Organic chemistry of dinuclear metal centres. Part 8. Organo–iron–ruthenium chemistry. X-Ray structure of trans-[FeRu(CO)₂(µ-CO)₂(η-C₅H₅)₂]

Abstract

The iron-ruthenium complex [FeRu(CO),(q-C,H,),] is obtained in 60% yield from the reaction of Na[Fe(CO),(q-C,H,)]with [Rul (CO),(q-C,H,)].In the solid state a trans- [FeRu(CO),(p-CO),(q-C, H, ) , ] structure has been established by X-ray diffraction. Crystals are monoclinic, space group R , / c (no. 14), with Z = 2 in a unit cell for which a = 7.064(2), b = 12.51 8(3), c = 8.01 1 (2) A, and = 106.23(2)". The structure was solved by heavy-atom methods and refined to R 0.0275 (R' 0.031 3) for 1 532 independent intensities. The molecule is disordered about a centre of inversion at the mid-point of the metal-metal bond, each metal site being occupied by half an iron and half a ruthenium atom, with an iron-ruthenium bond length of 2.626(1) A. In solution the cis-[FeRu( CO),(p-CO),(q-C,H,),] isomer is dominant, and shown by 13C n.m.r. to be undergoing cis e trans isomerisation with bridge eterminal carbonyl exchange at room temperature, but to be static at -80 "C. The complex is an excellent precursor of organo-iron-ruthenium chemistry.Treatment with alkynes R1C2R2 (R' = R2 = H, Me, Ph, or C0,Me; R' = M e or Ph, R2 = H) under U.V. irradiation gives complexes [FeRu(CO) (p-CO){p-C(0)CR1CR2)(rl-CSHs)2] in 2 0 4 5 5 % yield as a result of alkyne-CO linkage. This link in the complexes derived from ethyne, propyne, and but-2yne is broken upon protonation, generating p-vinyl cations [FeRu(CO),(p-CO) (p-CR1=CHR2) (q-C, H, ) , ] + ( R' = R2 = H or Me; R' = H, R2 = Me). These are attacked by hydride at the p carbon of the p-vinyl to give p-alkylidene complexes [FeRu(CO),(p-CO)(p-CR1R2) (q-C,H,),] ( R1 = H, R2 = M e or Et; R' = Me, R2 = Et). Reaction of [FeRu(CO)(p-CO){p-C(O)CPhCPh}(q-C,H,),] with Ph,P=CHR or CH (C0,Et) N, in boiling toluene also gives p-alkylidene complexes [ FeRu( CO),(p-CO)(p-CHR)(q-C,H,),](R = H, Me, or C0,Et) in good yield, through ready displacement of diphenylacetylene. The p-CH, complex is best obtained (75%) by treating [FeRu(CO),(q-C,H,),] with LiBHEt, then water, and in a related manner sequential addition of methyl-lithium, HBF,-OEt,, and NaBH, affords [FeRu(CO),(p-CO) (p-CHMe) (q-C5HJ2]. Under U.V. irradiation alkynes react with p-alkylidene complexes [FeRu(CO),(p-CO) (p-CHR') (q-C5H5),] to give products of alkynealkylidene linking [FeRu(CO)(p-CO)(p-CR3CR2CHR1)(q-C,H,),] (R' = H or Me, R2 = R3 = H, Me, Ph, or C0,Me; R' = H or Me, R2 = M e or Ph, R3 = H). These exist as non-interconverting isomers in which the new C, ligand is either bound CJ to iron and (T, q2 t o ruthenium or vice versa. The scope of organo-iron-ruthenium chemistry closely resembles that of the di-iron system but it is apparent that in reactivity terms there is an order: FeRu > Fe, > Ru, .

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]).…”

Reaction of a (π-Vinylcarbene)iron Complex with Tricarbonyl(η4-1,5-cyclooctadiene)ruthenium. Preparation, Structure, and Reactivity of Novel (μ-Vinylcarbene)(Fe−Ru) Complexes

“…For the past two decades, much attention has been focused on the chemistry of mononuclear 1 − and binuclear transition-metal vinylcarbene complexes 2 , (η 4 -metallabutadiene)metal complexes 2 ‘, or η 3 :η 1 -allylidene complexes 2 ‘‘ (Chart ). − Especially, heterobinuclear vinylcarbene complexes − are of interest; however, methods of preparation of these complexes are not completely established. As for the preparation of (μ-vinylcarbene)(M 1 −M 2 ) complexes, the following two representative methods are reported: (1) reaction of (μ-methylene)(M 1 −M 2 ) 3 with alkynes (eq 1); (2) reaction of (η 1 -vinylcarbene)M 1 or 1-metallabutadiene 4 with M 2 (eq 2) . In the reaction of eq 1, usually a mixture of two kinds of products 2A ((η 1 -μ-methylene)M 1 −(η 3 -allyl)M 2 ) and 2B ((η 1 -μ-methylene)M 2 −(η 3 -allyl)M 1 ) is produced .…”

“…As for the preparation of (μ-vinylcarbene)(M 1 −M 2 ) complexes, the following two representative methods are reported: (1) reaction of (μ-methylene)(M 1 −M 2 ) 3 with alkynes (eq 1); (2) reaction of (η 1 -vinylcarbene)M 1 or 1-metallabutadiene 4 with M 2 (eq 2) . In the reaction of eq 1, usually a mixture of two kinds of products 2A ((η 1 -μ-methylene)M 1 −(η 3 -allyl)M 2 ) and 2B ((η 1 -μ-methylene)M 2 −(η 3 -allyl)M 1 ) is produced . In the reaction of eq 2, only 2 ‘ A was selectively obtained. , Thus no method for selective preparation of 2B from (η 3 -C 3 -ligand)M 1 and M 2 has been reported.…”

Über die Reaktionen von Phosphoryliden mit homodinuklearen Organometallverbindungen des Molybdän und Wolfram / On the Reaction of Phosphorylides with Homodinuclear Organometallic Compounds of Molybdenum and Tungsten

“…(15a)) [13]. Die YlidMethode wurde später von S. A. R. Knox zur Synthese von ^-Alkylidenkomplexen des Typs [Cp(CO)Ru(«-CHR)(M-CO)M(CO)Cp] (M = Fe, Ru; R = H, CH 3 ) angewandt [14,15].…”