Marisa Tiripicchio-Camellini

The reactions of [Ru3(CO)12] with nitrogen-containing heterocycles. Crystal structures of [Ru3(µ-H)(µ3-ppy)(CO)9] and [Ru3(µ-napy)(µ-CO)3(CO)7]

The reactions of [Ru3(CO)12] with several nitrogen-containing heterocycles under thermal conditions have been studied. 1H-Pyrrolo[2,3,-b]pyridine (Hppy) and benzimidazole (Hbzim) give the trinuclear clusters [Ru3(µ-H)(µ3-ppy)(CO)9](1a) and [Ru3(µ-H)(µ-bzim)(CO)10](2a), respectively. However, benzotriazole (Hbztz) affords the dinuclear complex [Ru2(µ-bztz)2(CO)6](3a). 1,8-Naphthyridine(napy) produces the carbonyl-bridged cluster [Ru3(µ-napy)(µ-CO)3(CO)7](4). Complex (4) reacts with HBF4 to give the cationic complex [Ru3(µ-H)(µ-napy)(CO)10][BF4](5) which has all terminal carbonyls. Complex (5) regenerates complex (4) on reaction with NEt3, 1,10-Phenanthroline(phen),2,2′-biquinoline(biquin) or 2,2′-bipyrimidine (bipym) react with [Ru3(CO)12] to give [Ru3(L–L)(µ-CO)2(CO)8][L–L = phen (6a), biquin (6b), or bipym (6c)], in which the L–L ligand chelates one ruthenium, and two carbonyl groups bridge the same edge of the tringle. The structures of compounds (1a) and (4) have been established by X-ray diffraction studies. Complex (1a) crystallizes in the monoclinic space group P21/a with a= 14.688(5), b= 16.251(7), c= 8.594(5)A, β= 97.64(2)°, and Z= 4. Crystals of (4) are monoclinic, space group P21/c with a= 15.374(7), b= 17.336(6), c= 16.167(7)A, β= 98.02(3)°, and Z= 8. Both structures were solved from diffractometer data by direct and Fouier methods and refined by full-matrix [(1a)] and block-matrix [(4)] least-squares to R= 0.0349 for 3 211 observed reflections for (1a) and to R= 0.0405 for 4 205 observed reflections for (4). In (1a) the pyrrolopyridinate ligand is co-ordinated to three Ru atoms, through the pyridinic N atom to one metal and through the pyrrolic N atom symmetrically bridging the other two, which are involved also in a hydridic bridge. In (4) there are two independent, but very similar, complexes in which three carbonyls bridge the three edges of a triangular metal array; the 1,8-naphthyridine ligand bridges two metal atoms through the two N atoms.

Trinuclear angular aggregates of rhodium: synthesis and crystal structures of [Rh3(µ3-SC5H4N)2(CO)6][ClO4](SC5H4N = pyridine-2-thiolate) and [Rh3(µ3-C7H4NS2)2(CO)2(PPh3)2(tfbb)][ClO4](C7H4NS2= benzothiazole-2-thiolate, tfbb = tetrafluorobenzobarrelene)

The binuclear complexes [{Rh(µ-L)L′2}2]{L = pyridine-2-thiolate (SC5H4N–) or benzothiazole-2-thiolate (C7H4NS2–); L′2= cyclo-octa-1,5-diene (cod), norborna-2,5-diene (nbd), tetrafluorobenzobarrelene (tetrafluorobenzo[5,6]bicyclo[2.2.2]octa-2,5,7-triene, tfbb), (CO)2, or (CO)(PPh3)} react with the appropriate species cis-[RhL′2(Me2CO)x]+ to give trinuclear aggregates [Rh3(µ3-L)2(L′2)3][ClO4]. A study of this reaction has led to the controlled synthesis of a single isomer of the complexes [Rh3(µ3-C7H4NS2)2(CO)2(PPh3)2L′2][ClO4]. The trinuclear complexes have been characterized by 1H, 31P n.m.r., and u.v.-visible spectroscopy and in the case of [Rh3(µ3-SC5H4N)2(CO)6][ClO4]·0.5CH2Cl2(4) and [Rh3(µ3-C7H4NS2)2(CO)2(PPh3)2(tfbb)][ClO4](12) by single-crystal X-ray diffraction methods. In both structures trinuclear cationic rhodium complexes are present, in which two pyridine-2-thiolate[(4)] or benzothiazole-2-thiolate[(12)] ligands, acting as triple bridges through the nitrogen and one sulphur atom, interact with all three metal atoms, which are in a bent arrangement. Carbonyl ligands [(4)] and carbonyl, PPh3, and tfbb (through the two double bonds) ligands [(12)] complete the slightly distorted square-planar co-ordination of the Rh atoms.

