Reactions of dimethyl(dimethylsulphoxide)pentamethylcyclopentadienyl-rhodium and -irridum with acids

The complexes [C₅Me₅MMe₂(Me₂SO)] (Ia, M = Rh; Ib, M = Ir) react with p-toluenesulphonic acid in acetonitrile to give [C₅Me₅MMe(Me₂SO)(MeCN)]⁺, (II), and with trifluoroacetic acid to give first [C₅Me₅MMe(Me₂SO)(O₂CCF₃)] and then [C₅Me₅M(Me₂SO)(O₂CCF₃)₂]. Complexes II react with halide (X^?) to give the halomethyl complexes [C₅Me₅MMe(X)(Me₂SO)]. The IR, far-IR, ¹H and ¹³C NMR spectra are all in agreement with structures proposed.     

Mono- and binuclear ruthenium(II) trifluoroacetato complexes containing monodentate co-ligands

Summary The syntheses of new dinuclear and mononuclear complexes of Ru^II trifluoroacetate containing monodentate co-ligands, namely [Ru₂(-O₂CCF₃)₄L₂] (L = py, 2-Mepy or 3-Mepy); trans-[Ru(O₂CCF₃)₂L₄] (L = 2-Mepy or 3-Mepy); [Ru(O₂CCF₃)(PPh₃)₄](O₂CCF₃) and [Ru(O₂CCF₃)₂(CO)(MPh₃)₃] (M = P or As), are described. The complexes have been characterized by physical and electrochemical studies.     

Coordination,oligomerisation and transfer hydrogenation of acetylenes by some ruthenium and osmium carboxylates: Crystal and molecular structures of bis(trifluoroacetato)carbonyl-(methanol) bis(triphenylphosphine)ruthenium(II) and (1,4-diphenylbut-1-en-3-yn-2-yl)trifluoroacetato-(carbonyl) bis(triphenylphosphine)ruthenium(II)

The hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] (M = Ru or Os) react with disubstituted acetylenes PhCCPh and PhCCMe to afford vinylic products [M{C(Ph)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] and [M{C(Ph)CHMe}(O₂CCF₃)(CO) (PPh₃)₂]/[M{C(Me)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] respectively. Acidolysis of these products with trifluoroacetic acid in cold ethanol liberates cis-stilbene and cis-PhHCCHMe respectively thus establishing the cis-stereochemistry of the vinylic ligands. The complexes [M(O₂CCF₃)₂(CO)(PPh₃)₂] formed during the acidolysis step undergo facile alcoholysis followed by β-elimination of aldehyde to regenerate the parent hydrides [MH(O₂CCF₃)(CO)(PPh₃)₂] and thereby complete a catalytic cycle for the transfer hydrogenation of acetylenes. The molecular structure of the methanol-adduct intermediate, [Ru(O₂CCF₃)₂(MeOH)(CO)(PPh₃)₂] has been determined by X-ray methods and shows that the coordinated methanol is involved in H-bonding with the monodentate trifluoroacetate ligand [MEO-H---OC(O)CF₃; O...O = 2.54 Å]. The hydrides [MH(O₂CCF₃)(CO) (PPh₃)₂]react with 1,4-diphenylbutadiyne to afford the complexes [M{C(CCPh)CHPh} (O₂CCF₃)(CO)(PPh₃)₂]. The ruthenium product, which has also been obtained by treatment of [RuH(O₂CCF₃)(CO)(PPh₃)₂] with phenylacetylene, has been shown by X-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand. The osmium complexes [Os(O₂CCF₃)₂(CO)(PPh₃)₂], [OsH(O₂CCF₃)(CO)(PPh₃)₂] and [Os{C(CCPh)CHPh}(O₂CCF₃)(CO)(PPh₃)₂] all serve as catalysts for the oligomerisation of phenylacetylene. Acetylene reacts with [Ru(O₂CCF₃)₂(CO)(PPh₃)₂] in ethanol to afford the vinyl complex [Ru(CHCH₂)(O₂CCF₃)(CO)(PPh₃)₂].     

