John L. Davidson

Metal perfluoroalkane- and perfluoroarene-thiolates. Part V. The reactions of tricarbonyl(π-cyclopentadienyl)-molybdenum and -tungsten thiolates and acetylenes

The thiolates [(η5-C5H5)M(CO)3SRF](M = Mo or W; RF = CF3 or C6F5) react with acetylenes, RCCR (R = CF3, Me, or Ph) to give the formally electron-deficient π-acetylene complexes [(η5-C5H5)M(CO)(RC2R)SRF]. The bonding and isomerism in these complexes at low temperatures is discussed. On oxidation [(η-C5H5)MoO(CF3C2CF3)SC6F5] can be isolated. Trifluoropropyne reacts with the thiolates to give the acetylene complex [(η5-C5H5)Mo(CO)(CF3C2H)SC6F5] and cyclopentadienone complexes [(η5-C5H5)Mo(CO){(CF3C2H)2CO}SCF3] and [{(η5-C5H5)[(CF3C2H)2CO]SCF3}2].

Insertion reactions of hexafluorobut-2-yne, tetrafluoroethylene, and hexafluoroacetone with η5-cyclopentadienyl-iron, -ruthenium, -palladium, and -molybdenum complexes; molecular and crystal structures of [Fe2(CO){C4(CF3)4CO}(η5-C5H5)2] and [Fe{COCF2C5H5}(η5-C5H5)]

Reaction (u.v. irradiation) of [{Fe(CO)2(η5-C5H5)}2] with hexafluorobut-2-yne (hfb) gives [Fe2(CO){C8F12CO}(η5-C5H5)2], structurally identified by X-ray crystallography as a ferracyclohexadienone complex. The ruthenium compound [{Ru(CO)2(η5-C5H5)}2] reacts with hfb to give [Ru{trans-C(CF3):C(CF3)H}(CO)2(η5-C5H5)], which subsequently affords the bis-insertion product [[graphic omitted](CF3)H}(CO)(η5-C5H5)]. Irradiation of [FeMe(CO)2(η5-C5H5)] and hfb affords [[graphic omited]Me(η5-C5H5)], which exists in solution as two interconverting conformers. Treatment of [MnMe(CO)5] with hfb gives the insertion product [Mn{cis-C(CF3):C(CF3)Me}(CO)5]. Reaction of [Fe(η1-C3H5)(CO)2(η5-C5H5)] with hfb gives only the cis mono-insertion product, whereas, the corresponding molybdenum system [Mo(η1-C3H5)(CO)3(η5-C5H5)]affords a bis-insertion product; the first step probably involves a trans-insertion. A second product is [Mo2(CO)4(CF3C2CF3)(η5-C5H5)2]. The photolytic reaction of [Pd(η3-C3H5)(η5-C5H5)] and hfb, in contrast with the Fe and MO systems, gives a dinuclear complex [Pd2C4(CF3)4(η3-C3H5)(η5-C5H5)]. Irradiation of hfb and [Fe(η1-C5H5)(CO)2(η5-C5H5)] gives a product corresponding to a formal (2 + 4)π addition to an unco-ordinated substituted cyclopentadiene, followed by a carbonyl insertion reaction. Tetrafluoroethylene undergoes an unusual carbon–carbon double bond cleavage on reaction with [Fe(η1-C5H5)(CO)2(η5-C5H5)] to give [Fe(COCF2C5H5)(η5-C5H5)], structurally characterised by X-ray crystallography. Hexafluoroacetone (hfa) readily reacts at low temperature with [Fe(η1-C5H5)(CO)2(η5-C5H5)] to give products, in which the hfa has formally inserted into a C–H bond on the σ-bonded C5 ring.

Reactions of acyl- and alkyl-(tricarbonyl)(5-cyclopentadienyl)-molybdenum and -tungsten complexes with but-2-yne; molecular structures of [Mo(CO)(ButNC)(3-{OC(O)CMeCMeCMe})(5-C5H5)] and [MoC(O)C(Me){C(Me)}2C(Me)C(CF3)O(CO)(5-C5H5)]

Reaction of [MR(CO)3(η5-C5H5)](M = Mo, W; R = Me, CH2Ph, COCF3) with but-2-yne affords either the vinylketone complexes [[graphic omitted])R(CO)2(η5-C5H5)], which on treatment with ligands L form lactone complexes [M(CO)L(η3-{[graphic omitted]Me})(η5C5H5)], or the eight-membered ring complex [[graphic omitted](CO)(η5-C5H5)]; the identity of the products is established by X-ray crystallography.

Formation of sixteen-electron alkyne complexes by reaction of halogeno(tricarbonly)(η5-cyclopentadienyl)-molybdenum and -tungsten complexes with alkynes; crystal and molecular structure of [WCl(CF3C2CF3)2(η5-C5H5)]

