Cationic Carbyne Complexes Research Articles

Terminal Carbido Complexes of Osmium: Synthesis, Structure, and Reactivity Comparison to the Ruthenium Analogues

The first terminal carbide complex of osmium, Os(⋮C)(PCy3)2Cl2 (4), was synthesized via S-atom abstraction from Os(CS)(PCy3)2Cl2 (4-S) by Ta(OSi-t-Bu3)3 (7). Compound 4 reacts with HO3SCF3 (HOTf) to form the first cationic osmium methylidyne complex [Os(⋮CH)(PCy3)2Cl2][OTf] (18). The analogous ruthenium complex [Ru(⋮CH)(H2IMes)(PCy3)Cl2][OTf] is not observed upon protonation of Ru(⋮C)(H2IMes)(PCy3)Cl2 (2) with HOTf. Substitution of the chloride ligands in 4 is surprisingly difficult compared to the case of 4-S, but Os(⋮C)(PCy3)2I2 can be obtained. Compound 4 also reacts with a variety of electrophiles to afford cationic five-coordinate and neutral six-coordinate carbyne complexes. In general, 4 reacts more readily with electrophiles than does 1, and cationic carbyne complexes formed from 4 are more resistant to degradation than are their Ru counterparts.

Unusual Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with the Carbonylmetal Anions [Ir(CO)4]-and [Ru(CO)4]2-. Novel Route to Heteropolymetallic Bridging Carbyne Complexes

The reaction of a cationic carbyne complex of manganese, [(η5-C5H5)(CO)2Mn⋮CC6H5]BBr4 (1), with [(Ph3P)2N][Ir(CO)4] (3) in THF at low temperature gives a novel Mn2−Ir2 mixed-tetrametal bridging carbyne complex with μ and μ3 bridging carbyne ligands, [Mn2Ir2(μ-CC6H5)(μ3-CC6H5)(μ-CO)3(CO)3(η5-C5H5)2] (5), and a related Mn2−Ir2 mixed-tetranuclear cluster with a μ bridging carbene ligand and a μ3 bridging carbyne ligand, [Mn2Ir2{μ-C(CO)C6H5}(μ3-CC6H5)(μ-CO)3(CO)4(η5-C5H5)2] (6). A cationic carbyne complex of rhenium, [(η5-C5H5)(CO)2Re⋮CC6H5]BBr4 (2), reacts similarly with 3 to afford the corresponding Re2−Ir2 mixed-tetrametal cluster [Re2Ir2{μ-C(CO)C6H5}(μ3-CC6H5)(μ-CO)3(CO)4(η5-C5H5)2] (8) and a novel Re−Ir2 mixed-trimetal bridging carbyne complex with an allyl ligand, [ReIr2(μ-η1:η2-C3H5)(μ3-CC6H5)(μ-CO)2(CO)4(η5-C5H5)] (7). The cationic carbyne complex 1 also reacts with the anionic compound Na2[Ru(CO)4] (4) to give a heterotrimetal bridging carbyne complex with a μ-H ligand, [MnRu2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η5-C5H5)] (10), and the manganese aminocarbene complex [(η5-C5H5)(CO)2MnC(C6H5)NH2] (11), while the analogous reaction of the cationic carbyne complex 2 with 4 produces a novel Re2−Ru2 mixed-tetrametal cluster with a μ3-C(CC6H5)(μ-CC6H5) bridging carbene ligand, [Re2Ru2{μ3-C(CC6H5)(μ-CC6H5)}(μ-CO)(CO)8(η5-C5H5)2] (13), in addition to the corresponding heterotrimetal bridging carbyne complex [ReRu2(μ3-CC6H5)(μ-H)(μ-CO)2(CO)6(η5-C5H5)] (12) and aminocarbene complex [η5-C5H5(CO)2ReC(C6H5)NH2] (14). The structures of complexes 6, 7, 11, 13, and 14 have been established by X-ray diffraction studies.

Subtle reactivity patterns of non-heteroatom-substituted manganese alkynyl carbene complexes in the presence of phosphorus probes