Coordination,Oligomerisation and Transfer Hydrogenation of Acetylenes by Some Ruthenium and Osmium Carboxylato Complexes: Crystal and Molecular Structure of (1,4-Diphenylbut-1-en-3-yn-2-yl)trifluoroacetato(carbonyl) bis(triphenylphosphine)ruthenium(II)

The complexes (MH(O₂CCF₃) (CO) (PPh₃)₂] and (M(O₂CCF₃)₂(CO)(PPh₃)₂] (M = Ru or Os) react with terminal and internal acetylenes to afford oligomerisation and hydrogenation products, respectively, together with vinylic complexes, including the ruthenium species [Ru(C₄HPh₂)(O₂CCF₃)(CO) (PPh₃)₂], which has been shown by x-ray diffraction methods to contain a 1,4-diphenylbut-1-en-3-yn-2-yl ligand.     

Synthesis,spectroscopic characterization,in vitro cytotoxic and structure activity relationships of some mononuclear Ru(II) complexes

New mononuclear Ru(II) complexes [Ru(A)₂(B)]²⁺, where A?=?2,2′-bipyridine/1,10-phenanthroline and B?=?3,4,5-tri-OCH₃-DPC, 4-CH₃-DPC, 4-N(CH₃)₂-DPC, 4-NO₂-DPC, N-BITSZ, PTSZ and PINH, were prepared and characterized by spectroscopic methods. The in vitro cytotoxic activities of the complexes and their corresponding ligands were investigated against the human cancer T-lymphocyte cell lines molt 4/c8 and CEM and the murine tumor leukemia cell line L1210, human promyelocytic leukemia cells (HL-60) and Bel-7402 liver cancer cells by MTT assay. The complexes [Ru(A)₂(B)]²⁺ (A?=?1,10-phenanthroline, B?=?3,4,5-tri-OCH₃-DPC) exerts rather more potent activities against all of these cell lines, especially for CEM and L1210. Ru complexes and structure–activity relationships and anticancer mechanisms are also discussed.     

Reaction of alkenyl carbonyl ruthenium(II) complexes with t-butyl isocyanide. Synthesis of η1-acylruthenium(II) complexes by intramolecular CO insertion

Reaction of Ru(CO)Cl(CHCHR)(PPh₃)₂ or Ru(CO)Cl(CHCHR)(PPh₃)₂L (L = py, Me₂Hpz) with 1 equivalent of t-butyl isocyanide gives the alkenyl derivatives Ru(CO)Cl(CHCHR)(PPh₃)₂(t-BuNC). When an excess of isocyanide is used, further reaction results in intramolecular CO insertion to yield η¹-acyl complexes [Ru(COCHCHR) (t-BuNC)₃(PPh₃)₂]Cl. Related complexes were obtained from [Ru(CO)(CHCHR)(MeCN)₂(PPh₃)₂]PF₆ and an excess of isocyanide.     

Complexes with metal-carbon bonds,part IV(1). Binuclear diarylplatinum(III) complexes. Long-rangetrans-effect in platinum-platinum bonded compounds containing methyl and aryl groups

Summary The platinum-platinum bonded [PtR₂(OAc)L¹]₂ complexes (R = Ph, L¹ = Et₂S, n-Pr₂S; R =p-tolyl, L¹ = Et₂S), have been prepared by oxidising [PrR₂L¹ ]₂ with AgOAc or Tl(OAc)₃. The sulphide ligand is replaced by weak ligands to give [PtR₂(OAc)L²]₂ (L² = PhNH₂, 4-picoline, CI^–) whereas PEt₃ or P(OMe)₃ react to give Pt₂R₄(OAc)₂(PR₃)(R = Et, OMe). The methyl platinum analogues could also be prepared. Similar complexes Pt₂Me₄(O₂CCF₃)₂L³ (L³ = Et₂S₁ 4-picoline) were obtained by the reaction of Hg(O₂CCF₃)₂ with [PtMe₂(O₂CCF₃)L³]₂.³¹p,¹H and¹³C n.m.r. of the complexes are reported.     

