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1.
Raquel Gracia 《Inorganica chimica acta》2010,363(14):3856-3864
A series of complexes containing the bulky carboxylate ligand 2,4,6-triisopropylbenzoate (TiPB) of type trans-[Ru2(TiPB)2(O2CCH3)2X] [X = Cl (1), PF6 (2)] and [Ru2(TiPB)4X] [X = Cl (3), PF6 (4)] have been synthesised. The corresponding complexes trans-[Ru2(TiPB)2(O2CCH3)2] (5) and [Ru2(TiPB)4] (6) were also isolated. Magnetic susceptibility measurements indicate that the diruthenium cores have the expected three (1-4) or two (5 and 6) unpaired electrons consistent with σ2π4δ2(δ∗π∗)3 and σ2π4δ2δ∗2π∗2 electronic configurations. Compounds 1-4 and 6 were structurally characterised by X-ray crystallography, and show the expected paddlewheel arrangement of carboxylate ligands around the diruthenium core. The diruthenium cores of complexes 3, 4 and 6 are all distorted to minimise steric interactions between the bulky carboxylate ligands. The Ru-Ru bond length in the complex 6 [2.2425(6) Å] is the shortest observed for a diruthenium tetracarboxylate and, surprisingly, is 0.014 Å shorter than in the analogous complex 4, despite an increase in the formal Ru-Ru bond order from 2.0 (6) to 2.5 (4). This is rationalised in terms of the extent of internal rotation, or distortion, about the diruthenium core. This was supported by density functional theory calculations on the model complexes [Ru2(O2CH)4] and [Ru2(O2CH)4]+, that demonstrate the relationship between Ru-Ru bond length and internal rotation. Electrochemical and electronic absorption data were recorded for all complexes in solution. Comparison of the data for the ‘bis-bis’ (1, 2 and 5) and tetra-substituted (3, 4 and 6) complexes indicates that the shortening of the Ru-Ru bond length results in a small increase in energy of the near-degenerate δ∗ and π∗ orbitals. 相似文献
2.
Brendan R.A. Bland George Vamvounis T. Stanley Cameron 《Inorganica chimica acta》2005,358(13):3927-3936
Three diadduct complexes of the mixed-valent form of diruthenium tetraacetate, [Ru2(μ-O2CCH3)4L2](PF6), where L are the biologically relevant ligands imidazole, 1, 7-azaindole, 2, and caffeine, 3, were synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy and X-ray crystallography. In order to further elucidate the potential interactions of these dimers with DNA, the nature of the ligand coordination and the secondary inter- and intramolecular hydrogen-bonding interactions in all three complexes were assessed. Complex 1 · CH2Cl2 shows, exclusively, intermolecular interactions with the counterion whereas complexes 2 · ClCH2CH2Cl and 3 · OC(CH3)2 · H2O, in addition to extensive intermolecular interactions, show intramolecular hydrogen bonding from the axial ligand to the bridging acetate oxygens, locking the ligand mean planes in place between the bridging acetate mean planes. In addition, all three complexes display π-π stacking of axial ligand rings on adjacent diadduct units. 相似文献
3.
Dietrich P. Steinhuebel Peter Fuhrmann Stephen J. Lippard 《Inorganica chimica acta》1998,270(1-2):527-536
A series of zirconium(IV) complexes, [ZrX2(XDK)], where XDK is the constrained carboxylate ligand m-xylylenediamine bis(Kemp's triacid imide), were prepared and structurally characterized. The solid state structure of the mononuclear carboxylate alkyl complex [Zr(CH2Ph)2(XDK)] reveals that one benzyl group is bonded in an η2-fashion to the metal center. The reactivity of [Zr(CH2Ph)2(XDK)] displays its electrophilic character toward nucleophiles strong enough to displace the η2-benzyl group. Thus, weak sigma donor ligands such as CO, alkynes and anilines do not react, whereas strong sigma donors, such as pyridines and isocyanides, rapidly form the monoadduct [Zr(CH2Ph)2(4-tert-butylpyridine)(XDK)] and [Zr{η2-2,6-Me2PhNCCH2Ph}2(XDK)], an η2-iminoacyl derivative, respectively. Attempts to prepare zirconium amido complexes with H2XDK generally afforded the eight-coordinate [Zr(XDK)2] complex but use of the small amido ligand precursorZr(NMe2)4 allowed [Zr(NMe2)2(4-tert-butylpyridine)(XDK)] to be isolated in good yield. 相似文献
4.
