684. Transition-metal–fluorocarbon complexes. Part III. Some derivatives of hexafluorobut-2-yne

Abstract

Reaction of hexafluorobut-2-yne with iron and cobalt carbonyls and with carbonyl-x-cyclopentadienyl-cobalt and -nickel has given the very stable and unreactive complexes C,F,,OFe(CO) 3, C4F,Co,(CO),, n-C,H,CoC,F,,, and C,F,Ni,(x-C,H,) , , respectively. Infrared and nuclear magnetic resonance spectra of these compounds and of ~-C,H,COC~(C,H,)~ are given and the structures of the compounds discussed.A number of transition-metal complexes have been found to polymerise hexafluorobut-2-yne under mild conditions either to hexakistrifluoromethylbenzene or to a white infusible high polymer.

Organic Fluorine Chemistry

“…The former reaction gives derivatives of pyridine [566], the latter those of dihydro-oxazine [567]: Cycloadditions a1'e involved in several interesting reactions of hexafluoro-2-butyne [568][569][570][571]: (339) [571) CFa CFa…”

The crystal and molecular structure of tricarbonyltetrakis(trifluoromethyl)cyclopentadienone-iron

“…The preparation and characterization of a number of fluorocarbon complexes of transition metal ions have been reported by Boston, Sharp & Wilkinson (1960, Boston, Grim & Wilkinson (1963) and Dickson & Wilkinson (1964). The reaction of hexafluorobut-2-yne with pentacarbonyliron (Boston et al, 1962) yields a single product which, on the basis of infrared studies, may be formulated as tricarbonyltetrakis(tri-fluoromethyl)cyclopentadienone-iron. High resolution 19F nuclear magnetic resonance studies indicate two distinct environments for the fluorine atoms, and this was taken to indicate that the bonding between the metal ion and cyclic ligand was asymmetric.…”

A synthetic, structural and reactivity study of [(η4-C4R4)Co(η5-C5H4X)] complexes, R=Me or Et; X=CHO, CHCHFc, CHCH(η5-C5H4)Co(η4-C4Ph4), CHC(CN)2: Unexpected formation of [(η5-cyclopentadienyl)(η4-3,4,5,6-tetraethyl-α-pyrone)cobalt]

“…(g 4 -C 4 Ph 4 ) complexes of Co III , such as [(g 5 -C 5 H 5 )Co(g 4 -C 4 Ph 4 )], are most conveniently prepared by the thermal dimerisation of diphenyl acetylene, PhC"CPh, using suitable cyclopentadienylcobalt substrates such as [(g 5 -C 5 H 5 )Co(C 2 H 2 ) 2 ] [16], [(g 5 -C 5 H 5 ) 2 Co] [17], [(g 5 -C 5 H 5 )Co(CO) 2 ] [18], [(g 5 -C 5 H 5 )Co(g 4 [19] or [(g 5 -C 5 H 5 )Co(PPh 3 ) 2 ] [20]. However, this requires relatively high temperatures, e.g.…”

“…1. The molecule adopts a piano stool structure with Co-Cb(centroid) and Co-C(Cb) distances of 1.760(1) and 2.0248(18)-2.0488 (17) respectively. These are the longest such distances observed of the C 4 Et 4 complexes reported herein.…”