The non-heteroatom-substituted manganese alkynyl carbene complexes (eta5-MeC5H4)(CO)2Mn=C(R)C[triple bond]CR'(3; 3a: R = R'= Ph, 3b: R = Ph, R'= Tol, 3c: R = Tol, R'= Ph) have been synthesised in high yields upon treatment of the corresponding carbyne complexes [eta5-MeC5H4)(CO)2Mn[triple bond]CR][BPh4]([2][BPh4]) with the appropriate alkynyllithium reagents LiC[triple bond]CR' (R'= Ph, Tol). The use of tetraphenylborate as counter anion associated with the cationic carbyne complexes has been decisive. The X-ray structures of (eta5-MeC5H4)(CO)2Mn=C(Tol)C[triple bond]CPh (3c), and its precursor [(eta5-MeC5H4)(CO)2Mn=CTol][BPh4]([2b](BPh4]) are reported. The reactivity of complexes toward phosphines has been investigated. In the presence of PPh3, complexes act as a Michael acceptor to afford the zwitterionic sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)=C=C(PPh3)R' (5) resulting from nucleophilic attack by the phosphine on the remote alkynyl carbon atom. Complexes 5 exhibit a dynamic process in solution, which has been rationalized in terms of a fast [NMR time-scale] rotation of the allene substituents around the allene axis; metrical features within the X-ray structure of (eta5-MeC5H4)(CO)2MnC(Ph)=C=C(PPh3)Tol (5b) support the proposal. In the presence of PMe3, complexes undergo a nucleophilic attack on the carbene carbon atom to give zwitterionic sigma-propargylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)(PMe3)C[triple bond]CR' (6). Complexes 6 readily isomerise in solution to give the sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R')=C=C(PMe3)R (7) through a 1,3 shift of the [(eta5-MeC5H4)(CO)2Mn] fragment. The nucleophilic attack of PPh2Me on 3 is not selective and leads to a mixture of the sigma-propargylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)(PPh(2)Me)C[triple bond]CR' (9) and the sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)=C=C(PPh(2)Me)R' (10). Like complexes 6, complexes 9 readily isomerize to give the sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R')=C=C(PPh2Me)R'). Upon gentle heating, complexes 7, and mixtures of 10 and 10' cyclise to give the sigma-dihydrophospholium complexes (eta5-MeC5H4)(CO)2MnC=C(R')PMe2CH2CH(R)(8), and mixtures of complexes (eta5-MeC5H4)(CO)2MnC=C(Ph)PPh2CH2CH(Tol)(11) and (eta5-MeC5H4)(CO)2MnC=C(Tol)PMe2CH2CH(Ph)(11'), respectively. The reactions of complexes 3 with secondary phosphines HPR(1)(2)(R1= Ph, Cy) give a mixture of the eta2-allene complexes (eta5-MeC5H4)(CO)2Mn[eta2-{R(1)(2)PC(R)=C=C(R')H}](12), and the regioisomeric eta4-vinylketene complexes [eta5-MeC5H4)(CO)Mn[eta4-{R(1)(2)PC(R)=CHC(R')=C=O}](13) and (eta5-MeC5H4)(CO)Mn[eta4-{R(1)(2)PC(R')=CHC(R)=C=O}](13'). The solid-state structure of (eta5-MeC5H4)(CO)2Mn[eta2-{Ph2PC(Ph)=C=C(Tol)H}](12b) and (eta5-MeC5H4)(CO)Mn[eta4-{Cy2PC(Ph)=CHC(Ph)=C=O}](13d) are reported. Finally, a mechanism that may account for the formation of the species 12, 13, and 13' is proposed.

Novel Rh–Mn mixed-metal carbonyl cluster containing μ 3 and μ-bridging carbyne ligands, [(μ 3-CC 6H 5)(μ-CC 6H 5)Rh 2Mn 2Cp 2(μ-CO) 3(CO) 3]: structure, electrochemistry and catalytic properties

The cationic carbyne complex [Cp(CO) 2MnCC 6H 5]BBr 4 ( 1) reacts with PPN[Rh(CO) 4] ( 2) to give the title cluster [(μ 3-CC 6H 5)(μ-CC 6H 5) Rh 2Mn 2Cp 2(μ-CO) 3(CO) 3] ( 3) whose structure has been determined by X-ray diffraction. The electrochemical properties of 3 have been investigated using cyclic voltammetric method. At 60 °C and 2.0 MPa of initial total CO/H 2 (1:1) pressure, the catalytic activity of 3 towards hydroformylation of styrene has also been checked.

Remarkable reactions of cyclooctatetraene diiron-bridging carbyne complexes with amino and amido compounds: nucleophilic addition to and breaking of the cyclooctatetraene ring.