Chihiro Kachi-TerajimaHitoshi Miyasaka Tomohiko IshiiKen-ichi Sugiura Masahiro Yamashita 《Inorganica chimica acta》2002,332(1):210-215
The ligand substitution reaction of Ru2(O2CCH3)4Cl with 2-amino-4,6-dimethylpyrimidine (Hadmpym) under gentle refluxing conditions in methanol led to the formation of a bridging-ligand mono-substituted compound, [Ru2(O2CCH3)3(admpym)(Cl)(MeOH)] (1). Compound 1 crystallized in monoclinic space group P21/n (no. 14) with a=8.3074(8) Å, b=12.3722(8) Å, c=18.913(1) Å, β=95.559(3)°, V=1934.8(3) Å3, and Z=4. Temperature dependence of the magnetic susceptibility of 1 revealed it to be in a spin ground state S=3/2 arising from the electronic configuration of σ2π4δ2(δ*π*)3. Compound 1 undergoes three metal-centered redox reactions in electrochemistry: E1/2 (ox)=+0.72 V (Ia/Ic<1, ΔEp=0.17 V); E1/2 (1,red)=−0.65 V (Ia/Ic≈1, ΔEp=0.10 V); and E1/2 (2,red)=−1.80 V (Ia/Ic?1, ΔEp=0.16 V). Then, the redox species produced by electrolysis were characterized by spectroscopic studies. 相似文献
5.
Lutz Schäffler 《Inorganica chimica acta》2006,359(3):970-977
The complexes [Ru2(CO)5(μ-FpyO)2]2 (1), [Ru2(CO)4(μ-ClpyO)2]2 (2), and [Ru2(CO)4(μ-BrpyO)2]2 (3) were prepared from Ru3(CO)12 and 6-fluoro-2-hydroxypyridine (FpyOH), 6-chloro-2-hydroxypyridine (ClpyOH) and 6-bromo-2-hydroxypyridine (BrpyOH), respectively, in hot toluene. Compounds 1-3 are coordination dimers with a cyclo-RuORuO motif. By carrying out the reaction in hot methanol, the dinuclear complexes [Ru2(CO)4(μ-ClpyO)2(CH3OH)] (4) and [Ru2(CO)4(μ-BrpyO)2(CH3OH)] (5), respectively, were obtained. Treatment of 2 and 3 with triphenylphosphane provided the complexes [Ru2(CO)4(μ-ClpyO)2(PPh3)] (6) and [Ru2(CO)4(μ-BrpyO)2(PPh3)] (7), respectively. The solid-state structures of complexes 1, 2, 4, 6, and 7 were determined by single crystal X-ray diffraction. In all cases, a head-head coordination of the two 6-halopyridinolate ligands at the core was found. In all chlorine- or bromine-containing complexes, the axial coordination site at the ruthenium atom neighbored by two Cl or Br atoms remains unoccupied due to steric shielding by the halogen atom. In the fluoropyridinolate complex 1, the same coordination site is occupied by a carbonyl ligand. 相似文献
6.