Pyrazolate bridged ruthenium(I) complexes. A convenient synthesis of ruthenium(I) compounds. The X-ray structure of bis-μ-(3,5-dimethylpyrazolate)bis(tricarbonyl-ruthenium(I)) (RuRu)

Abstract RuCl 3 · n H 2 O reacts with carbon monoxide in boiling 2-methoxyethanol to give a solution which upon treatment with pyrazole-type ligands (HPz) in the presence of zinc and carbon monoxide yields the complexes [Ru(μ-Pz)(CO) 3 ] 2 . This provides an easy high-yield route to ruthenium(I) complexes. In the crystal structure of [Ru(μ-dpmz)(CO) 3 ] 2 (dpmz = 3,5-dimethylpyrazolate) the Ru 2 N 4 framework adopts a boat conformation with a RuRu distance of 2.705(2) A.

Syntheses, structures, and bonding of heteropentametallic clusters [MCo3(CO)12{µ3-M′(EPh3)}](M = Fe or Ru; M′= Cu or Au; E = P or As): X-ray crystal structures of [RuCo3(CO)12{µ3-M′(PPh3)}](M′= Cu or Au)

The cluster anions [MCo3(CO)12]–[M = Fe (1) or Ru (2)] react with [{Cu(PPh3)Cl}4] in toluene to give the neutral pentametallic clusters [FeCo3(CO)12{µ3-Cu(PPh3)}](3) and [RuCo3(CO)12{µ3-Cu(PPh3)}](4). The latter two products react with PPh3 to give the ionic cluster species [Cu(PPh3)3][MCo3(CO)12]. The pentametallic cluster [RuCo3(CO)12{µ3-Au(PPh3)}](5), obtained by reaction of (2) with Au(PPh3)Cl in diethyl ether-toluene, also reacts with PPh3 to give [Au(PPh3)2][RuCo3(CO)12]. The structures of (4) and (5) have been determined by X-ray methods. Crystals of (4) are monoclinic, space group P 21/m, with Z= 2 in a unit cell of dimensions a= 9.122(3), b= 15.010(6), c= 12.580(7)A, and β= 107.86(3)°. Crystals of (5) are monoclinic, space group P21/c, with Z= 4 in a unit cell of dimensions a= 8.921 (3), b= 14.165(2), c= 26.72(1)A, and β= 91.95(4)°. The structures have been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R= 0.049 and 0.058 for 1 329 and 1 994 observed reflections, respectively. Both structures consist of a trigonal bipyramid of metal atoms with the cobalt atoms occupying the triangular equatorial plane and the copper or gold and ruthenium atoms situated at the apices. Three carbonyl groups bridge the Co–Co edges; the other nine are terminal, three attached to the Ru atom and two to each Co atom. Similarities in the bonding relationships of (4) and (5) are analyzed and rationalized through extended Huckel calculations.

