Preparation, coordination properties and catalytic use of 1′-(diphenylphosphanyl)-1-ferrocenecarboxamides bearing 2-hydroxyethyl pendant groups

Polar amido-phosphane ligands, viz 1-(diphenylphosphanyl)-1′-[N-(2-hydroxyethyl)carbamoyl]ferrocene (1) and 1-(diphenylphosphanyl)-1′-[N,N-bis(2-hydroxyethyl)carbamoyl]ferrocene (2) were synthesised from 1′-(diphenylphosphanyl)-1-ferrocenecarboxylic acid (Hdpf) by direct amide coupling or via Hdpf-pentafluorophenyl ester 3. Subsequent reactions of 1 and 2 with [PdCl₂(cod)] (cod = η²:η²-cyclocta-1,5-diene) gave the respective bis(phosphane) complexes trans-[PdCl₂L₂] (4, L = 1; 5, L = 2). Depending on the solvent used in their subsequent crystallisation (ethanol or chloroform), these complexes were isolated in several defined solvated forms. The structure determination for free ligands and their solvated complexes (4·2EtOH, 4·6CHCl₃, 5·2EtOH, and 5·4CHCl₃) revealed the dominating role of hydrogen bonding in their crystal assemblies, the nature and complexity of the formed hydrogen-bonded arrays strongly varying with the ligand structure (one vs. two 2-hydroxethyl chains), their number in the discrete species (free ligands vs. the complexes), and also with the solvate. Catalytic tests performed with 4 and 5 in Suzuki-Miyaura cross-coupling reaction showed that both complexes form active catalysts for the coupling of aryl bromides with phenylboronic acid in common polar organic solvents, in water and in toluene-water biphasic mixture. Yet, complex 4 gave rise to hydrolytically more stable catalyst, which could be used five times without any detectable loss of activity in the toluene/water system. Complex 4 was also successfully applied to the synthesis of biaryl anti-inflammatory drugs and their analogues in pure water and in the toluene-water mixture.     

Rhodium(I) complexes with 1′-(diphenylphosphino)ferrocenecarboxylic acid as active and recyclable catalysts for 1-hexene hydroformylation

The rhodium complex trans-[Rh(CO)(Hdpf-κP)(dpf-κ²O,P)] (1), (Hdpf = 1′-(diphenylphosphino)ferrocenecarboxylic acid) was used as an efficient and recyclable catalyst for 1-hexene hydroformylation producing ca. 80% of aldehydes at 10 atm CO/H₂ and 80 °C. After the reaction, unchanged complex 1 was separated from the reaction mixture and used again three times with the same catalytic activity. The effect of modifying ligands, phosphines and phosphites, on the reactivity of 1 was investigated. The active catalytic systems containing 1 or trans-[Rh(CO)(L)(dpf-κ²O,P)] (2) were formed in situ from acetylacetonato rhodium(I) precursors [Rh(CO)₂(acac)] (3) or [RhL(CO)(acac)] (4) and Hdpf or Medpf (L = phosphine, Medpf = methyl ester of Hdpf).     

Preparation of phosphinoferrocene carboxamides from isocyanates. Synthesis and structural characterisation of palladium(II) and platinum(II) complexes with 1′-(diphenylphosphino)-1-(N-phenylcarbamoyl)ferrocene

The reaction of in situ generated 1′-(diphenylphosphino)-1-lithioferrocene with isocyanates RNCO affords the respective phosphino-carboxamides Ph₂PfcCONHR (fc = ferrocene-1,1′-diyl, R = cyclohexyl (2), and Ph (3)) in moderate yields. The coordination behaviour of 3 chosen as a representative was studied in palladium(II) and platinum(II) complexes. Depending on the metal precursor and the reaction conditions, the following compounds featuring this ligand as a P-monodentate or an O,P-chelating donor were isolated and characterised by spectroscopic methods (IR, multinuclear NMR and electrospray ionisation MS): trans-[PdCl₂(3-κP)₂] (5), trans-[PtCl₂(3-κP)₂] (6), cis-[PtCl₂(3-κP)₂] (7), [SP-4-4]-[(L^NC)PdCl(3-κP)] (8; L^NC = 2-[(dimethylamino-κN)methyl]phenyl-κC¹), and [SP-4-3]-[(L^NC)PdCl(3-κ²O,P)]SbF₆ (9). Besides, the crystal structures of a phosphine oxide resulting by oxidation of 2, viz Ph₂P(O)fcCONHCy (4), and of complexes 5·2Et₂O and 9 have been determined by single-crystal X-ray diffraction analysis.     