This work describes the reactivity of compounds [Pd(dmpz)2(Hdmpz)2] (A) (dmpz = 3,5-dimethylpyrazolate, Hdmpz = 3,5-dimethylpyrazol) and [Pd2(μ-dmpz)2(dmpz)2(Hdmpz)2] (B) towards several dicarboxylic acids and also towards perchloric acid. The compounds [Pd(Hdmpz)4](O2C-(CH2)n-CO2H)2 [n = 1 (1), 3 (2)] have been obtained by treatment of [Pd(dmpz)2(Hdmpz)2] (A) with two equivalents of malonic (HO2C-CH2-CO2H) and glutaric (HO2C-(CH2)3-CO2H) acids. The X-ray study on a crystal of [Pd(Hdmpz)4](O2C-(CH2)3-CO2H)2 (2) revealed that the glutarate anions link to the cationic complex [Pd(Hdmpz)4]2+ through the carboxylate group by charge-assisted N-H(+)?O(−) hydrogen bonds. Additionally, the carboxylate anions form uncommon dimeric rings on both sides of the metal complex via a pair of O-H?O hydrogen bonds, yielding a hydrogen bonded polymeric chain with alternating inorganic [Pd(Hdmpz)4]2+ and organic fragments. The dinuclear complexes [Pd2(μ-dmpz)2(O2C-(CH2)n-CO2)(Hdmpz)2] [n = 0 (5), 1 (6)] were obtained from equimolar amounts of [Pd2(μ-dmpz)2(dmpz)2(Hdmpz)2] (B) and the corresponding dicarboxylic acid, HO2C-(CH2)n-CO2H (n = 0, 1). However, the synthesis of 5 and 6 requires two steps, the protonation of both terminal dmpz groups in B with HClO4 to give [Pd2(μ-dmpz)2(Hdmpz)4](ClO4)2 (4) and the subsequent treatment of this cationic palladium complex with salts of the corresponding dicarboxylic acids. The X-ray structures of compounds 5 and 6 are reported. Both in 5 and 6, the Pd2N4 ring shows a typical boat-like conformation and the metal atoms are separated in about 3.3 Å. Both 5 and 6 are asymmetric and contain two Hdmpz groups - H-bond donors - at one end, and two CO groups from the dicarboxylate anion - H-bond acceptors - at the other, in such a way that the donor end of one molecule links with the acceptor end of its neighbour forming a hydrogen-bonded polymeric chain. The synthesis and X-ray study of compounds [Pd(Hdmpz)4](ClO4)2 (3) and [Pd2(μ-dmpz)2(Hdmpz)4](ClO4)2 (4), obtained by reaction of [Pd(dmpz)2(Hdmpz)2] (A) and [Pd2(μ-dmpz)2(dmpz)2(Hdmpz)2] (B) with two equivalents of perchloric acid, are also reported. 相似文献
7.
Reactions between Hdpa (2,2′-dipyridylamine) and either RuCl3 · xH2O and Ru2(OAc)4Cl produce mono-, di-, and tri-ruthenium complexes under various conditions. The ligand Hdpa and RuCl3 · xH2O react in boiling DMF to form the ionic species [Ru(Hdpa)2Cl2]Cl (1). Reaction of Ru2(OAc)4Cl with molten Hdpa leads to scission of the Ru-Ru bond and formation of the vertex-sharing bioctahedral complex Ru2(dpa)3(OAc)0.64Cl1.36 (2). A mixture of both of these species results from the reaction of Ru2(OAc)4Cl with Hdpa and LiCl in refluxing o-dichlorobenzene/EtOH mixtures. This mixture of compounds reacts further with KOBut and n-butanol in refluxing naphthalene to give low yields of the extended metal atom chain (EMAC) complex Ru3(dpa)4Cl2 (I). 相似文献
8.
A series of mixed-ligand ruthenium(II) complexes of the type [Ru(en)(2)bpy](2+) (bpy=2,2-bipyridine; 1), [Ru(en)(2)phen](2+) (phen=1,10-phenantroline; 2), [Ru(en)(2)IP](2+) (IP=imidazo[4,5-f][1,10]phenanthroline; 3), and [Ru(en)(2)PIP](2+) (PIP=2-phenylimidazo[4,5-f][1,10]phenanthroline; 4) have been isolated and characterized by UV/VIS, IR, and (1)H-NMR spectral methods. The binding of the complexes with calf thymus DNA has been investigated by absorption, emission spectroscopy, viscosity measurements, DNA melting, and DNA photo-cleavage. The spectroscopic studies together with viscosity measurements and DNA melting studies support that complexes 1 and 2 bind to CT DNA (=calf thymus DNA) by groove mode. Complex 2 binds more avidly to CT DNA than complex 1, complexes 3 and 4 bind to CT DNA by intercalation mode, 4 binds more avidly to CT DNA than 3. Noticeably, the four complexes have been found to be efficient photosensitisers for strand scissions in plasmid DNA. 相似文献
9.