Heterotrinuclear angular aggregates of rhodium, iridium, palladium and Group 11 metals. X-Ray structure of the complex [(cod)2Rh2(µ3-C7H4NS2)2Ag(O2ClO2)](cod = cycloocta-1,5-diene)

The binuclear complexes [{Ir(µ-C7H4NS2)(cod)}2]1(cod = cycloocta-1,5-diene) and [{Pd(µ-C7H4NS2)(η3-C3H5)}2]2 are isolated from the reaction of the chloro-bridged compounds [{M(µ-Cl)L2}2](M = Ir, L2= cod; M = Pd, L2= allyl) and lithium benzothiazole-2-thiolate. Reactions of 1 and 2 with the appropriate species [ML2(Me2CO)2]+ afford the homotrinuclear angular aggregates [M3(µ3-C7H4NS2)2(L2)3]+. Starting from [{Rh(µ-C7H4NS2)(CO)(PPh3)}2] and [{M′(µ-C7H4NS2)(cod)}2](M′= Rh or Ir), this method is highly useful to prepare the heterotrinuclear aggregates [(Ph3P)2(OC)2Rh2(µ3-C7H4NS2)2ML2]+[ML2= Ir(cod) or Pd(allyl)], [(cod)2M′2(µ3-C7H4NS2)2AgX]n+(n= 0, X = ClO4, Cl, NO3 or BF4; n= 1, X = PPh3 or pyridine) and [(cod)2M′2(µ3-C7H4NS2)2M″Cl](M″= Cu or Au). They have been characterized by 1H, 31P NMR and IR spectroscopy and [(cod)2Rh2(µ3-C7H4NS2)2Ag(O2ClO2)]8 by X-ray diffraction methods. Crystals of 8 are orthorhombic, space group Pbcn, with a= 7.635(5), b= 27.564(11), c= 15.564(8)A, Z= 4. The structure has been solved from diffractometer data by direct and Fourier methods and refined by full-matrix least squares to R= 0.062 for 1863 observed reflections. The complex, having an imposed C2 symmetry, shows two Rh and one Ag atoms in a bent arrangement with two molecules of benzothiazole-2-thiolate interacting with all three metals. Each ligand is bonded to one Rh atom through the nitrogen and asymmetrically bridges one Rh and one Ag atom through the sulphur. The Rh atoms complete their co-ordination with a cod ligand interacting through the two olefinic bonds, while the Ag atom completes the co-ordination with two oxygen atoms from a perchlorate anion, which has been found disordered and distributed in two positions of equal occupancy factor with three oxygen atoms in common.

Preparation and properties of thiophosphinito-bridged rhodium complexes. Crystal structure of [Rh2(μ-SPPh2)2(COD)2]

Abstract Reaction of Ph2P(S)H with [M(acac)(diolefin)] (M = Rh or Ir) yields [M2(SPPh2)2(diolefin)2] complexes. The reactions of [Rh2(SPPh2)2(COD)2] with t-butylisocyanide, diphosphine, or carbon monoxide have been studied. Several dirhodium(II) complexes have been prepared by a two centre oxidative-addition reaction, or by exchange reactions of [Rh2(O2CMe)4]. A variety of related complexes is discussed. The crystal structure of [Rh2(SPPh2)2(COD)2] has been determined by X-ray diffraction methods. It crystallizes in the triclinic space group P1¯ with cell dimensions a 12.152(7), b 16.117(8), c 10.805(7)A˚, α 90.42(4), β 112.90(3), γ 109.27(3)°, and Z = 2. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares to R = 0.0405 and Rw = 0.0584 for 5149 observed reflections. In the dimeric complex two SPPh2-ligands bridge the rhodium atoms through their S and P atoms; the coordination around each metal atom is completed by a COD molecule interacting through the two olefinic bonds. The Rh-Rh distance is of 3.770(1)A˚, ruling out the possibility of metal-metal interaction. The two Rh(1)-S(1)-P(2)-Rh(2) and Rh(1)-P(1)-S(2)-Rh(2) units are roughly planar, and the six-atom R h ( 1 ) − S ( 1 ) − P ( 2 ) − R h ( 2 ) − S ( 2 ) − P ︹ ( 1 ) ring has a boat conformation.