Direct functionalization of the cyclometalated 2-(2′-pyridyl)phenyl ligand bound to iridium(III)

Treatment of [Ir(ppy)₂(μ-Cl)]₂ and [Ir(ppy)₂(dtbpy)][OTf] (ppy = 2-(2′-pyridyl)phenyl; dtbpy = 4,4′-di-tert-butyl-2,2′-bipyridine; OTf = triflate) with pyridinium tribromide in the presence of Fe powder led to isolation of [Ir(4-Br-ppy)(μ-Br)]₂ (1) and [Ir(4-Br-ppy)₂(dtbpy)][OTf] (2), respectively. Pd-catalyzed cross-coupling of 2 with RB(OH)₂ afforded [Ir(4-R-ppy)₂(dtbpy)][OTf] (R = 4′-FC₆H₄ (3)), 4′-PhC₆H₄ (4), 2′-thienyl (5), 4′-C₆H₄CH₂OH (6). Treatment of 4 with B₂(pin)₂ (pin = pinacolate) afforded [Ir{4-(pin)B-ppy}₂(dtbpy)][OTf] (7). The alkynyl complexes [Ir(4-PhCC-ppy)₂(dtbpy)][OTf] (8) and [Ir{4-Me₂(OH)CC-ppy}(4-Br-ppy)(dtbpy)][OTf] (9) were prepared by cross-coupling of 2 with PhCCSnMe₃ and Me₂C(OH)CCH, respectively. Ethynylation of [Ir(fppy)₂(dtbpy)][OTf] (fppy = 5-formyl-2-(2′-pyridyl)phenyl) with Ohira’s reagent MeCOC(N₂)P(O)(OEt)₂ afforded [Ir{5-HCC-ppy}₂(dtbpy)][OTf] (10). The solid-state structures of 2, 5, 7, and 10 have been determined.     

Synthesis and structural characterization of 1′-(diphenylphosphino)ferrocene-1-carboxamide, its corresponding hydrazide, some heterocycles derived from the hydrazide and palladium(II) complexes with these functional phosphinoferrocene ligands

Two polar phosphinoferrocene ligands, 1′-(diphenylphosphino)ferrocene-1-carboxamide (1) and 1′-(diphenylphosphino)ferrocene-1-carbohydrazide (2), were synthesized in good yields from 1′-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf) via the reactive benzotriazole derivative, 1-[1′-(diphenylphosphino)ferrocene-1-carbonyl]-1H-1,2,3-benzotriazole (3). Alternatively, the hydrazide was prepared by the conventional reaction of methyl 1′-(diphenylphosphino)ferrocene-1-carboxylate with hydrazine hydrate, and was further converted via standard condensation reactions to three phosphinoferrocene heterocycles, viz 2-[1′-(diphenylphosphino)ferrocen-1-yl]-1,3,4-oxadiazole (4), 1-[1′-(diphenylphosphino)ferrocen-1-carbonyl]-3,5-dimethyl-1,2-pyrazole (5), and 1-[1′-(diphenylphosphino)ferrocene-1-carboxamido]-3,5-dimethylpyrrole (6). Compounds 1 and 2 react with [PdCl₂(cod)] (cod = η²:η²-cycloocta-1,5-diene) to afford the respective bis-phosphine complexes trans-[PdCl₂(L-κP)₂] (7, L = 1; 8, L = 2). The dimeric precursor [(L^NC)PdCl]₂ (L^NC = 2-[(dimethylamino-κN)methyl]phenyl-κC¹) is cleaved with 1 to give the neutral phosphine complex [(L^NC)PdCl(1-κP)] (9), which is readily transformed into a ionic bis-chelate complex [(L^NC)PdCl(1-κ²O,P)][SbF₆] (10) upon removal of the chloride ligand with Ag[SbF₆]. Pyrazole 5 behaves similarly affording the related complexes [(L^NC)PdCl(5-κP)] (12) and [(L^NC)PdCl(5-κ²O,P)][SbF₆] (13), in which the ferrocene ligand coordinates as a simple phosphine and an O,P-chelate respectively, while oxadiazole 4 affords the phosphine complex [(L^NC)PdCl(4-κP)] (11) and a P,N-chelate [(L^NC)PdCl(4-κ²N³,P)][SbF₆] (14) under similar conditions. All compounds were characterized by elemental analysis and spectroscopic methods (multinuclear NMR, IR and MS). The solid-state structures of 1⋅½AcOEt, 2, 7⋅3CH₃CN, 8⋅2CHCl₃, 9⋅½CH₂Cl₂⋅0.375C₆H₁₄, 10, and 14 were determined by single-crystal X-ray crystallography.     