Montserrat Barquín María J. González Garmendia Elena Pinilla María R. Torres 《Inorganica chimica acta》2009,362(7):2334-12
By the reactions of Cu(OAc)2 · H2O and Cu(HCOO)2 · 4H2O with 2-(aminomethyl)pyridine in different proportions, the compounds Cu(OAc)2(2-amp) (1), Cu(HCOO)2(2-amp) (2), Cu(HCOO)2(2-amp)1/2 (5), Cu(OAc)2(2-amp)2 · H2O (6) and Cu(HCOO)2(2-amp)2 · H2O (7) were obtained. In 1 the copper shows an elongated rhombic octahedral stereochemistry determined by a 2-amp molecule and two asymmetrical bidentate acetate groups. The hydrogen bonds between the NH2 groups and O atoms yield to the formation of a double chain. Compound 2 instead consists in monodimensional chains of Cu(2-amp)(HCOO) units, with monodentate formate groups, linked by syn-anti bridging formate groups. Sheets are formed by hydrogen bonds between the chains. By crystallization of a solution of 6 in chloroform, CuCl2(2-amp)2 (3) was obtained. It presents a highly distorted square pyramidal geometry around the copper atom. The sheets, formed by the hydrogen bonds between NH2 and Cl, are interpenetrated and shows π stacking. Magnetic properties and EPR spectra for these new compounds have been studied. Also the magnetic behaviour of Cu(OAc)2(2-amp)1/2 (4) is described. 相似文献
10.
Ruthenium(II) bis(2,2″-pyridyl) complexes with bridging ligands: 6,7-dichloro-2,3-di(2-pyridyl)quinoxaline; 2,3-di(2-pyridyl)-quinoxaline; 5-methyl-2,3-di(2-pyridyl) quinoxaline; 6,7-dibenzo-2,3-di(2-pyridyl)quinoxaline have been prepared. The electrochemical and spectroscopic properties of these complexes are reported. The resonance Raman spectroelectrochemical results indicate the presence of oxidation state sensitive marker bands in the resonance Raman spectra of the oxidized complexes. The spectroscopic data for the reduced complexes is similar for all four species. The resonance Raman data for the reduced species are dominated by 2,2″-bipyridyl vibrations. 相似文献
11.
Cis(or trans)-[RuCl2(CO)2(PPh3)2] react with two and one equivalents of AgBF4 to give the recently reported [Ru(CO)2(PPh3)2][BF4]2·CH2Cl2 (1) and novel [RuCl(CO)2(PPh3)2][BF4] · 1/2 CH2Cl2 (2), respectively. Cis-[RuCl2(CO)2(PPh3)2] also reacts with two equivalents of AgBF4 in the presence of CO to give [Ru(CO)3(PPh3)2][BF4]2 (3). Reactions of 1 and 2 with NaOMe and CO at 1 atm produce the carbomethoxy species [Ru(COOMe)2(CO)2(PPh3)2] (4) and [RuCl(COOMe)(CO)2(PPh3)2] (5), respectively. Complex 4 can also be formed from the reaction of 3 with NaOMe and CO. Alternatively, 4 is formed from cis-[RuCl2(CO)2(PPh3)2] with NaOMe and CO at elevated pressure (10 atm); if these reactants are refluxed under 1 atm of CO, [Ru(CO)3(PPh3)2] is the product. The reaction of [RuCl(CO)3(PPh3)2][AlCl4] with NaOMe provides an alternative route to the preparation of 5, but the product is contaminated with [RuCl2(CO)2(PPh3)2]. Compounds 1. 2, 4 and 5 have been characterised by IR, 1H NMR and analysis, whilst the formulation of 3 is proposed from spectroscopic data only. This account also examines the reactivity of [Ru(CO)2(PPh3)2][BF4]2 · CH2Cl2 with NaBH4, conc. HCl, KI and, finally, MeCOONa in the presence of CO. The products of these reactions, namely cis-[RuH2(CO)2(PPh3)2], cis-[RuCl2(CO)2(PPh3)2], cis-[RuI2(CO)2(PPh3)2] and [Ru(OOCMe)2(CO)2(PPh3)2], have been identified by comparison of their spectra with previous literature. 相似文献
12.
