José Gimeno

Novel Copper(I) Complexes Containing 1,1‘-Bis(diphenylphosphino)ferrocene (dppf) as a Chelate and Bridging Ligand: Synthesis of Tetrabridged Dicopper(I) Complexes [Cu2(μ-η1-C⋮R)2(μ-dppf)2] and X-ray Crystal Structure of [Cu2(μ-η1-C⋮CC6H4CH3-4)2(μ-dppf)2]

Binuclear copper(I) complexes [Cu(κ2-P,P-dppf)(CH3CN)2][BF4] (1), [Cu(κ2-P,P-dppf)(bipy)][BF4] (2) containing the chelating dppf ligand (dppf = 1,1‘-bis(diphenylphosphino)ferrocene) have been prepared by substitution reactions of the acetonitrile ligands from the complexes [Cu(CH3CN)4][BF4] and (1) with dppf and bipy, respectively. Similarly, the treatment of the complex [Cu2(μ-dppm)2(CH3CN)2][BF4]2 with dppf in CH2Cl2 at room temperature gives the tetranuclear complex [Cu2(μ-dppm)2(κ2-P,P-dppf)2][BF4]2 (3). The analogous bridging chloride tetranuclear complex [Cu2(μ-Cl)2(κ2-P,P-dppf)2] (4) has been also prepared by the addition of dppf to a solution in THF containing an equimolar mixture of CuCl and tetramethylethylenediamine. Complex 4 has been used as a precursor for μ-η1-alkynyl bridging dicopper(I) complexes containing the framework [Cu2(μ-dppf)2]. Complexes [Cu2(μ-η1-C⋮CR)2(μ-dppf)2] (R = C6H4CH3-4 (5), C6H5 (6), CH2OCH3 (7), CH2CH2CH3 (8), (η5-C5H4)Fe(η5-C5H5) (9)) are obtained by the treatment of ...

Bis (pentafluorophenyl) complexes of palladium(II) and of platinum(II)

Abstract The preparation of eight bis(pentaflurophenyl) complexes of Pd 11 and of Pt 11 with monodentate and bidentate nitrogen-donor ligands is described together with a preparation of a Pd 11 complex of 1,2-bis(diphenylphosphino)ethane. Some properties of the complexes are given. New possibilities for assignment of cis or trans configuration are discussed which depend upon the splitting or disappearance of certain bands in the IRspectra.

An unusual coordination mode of acetylide ligands: synthesis of tetranuclear copper(I) complexes containing μ3-ν1 acetylide bridging ligands. Crystal structure of [Cu(μ3-ν1-CCPh)- (Ph2Ppy-P]4(Ph2Ppy = 2-(diphenylphosphine)pyridine)

Abstract The preparation and properties of novel tetranuclear copper(I) complexes of the type [Cu(Cue5fcCR)(Lue5f8L)]4 (Lue5f8L = 2-(diphenylphosphine)pyridine (Ph2Ppy), R = tBu, ph; Lue5f8L = bis(diphenylphosphino)methane (dppm), R = Ph) are described. The crystal structure of [Cu(μ3-η1-Cue5fcCph)(Ph2Ppy-P)]4 has been determined by X-ray diffraction. Crystals are monoclinic, space group C2/c with Z = 4 in a unit cell of dimensions a 14.859(3), b 24.405(4), c 23.279(4) A and β 95.35(2)°; refinement gave R = 0.056 for 3586 reflections with I ≥ 2.5σ(I). The molecule consists of a tetrahedral “cluster” of copper atoms bearing four μ3-η1 phenylacetylide and four monodentate P-bonded 2-((diphenylphosphine)pyridine ligands (Ph2Ppy-P). IR, 1H and 31P{1H} NMR data are discussed.

Binuclear copper(I) complexes containing two or three 2-(diphenylphosphine) pyridine (dppy) bridging ligands: X-ray crystal structure of [Cu2(µ-dppy)3(MeCN)][BF4]2 and variable-temperature 1H and 31P-{1H} nuclear magnetic resonance studies