Tricarbonyl Derivatives of Manganese(I) with Diphosphinite Chelating Ligands

Reaction of [MnBr(CO)₃L] [L = Ph₂POCH₂CH₂OPPh₂, L¹ , {(CH₃)₂CH}₂POCH₂CH₂OP{CH(CH₃)₂}₂, L² ] with AgO₃SCF₃ and AgO₂CCF₃ in dichloromethane afforded the new complexes [Mn(O₃SCF₃)(CO)₃L] and [Mn(O₂CCF₃)(CO)₃L], respectively. Substitution of O₃SCF₃ resulted in the new species [Mn(SCN)(CO)₃L], [Mn(NCCH₃)(CO)₃L](O₃SCF₃) and, in the case of L² , [Mn(CN)(CO)₃L²]. By contrast, any attempt to displace the O₂CCF₃ ligand in the same way was unsuccessful. After maintaining for some days the complex [Mn(CH₃CN)(CO)₃L¹](O₃SCF₃) in dichloromethane at room temperature, the new complex [MnCl(CO)₃L¹] was formed. All the new complexes were characterized by elemental analysis, mass spectrometry and IR and NMR spectroscopies. In the case of [Mn(O₃SCF₃)(CO)₃L¹], [Mn(O₂CCF₃) (CO)₃L¹], [MnCl(CO)₃L¹], [Mn(CH₃CN) (CO)₃L²] (O₃SCF₃), [Mn(CN)(CO)₃L²] and [Mn(O₂CCF₃)(CO)₃L²], together with the previously synthesized complex [MnBr(CO)₃L²], suitable crystals for X‐ray structural analysis were isolated. In all of them the Mn atom adopts six‐coordination by bonding to the three CO ligands, the two P atoms of L and either one C atom (CN), one oxygen atom (O₂CCF₃, O₃SCF₃), one N atom (CH₃CN, SCN) or the halogen atom (Cl, Br).     

Bonding modes of nitrite and nitrate in palladium(II) and platinum(II) complexes

The crystal structures of the well-known complexes, [(Me₄en)M(II)X₂] (Me₄en?=?N,N,N??,N??-tetramethylethylenediamine; M(II)?=?Pd(II) or Pt(II); X ^??=?NO₂ ^? or NO₃ ^?) have been determined. For [(Me₄en)Pd(NO₂)₂] and [(Me₄en)Pt(NO₂)₂], the nitrite anion acts as a monodentate N-donor ligand in the solid state. In contrast, for [(Me₄en)Pd(ONO₂)(O₂NO)], the two nitrate anions act as a monodentate O-donor (ONO₂) and a bidentate O,O??-donor (O₂NO). Recrystallization of [(Me₄en)Pt(NO₃)₂] from Me₂SO yields the Me₂SO adduct with a monodentate O-donor nitrate and a counteranionic nitrate, [(Me₄en)Pt(ONO₂)(S-Me₂SO)](NO₃). The solution behavior of these complexes, including the equilibrium between coordinated and free Me₂SO, has been investigated.     

Synthesis and spectroscopic studies of some halogen-dimethylsulphoxide/tetramethylenesulphoxide-ruthenium(II) and ruthenium(III) complexes with 2-aminobenzimidazole

Synthesis and characterization of seven ruthenium(II) and ruthenium(III) complexes of sulphoxide with 2-aminobenzimidazole are reported. Three different formulations exist; [cis-RuCl₂(SO)₃(2-ABZ)]; [trans-RuCl₂(SO)₃)(2-ABZ)]; and [trans-RuCl₄(SO)(2-ABZ (where SO?=?dimethylsulphoxide(DMSO)/tetramethylenesulphoxide(TMSO); 2-ABZ?=?2-aminobenzimidazole). These complexes are characterized by elemental analysis, conductivity magnetic susceptibility, ¹H-NMR, ¹³C{¹H}-NMR and electronic spectroscopy.     