The reactions of the cationic, diiron-bridging carbyne complexes [Fe(2)(mu-CAr)(CO)(4)(eta(8)-C(8)H(8))]BF(4) (1, Ar=C(6)H(5); 2, Ar=p-CH(3)C(6)H(4); 3, Ar=p-CF(3)C(6)H(4)) with LiN(C(6)H(5))(2) in THF at low temperature gave novel N-nucleophilic-addition products, namely, the neutral, diiron-bridging carbyne complexes [Fe(2)(mu-CAr)(CO)(4)(eta(7)-C(8)H(8)N(C(6)H(5))(2))] (4, Ar=C(6)H(5); 5, Ar=p-CH(3)C(6)H(4); 6, Ar=p-CF(3)C(6)H(4))). Cationic bridging carbyne complexes 1-3 react with (C(2)H(5))(2)NH, (iC(3)H(7))(2)NH, and (C(6)H(11))(2)NH under the same conditions with ring cleavage of the COT ligand to produce the novel diiron-bridging carbene inner salts [Fe(2)[mu-C(Ar)C(8)H(8)NR(2)](CO)(4)] (7, Ar=C(6)H(5), R=C(2)H(5); 8, Ar=p-CH(3)C(6)H(4), R=C(2)H(5); 9, Ar=p-CF(3)C(6)H(4), R=C(2)H(5); 10, Ar=C(6)H(5), R=iC(3)H(7); 11, Ar=p-CH(3)C(6)H(4), R=iC(3)H(7); 12, Ar=p-CF(3)C(6)H(4), R=iC(3)H(7); 13, Ar=C(6)H(5), R=C(6)H(11); 14, Ar=p-CH(3)C(6)H(4), R=C(6)H(11), 15, Ar=p-CF(3)C(6)H(4), R=C(6)H(11)). Piperidine reacts similarly with cationic carbyne complex 3 to afford the corresponding bridging carbene inner salt [Fe(2)[mu-C(Ar)C(8)H(8)N(CH(2))(5)](CO)(4)] (16). Compound 9 was transformed into a new diiron-bridging carbene inner salt 17, the trans isomer of 9, by heating in benzene. Unexpectedly, the reaction of C(6)H(5)NH(2) with 2 gave a novel COT iron-carbene complex [Fe(2)[=C(C(6)H(4)CH(3)-p)NHC(6)H(5)](mu-CO)(CO)(3)(eta(8)-C(8)H(8))] (18). However, the analogous reactions of 2-naphthylamine with 2 and of p-CF(3)C(6)H(4)NH(2) with 3 produce novel chelated iron-carbene complexes [Fe(2)[=C(C(6)H(4)CH(3)-p)NC(10)H(7)](CO)(4)(eta(2):eta(3):eta(2)-C(8)H(9))] (19) and [Fe(2)[=C(C(6)H(4)CF(3)-p)NC(6)H(4)CF(3)-p](CO)(4)(eta(2):eta(3):eta(2)-C(8)H(9))] (20), respectively. Compound 18 can also be transformed into the analogous chelated iron-carbene complex [Fe(2)[=C(C(6)H(4)CH(3)-p)NC(6)H(5)](CO)(4)(eta(2):eta(3):eta(2)-C(8)H(9))] (21). The structures of complexes 6, 9, 15, 17, 18, and 21 have been established by X-ray diffraction studies.

Remarkable Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with the Carbonylrhodium Anion [Rh(CO)4]-. A Novel Route to Heteropolymetallic Bridging Carbyne Complexes with μ- and μ3-Carbyne Ligands

The reaction of cationic carbyne complexes of manganese and rhenium, [η5-C5H5(CO)2M⋮CC6H5]BBr4 (1, M = Mn; 2, M = Re), with [(Ph3P)2N][Rh(CO)4] in THF at low temperature gives the novel Mn2−Rh2 mix...

Novel N-Nucleophilic Addition to and Ring-Breaking of Coordinated Cyclooctatetraene in Diiron Bridging Carbyne Complexes

The reactions of the diiron cationic carbyne complexes 1−3 with NaN(SiMe3)2 or LiN(SiMe3)2 in THF at low temperature give novel N-nucleophilic addition products, the neutral diiron bridging carbyne complexes 4−6, while the reactions of 1−3 with LiNEt2 lead to breaking of the COT ring to produce the diiron bridging carbene inner salts 7−9, among which the structures of 4 and 7 have been established by X-ray diffraction studies.

Unusual reactions of cationic bridging carbyne complexes of dimethylsilane-bridged bis(η 5-cyclopentadienyl)diiron tricarbonyl with carbonylmetal anions

