Isabel Moldes

Ruthenium(II) complexes containing both arene and functionalized phosphines. Synthesis and catalytic activity for the hydrogenation of styrene and phenylacetylene

Abstract The [RuCl2(η6-arene)]2 complex reacts with PPh2R (R=H, Py, CH2Py, CCPh, CCtBu and CCp-Tol) ligands in CH2Cl2 to give neutral P-coordinated ruthenium(II) complexes [RuCl2(p-cymene)PPh2R]. The structure of [RuCl2(p-cymene)PPh2H] and [RuCl2(p-cymene)PPh2Py] complexes has been established by X-ray diffraction. The neutral P-coordinated complexes [RuCl2(p-cymene)PPh2Py] and [RuCl2(p-cymene)PPh2CH2Py] react with NaBF4 in CH2Cl2–MeOH mixture to give [RuCl(η6-p-cymene)PPh2Py]BF4 and [RuCl(η6-p-cymene)PPh2CH2Py]BF4 complexes, in which PPh2Py and PPh2CH2Py act as bidentate ligands. The structure of [RuCl(η6-p-cymene)PPh2Py]BF4 was determined by X-ray diffraction. The reaction of [RuCl2(η6-arene)]2 with PPh2CCPPh2 led to the [RuCl2(p-cymene)]2PPh2CCPPh2 complex, in which the diphosphine ligand bridges two [RuCl2(p-cymene)] units. [RuCl2(p-cymene)PPh2Py] and [RuCl(η6-p-cymene)PPh2Py]BF4 are suitable catalyst precursors for the hydrogenation of styrene and phenylacetylene.

Synthesis of dinuclear alkenyl-bridged iron—nickel and diiron complexes. The crystal structure of [Fe2(CO)4(C5H5)(μ-CO)(μ-CPhCPhH)]

Abstract The reaction of the anions [Fe(η 3 -R 1 HCCR 2 CO)(CO) 3 ] − (R 1  H, R 2 CO 2 Me and CO 2 Et; R 1  R 2  CO 2 Me) with [Ni(C 5 H 5 )(PPh 3 )Br] gives the complexes [FeNi(CO) 3 (C 5 H 5 )(PPh 3 )(μ-R 2 CCH 2 )] (R 2  CO 2 Me ( 1 ) and CO 2 Et( 2 )) and [FeNi(CO) 2 (C 5 H 5 )(PPh 3 )(μ-MeO 2 CCC(H)CO 2 Me)] ( 3 ). Complexes 1 and 2 have been also obtained by heating mixtures of [PPh 4 ][HFe(CO) 4 ] − , R 1 CCR 2 , and [Ni(C 5 H 5 )(PPh 3 )Br] in THF. Use of the [HFe(CO) 4 ] − /PhCCPh/M(C 5 H 5 )L x X (M  Ni, L x  PPh 3 and M  Fe, L x  (CO) 2 ) system was successful for the synthesis of [FeNi(CO) 3 (C 5 H 5 )(PPh 3 )(μ-CPhCCPhH)] ( 4 ) and [Fe 2 (CO) 4 (C 5 H 5 )(μ-CO)(μ-PhCCPhH)] ( 5 ) complexes. The structure of 5 was determined by an X-ray diffraction study.

Substitution reactions of dinuclear alkenyl-bridged iron-cobalt complexes with phosphines. Crystal structures of [(CO)3 Fe-Co(CO)2(PMe2Ph)] (μ-C(CO2Me)C(CO2Me)H) and [(CO)2(PMe2Ph)FeCo(CO)2(PMe2Ph)]-(μ-C(CO)2Me)C(CO2Me)H)

Abstract The bridging alkenyl iron-cobalt complexes [(CO) 4 FeCo(CO) 3 (μ-CR 1 CR 2 H) (R 1 CO 2 Me or CO 2 Et and R 2  H; R 1  H and R 2  H or Ph react with one equivalent of PMe 2 Ph or PPh 3 to give monosubstituted complexes with the phosphine ligand coordinated to the iron atom. When R 1  CO 2 Me or CO 2 Et and R 2  H, addition of two equivalents of PPh 3 produces complexes with two PPh 3 ligands coordinated to each metal. The complex [(CO) 3 FeCo(CO) 3 ](μ-C(CO 2 Me)(CO 2 Me)H) also reacts with one equivalent of PMe 2 Ph, PMePh 2 , PPh 3 or PPh 2 H to give monosubstituted complexes with the phosphine ligand bonded to the cobalt atom. The reaction of the complex [(CO) 3 FeCo(CO) 3 ](μ-C(CO 2 Me)(CO 2 Me)H) with PPh 3 gives a complex with the phosphine coordinated to the iron atom, but addition of two phosphines gives complexes with one phosphine ligand bonded to each metal. The structures of the products [(CO) 3 FeCo(CO) 2 (PMe 2 Ph)](μ-C(CO 2 Me)C(CO 2 Me)H) and [(CO) 2 (PMe 2 -Ph)FeCo(CO) 2 (PMe 2 Ph)]μ-C(CO 2 Me)(CO 2 Me)H) obtained from the reaction of the [(CO) 3 FeCo-(CO) 3 ](μ-C(CO 2 Me)C(CO 2 Me)H) complex with one and two equivalents of PMe 2 Ph, respectively, have been determined by X-ray crystallography.