Synthesis, characterization and luminescence study of dialkyl[1-arylmethyleneimino-2-naphthonato]gallium complexes: Crystal structure of dimethyl[1-(2-pridyl) methyleneimino-2-naphthonato]gallium

Eight dialkylgallium complexes of type R₂GaL [(M = Me, L = 1-(2-pyridyl)methyleneimino-2-naphthonato (1), M = Et, L = 1-(2-pyridyl)methyleneimino-2-naphthonato (2), M = Me, L = 1-phenylmethyleneimino-2-naphthonato (3), M = Et, L = 1-phenylmethyleneimino-2-naphthonato (4), M = Me, L = 1-(p-methoxylphenyl)methyleneimino-2-naphthonato (5), M = Me, L = 1-(3,4-dimethoxylphenyl)methyleneimino-2-naphthonato (6), M = Me, L = 1-naphthylmethyleneimino-2-naphthonato (7), M = Me, L = 1-naphthylmethyleneimino-2-naphthonato (8)) have been synthesized by reaction of trialkylgallium with appropriate 1-arylmethyleneimino-2-naphthols. The complexes have been characterized by elemental analysis, ¹H NMR, IR and mass spectrometry. Structure of dimethyl[1-(2-pyridyl)methyleneimino-2-naphthonato]gallium (1) has been determined by X-ray single crystal analysis. Ga atom is five coordinate in the structure. Photoluminescent properties have been measured. The maximum emission wavelengths are in the range of 358 and 412 nm with the intensity of 13-325 a.u. The electroluminescent properties of 3, 5, 7 and 8 have been measured. The maximum emission wavelengths are in the range of 450 and 480 nm.     

F NMR spectroscopy as useful tool for determining the structure in solution of coordination compounds of MF5 (M = Nb, Ta)

The salts [S(NMe₂)₃][MF₆] (M = Nb, 2a; M = Ta, 2b) and [S(NMe₂)₃][M₂F₁₁] (M = Nb, 2c; M = Ta, 2d) have been prepared by reacting MF₅ (M = Nb, 1a; M = Ta, 1b) with [S(NMe₂)₃][SiMe₃F₂] (TASF reagent) in the appropriate molar ratio. The solid state structure of 2b has been ascertained by X-ray diffraction. The 1:1 molar ratio reactions of 1a with a variety of organic compounds (L) give the neutral adducts NbF₅L [L = Me₂CO, 3a; L = MeCHO, 3b; L = Ph₂CO, 3c; L = tetrahydrofuran (thf), 3d; L = MeOH, 3e; L = EtOH, 3f; L = HOCH₂CH₂OMe, 3g; L = Ph₃PO, 3h; L = NCMe, 3i] in good yields. The complexes MF₅L [M = Nb, L = HCONMe₂, 3j; M = Nb, L = (NMe₂)₂CO, 3k; M = Ta, L = (NMe₂)₂CO, 3l; M = Nb, L = OC(Me)CHCMe₂, 3m] have been detected in solution in admixture with other unidentified products, upon 2:1 molar reaction of 1 with the appropriate reagent L. The ionic complexes [NbF₄(tht)₂][NbF₆], 4a, and [NbF₄(tht)₂][Nb₂F₁₁], 4b, have been obtained by combination of tetrahydrothiophene (tht) and 1a, in 1:1 and 2:3 molar ratios, respectively. The treatment of 1 with a two-fold excess of L leads to the species [MF₄L₄][MF₆] [M = Nb, L = HCONMe₂, 5a; M = Ta, L = HCONMe₂, 5b; M = Nb, L = thf, 5c; M = Ta, L = thf, 5d; M = Nb, L = OEt₂, 5e]. The new complexes have been fully characterised by NMR spectroscopy. Moreover, the revised ¹⁹F NMR features of the known compounds MF₅L [M = Ta, L = Me₂CO, 3n; M = Ta, L = Ph₂CO, 3o; M = Ta, L = MePhCO, 3p; M = Ta, L = thf, 3q; M = Nb, L = CH₃CO₂H, 3r; M = Nb, L = CH₂ClCO₂H, 3s; M = Ta, L = CH₂ClCO₂H, 3t], TaF₄(acac), TaF₄(Me-acac) and [TaF(Me-acac)₃][TaF₆] (Me-acac = methylacetylacetonato anion) are reported.     