Egger A Cebrián-Losantos B Stepanenko IN Krokhin AA Eichinger R Jakupec MA Arion VB Keppler BK 《化学与生物多样性》2008,5(8):1588-1593
The antiproliferative properties of the osmium(II) complexes cis,fac-[Os(II)Cl(2)(DMSO)(3)(L)] and trans,cis,cis-[Os(II)Cl(2)(DMSO)(2)(L)(2)] (L = 1H-pyrazole, 1H-imidazole) were studied in three human cancer cell lines, namely 41M (ovary), SK-BR-3 (breast), and SW480 (colon). Their activities were compared with those of osmium(III) and ruthenium(III) NAMI-A type complexes on HT-29 (colon) and SK-BR-3 cancer cell lines. While IC(50) values of all the Os(II) complexes were found to be >1000 microM in all cell lines, Os and Ru-NAMI-A type complexes showed remarkable antiproliferative activity. The marginal in vitro cytotoxicity of the Os(II) compounds is presumably attributed to their resistance to hydrolysis. However, the Os-NAMI-A complexes, which are also kinetically stable in aqueous solution, showed reasonable antiproliferative activity in vitro when compared with the analogous Ru compounds and with the Os(II)-DMSO-azole species, indicating that hydrolysis might be not a prerequisite for the antitumor activity of Os-NAMI-A type complexes. 相似文献
13.
Hirotaka Nagao Dai Ooyama Toshiyuki Hirano Hiroshi Naoi Megumi Shimada Sachiko Sasaki Noriharu Nagao Masao Mukaida Takao Oi 《Inorganica chimica acta》2001,320(1-2):60-66
Isocyanato and isothiocyanatopolypyridineruthenium complexes, [Ru(NCX)Y(bpy)(py)2]n+ (bpy=2,2′-bipyridine, PY=pyridine; X=O, Y=NO2 for n=0, and Y=py for n=1; X=S, Y=NO2 for n=0, Y=NO for n=2, and Y=py for n=1), were synthesized by the reaction of polypyridineruthenium complexes with potassium cyanate or sodium thiocyanate salt. Isocyanatoruthenium(II) complexes, [Ru(NCO)(NO2)(bpy)(py)2] and [Ru(NCO)(bpy)(py)3]+, react under acidic conditions to form the corresponding ammineruthenium complexes, [Ru(NO)(NH3)(bpy)(py)2]3+. The molecular structures of [Ru(NCO)(bpy)(py)3]ClO4, [Ru(NCS)(NO)(bpy)(py)2](PF6)2 and [Ru(NO)(NH3)(bpy)(py)2](PF6)3 were determined by X-ray crystallography. 相似文献
14.
Benjamin G. Harvey 《Inorganica chimica acta》2006,359(3):839-845
The reactions of RuCl2[P(C6H5)3]3, RuCl2(tmeda)2, and RuCl2(1,5-COD)(tmeda) with polybasic amines such as pyrazole have been studied. From the phosphine complex, a binuclear complex has been isolated in which one pyrazole has been incorporated, while reactions of the latter two with excess pyrazole lead to the replacement of a tmeda ligand by two pyrazoles. 相似文献
15.