Synthesis of homo and hetero palladium–platinum bimetallic complexes; X-ray crystal structure of Pt2Cl2(µ-CO)(PPh3)3

The compounds M1(CO)(PPh3)3(M1= Pt, Pd) react with M2Cl2(PhCN)2(M2= Pt, Pd) in tetrahydrofuran at room temperature to afford the new homo [M1= M2= Pt (1); M1= M2= Pd (2)] or hetero [M1= Pt, M2= Pd (3); M1= Pd, M2= Pt(4)] bimetallic complexes M1M2Cl2(µ-CO)(PPh3)3via formal oxidative-addition of the M2(II)–Cl bond at the M1(0) centre; complex (1) has been structurally characterized by X-ray diffraction.

Novel co-ordination modes for bimetallic HgCo and HgMo fragments when bonded to clusters; X-ray crystal structure of RuCo3(µ-CO)3(CO)9[µ3-HgCo(CO)4]

Hexametallic clusters have been prepared and characterized in which the Hg–Co(CO)4 or Hg–Mo(CO)3(η-C5H5) fragment is µ3-bonded below the C03 face of the MCo3(M = Fe, Ru) tetrahedral precursor species; the structure of RuCo3(µ-CO)3(CO)9[µ3-HgCo(CO)4] has been determined by X-ray diffraction.

Reactivity of binuclear pyrazolate-bridged rhodium complexes with isocyanides. Molecular structure of [Rh2(µ-pz)I2(CNBut)2–(µ-Ph2PCH2PPh2)2]BF4(pz = pyrazolate)

The CO groups of [Rh2(µ-pz)I2(CO)2(µ-dppm)2]ClO4(pz = pyrazolate, dppm = Ph2PCH2PPh2) have been gradually substituted by reaction with isocyanides CNR (R = But or C6H4Me-p) to give [(OC)IRh(µ-pz)(µ-dppm)2Rhl(CNR)]ClO4[R = But(3) or C6H4Me-p(4)]via[(OC)IRh(µ-pz)(µ-CO)(µ-dppm)2Rhl(CNR)]ClO4[R = But(1) or C6H4Me-p(2)] and, finally, [Rh2(µ-pz)I2(CNR)2(µ-dppm)2] ClO4[R = But(7) or C6H4,Me-p(8)]via[Rh2(µ-pz)I2(µ-CO)(CNR)2(µ-dppm)2]ClO4[R = But(5) or C6H4Me-p(6)]. The CO bridging groups of (1), (2), (5), and (6) are ketonic carbonyls according to their spectroscopic properties. The reactivity of [Rh2(µ-pz) I2(CO)2(µ-dpam)2]ClO4(dpam = Ph2AsCH2AsPh2) with isocyanides was studied for comparison. The structure of the BF4–analogue of (7), [Rh2(µ-pz)I2(CNBut)2(µ-dppm)2]BF4(7b), has been determined by X-ray diffraction methods. Crystals are monoclinic, space group P21/n with unit-cell parameters a= 20.347(8), b= 21.221(8), c= 14.514(6)A, β= 94.11(2)°, and Z= 4. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by block-matrix least squares to R= 0.0630 for 4 969 observed reflections. In the cationic complex the two Rh atoms, at a distance of 2.829(3)A, are connected by a triple bridge, involving two dppm ligands and the pyrazolate anion.

Synthesis of mixed-metal trinuclear complexes. X-Ray crystal structure of [(cod)2Rh2(µ3-C7H4NS2)2AgO2ClO2](cod = cyclo-octa-1,5-diene; C7H4NS2= benzothiazole-2-thiolate)

The complex [{Rh(µ2-C7H4NS2)(cod)}2] reacts with compounds of the group 11 metals to give heterotrinuclear complexes, one of which, the title compound, has been characterized by X-ray diffraction methods showing short Rh–Ag separations in a bent arrangement.