Photophysical properties and computational investigations of tricarbonylrhenium(I)[2-(4-methylpyridin-2-yl)benzo[d]-X-azole]L and tricarbonylrhenium(I)[2-(benzo[d]-X-azol-2-yl)-4-methylquinoline]L derivatives (X = N-CH3, O, or S; L = Cl, pyridine)

We report a combined experimental and computational study of new rhenium tricarbonyl complexes based on the bidentate heterocyclic N-N ligands 2-(4-methylpyridin-2-yl)benzo[d]-X-azole (X = N-CH₃, O, or S) and 2-(benzo[d]-X-azol-2-yl)-4-methylquinoline (X = N-CH₃, O, or S). Two sets of complexes are reported. Chloro complexes, described by the general formula Re(CO)₃[2-(4-methylpyridin-2-yl)benzo[d]-X-azole]Cl (X = N-CH₃, 1; X = O, 2; X = S, 3) and Re(CO)₃[2-(benzo[d]-X-azol-2-yl)-4-methylquinoline]Cl (X = N-CH₃, 4; X = O, 5; X = S, 6) were synthesized heating at reflux Re(CO)₅Cl with the appropriate N-N ligand in toluene. The corresponding pyridine set {Re(CO)₃[2-(4-methylpyridin-2-yl)benzo-X-azole]py}PF₆ (X = N-CH₃, 7; X = O, 8; X = S, 9) and {Re(CO)₃[2-(benzo[d]-X-azol-2-yl)-4-methylquinoline]py}PF₆ (X = N-CH₃, 10; X = O, 11; X = S, 12) was synthesized by halide abstraction with silver nitrate of 1-6 followed by heating in pyridine and isolated as their hexafluorophosphate salts. All complexes have been fully characterized by IR, NMR, electrochemical techniques and luminescence. The crystal structures of 1 and 7 were obtained by X-ray diffraction. DFT and time-dependent (TD) DFT calculations were carried out for investigating the effect of the organic ligand on the optical properties and electronic structure of the reported complexes.     

Syntheses, characterizations and crystal structures of new organoantimony(V) complexes with heterocyclic (S, N) ligand

Eight new organoantimony(V) complexes with 1-phenyl-1H-tetrazole-5-thiol [L¹H] and 2,5-dimercapto-4-phenyl-1,3,4-thiodiazole [L²H] of the type R_nSbL_5 − n (L = L¹: n = 4, R = n-Bu 1, Ph 2, n = 3, R = Me 3, Ph 4; L = L²: n = 4, R = n-Bu 5, Ph 6, n = 3, R = Me 7, Ph 8) have been synthesized. All the complexes 1-8 have been characterized by elemental, FT-IR, ¹H and ¹³C NMR analyses. Among them complexes 2, 6 and 8 have also been confirmed by X-ray crystallography. The structure analyses show that the antimony atoms in complexes 2 and 6 display a trigonal bipyramid geometry, while it displays a distorted capped trigonal prism in complex 8 with two intramolecular Sb?N weak interactions. Furthermore, the supramolecular structure of 2 has been found to consist of one-dimensional linear molecular chain built up by intermolecular C-H?N weak hydrogen bonds, while a macrocyclic dimer has been found in complex 6 linked by intermolecular C-H?S weak hydrogen bonds with head-to-tail arrangement. Interestingly, one-dimensional helical chain is recognized in complex 8, which is connected by intermolecular C-H?S weak hydrogen bonds.     