Yoshimasa Hoshino Motoki Eto Yasuhiko Yukawa Akira Endo G.P Satô 《Inorganica chimica acta》2004,357(2):600-604
Two mononuclear mixed-ligand ruthenium(III) complexes with oxalate dianion (ox2−) and acetylacetonate ion (2,4-pentanedionate, acac−), K2[Ru(ox)2(acac)] (1) and K[Ru(ox)(acac)2] (2), were prepared as a candidate for a building block. In fact, reaction of complex 2 with manganese(II) sulfate gave a heterometallic tetranuclear complex, TBA[MnII{(μ-ox)RuIII(acac)2}3] (5) in the presence of tetrabutylammonium (TBA) bromide. The 1H NMR, UV-Vis, selected IR and FAB mass spectral data of these complexes are presented. Both mixed-ligand ruthenium(III) complexes gave a Nernstian one-electron reduction step in 0.1 mol dm−3 Na2SO4 aqueous solution on a mercury electrode at 25 °C. Comparison of observed reversible half-wave potentials with calculated values for a series of [Ru(ox)n(acac)3 − n]n− (n=0-3) complexes by using Lever’s ligand electrochemical parameters is presented. 相似文献
16.
Some cobalt carboxylate (both mononuclear as well as binuclear) complexes have been prepared by using hindered hydrotris(3,5-diisopropyl-1-pyrazolyl)borate (TpiPr2) as supporting ligand. The reaction of [TpiPr2Co(NO3)] (2) with sodium benzoate resulted in the formation of acetonitrile coordinated complex [TpiPr2Co(OBz)(CH3CN)] (3) whereas the reaction of 2 with sodium fluorobenzoate gave coordinately unsaturated five coordinate complex of the type [TpiPr2Co(F-OBz)] (4). The oxidation of compound 4 in the presence of 3,5-diisopropylpyrazole resulted in the formation of a unique compound (5) where only one methine carbon of isopropyl group on pyrazole ring of hydrotris(3,5-diisopropyl-1-pyrazolyl)borate oxidized and coordinated with cobalt center. In compound 5, the binding behavior of fluorobenzoate also changes from bidentate to monodentate and the nonbonded oxygen atom formed intramolecular hydrogen bond with the hydrogen atom of the NH fragment of the coordinated . X-ray crystallography and IR studies confirmed the existence of hydrogen bonding in complex 5. The pyrazolato bridged binuclear cobalt(II) complex (6) was prepared by the reaction of hydrated cobalt(II) nitrate, 3,5-diisopropylpyrazole and sodium nitrobenzoate where, each cobalt is four coordinate. The X-ray structure of 6 showed that the NH fragment of terminally coordinated formed intramolecular hydrogen bonding with nonbonded oxygen atom of monodentately coordinated nitrobenzoate. 相似文献
17.
The dinuclear bis(6-X-pyridin-2-olato) ruthenium complexes [Ru2(μ-XpyO)2(CO)4(PPh3)2] (X = Cl (4B) and Br (5B)), [Ru2(μ-XpyO)2(CO)4(CH3CN)2] (X = Cl (6B), Br (7B) and F (8B)) and [Ru2(μ-ClpyO)2(CO)4(PhCN)2] (9B) were prepared from the corresponding tetranuclear coordination dimers [Ru2(μ-XpyO)2(CO)4]2 (1: X = Cl; 2: X = Br) and [Ru2(μ-FpyO)2(CO)6]2 (3) by treatment with an excess of triphenylphosphane, acetonitrile and benzonitrile, respectively. In the solid state, complexes 4B-9B all have a head-to-tail arrangement of the two pyridonate ligands, as evidenced by X-ray crystal structure analyses of 4B, 6B and 9B, in contrast to the head-to-head arrangement in the precursors 1-3. A temperature- and solvent-dependent equilibrium between the yellow head-to-tail complexes and the red head-to-head complexes 4A-7A and 9A, bearing an axial ligand only at the O,O-substituted ruthenium atom, exists in solution and was studied by NMR spectroscopy. Full 1H and 13C NMR assignments were made in each case. Treatment of 1 and 2 with the N-heterocyclic carbene (NHC) 1-butyl-3-methylimidazolin-2-ylidene provided the complexes [Ru2(μ-XpyO)2(CO)4(NHC)], X = Cl (11A) or Br (12A). An XRD analysis revealed the head-to-head arrangement of the pyridonate ligands and axial coordination of the carbene ligand at the O,O-substituted ruthenium atom. The conversion of 11A and 12A into the corresponding head-to-tail complexes was not possible. 相似文献
18.