Substitution reactions of dinuclear alkenyl-bridged iron-cobalt complexes with alkynylphosphines and diphosphines

Abstract Reaction of [(CO) 3 FeCo(CO) 3 ]( μ -C(CO 2 Me= = CH(CO 2 Me) ( 1 ) with Ph 2 PCCR produces: (i) mono-substituted [(Ph 2 PCCR)(CO) 2 FeCo(CO) 3 ]( μ -C(CO 2 Me)=CH(CO 2 Me (R=Me ( 4 ), Ph ( 6 ), t Bu (8)) and [(CO) 3 FeCo(CO) 2 -(Ph 2 PCCR)]( μ -C(CO) 2 Me) =CH(CO 2 Me) (R=Me ( 5 ), Ph ( 7 ), t Bu ( 9 ), H ( 10 )) and (ii) di-substituted [Ph 2 CCR)(CO) 2 -FeCo(CO) 2 (Ph 2 CCR)]( μ -C(CO 2 Me)= CH(CO 2 Me) (R=Ph ( 11 ), t Bu ( 12 ), H ( 13 ) FeCo complexes. Alkenyl [(CO 4 FeCo(CO) 3 ]( μ -CR′=CH 2 ] (R′=CO 2 Me ( 2 ) or CO 2 Et ( 3 )) compounds also react with phosphinoalkynes, leading to the iron-substituted [(Ph 2 PCCR)(CO) 3 FeCo(CO) 3 ]( μ -CR′=CH 2 ) (R′=CO 2 Me, R=Ph ( 14 ); R′=CO 2 Et, R=Ph ( 14 ); R′=CO 2 Et, R=Me ( 15 )) R′=CO 2 Et, R=Me ( 16 )) compounds. The reaction of 1 with dppe gives a mixture of two types of product: (i) compounds 17 and 18 of formulae dppe[FeCo(CO) 5 ( μ -(C(CO) 2 Me)H] 2 , the structure of which consists of two [FeCo(CO) 5 ( μ -(CO 2 Me)=C(CO) 2 MeH] units bridged by a dppe ligand bonded to two Co and two Fe atoms, respectively, and (ii) compound 19 of formula dppe[FeCo(CO) 4 ( μ -(CO 2 Me)=C(CO 2 Me)H], in which the dppe ligand bridges the FeCo bond. Reaction with dppm produces dppm[FeCo(CO) 5 ( μ -(CO 2 Me)H] 2 ( 20 ) and [FeCo(CO) 5 ( μ -(CO 2 Me= C(CO) 2 MeH] ( 21 ), the structures of which are similar to those of compounds 17 and 19 . The monosubstituted phosphinoalkyne FeCo complexes react with Co 2 (CO) 8 to form a new family of products [(Co) 2 (CO) 6 ( μ -Ph 2 PCCR)) [FeCo(CO) 5 (( μ -(CO 2 Me=C(CO 2 Me)H) ( 22 – 26 ), which contain the Co 2 (CO) 6 fragment coordinated to the CC bond of the phosphine ligand.

Synthesis and crystal structure of a heterodinuclear complex with a bridged ethenyl ligand FeCo(CO)7(μ-CH=CPhH)

[Fe2(CO)6(μ-CO)(μ-CHCPhH)]− reacts with Co2(CO)8 at room temperature to give the neutral heterodinuclear complex FeCo(CO)7(μ-CHCPhH), which has been characterized by elemental analysis and spectroscopic (mass, IR and 1H NMR) methods and by determination of its structure by X-ray diffraction.