2,2′-Bipyrimidine transition metal complexes: Synthesis, reaction chemistry and solid state structures

2,2′-Bipyrimidine metal complexes with Ti, Mo, Fe, Ru, Pt, Ag, and Cu transition metal atoms have been synthesized and structurally characterized. These molecules were prepared by following synthesis methodologies. The reaction of 2,2′-bipyrimidine (1; bipym) with {[Ti](μ-σ,π-CCSiMe₃)₂}AgOTf ([Ti] = (η⁵-C₅H₄SiMe₃)₂Ti, OTf = OSO₂CF₃) (2) in a 1:1 molar ratio gave [{[Ti](μ-σ,π-CCSiMe₃)₂}Ag(bipym)]OTf (3) which on further treatment with another equivalent of 2 produced [({[Ti](μ-σ,π-CCSiMe₃)₂}Ag)₂(μ-1,2,3,4-bipym)](OTf)₂ (4). As consequence thereof, the coordination number of Ag(I) was changed from 3 to 4. A platinum-bipym complex with two acetylide substituents was accessible by the gradual reaction of 1 with K₂[PtCl₄] (5) and two equivalents of HCCR (7a, R = SiMe₃; 7b, R = Fc; 7c, R = Rc; Fc = (η⁵-C₅H₄)(η⁵-C₅H₅)Fe; Rc = (η⁵-C₅H₄)(η⁵-C₅H₅)Ru) in di-iso-propylamine and in presence of [CuI]. Originating from cis-[(bipym)Pt(CCR)₂] (8a, R = SiMe₃; 8b, R = Fc; 8c, R = Rc) diverse multinuclear complexes with two, three or four different transition metals could be obtained. These are: [((CO)₄Mo)(μ-1,2,3,4-bipym)Pt(CCFc)₂] (10), [(AgClO₄)(μ-1,2,3,4-bipym){[Pt(μ-σ,π-CCFc)₂]AgOClO₃}] (12), [(McCC)₂Pt(μ-1,2,3,4-bipym)({[Ti](μ-σ,π-CCSiMe₃)₂}M)]X (15a, Mc = Fc, M = Cu, X = PF₆; 15b, Mc = Rc, M = Cu, X = PF₆; 15c, Mc = Fc, M = Ag, X = ClO₄), and [(McCC)₂Pt(μ-1,2,3,4-bipym)PtCl₂] (17). Like other organometallic Pt-Ag tweezer complexes, compound 12 decomposed to give FcCC-CCFc (13). During prolonged stirring of 15a and 15b, respectively, [(McCC)₂Pt(μ-1,2,3,4-bipym)({[Ti](μ-σ,π-CCSiMe₃)(μ-σ,π-CCH)}M)]X (15′a, M = Cu, X = PF₆; 15′b, M = Cu, X = PF₆) was formed.The structures of 8b, 8c, 15a′, and 15b′ in the solid state are reported. All complexes exhibit the anticipated planar dinuclear Pt-M structure (M = Pt, Cu, Ag) with the 2,2′-bipyrimidine unit in a μ-1,2,3,4-bridging mode.Electrochemical investigations were carried out with 8a, 8b, and 8c and show that no significant influence of R on the bipym redox potentials exists. The typical redox behavior for the bipym, ferrocene, ruthenocene units and platinum were observed.     

Self-assembly syntheses and crystal structures of triorganotin(IV) pyridinecarboxylate: 1D polymers and a 42-membered macrocycle

A series of new triorganotin(IV) pyridinecarboxylates with 6-hydroxynicotinic acid (6-OH-3-nicH), 5-hydroxynicotinic acid (5-OH-3-nicH) and 2-hydroxyisonicotinic acid (2-OH-4-isonicH) of the types: [R₃Sn (6-OH-3-nic)·L]_n (I) (R = Ph, L = Ph·EtOH, 1; R = Bn, L = H₂O·EtOH, 2; R = Me, L = 0, 3; R = n-Bu, L = 0, 4), [R₃Sn (5-OH-3-nic)]_n (II) (R = Ph, 5; R = Bn, 6; R = Me, 7; R = n-Bu, 8), [R₃Sn (2-OH-4-isonic·L)]_n (III) (R = Bn, 9, L = MeOH; R = Me, L = 0, 10; R = Ph, 11, L = 0.5EtOH) have been synthesized. All the complexes were characterized by elemental analysis, TGA, IR and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy analyses. Among them, except for complexes 5 and 6, all complexes were also characterized by X-ray crystallography diffraction analysis. Crystal structures show that complexes 1-10 adopt 1D infinite chain structures which are generated by the bidentate O, O or N, O and the five-coordinated tin centers. Significant O-H?O, and N-H?O intermolecular hydrogen bonds stabilize these structures. Complex 11 is a 42-membered macrocycle containing six tin atoms, and forms a 2D network by intermolecular N-H?O hydrogen.     