The reactions of the dimethylsilane-bridged cationic carbyne complexes of diiron, [Fe 2(μ-CO)(μ-CAr)(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}]BBr 4 ( 1, Ar=C 6H 5; 2, Ar= p-CF 3C 6H 4), with carbonylmetal anionic compounds Na[M(CO) 5CN] ( 4, M=Cr; 5, M=Mo; 6, M=W) in THF at low temperature afford diiron bridging carbene complexes [Fe 2(μ-CO){μ-C(Ar)NCM(CO) 5}(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}] ( 9, M=Cr, Ar=C 6H 5; 10, M=Mo, Ar=C 6H 5; 11, M=W, Ar=C 6H 5; 12, M=Cr, Ar= p-CF 3C 6H 4; 13, M=Mo, Ar= p-CF 3C 6H 4; 14, M=W, Ar= p-CF 3C 6H 4). In contrast to the reaction of 1 and 2, cationic carbyne complex [Fe 2(μ-CO)(μ-CC 6H 4CH 3- p)(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}]BBr 4 ( 3) reacts with 4– 6 under the same conditions to produce novel cationic bridging carbyne complexes [Fe 2(μ-CO)(μ-CC 6H 4CH 3- p)(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}] +[M(CO) 5CN] − ( 15, M=Cr; 16, M=Mo; 17, M=W). Analogous cationic bridging carbyne complex [Fe 2(μ-CO)(μ-CC 6H 4CH 3- p)(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}] +[Fe(CO) 4CN] − ( 18) can also be obtained from the reaction of 3 with Na[Fe(CO) 4CN] ( 7). Complex 15 or 16 reacts with NaSR (R=CH 3, C 6H 5, p-CH 3C 6H 4) to give bridging mercaptocarbene complexes [Fe 2(μ-CO){μ-C(SR)C 6H 4CH 3- p}(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}] ( 19, R=CH 3; 20, R=C 6H 5; 21, R= p-CH 3C 6H 4) in high yields. The related reaction of 1 with NaN(SiMe 3) 2 affords a novel benzonitrile-coordinated diiron complex [Fe 2(μ-CO) 2(CO)NCC 6H 5{(η 5-C 5H 4) 2Si(CH 3) 2}] ( 22). Unexpectedly, the reactions of 1 and 2 with 7 yield diiron bridging arylcarbene complexes [Fe 2(μ-CO){μ-C(H)Ar}(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}] ( 23, Ar=C 6H 5; 24, Ar= p-CF 3C 6H 4). The products 23 and 24 and bridging p-tolyl-carbene complex [Fe 2(μ-CO){μ-C(H)C 6H 4CH 3- p}(CO) 2{(η 5-C 5H 4) 2Si(CH 3) 2}] ( 25) were also obtained from the reactions of 1– 3 with [(PPh 3) 2N][Cr(CO) 4NO] ( 8). The structures of 14, 15, 22, and 23 have been established by X-ray crystallography.

Novel Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Polymetal Carbonyl Anions. An Approach to Trimetal Bridging Carbyne Complexes

The reaction of a cationic carbyne complex of manganese, [(η-C5H5)(CO)2Mn⋮CC6H5]BBr4 (1), with [(Ph3P)2N]2[Ru3(CO)11] (3) in THF at low temperature gave the heteronuclear trimetal bridging carbyne complex [MnRu2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (7). A cationic carbyne complex of rhenium, [(η-C5H5)(CO)2Re⋮CC6H5]BBr4 (2), reacts similarly with 3, affording the corresponding bridging carbyne complex [ReRu2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (8) and neutral Re−carbyne dimer [Re(CO)2(η-C5H5)(μ-CC6H5)]2 (9). The compound [(Ph3P)2N]2[Os3(CO)11] (4) only reacts with 1 to give the trimetal bridging carbyne complex [MnOs2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (10) and neutral Mn−carbyne dimer [Mn(CO)2(η-C5H5)(μ-CC6H5)]2 (11). [(Ph3P)2N]2[Fe4(CO)13] (5) also reacts with cationic carbyne complexes 1 and 2 to give the trimetal bridging carbyne complexes [MnFe2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (12) and [ReFe2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (13), respectively. Product 13, when treated with an excess of PPh3, g...

Unusual Reactions of Cationic Bridging Carbyne Complexes of Dimethylsilane-Bridged Bis(η5-cyclopentadienyl)diiron Tricarbonyl with Nucleophiles. A Route to Iron−Sulfur Cluster Bridging Carbene Complexes

The reactions of diiron cationic carbyne complexes [Fe2(μ-CO)(μ-CAr)(CO)2{(η5-C5H4)2Si(CH3)2}]BBr4 (4, Ar = C6H5; 5, Ar = p-CH3C6H4; 6, Ar = p-CF3C6H4) with NaSR (R = CH3, C6H5, p-CH3C6H4) in THF at low temperature afford diiron bridging mercaptocarbene complexes [Fe2(μ-CO){μ-C(SR)Ar}(CO)2{(η5-C5H4)2Si(CH3)2}] (9, Ar = C6H5, R = CH3; 10, Ar = C6H5, R = C6H5; 11, Ar = C6H5, R = p-CH3C6H4; 12, Ar = p-CH3C6H4, R = CH3; 13, Ar = p-CH3C6H4, R = C6H5;14, Ar = p-CH3C6H4, R = p-CH3C6H4; 15, Ar = p-CF3C6H4, R = CH3; 16, Ar= p-CF3C6H4, R = C6H5; 17, Ar = p-CF3C6H4, R = p-CH3C6H4). Compound 6 reacts with [(μ-SLi)(μ-SC6H5)Fe2(CO)6] to give the novel iron−sulfur cluster bridging carbene complex [Fe2(μ-CO)(μ-CC6H4CF3-p)(CO)2{(η5-C5H4)2Si(CH3)2}(μ-S)(μ-SC6H5)Fe2(CO)6] (18). Analogous iron−sulfur cluster bridging carbene complexes [Fe2(μ-CO)(μ-CAr)(CO)2(η5-C5H5)2(μ-S)(μ-SC6H5)Fe2(CO)6] (19, Ar = C6H5; 20, Ar = p-CH3C6H4) can also be obtained by the reactions of diiron cationic carbyne complexes [Fe2(μ-CO)(μ-CAr)(CO)2(η5-C5H5)2]BBr4 (7, Ar = C6H5; 8, Ar = p-CH3C6H4) with [(μ-SLi)(μ-SC6H5)Fe2(CO)6]. The structures of complexes 9, 13, 16, and 18 have been established by X-ray crystallography.