Ritam Mukherjee 《Inorganica chimica acta》2007,360(11):3633-3636
Titanium(II) solutions, prepared by dissolving titanium wire in triflic acid + HF, contain equimolar quantities of Ti(IV). Treatment of such solutions with excess Fe(III) or Ru(III) complexes yield Ti(IV), but reactions with Ti(II) in excess give Ti(III). Oxidations by (NH3)5Ru(III) complexes, but not by Fe(III) species, are catalyzed by titanium(IV) and by fluoride. Stoichiometry is unchanged. The observed rate law for the Ru(III)-Ti(II)-Ti(IV) reactions in fluoride media points to competing reaction paths differing by a single F−, with both routes involving a Ti(II)-Ti(IV) complex which is activated by deprotonation. It is suggested that coordination of Ti(IV) to TiII(aq) minimizes the mismatch of Jahn-Teller distortions which would be expected to lower the Ti(II,III) self-exchange rate. 相似文献
19.
The first complexes that contain the 2,6-bis(dicyclohexylphosphinomethyl)pyridine ligand (PNP) have been isolated and characterized. The reactions of K4Mo2Cl8, (n-Bu4N)2Re2Cl8 and PdBr2(1,5-COD) afford Mo2Cl4(PNP)(HPCy2) (1), ReCl3(PNP) (2) and PdBr2(PNP) (4), respectively, while from the reaction of PNP with cis-Re2(μ-O2CCH3)2Cl4(H2O)2 the heteromacrocylic dication [Cy2P{CH2pyCH2}2PCy2]2+ has been isolated as its mixed [Cl]−/[ReO4]− salt (3). The reaction of cis-Re2(μ-O2CCH3)2Cl4(H2O)2 with bis(diphenylphosphinomethyl)sulfide (PSP) gives the mononuclear Re(V) complex ReO(OEt)Cl2(PSP) (5) in which the S atom is not coordinated. The structures of 1-5 have been established by X-ray crystallography, that of 5 being the first for a complex of this ligand. 相似文献
20.
A spectroscopic and spectroelectrochemical comparison is made among homo- and heterobimetallic complexes of the form [(bpy)2Ru(BL)Os(byp)2]4+, [(bpy)2Ru(BL)Ru(bpy)2]4+ and [(bpy)2Os(BL)Os(bpy)2]4+ (BL = 2,3,-bis(2′-pyridyl)pyrazzine(dpp),2,3-bis(2′-pyridyl)quinoxaline(dpq) or 2,3-bis(2′-pyridyl)benzoquinoxaline(dpb); bpy = 2,2′-bipyridine). It has been postulated that the spectroscopy of the mixed-metal bimetallic complexes bridged by polyazine bridging ligands can be assigned by comparison to those of the homobimetallic analogs. We have in hand a unique series of complexes where such a postulate can be tested. Utilizing the visible spectra of the homobimetallic Os,Os and Ru,Ru systems, we have been able to generate the spectra of the mixed-metal complexes. Some differences have been seen, particularly in the energy of the Os → dpp 3MLCT. Oxidative spectroelectrochemistry studies on the homobimetallic ruthenium or osmium based systems indicate that upon complete oxidation of both metal centers, transitions in the visible are lost. Hence, partial oxidation of the ruthenium based homobimetallics and Os, Ru mixed-metal bimetallics allows for the direct comparison of the spectroscopic character of the one remaining ruthenium chromophore within these mixed-valence systems. Oxidation to form the Os(III)/Ru(II) species and the Ru(III)/Ru(II) species resulted in similar spectra. This establishes further that the visible spectroscopy of mixed-metal systems of this nature can be accurately interpreted by comparison to the homobimetallic analogs. 相似文献