Weak ferromagnetism in 1D coordination polymers: Syntheses,crystal structures,spectroscopic and magnetic properties of [Cu(L)(Memal)]n (Memal = the dianion of methylmalonic acid,L = 1,10-phenanthroline, 2,2′-bipyridine)

Investigation of the CuCl₂/H₂Memal/L (H₂Memal = methylmalonic acid, L = 1,10-phenanthroline or 2,2′-bipyridine) reaction system in MeOH and various molar ratios has lead to the isolation of two one-dimensional coordination polymers presenting the [Cu(L)(Memal)] repeating unit (1, L = 1,10-phen; 2, L = 2,2′-bpy). The Memal²⁻ ligand adopts the bidentate [chelating] + unidentate coordination mode between the Cu^II ions. Magnetic susceptibility measurements on 1 and 2 indicated the existence of weak ferromagnetic intrachain interactions and X-band EPR spectra from powdered samples of 1 and 2 are consistent with the stereochemistry of the Cu^II ions and with the presence of weak exchange interactions.     

Heterometallic complexes containing 1,1′-(CC)2Fc′ units linking two different metal centres

Proto-desilylation of 1-(Me₃SiCC)-1′-{Cp^∗(dppe)RuCC}Fc′ (1) afforded the corresponding ethynyl derivative 2, from which the green Co₂(μ-dppm)_n(CO)_8−2n (n = 0, 1) adducts 3 and 4 were obtained. Replacement of the ethynyl proton in reactions between 2 and AuCl(PPh₃), Hg(OAc)₂ or FeCl(dppe)Cp^∗ gave complexes 1-(RCC)-1′-{Cp^∗(dppe)RuCC}Fc′ [R = Au(PPh₃) 5, 1/2Hg 6, Fe(dppe)Cp^∗8]; the latter gave bis-vinylidene 9 with MeI, characterised (as was 2) by a single crystal X-ray study. Oxidative coupling of 2 (CuCl/tmeda/acetone, air) gave diyne 10, while coupling of 5 with Co₃(μ₃-CBr)(μ-dppm)(CO)₇ afforded 1-{Cp^∗(dppe)RuCC}-1′-{(OC)₇(μ-dppm)Co₃(μ₃-CCC)}Fc′ (11). Cyclic voltammetric measurements indicated that there was no significant electronic coupling between the end-groups through the ferrocene centre in any of these compounds.     

Self-assembly of triorganotin(IV) moieties with 2,3,4,5-tetrafluorobenzoic acid and 4,4′-bipy, triphenylphosphine oxide or phen: Syntheses, characterizations and supramolecular structures

A series of triorganotin (IV) complexes with 2,3,4,5-tetrafluorobenzoic acid and mixed-ligands of the types: R₃Sn(O₂CC₆HF₄)_m · L (m = 1, L = 0, R = Ph 1; m = 1, L = Ph₃PO, R = Ph 4, Me 5), [R₃Sn(O₂CC₆HF₄)]_m · L (m = 2, L = 4,4′-bipy, R = Ph 2, Me 3; m = n, L = 0, R = Me 6), and [R₃Sn(O₂CC₆HF₄) · (H₂O)]_m · L · C₂H₅OH (m = 2, L = Phen, R = Ph 7, Me 8), (4,4′-bipy = 4,4′-bipyridyl; Phen = 1,10-phenanthroline), have been synthesized by the reaction of triorganotin chloride and 2,3,4,5-tetrafluorobenzoic acid in the presence of mixed-ligands: 4,4′-bipy, triphenylphosphine oxide, or phen. All complexes were characterized by elemental analysis, IR, ¹H, ¹³C, ¹¹⁹Sn NMR spectroscopy analysis. Except for 5 and 8, all the complexes were also characterized by X-ray crystallography.     

Some complexes containing carbon chains end-capped by M(CO)2Tp′ [M = Mo, W; Tp′ = HB(pz)3, HB(dmpz)3] groups