Reaction of hexafluorobut-2-yne with [MoCl(CO)3(η5-C5H5)] affords the cyclopentadienone complex [MoCl(CO)(C8F12CO)(η5-C5H5)]. If the displaced carbon monoxide is removed, then the product is [MoCl(CF3C2CF3)2-(η-C5H5)] together with minior amonuts of [{MoCl(CF3C2CF3)(η5-C5H5)}2]. The reaction of CF3C2CF3 with [WCl(CO)3(η5-C5H5)] affords only [WCl(CF3C2CF3)2(η5-C5H5)](II), which was structurally identified by X-ray crystallography as an octahedral 16-electron species, in which the acetylene acts as a 2-electron donor. Treatment of [MoCl(CO)3(η5-C5H5)] with MeC⋮CMe affords either[MoCl(MeC2Me)2(η5-C5H5)] or [MoCl(CO){C4Me4(CO)2}(η5-C5H5)] depending on the reaction conditions. The latter compound is formulated as a duroqunione complex. U.v. irradiation of [WCl(CO)3(η5-C5H5)] and PhC⋮Cph gives [WCl(CO)(PhC2Ph)(η5-C5H5)]. In refluxing hexane, [MoCl(CO)3(η5-C5H5)] reacts with PhC2Ph to give [MoCl(CO)(PhC2Ph)(η5-C5H5)] and [MoCl(PhC2Ph)(η5-C5H5)]. The thermal reaction of MeC2Ph with [MoCl(CO)3(η5-C5H5)] gives initially [MoCl(CO)(PhC2Me)(η5-C5H5)] which reacts further to yield [MoCl(PhCMe)2(η5-C5H5)]. Treatment (60 °C) of [MoCl(CO)(PhC2Ph)(η5-C5H5)] with MeC2Me or CF3C2CF3 affords [MoCl(RC2R)2(η5-C5H5)] R = Me or CF3). At room temperature, [MoCl(CF3C2CF3)(PhC2Me)(η5-C5H5)] is formed. Similar reactions afforded the mixed acetylene complexes [MoCl(CF3C2CF3)(PhC2Me)(η5-C5H5)], [WCl(CF3C2CF3)(PhC2Ph)(η5-C5H5)], and (WCl(CF3C2H)(PhC2Ph)(η5-C5H5). Reaction of [MoCl(CO)(PhC2Ph)(η5-C5H5)] with CF3C⋮CH gives [MoCl(CF3C2H)2(η5-C5H5)]. The temperature-dependent dynamix behaviour of these complexes is discussed in terms of a propeller-type rotation of the acetylene.

Interaction between some trifluorophosphine metallates and acetylenes

Abstract Hexafluorobut-2-yne undergoes trimerisation to C 6 (CF 3 ) 6 with Ni(PF 3 ) 4 . CF 3 C 2 CF 3 reacts with CpCo(PF 3 ) 2 with oxidative addition to the phosphorus (III) to give CpCo[(CF 3 C 2 CF 3 ) 2 PF 3 ] which is successively hydrolysed to CpCo[(CF 3 C 2 CF 3 ) 2 POF] and CpCo[(CF 3 C 2 CF 3 ) 2 P(O)OH]. CpRh (PF 3 ) 2 does not react with CF 3 C 2 CF 3 . MeC 2 Me and PhC 2 Ph do not give identifiable products with these trifluorophosphine derivatives.

Metal perfluoro-alkane- and -arene-thiolates. Part III. Cyclopentadienylcobalt derivatives

The products of the reactions between [(cp)Co(CO)2] and RS·SR (R = CF3 or C6F5) depend upon the conditions used.[{(cp)CoSR}2](R = CF3 or C6F5), [(cp)Co(CO)(SC6F5)2], and [(cp)Co2(SC6F5)3] are described.

Perfluoroalkane- and perfluoroarene-thiolates. Part VI. Reactions of some cyclopentadienylnickel derivatives with hexafluorobut-2-yne

The reactions of CF3C2CF3 with [{Ni(η-C5H5)(SCF3)}2], [Ni(η-C5H5)2], [Ni(η-C5H5){C5H5(CF3C2CF3)}], [Ni(η-C5H5){C5H5(C2F2Cl)}], and [{Ni(η-C5H5)}2(CF3C2CF3)] have been examined. The new products charscterised are [Ni(η-C5H5){(CF3C2CF3)2H}], [Ni3(η-C5H5)2(CF3C2CF3)3], [Ni2(C5H5)2(CF3C2CF3)3], [Ni(C5H5)2(CF3C2CF3)3], [Ni(η-C5H5){C5H5(CF3C2CF3)2}], [{Ni(C5H5)(CF3C2CF3)}4] and [Ni(C5H5)(CF3C2CF3)2{C5H5(C2CF3Cl)}].

Interaction of tricarbonyl(π-cyclopentadienyl)molybdenum halides and acetylenes

Tricarbonyl(π-cyclopentadienyl)molybdenum halides, [(cp)Mo(CO)3X](X = Cl, Br, or I), (cp =η5-C5H6) react with MeCCMe and CF3CCF3 to give the 16-electron bisalkyne complexes [(cp)Mo(RC2R)2X] whilst PhCCPh gives [(cp)Mo(CO)(PhC2Ph)X] and the cyclobutadiene complexes [(cp)Mo(CO)(PhC2Ph)2X].

Metal perfluoro-alkane- and -arene-thiolates. Part IV. The reactions of some manganese, iron, and cobalt derivatives with alkynes

The products of reactions between the thiolates [{Mn(CO)4(SR)}2], [(cp)Fe(CO)2(SR)], [{Fe(CO)3(SR)}2], [{(cp)Co(SCF3)}2], [(cp)Co(CO)(SC6F5)2], and [{Co(CO)3(SC6F5)}2](R = CF3 or C6F5) and the alkynes C(CF3)⋮C(CF3) and C(CF3)⋮CH are described. The products include metallothiacyclobutenes [Mn(CO)4{(alkyne)SR}] and [(cp)Fe(CO){(alkyne)SR}], metallated vinyls [(cp)Fe(CO)2{(alkyne)SR}], dimetallated olefins [{Fe(CO)3(SR)}2(alkyne)], η4-C4S complexes [Mn(CO)3{(alkyne)2SR}] and [(cp)Fe{(alkyne)2SR}], the η4 benzene complex [(cp)CO{(alkyne)3}], and the ‘flyover’ complex [Co2(CO)4{(alkyne)2S}](cp =η-cyclo-pentadienyl).