbomethoxycyclopentadienyl)(triphenylphosphine)-2,5-bis(pentafluorocyclotriphosphazenyl)-3,4-diphenyl cobaltacyclopentadiene (1) and (eta(5)-carbomethoxycyclopentadienyl)(triphenylphosphine)-2,4-bis(pentafluorocyclotriphosphazenyl)3,5-diphenyl cobaltacyclopentadiene (2), along with the sandwich compound [eta(5)-carbomethoxycyclopentadienyl][[eta(4)-1,3-bis(pentafluorocyclotriphosphazenyl)-2,4-diphenylcyclobutadiene] cobalt (3). Formation of cobaltacyclopentadienylmetallacycles or cyclobutadienylmetallocene having two fluorophosphazene units on vicinal carbon atoms of the rings was not observed in this reaction. Reaction of 1 with diphenylacetylene resulted in the formation of a novel aryl-bridged fluorophosphazene, 1,4-bis(pentafluorocyclotriphosphazenyl) -2,3,5,6-tetraphenyl benzene (4), and the conversion of cobaltametallacycle to the sandwich compound, [eta(5)-(MeOC(O)C5H4] Co(eta(4)-C4Ph4) (5). Reaction of 1 with phenylacetylene resulted in the formation of aryl-bridged fluorophosphazene, 1,4-bis(pentafluorophosphazenyl) 2,3,5,-triphenyl benzene (6). New compounds 1 -4 were structurally characterized. In compound 1, the two fluorophosphazene units were oriented in gauche form with respect to each other. However, in compounds 2 and 3, they were eclipsed to each other, and in compound 4, they were oriented anti to each other.