Treatment of [Cu(MeCN)4] BF4 with 2-(diphenylphosphino)pyridine (dppy) at room temperature in acetonitrile or dichloromethane gives [Cu2(µ-dppy)2(MeCN)x][BF4]2, x= 4 or 2, respectively. Reaction with an excess of dppy in refluxing acetone leads to the formation of [Cu2(µ-dppy)3]-[BF4]2, which gives [Cu(µ-dppy)3(MeCN)][BF4]2 upon recrystallization from acetonitrile. This complex can also be obtained from [Cu(MeCN)4]BF4 by reaction with an excess of dppy in refluxing acetonitrile. Substituted complexes [Cu2(µ-dppy)3Lx][BF4]2[x= 1, L = 2-methylpyridine, x= 2, L = 4-methylpyridine, P(OMe)3, or PMe3] are also described. Variable-temperature 1H and 31P-{1H} n.m.r. studies show that MeCN and dppy dissociation and rapid ligand-exchange processes take place in solution. The crystal structure of [Cu2(µ-dppy)3(MeCN)][BF4]2 has been determined by X-ray methods. Crystals are monoclinic, space group P21/c with Z= 4 in a unit cell of dimensions a= 21.424(7), b= 13.186(6), c= 18.232(6)A, and β= 99.77(2)°. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by blockmatrix least squares to R= 0.0657 for 6 539 observed reflections [I 2σ(I)]. The structure consists of [Cu2(µ-dppy)3(MeCN)]2+ cations and of BF4– anions. In the cations the two copper atoms are held in close proximity [2.721(3)A] by three dppy ligands acting as bridges through the P and N atoms. One copper atom is three-co-ordinate, being bonded to two N and one P atom from dppy ligands, the other is four-co-ordinate, being bonded to two P and one N atom from dppy ligands and to an additional N atom from an acetonitrile molecule. As expected, the Cu–P and Cu–N bonds for the three-co-ordinate copper are shorter than these of the four-co-ordinate copper.

2,2′-biimidazole, 2,2′-bibenzimidazole and imidazoles as ligands in cationic rhodium(I) complexes

SummaryCationic rhodium(I) complexes of the type [Rh(diolefin)(L-L)]ClO4 and [Rh(diolefin)L2]ClO4, (diolefin = 1,5-cyclooctadiene, 2,5-norbornadiene and tetrafluorobenzobarrelene; L-L = 2,2′-biimidazole, 2,2′-bibenzimidazole; L = pyrazole or imidazoles) are described. [Rh(CO)2(L-L)]-C1O4 complexes, which can be obtained by reaction of cyclooctadiene derivatives with CO, react with P-donor ligands in equimolar ratios to yield [Rh(CO)(P-donor)(L-L)]ClO4 monocarbonyl derivatives. The catalytic activity of some of these complexes is considered.

Cationic tri- and dicarbonyl complexes of manganese(I)

SummaryIn complexes of the Mn(CO)3(chelate)OClO3 and [Mn(CO)3(chel)(Me2CO)]ClO4 type, the facile replacement of the OClO3- or, respectively, Me2CO-groups by a variety of neutral ligands allows the preparation of novel cationic Dicarbonyl complexes, [Mn(CO)3(chelate)LL′]ClO4, at room temperature. Dicarbonyl derivatives, [Mn(CO)2(chelate)L2]ClO44 or [Mn(CO)2(chelate)LL′]ClO4, can be obtained by working at the reflux temperature. The properties of the novel compounds are given and their structures are discussed.A cationic tetracarbonyl manganese(I) complex has also been isolated.

Synthesis and structure of ruthenium(IV) complexes featuring N-heterocyclic ligands with an N-H group as the hydrogen-bond donor: hydrogen interactions in solution and in the solid state.

The synthesis and characterization of novel ruthenium(IV) complexes [Ru(η(3):η(3)-C(10)H(16))Cl(2)L] [L = 3-methylpyrazole (2b), 3,5-dimethylpyrazole (2c), 3-methyl-5-phenylpyrazole (2d), 2-(1H-pyrazol-5-yl)phenol (2e), 6-azauracile (3), and 1H-indazol-3-ol (4)] are reported. Complex 2e is converted to the chelated complex [Ru(η(3):η(3)-C(10)H(16))Cl(κ(2)-N,O-2-(1H-pyrazol-3-yl)phenoxy)] (5) by treatment with an excess of NaOH. All of the ligands feature N-H, O-H, or C═O as the potential hydrogen-bonding group. The structures of complexes 2a-2c, 2e, 3, and 5 in the solid state have been determined by X-ray diffraction. Complexes 2a-2c and 3, which contain the pyrazole N-H group, exhibit intra- and intermolecular hydrogen bonds with chloride ligands [N-H···Cl distances (Å): intramolecular, 2.30-2.78; intermolecular, 2.59-2.77]. Complexes 2e and 3 bearing respectively O-H and C═O groups also feature N-H···O interactions [intramolecular (2e), 2.27 Å; intermolecular (3), 2.00 Å]. Chelated complex 5, lacking the O-H group, only shows an intramolecular N-H···Cl hydrogen bonding of 2.42 Å. The structure of complex 3, which turns out to be a dimer in the solid state through a double intermolecular N-H···O hydrogen bonding, has also been investigated in solution (CD(2)Cl(2)) by NMR diffusion studies. Diffusion-ordered spectroscopy experiments reveal an equilibrium between monomer and dimer species in solution whose extension depends on the temperature, concentration, and coordinating properties of the solvent. Preliminary catalytic studies show that complex 3 is highly active in the redox isomerization of the allylic alcohols in an aqueous medium under very mild reaction conditions (35 °C) and in the absence of a base.