Remarkable Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Diiron Anions [Fe2(μ-CO)(μ-SeR)(CO)6]-. A Route to RSe-Bridged Dimetal Bridging Carbene Complexes

The reactions of cationic carbyne complexes of manganese and rhenium, [η-C5H5(CO)2M⋮CC6H5]BBr4 (1, M = Mn; 2, M = Re), with diiron anionic compounds [Et3NH][Fe2(μ-CO)(μ-SeR)(CO)6] (3, R = C6H5; 4, R = p-CH3C6H4) in THF at low temperature gave the dimetal bridging carbene complexes [MFe{μ-C(SeR)C6H5}(CO)5(η-C5H5)] (10, M = Mn, R = C6H5; 11, M = Mn, R = p-CH3C6H4; 13, M = Re, R = C6H5; 14, M = Re, R = p-CH3C6H4), [η-C5H5M(CO)3] (7, M = Mn; 12, M = Re), and [Fe2(μ-SeR)2(CO)6] (8, R = C6H5; 9, R = p-CH3C6H4). Complexes 1 and 2 also react with [MgBr][Fe2(μ-CO)(μ-SeC2H5)(CO)6] (5) to produce [Fe2(μ-SeC2H5)2(CO)6] (15) and dimetal bridging carbene complexes [MnFe{μ-C(SeC2H5)C6H5}(CO)5(η-C5H5)] (17) and [ReFe{μ-C(SeC2H5)C6H5}(CO)5(η-C5H5)] (18), respectively. 2 reacts similarly with [MgBr][Fe2(μ-CO)(μ-SeC4H9-n)(CO)6] (6) to give [Fe2(μ-SeC4H9-n)2(CO)6] (16) and a Re−Fe bridging carbene complex [ReFe{μ-C(SeC4H9-n)C6H5}(CO)5(η-C5H5)] (19), while the analogous reaction of 1 with 6 produced an unexpected trimetal bridging carbyne complex [MnFe2(μ-H)(μ-CO)2(μ3-CC6H5)CO)6(η-C5H5)] (20). The structures of complexes 9, 10, 13, 18, and 20 have been established by X-ray diffraction studies.

Unusual Reactions of Cationic Bridging Carbyne Complexes of Bis(η5-cyclopentadienyl)diiron Tricarbonyl with Carbonylmetal Anions. A Route to Diiron Bridging Carbyne Complexes

The reactions of cationic carbyne complexes of diiron, [Fe2(μ-CO)(μ-CPh)(CO)2(η5-C5H5)2]BBr4 (1), with the anionic carbonylmetal compounds Na[M(CO)5CN] (3, M = Cr; 4, M = Mo; 5, M = W) in THF at low temperature afford the novel bridging carbyne complexes [Fe2(μ-CO)(μ-CPh)(CO)2(η5-C5H5)2NCM(CO)5] (6, M = Cr; 7, M = Mo; 8, M = W). In contrast to the reaction of 1, the cationic carbyne complex [Fe2(μ-CO)(μ-CC6H4Me-p)(CO)2(η5-C5H5)2]BBr4 (2) reacts with carbonylmetal anions 3−5 under the same conditions to produce the novel bridging p-tolyl(pentacarbonylcyanotungsten)carbene complexes [Fe2(μ-CO){μ-C(C6H4Me-p)(CO)2(η5-C5H5)2NCM(CO)5}] (9, M = Cr; 10, M = Mo; 11, M = W). However, the analogous reaction of Na[Fe(CO)4CN] with 1 yields the diiron bridging phenylcarbene complex [Fe2(μ-CO){μ-C(H)Ph}(CO)2(η5-C5H5)2] (12). The structures of 7, 8, and 11 have been established by X-ray crystallography.