Synthesis, characterization and DNA-binding characteristics of Ru(II) molecular light switch complexes

A series of four polypyridyl Ru(II) complexes such as [Ru(L)₄(PIP)]²⁺ and [Ru(L)₄PPIP]²⁺ where L is 4-amino pyridine and Pyridine (PIP?=?2-phenylimidazo[4,5-f] [1, 10] phenanthroline), (PPIP?=?2-(4??-phenoxy-phenyl) imidazo[4,5-][1, 10]phenanthroline) have been synthesized and characterized by elemental analysis, physicochemical methods such as UV?Cvis, IR and NMR spectroscopic techniques. The DNA-binding behavior of these complexes was investigated by electronic absorption titrations, fluorescence spectroscopy, viscosity measurements and salt-dependent studies. The experimental results indicate that all these complexes can bind to DNA through an intercalation mode, the DNA-binding affinities of these complexes follow the order [Ru(4-APy)₄(PPIP)]²⁺(1)?>?[Ru(Py)₄PPIP]²⁺(2)?>?[Ru(4-APy)₄(PIP)]²⁺(3)?>?[Ru(Py)₄PIP]²⁺(4). Noticeably, these complexes have been found to be efficient photosensitisers for strand scissions in plasmid DNA. Further, all four complexes screened for their antimicrobial activity indicate that the complexes show appreciable activity against Escherichia coli and Neurospora Crassa. In addition, in the presence of Co²⁺, the emission of DNA-[Ru(L₄)PPIP/PIP]²⁺ can be quenched and recovered by the addition of EDTA, which exhibited the DNA ??light switch?? properties.     

Dimeric ruthenium(II) complexes containing bridging carboxylato and aquo ligands. The crystal structure of μ-aquobis(μ-trifluoroacetato)bis[(η4-cycloocta-1,5-diene)(trifluoroacetato)ruthenium(II)]

Protonation of [Ru(μ³-C₃H₄R)₂(C₈H₁₂)] (R = H, Me; C₈H₁₂ = cycloocta-1,5-diene) with haloacetic acids gives the dimers [Ru₂(C₈H₁₂)₂(O₂CR′)₂(μ-O₂CR′)₂-(μ-OH₂)] (R′ = CF₃, CCl₃ and CH₂Cl), which are precursors for a range of monomeric and dimeric ruthenium carboxylate complexes. The complex [Ru₂(C₈H₁₂)₂-(O₂CCF₃)₂(μ-O₂CCF₃)₂(μ-OH₂)] has been characterized by X-ray analysis.     

Spectroscopic characterization and electrochemical studies of ruthenium(II) carbonyl complexes containing bidentate Schiff bases and triphenylphosphine or a nitrogen heterocycle

Reactions of ruthenium(II) carbonyl complexes of the type [RuHCl(CO)(PPh₃)₂(B)] [B?=?PPh₃, pyridine (py), piperidine (pip) or morpholine (mor)] with bidentate Schiff base ligands derived from the condensation of 2-hydroxy-1-naphthaldehyde with aniline, o-, m- or p-toluidine in a 1?:?1 mol ratio in benzene resulted in the formation of complexes formulated as [RuCl(CO)(L)(PPh₃)(B)] [L?=?bidentate Schiff base anion, B?=?PPh₃, py, pip, mor]. The complexes were characterized by analyses, IR, electronic and ¹H NMR spectroscopy, and cyclic voltammetric studies. In all cases, the Schiff bases replace one molecule of phosphine and a hydride ion from the starting complexes, indicating that Ru–N bonds in the complexes containing heterocyclic nitrogenous bases are stronger than the Ru–P bond to PPh₃. Octahedral geometry is proposed for the complexes.     

Heterodinuclear Ruthenium(II) Complexes of the Bridging Ligand 1,6,7,12‐Tetraazaperylene with Iron(II), Cobalt(II), Nickel(II), as well as Palladium(II) and Platinum(II)