Hydrogenation and isomerization reactions in the addition of carboxylic acids containing alkyne or alkene groups to RuClH(CO) (PPh3)3

Abstract The reaction of the complex [RuClH(CO)(PPh3)3] with alkynecarboxylic acids (HO2CCCR; RPh and Me) gives the complexes [RuCl(O2CCHCRH)(CO)(PPh3)2], which contain an η2-alkenecarboxylate ligand. The same type of compounds with RMe can be obtained from the reaction of [RuClH(CO)(PPh3)3] with allylacetic acid (HO2CCH2CHCH2), which is isomerized to a 2-buten-1-carboxylate ligand. The reaction of [RuClH(CO)(PPh3)3] with 4-pentynoic acid (HO2CCH2CH2CCH) produces the compound [RuCl(O2CCH2CH2CHCH2)(CO)(PPh3)2], which contains an η2-carboxylate ligand resulting from the hydrogenation of the alkyne group. Possible reaction mechanisms of hydrogenation and isomerization are discussed.

The structure of [Co2(CO)5(μ2,η4-CPhCHCHCPh)] a cobalt analogue of the ‘ferroles’

[Co2(CO)5(μ2,η4-CPhCHCHCPh)], a new cobaltacyclopentadiene dinuclear compound, was isolated and characterized by spectroscopic techniques. The X-ray structure of this compound has been determined.

Formation of [FeM(η-C5H5)(CO)4(µ-CO)(µ-CRCR′H)](M = Fe or Ru) complexes from the reaction of [MH(η-C5H5)(CO)2] with [Fe2(CO)9] and acetylenes. X-Ray structure of [FeRu(η-C5H5)(CO)4(µ-CO)(µ-CPhCPhH)]

The complexes [MH(η-C5H5)(CO)2](M = Fe or Ru) react with an equimolar [Fe2(CO)9]–acetylene mixture in tetrahydrofuran affording [FeM(η-C5H5)(CO)4(µ-CO)(µ-CRCR′H)][M = Fe, R = R′= Ph, (1), or H, (2); R = Ph, R′= H (3); R = H, R′= But, (4); M = Ru, R = R′= Ph (5); R = SiMe3, R′= H (6)]. The structure of (5) was established by single-crystal X-ray crystallography. It crystallizes in the space group P21/n with Z= 4 and a= 14.863(4), b= 14.542(4), c= 10.186(3)A, and β= 97.09(3)°. The structure was solved by direct methods and refined by least squares to a final R of 0.067. It consists of Ru(C5H5)(CO) and Fe(CO)3 fragments linked by CO and 1,2-diphenylethenyl bridges and a metal–metal bond. A possible mechanism for the formation of the complexes is proposed on the basis of the activation of the acetylenes by [Fe2(CO)9] and subsequent insertion into the M–H (M = Fe or Ru) bond.

REACTIONS OF DINUCLEAR CARBOXYLATE RUTHENIUM (I) COMPLEXES WITH ALCOHOLS. THE UNEXPECTED OXIDATION OF PRIMARY ALCOHOLS TO CARBOXYLIC LIGANDS

Abstract The dinuclear ruthenium (I) complexes [Ru2(HCO2)2(CO)4(PPh3)2] react with primary alcohols R′CH2OH in refluxing toluene, giving rise to [Ru2(R′CO2)2(CO)4(PPh3)2] compounds. Other carboxylate bridging complexes react with alcohols R″OH to give very unstable alkoxide compounds [Ru2(R″O)2(CO)4(PPh3)2].

Synthesis and characterization of new heterobimetallic iron–cobalt complexes with ethenyl bridges CR2CHR1[R1= H or C(O)OMe, R2= C(O)OMe or C(O)OEt]. X-Ray structure of [FeCo(CO)6{µ-MeOC(O)CC(H)C(O)OMe}]

The reaction of [Fe(η3-R1HCCR2CO)(CO)3]–(1) with [Co2(CO)8] yields two types of new heterobimetallic Fe–Co complexes. When R1= H and R2= C(O)OMe or C(O)OEt, the products are the µ-ethenyl complexes [FeCo(CO)7(µ-R2CCH2)](2), while when R1= R2= C(O)OMe the complex [FeCo(CO)6{µ-MeOC(O)CC(H)C(O)OMe}](3) is formed. In this complex one ester group of the µ-ethenyl ligand is co-ordinated via oxygen to iron. This feature has been confirmed by a single-crystal X-ray diffraction study. The reaction of (2) and (3) with one equivalent of PMe2Ph yields the complexes (4) and (5), respectively, in which one molecule of CO has been substituted by the phosphine. The site of substitution is different in (4) and (5); thus in complexes (4) the phosphine ligand is bonded to iron but in (5) it is bonded to cobalt.