Reactions of Cationic Bridging Carbyne Complexes of Bis(η-cyclopentadienyl)diiron Tricarbonyl with Nucleophiles. A Route to Diiron Bridging Carbene Complexes

The reactions of the cationic carbyne complex of diiron, [Fe2(μ-CO)(μ-CPh)(CO)2(η-C5H5)2]BBr4 (3), with NaSMe, NaSEt, NaSPh, NaSC6H4Me-p, and NaSC6H4NO2-p in THF at low temperature afforded diiron bridging thiocarbene complexes [Fe2(μ-CO){μ-C(SR)Ph}(CO)2(η-C5H5)2] (5, R = Me; 6, R = Et; 7, R = Ph; 8, R = p-MeC6H4; 9, R = p-NO2C6H4). Complex [Fe2(μ-CO)(μ-CC6H4Me-p)(CO)2(η-C5H5)2]BBr4 (4) reacted similarly with NaSPh and NaSC6H4Me-p to give corresponding bridging carbene complexes [Fe2(μ-CO){μ-C(SR)C6H4Me-p}(CO)2-(η-C5H5)2] (10, R = Ph; 11, R = p-MeC6H4). Complex 3 also reacted with NaOPh and NaN(SiMe3)2 to yield bridging carbene complexes [Fe2(μ-CO){μ-C(OPh)Ph}(CO)2(η-C5H5)2] (12) and [Fe2(μ-CO){μ-C(N(SiMe3)2)Ph}(CO)2(η-C5H5)2] (13), respectively. Complexes 3 and 4 reacted with reactive salt [Et3NH][Fe2(μ-CO)(μ-SBun)(CO)6] to yield the bridging mercaptocarbene complex [Fe2(μ-CO){μ-C(SH)Ph}(CO)2(η-C5H5)2] (14) and the bridging butylthiocarbene complex [Fe2(μ-CO){μ-C(SBun)C6H4Me-p}(CO)2(η-C5H5)2] (15), respectively. The analogous reactions of [Et3NH][Fe2(μ-CO)(μ-SPh)(CO)6] with 3 and 4 afforded the thiolato-bridged iron carbonyl compound [Fe2(μ-SPh)2(CO)6] (16) and the bridging arylcarbene complexes [Fe2(μ-CO){μ-C(H)Ar}(CO)2(η-C5H5)2] (17, Ar = Ph; 18, Ar = p-MeC6H4), while [Et3NH][Fe2(μ-CO)(μ-SC6H4Me-p)(CO)6] reacted with 3 to yield 17 and [Fe2(μ-SC6H4Me-p)2(CO)6] (19). The reaction of metal carbonyl anion compounds Na2W(CO)5 and Na2Fe(CO)4 with 3 gave the same product, 17. The structures of 6, 7, 15, and 17 have been established by X-ray diffraction studies.

Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Carbonylmetal Anions Containing Cyclopentadienyl, PPh3, and NO Ligands. A Route to Dimetal Bridging Carbyne Complexes

The reactions of cationic carbyne complexes of manganese and rhenium, [η-C5H5(CO)2M⋮CC6H5]BBr4 (1, M = Mn; 2, M = Re), with Na[η-C5H5Mo(CO)3] (3) in THF at low temperature afford η1,η2-ketene complexes [MnMo{C(CO)C6H5}(CO)4(η-C5H5)2] (8) and [ReMo{C(CO)C6H5}(CO)4(η-C5H5)2] (9), respectively. Analogous reactions of Na[η-C5H5W(CO)3] (4) with 1 and 2 give the corresponding ketene complexes [MnW{C(CO)C6H5}(CO)4(η-C5H5)2] (10) and [ReW{C(CO)C6H5}(CO)4(η-C5H5)2] (11). Na[Co(CO)3PPh3] (5) also reacts with 1 and 2 to yield ketenyl-bridged complexes [MnCo{C(CO)C6H5}(CO)4(PPh3)(η-C5H5)] (12) and [ReCo{C(CO)C6H5}(CO)4(PPh3)(η-C5H5)] (13), respectively. However, compound Na[η-C5H5Fe(CO)2] (6) reacts only with 2 to form a η1,η2-ketene complex [ReFe{C(CO)C6H5}(CO)3(η-C5H5)2] (14), while the reactions of (Ph3P)2N[Fe(CO)3NO] (7) with 1 and 2 produce dimetal bridging carbyne complexes [MnFe(μ-CC6H5)(CO)4(NO)(η-C5H5)] (15) and [ReFe(μ-CC6H5)(CO)4(NO)(η-C5H5)] (16), respectively. Compound 15 treated with an excess of Fe2(CO...

Remarkable Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Na[Fe(CO)4CN] and Et4N[Mn(CO)4(CN)2

The reaction of a cationic carbyne complex of manganese, [(η-C5H5)(CO)2Mn⋮CC6H5]BBr4 (1), with Na[Fe(CO)4CN] (3) in THF at low temperature gives the phenyl(tetracarbonylcyanoiron)carbene−manganese complex [(η-C5H5)(CO)2MnC(C6H5)NCFe(CO)4] (5). The analogous reaction of a cationic carbyne complex of rhenium, [(η-C5H5)(CO)2Re⋮CC6H5]BBr4 (2), with 3 affords the corresponding carbene−rhenium complex [(η-C5H5)(CO)2ReC(C6H5)NCFe(CO)4] (6). Complex 1 reacts with Et4N[Mn(CO)4(CN)2] (4) to yield the novel trinuclear metal dicarbene−manganese complex [{(η-C5H5)(CO)2MnC(C6H5)NC}2Mn(CO)3CN] (7) and the novel tetranuclear metal dicarbene−manganese complex [{(η-C5H5)(CO)2MnC(C6H5)NC}2Mn(CO)3CNMn(CO)2(η-C5H5)] (8). Complex 2 reacts similarly with 4 to afford the corresponding trinuclear dicarbene−rhenium complex [{(η-C5H5)(CO)2ReC(C6H5)NC}2Mn(CO)3CN] (9). The structures of complexes 5−9 have been established by X-ray crystallography.