Lithioalkynyl iron(II) or ruthenium(II) complexes as precursors of novel alkynyl and vinylidene derivatives: heterobimetallic complexes containing a bridging ethynediyl system

Deprotonation of ethynyl complexes [Fe(CCH)(η5-C5H5)(dppm)]1a(dppm = Ph2PCH2PPh2) and [Ru(CCH)(η5-C9H7)L2][L2= 2PPh31b, Ph2PCH2CH2PPh2(dppe)1c or (PMe3)(PPh3)1d] with LiBut at –78 °C gave the lithiated complexes [Fe(CCLi)(η5-C5H5)(dppm)]2a and [Ru(CCLi)(η5-C9H7)L2]2b–2d, respectively. These species have been used in situ as precursors of novel alkynyl and vinylidene complexes by reactions with electrophiles. Treatment of complexes 2a–2d with MeOSO2CF3 at –78 °C gave vinylidene complexes [Fe(CCMe2)(η5C5H5)(dppm)][CF3SO3]3a and [Ru(CCMe2)(η5-C9H7)L2][CF3SO3][L2= 2PPh33b, dppe 3c or (PPh3)(PMe3)3d]. Iodoalkynyl complexes [Ru(CCl)(η5-C9H7)L2](L2= 2PPh34b or dppe 4c) have been obtained by reaction of [I(py)2][BF4](py = pyridine) with 2b and 2c, respectively. Reaction of 2a–2d with SnPh3Cl yielded the ethynediyl bridging bimetallic complexes [(η5-C5H5)(dppm)Fe–CC–SnPh3]5a and [(η5-C9H7)L2Ru–CC–SnPh3][L2= 2PPh35b, dppe 5c or (PPh3)(PMe3)5d]. Similar heterobimetallic complexes [(η5-C5H5)(dppm)Fe–CC–Au(PPh3)]6a and [(η5-C9H7)L2Ru–CC–Au(PPh3)]6b–6d have been obtained by treatment of ethynyl complexes 1a–1d with [AuCl(PPh3)] and TI(acac)(acac = acetylacetonate) in dichloromethane. Complexes 6a and 6b can alternatively be obtained by reaction of 5a and with 5b with [AuCl(PPh3)] in the presence of [PdCl2(MeCN)2]. The crystal structure of 5a has been determined by X-ray diffraction methods. It shows a typical three-legged piano-stool geometry. The iron atom is bonded to the cyclopentadienyl ring, the two phosphorus atoms of a chelating dppm ligand, with a narrow bite angle [74.90(5)°] and the terminal carbon of the triphenyltin acetylide group. The ethynyl bridge is bound to the iron and tin forming an CC–Sn angle of 162.8(4)° and an almost linear Fe–CC arrangement [178.0(3)°].

Cationic pentafluorophenyl complexes of platinum(II)

Abstract The complex [O3ClOPt(C6F5)(PEt3)2] which we have prepared for the first time, is used as a precursor of a series of cationic complexes [LPt(C6F5)(PEt3)2]ClO4 (L = PEt3, AsPh3, H2O, CO, OPPh3, SPPh3, HNPr2, py), which are easily obtained by adding L to the perchlorato complex.

Synthesis of cationic pentacarbonyl, fac- and mer-tricarbonyl, and cis-and trans-dicarbonyl complexes of manganese(I)

The complexes [Mn(CO)5(OClO3)] and fac-[Mn(CO)3(OCMe2)3][ClO4] obtained by the reaction of [Mn(CO)5Br] with Ag[ClO4] in dichloromethane or acetone solution are suitable precursors for the synthesis of cationic complexes of the type [Mn(CO)5L][ClO4] and of the types fac-[Mn(CO)3L3][ClO4] and cis-[Mn(CO)2L4][ClO4](L = a Group 5B ligand) which, when L is a strong π acceptor, isomerize under reflux to mer-[Mn(CO)3L3][ClO4] or, respectively, to trans-[Mn(CO)2L4][ClO4].