The synthesis of [FeRu(CO)₂(μ-CO)₂(η-C₅H₅)(η-C₅Me₅)] and convenient entries to its organometallic chemistry

Abstract

The synthesis, fluxionality and reactivity of the heterobimetallic complex [FeRu(CO)2(mu-CO)2(eta-C5H5)(eta-C5Me5)] are described. Complex exhibits enhanced photolytic reactivity towards alkynes compared to its homometallic analogues, forming the dimetallacyclopentenone complexes [FeRu(CO)(mu-CO){mu-eta]1:eta3-C(O)CR"CR'}eta]-C5H5)(eta-C5Me5)]( R'= R"= H; R'= R"= CO2Me; R'= H, R"= CMe2OH). Prolonged photolysis with diphenylethyne gives the dimetallatetrahedrane complex [FeRu(mu-CO)(mu-eta2:eta2-CPhCPh)(eta-C5H5)(eta-C5Me5)], which contains the first iron-ruthenium double bond. Complexes containing a number of organic fragments can be synthesised using , and . Heating a solution of gave the alkenylidene complex [FeRu(CO)2(mu-CO){mu-eta]1:eta2-C=C(CO2Me)2}(eta-C5H5)(eta-C5Me5)] through an unusual methylcarboxylate migration. Protonation and then addition of hydride to gives the ethylidene complex [FeRu(CO)2(mu-CO)(mu-CHCH3)(eta-C5H5)(eta-C5Me5)] via the ionic vinyl species [FeRu(CO)2(mu-CO)(mu-eta]1:eta2-CH=CH2)(eta-C5H5)(eta-C5Me5)][BF4]. Compound exhibits cis/trans isomerisation at room temperature. Protonation of dimetallacyclopentenone complexes gives the allenyl species [FeRu(CO)2(mu-CO)(mu-eta1:eta2-CH=C=CMe2)(eta-C5H5)(eta-C5Me5)][BF4]. Compound exist as three isomers, two cis and one trans. The two cis isomers are shown to be interconverting by sigma-pi isomerisation. The solid state structures of these compounds were established by X-ray crystallography and are discussed.

Additions and intramolecular migrations of nucleophiles in cationic diruthenium μ-allenyl complexes

“…The IR spectrum of 3b (in CH 2 Cl 2 solution) shows two bands at 2005 and 1870 cm À1 , corresponding to the presence of one terminal and one semi-bridging carbonyl ligands, respectively. Complex 3b probably exists as mixtures of interconverting isomers, due to r, p and cis/trans fluxionality [10,12], allowing the NCMe ligand to be bound at either ruthenium atom.…”

“…A further strategy for the preparation of l-g 1 :g 2 allenyl complexes was recently reported [10], whereby the diruthenium complexes [Ru 2 (CO)(l-CO){l-g 1 :g 3 -C a (H)C b C c (OH)(Me)(R)-C(O)}(Cp) 2 ] [R = Me, 1a; R = Ph, 1b], prepared from the cyclopentenone adduct [Ru 2 (CO)(l-CO){l-g 1 :g 3 -C(Ph)-C(Ph)C(O)}(Cp) 2 ] by alkyne exchange [11], are treated with HBF 4 , resulting in formation of the allenyl [Ru 2 -(CO) 2 (l-CO){l-g 1 : g 2 -C a (H)@C b @C c (Me)(R)}(Cp) 2 ] [BF 4 ] [R = Me, 2a; R = Ph, 2b] (Scheme 1) [12].…”

Recent chemistry of the η5-cyclopentadienyl dicarbonyl iron anion

“…Stone and coworkers prepared [198] some novel di-and trinuclear metal complexes to extend their Scheme 127. Knox and coworkers prepared [199] a mixed iron-ruthenium complex by reaction with Fp anion (Scheme 134). In this way they were able to study and extend reactions to produce bimetallic complexes.…”

Reactions of nickel-group 6 complexes with a bulky terminal alkyne to afford alkyne–carbonyl coupled products: X-ray structure of the heterobimetallic nickelacyclobutenone complex [(η5-C5Me5)Mo(CO)2(η5-C5H4Me)] (Ni–Mo)

“…Both ring systems have been observed previously in homo-and in heterobimetallic systems. In our previously reported reactions of complex 1a with PhC 2 H, both complexes were obtained, but in most cases in the literature, there is a preference for one or the other isomer [8,9,[17][18][19][20][21][22][23][24][25][26]. With the bulky DPMP ligand, a five-membered dimetallacyclopentenone ring system might have been expected, but this isomer of complexes 3 is not observed.…”

“…Alkyne-carbonyl coupling reactions on bimetallic complexes to form CR-CR 0 -C(O) moieties have been reported by us and by others. This C 3 chain may either be r-bonded to a single metal of the bimetallic center, to form a four-membered [8,9,[17][18][19][20], [21][22][23][24][25][26]. (The CR@CR 0 AC(O) group is also known to bond to a di-metal center in other, non-cyclic bonding modes [27,28]).…”