Complexes M(CCCSiMe₃)(CO)₂Tp′ (Tp′ = Tp [HB(pz)₃], M = Mo 2, W 4; Tp′ = Tp^∗ [HB(dmpz)₃], M = Mo 3) are obtained from M(CCCSiMe₃)(O₂CCF₃)(CO)₂(tmeda) (1) and K[Tp′].Reactions of 2 or 4 with AuCl(PPh₃)/K₂CO₃ in MeOH afforded M{CCCAu(PPh₃)}(CO)₂Tp′ (M = Mo 5, W 6) containing C₃ chains linking the Group 6 metal and gold centres.In turn, the gold complexes react with Co₃(μ₃-CBr)(μ-dppm)(CO)₇ to give the C₄-bridged {Tp(OC)₂M}CCCC{Co₃(μ-dppm)(CO)₇} (M = Mo 7, W 8), while Mo(CBr)(CO)₂Tp^∗ and Co₃{μ₃-C(CC)₂Au(PPh₃)}(μ-dppm)(CO)₇ give {Tp^∗(OC)₂Mo}C(CC)₂C{Co₃(μ-dppm)(CO)₇} (9) via a phosphine-gold(I) halide elimination reaction. The C₃ complexes Tp′(OC)₂MCCCRu(dppe)Cp^∗ (Tp′ = Tp, M = Mo 10, W 11; Tp′ = Tp^∗, M = Mo 12) were obtained from 2-4 and RuCl(dppe)Cp^∗ via KF-induced metalla-desilylation reactions. Reactions between Mo(CBr)(CO)₂Tp^∗ and Ru{(CC)_nAu(PPh₃)}(dppe)Cp^∗ (n = 2, 3) afforded {Tp^∗(OC)₂Mo}C(CC)_n{Ru(dppe)Cp^∗} (n = 2 13, 3 14), containing C₅ and C₇ chains, respectively. Single-crystal X-ray structure determinations of 1, 2, 7, 8, 9 and 12 are reported.     

Novel hydridotris(pyrazolyl)borate ruthenium(II) complexes containing the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane: Synthesis and evaluation of DNA binding properties

A series of half-sandwich ruthenium(II) complexes containing κ³(N,N,N)-hydridotris(pyrazolyl)borate (κ³(N,N,N)-Tp) and the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA) [RuX{κ³(N,N,N)-Tp}(PPh₃)_2−n(PTA)_n] (n = 2, X = Cl (1), n = 1, X = Cl (2), I (3), NCS (4), H (5)) and [Ru{κ³(N,N,N)-Tp}(PPh₃)(PTA)L][PF₆] (L = NCMe (6), PTA (7)) have been synthesized. Complexes containing 1-methyl-3,5-diaza-1-azonia-7-phosphaadamantane(m-PTA) triflate [RuCl{κ³(N,N,N)-Tp}(m-PTA)₂][CF₃SO₃]₂ (8) and [RuX{κ³(N,N,N)-Tp}(PPh₃)(m-PTA)][CF₃SO₃] (X = Cl (9), H (10)) have been obtained by treatment, respectively, of complexes 1, 2 and 5 with methyl triflate. Single crystal X-ray diffraction analysis for complexes 1, 2 and 4 have been carried out. DNA binding properties by using a mobility shift assay and antimicrobial activity of selected complexes have been evaluated.     

Cationic half-sandwich complexes (Rh, Ir, Ru) containing 2-substituted-1,8-naphthyridine chelating ligands: Syntheses, X-ray structure analyses and spectroscopic studies

Reactions of the dinuclear complexes [(η⁶-arene)Ru(μ-Cl)Cl]₂ (arene = C₆H₆, p-ⁱPrC₆H₄Me) and [(η⁵-C₅Me₅)M(μ-Cl)Cl]₂ (M = Rh, Ir) with 2-substituted-1,8-naphthyridine ligands, 2-(2-pyridyl)-1,8-naphthyridine (pyNp), 2-(2-thiazolyl)-1,8-naphthyridine (tzNp) and 2-(2-furyl)-1,8-naphthyridine (fuNp), lead to the formation of the mononuclear cationic complexes [(η⁶-C₆H₆)Ru(L)Cl]⁺ {L = pyNp (1); tzNp (2); fuNp (3)}, [(η⁶-p-ⁱPrC₆H₄Me)Ru(L)Cl]⁺ {L = pyNp (4); tzNp (5); fuNp (6)}, [(η⁵-C₅Me₅)Rh(L)Cl]⁺ {L = pyNp (7); tzNp (8); fuNp (9)} and [(η⁵-C₅Me₅)Ir(L)Cl]⁺ {L = pyNp (10); tzNp (11); fuNp (12)}. All these complexes are isolated as chloro or hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV/Vis spectroscopy. The molecular structures of [1]Cl, [2]PF₆, [4]PF₆, [5]PF₆ and [10]PF₆ have been established by single crystal X-ray structure analysis.     