Novel Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with (Ph3P)2NW(CO)5NCO, (Ph3P)2NW(CO)5SCN, and NaW(CO)5CN

The reaction of a cationic carbyne complex of manganese, [η-C5H5(CO)2Mn⋮CC6H5]BBr4 (1), with (Ph3P)2NW(CO)5NCO (3) in THF at low temperature gave the novel chelated carbene complex [η-C5H4(CO)2MnC(NHCO)C6H5] (6). The analogous reaction of a cationic carbyne complex of rhenium, [η-C5H5(CO)2Re⋮CC6H5]BBr4 (2), with 3 afforded the azametallacyclic complex [η-C5H5(CO)2ReC(C6H5)(CO)NW(CO)5] (7). The reaction between 1 and (Ph3P)2NW(CO)5SCN (4) led to the loss of a sulfur atom to give the phenyl(pentacarbonylisocyanotungsten)carbene−manganese complex [η-C5H5(CO)2MnC(C6H5)CNW(CO)5] (8). However, the reaction of 2 with 4 afforded the (isothiocyanato)phenylcarbene−rhenium complex [η-C5H5(CO)2ReC(C6H5)SCN] (9). Complexes 1 and 2 react with NaW(CO)5CN (5) to produce novel phenyl(pentacarbonylcyanotungsten)carbene−manganese and −rhenium complexes, [η-C5H5(CO)2MnC(C6H5)NCW(CO)5] (10) and [η-C5H5(CO)2ReC(C6H5)NCW(CO)5] (11), respectively. The structures of 6, 7, 8, and 11 have been established by X-ray diffraction studies.

Seven-Coordinate Dihydrido Complex OsH2(κ2-O2CCH3){κ1-OC(O)CH3}(PiPr3)2 as Precursor of New Organometallic Compounds Containing Unsaturated η1-Carbon Ligands

The dichloro−dihydrido complex OsH2Cl2(PiPr3)2 (1) reacts with K[CH3CO2] to give the seven-coordinate dihydrido OsH2Cl(κ2-O2CCH3)(PiPr3)2 (2), while the reaction of 1 with Ag[CH3CO2] affords OsH2(κ2-O2CCH3){κ1-OC(O)CH3}(PiPr3)2 (3). The structure of 3 in the solid state has been determined by X-ray diffraction analysis. The geometry around the metal center could ideally be described as derived from a distorted square antiprism with a missing vertice. One of the two square planes is made up by the two phosphorus atoms and the hydrido ligands. The oxygen atoms of the acetato ligands are located in the second plane, which is rotated by 24.7° from the first one. Complex 3 reacts with 2-methyl-1-buten-3-yne to give the α,β-unsaturated vinylidene derivative OsH{CCHC(CH3)CH2}(κ2-O2CCH3)(PiPr3)2 (4), which by reaction with HBF4·OEt2 affords the cationic carbyne complex [OsH{⋮CCHC(CH3)CH2}(κ2-O2CCH3)(PiPr3)2]BF4 (5). The structure of 5 has been also determined by X-ray diffraction analysis. The coordination geometry around the osmium atom could be rationalized as a distorted octahedron with the two phosphorus atoms of the phosphine ligands occupying apical positions. The equatorial plane is formed by the bidentate ligand, the hydrido, and the carbyne group. Under carbon monoxide atmosphere, complex 5 evolves into the (Z)-dienyl complex Os{(Z)-CHCHC(CH3)CH2}{κ1-OC(O)CH3}(CO)2(PiPr3)2 (6), which does not isomerize into the (E)-dienyl isomer Os{(E)-CHCHC(CH3)CH2}{κ1-OC(O)CH3}(CO)2(PiPr3)2 (7). Treatment of 6 with HBF4·OEt2 produces isoprene and the cis-dicarbonyl [Os(κ2-O2CCH3)(CO)2(PiPr3)2]BF4 (8). The (E)-dienyl complex 7 has been prepared according to the following reaction sequence: the reaction of Os{(E)-CHCHC(CH3)CH2}Cl(CO)(PiPr3)2 (9) with Ag[CH3CO2] leads to Os{(E)-CHCHC(CH3)CH2}(κ2-O2CCH3)(CO)(PiPr3)2 (10), which under carbon monoxide atmosphere gives 7. The related chloro complex Os{(E)-CHCHC(CH3)CH2}Cl(CO)2(PiPr3)2 (11) is similarly prepared by starting from 9. The protonation of 10 with HBF4·OEt2 leads to the α,β-unsaturated carbene [Os{CHCHC(CH3)2}(κ2-O2CCH3)(CO)(PiPr3)2]BF4 (12).