Iron(0) and ruthenium(0) complexes with tridentate phosphonite ligands and their potential for ketene formation from methyl iodide, CO and a base

An efficient route to the novel tridentate phosphine ligands RP[CH₂CH₂CH₂P(OR′)₂]₂ (I: R = Ph; R′ = i-Pr; II: R = Cy; R′ = i-Pr; III: R = Ph; R′ = Me and IV: R = Cy; R′ = Me) has been developed. The corresponding ruthenium and iron dicarbonyl complexes M(triphos)(CO)₂ (1: M = Ru; triphos = I; 2: M = Ru; triphos = II; 3: M = Ru; triphos = III; 4: M = Ru; triphos = IV; 5: M = Fe; triphos = I; 6: M = Fe; triphos = II; 7: M = Fe; triphos = III and 8: M = Fe; triphos = IV) have been prepared and fully characterized. The structures of 1, 3 and 5 have been established by X-ray diffraction studies. The oxidative addition of MeI to 1-8 produces a mixture of the corresponding isomeric octahedral cationic complexes mer,trans-(13a-20a) and mer,cis-[M(Me)(triphos)(CO)₂]I (13b-20b) (M = Ru, Fe; triphos = I-IV). The structures of 13a and 20a (as the tetraphenylborate salt (21)) have been verified by X-ray diffraction studies. The oxidative addition of other alkyl iodides (EtI, i-PrI and n-PrI) to 1-8 did not afford the corresponding alkyl metal complexes and rather the cationic octahedral iodo complexes mer,cis-[M(I)(triphos)(CO)₂]I (22-29) (M = Ru, Fe; triphos = I-IV) were produced. Complexes 22-29 could also be obtained by the addition of a stoichiometric amount of I₂ to 1-8. The structure of 22 has been verified by an X-ray diffraction study. Reaction of 13a/b-20a/b with CO afforded the acetyl complexes mer,trans-[M(COMe)(triphos)(CO)₂]I, 30-37, respectively (M = Ru, Fe; triphos = I-IV). The ruthenium acetyl complexes 30-33 reacted slowly with 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) even in boiling acetonitrile. Under the same conditions, the deprotonation reactions of the iron acetyl complexes 34-37 were completed within 24-40 h to afford the corresponding zero valent complexes 5-8. It was not possible to observe the intermediate ketene complexes. Tracing of the released ketene was attempted by deprotonation studies on the labelled species mer,trans-[Fe(COCD₃)(triphos)(CO)₂]I (38) and mer,trans-[Fe(¹³COMe)(triphos)(CO)₂]I (39).     

Pd(0) and Pd(II) derivatives with heteroannularly bridged chiral ferrocenyl diphosphine ligands - A stereochemical analysis

The ligands (S_c, S_p)-1-diphenylphosphino-2,1′-(1-dicyclohexylphosphinopropanediyl)ferrocene, (S_c, S_p)-PP^CyPF, and (S_c, S_p)-1-diphenylphosphino-2,1′-(1-diphenylphosphinopropanediyl)ferrocene, (S_c, S_p)-PP^PhPF, have been used in the synthesis of the new Pd(0) and Pd(II) derivatives [Pd(PP^CyPF)(DMFU)] (1) (DMFU = dimethylfumarate), [Pd(PP^CyPF)(MA)] (2) (MA = maleic anhydride), [Pd(η³-2-Me-C₃H₄)(PP)]OTf (PP = PP^CyPF, 3; PP^PhPF, 4) (OTf = triflate), [PdRR′(PP)] (R = Me, R′ = Cl, PP = PP^CyPF, 5, PP^PhPF, 6; R = R′ = Me, PP = PP^CyPF, 7, PP^PhPF, 8; R = R′ = C₆F₅, PP = PP^CyPF, 9, PP^PhPF, 10). The molecular structure of 7 has been determined by X-ray diffraction. In the cases of complexes 1-4 two isomers are formed depending on the orientation of the ancillary ligand with respect to the ferrocenyl core. The stereochemistry of these complexes has been determined. In complex 6 the two possible isomers are obtained whereas in complex 5 the derivative with the Me group trans to PPh₂ is selectively formed. Restricted rotation of the pentafluorophenyl groups with respect to the Pd-C bond has been found in 9 and 10. In all derivatives the conformation of the ferrocenyl ligand is the same as that seen by X-ray diffraction and deduced from NMR data.