Vinylidene complexes of osmium(0) derived from 1-naphthyl- or 2-naphthyl-carbyne complexes by hydride addition to the naphthyl substituents. The crystal structure of Os(CC 10H 8)(CO) 2(PPh 3) 2

When treated with lithium triethylborohydride, the cationic carbyne complexes [Os(–CR)(CO) 2(PPh 3) 2] +(R=1-naphthyl, 1; R=2-naphthyl, 2) form 3 and 4, respectively, which both have the formula Os(C 11H 8)(CO) 2(PPh 3) 2. NMR studies of these two isomeric vinylidene complexes show that the product derived from the 1-naphthyl carbyne cation involves attack at the naphthyl ring in the position para to the carbyne carbon to give 3, while that derived from the 2-naphthyl carbyne cation involves attack at the naphthyl ring in the position ortho to the carbyne carbon to give 4. The structure of 4 has been confirmed by an X-ray crystal structure determination. Addition of HCl to the vinylidene complexes 3 or 4 results in the formation of the corresponding naphthylmethyl complexes, Os(CH 2R)Cl(CO) 2(PPh 3) 2 (R=1-naphthyl, 5; R=2-naphthyl, 6).

Synthesis, crystal structures and spectroscopic properties of cationic carbyne complexes of molybdenum and tungsten supported by tripodal nitrogen, phosphorus and sulphur donor ligands

Reaction of the tridentate ligands HCpy 3 or Ppy 3 (py=2-pyridyl) with Cl(CO) 2py 2MCPh (M=Mo, W) in THF at elevated temperature followed by metathesis with NaBPh 4 in CH 3CN affords [( η 3-Xpy 3)(CO) 2MCPh] + (M=W, X=P ( 2), HC ( 3); M=Mo, X=P ( 4)) in high yield. Interaction between 1,1,1-tris(diphenylphosphinomethyl)ethane (CH 3C(CH 2PPh 2) 3) or 1,4,7-trithiacyclononane (TTCN) and Cl(CO) 2py 2WCPh in the presence of AgPF 6 in refluxing CH 3CN gives [{CH 3C(CH 2PPh 2) 3}(CO) 2WCPh]PF 6 ( 5) and [(TTCN)(CO) 2WCPh]PF 6 ( 6), respectively. These complexes exhibit intense absorption bands at 320–340 nm and weak absorptions in the 400–500 nm region, while excitation at 330 nm in dichloromethane give intense orange to red emission. The structure of the product ( 1) from reaction of Ppy 3 with Cl(CO) 2py 2WCPh was established by X-ray crystallography and shows that only two of the pyridine rings in Ppy 3 are bound to the metal center. The crystal structures of 2·EtOH and 3·EtOH show that the W–N distance trans to the carbyne moiety is significantly longer than those which are cis, and this is attributed to the strong trans influence of CPh compared to CO.

Unexpected Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Mixed-Dimetal Carbonyl Anions. A New Route to Dimetal Bridging Carbyne Complexes

The reaction of a cationic carbyne complex of manganese, [η-C5H5(CO)2Mn⋮CC6H5]BBr4 (1), with (Ph3P)2NFeCo(CO)8 (3) in THF at low temperature gave a heteronuclear dimetal bridging carbyne complex [MnCo(μ-CC6H5)(CO)5(η-C5H5)] (5) and a bridging carbene complex [MnCo{μ-C(CO)C6H5}(CO)5(η-C5H5)] (6). Ph3P)2NWCo(CO)9 (4) also reacted with 1 to give the same products 5 and 6. The analogous reaction of the cationic carbyne complex of rhenium, [η-C5H5(CO)2Re⋮CC6H5]BBr4 (2), with 3 or 4 afforded the corresponding bridging carbyne complex [ReCo(μ-CC6H5)(CO)5(η-C5H5)] (7) and bridging carbene complex [ReCo{μ-C(CO)C6H5}(CO)5(η-C5H5)] (8). 5 can convert to 6 by reaction with carbon monoxide gas. 5 or 6 reacted with Fe2(CO)9 to afford a trimetal bridging carbyne complex [MnFeCo(μ3-CC6H5)(μ-CO)(CO)7(η-C5H5)] (9). Analogous reaction of 7 or 8 with Fe2(CO)9 yielded the trimetal bridging carbyne complex [ReFeCo(μ3-CC6H5)(CO)8(η-C5H5)] (10). The structures of 5, 7, 8, 9 and 10 have been established by X-ray diffraction studies.