The first heterodinuclear ruthenium(II) complexes of the 1,6,7,12‐tetraazaperylene (tape) bridging ligand with iron(II), cobalt(II), and nickel(II) were synthesized and characterized. The metal coordination sphere in this complexes is filled by the tetradentate N,N′‐dimethyl‐2,11‐diaza[3.3](2,6)‐pyridinophane (L‐N₄Me₂) ligand, yielding complexes of the general formula [(L‐N₄Me₂)Ru(µ‐tape)M(L‐N₄Me₂)](ClO₄)₂(PF₆)₂ with M = Fe {[ 2 ](ClO₄)₂(PF₆)₂}, Co {[ 3 ](ClO₄)₂(PF₆)₂}, and Ni {[ 4 ](ClO₄)₂(PF₆)₂}. Furthermore, the heterodinuclear tape ruthenium(II) complexes with palladium(II)‐ and platinum(II)‐dichloride [(bpy)₂Ru(μ‐tape)PdCl₂](PF₆)₂ {[ 5 ](PF₆)₂} and [(dmbpy)₂Ru(μ‐tape)PtCl₂](PF₆)₂ {[ 6 ](PF₆)₂}, respectively were also prepared. The molecular structures of the complex cations [ 2 ]⁴⁺ and [ 4 ]⁴⁺ were discussed on the basis of the X‐ray structures of [ 2 ](ClO₄)₄ · MeCN and [ 4 ](ClO₄)₄ · MeCN. The electrochemical behavior and the UV/Vis absorption spectra of the heterodinuclear tape ruthenium(II) complexes were explored and compared with the data of the analogous mono‐ and homodinuclear ruthenium(II) complexes of the tape bridging ligand.     

The Influence of N‐Heterocyclic Carbenes (NHC) on the Reactivity of [Ru(NHC)4H]+ With H2, N2, CO and O2

The five‐coordinate ruthenium N‐heterocyclic carbene (NHC) hydrido complexes [Ru(IiPr₂Me₂)₄H][BAr^F₄] ( 1 ; IiPr₂Me₂=1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene; Ar^F=3,5‐(CF₃)₂C₆H₃), [Ru(IEt₂Me₂)₄H][BAr^F₄] ( 2 ; IEt₂Me₂=1,3‐diethyl‐4,5‐dimethylimidazol‐2‐ylidene) and [Ru(IMe₄)₄H][BAr^F₄] ( 3 ; IMe₄=1,3,4,5‐tetramethylimidazol‐2‐ylidene) have been synthesised following reaction of [Ru(PPh₃)₃HCl] with 4–8 equivalents of the free carbenes at ambient temperature. Complexes 1 – 3 have been structurally characterised and show square pyramidal geometries with apical hydride ligands. In both dichloromethane or pyridine solution, 1 and 2 display very low frequency hydride signals at about δ ?41. The tetramethyl carbene complex 3 exhibits a similar chemical shift in toluene, but shows a higher frequency signal in acetonitrile arising from the solvent adduct [Ru(IMe₄)₄(MeCN)H][BAr^F₄], 4 . The reactivity of 1 – 3 towards H₂ and N₂ depends on the size of the N‐substituent of the NHC ligand. Thus, 1 is unreactive towards both gases, 2 reacts with both H₂ and N₂ only at low temperature and incompletely, while 3 affords [Ru(IMe₄)₄(η²‐H₂)H][BAr^F₄] ( 7 ) and [Ru(IMe₄)₄(N₂)H][BAr^F₄] ( 8 ) in quantitative yield at room temperature. CO shows no selectivity, reacting with 1 – 3 to give [Ru(NHC)₄(CO)H][BAr^F₄] ( 9 – 11 ). Addition of O₂ to solutions of 2 and 3 leads to rapid oxidation, from which the Ru^III species [Ru(NHC)₄(OH)₂][BAr^F₄] and the Ru^IV oxo chlorido complex [Ru(IEt₂Me₂)₄(O)Cl][BAr^F₄] were isolated. DFT calculations reproduce the greater ability of 3 to bind small molecules and show relative binding strengths that follow the trend CO ? O₂ > N₂ > H₂.     

Chemistry of ruthenium in N2P2X2 (X = Cl, Br) coordination sphere: Synthesis, characterization and reactivities

Reaction of 2-(phenylazo)pyridine (pap) with [Ru(PPh₃)₃X₂] (X = Cl, Br) in dichloromethane solution affords [Ru(PPh₃)₂(pap)X₂]. These diamagnetic complexes exhibit a weakdd transition and two intense MLCT transitions in the visible region. In dichloromethane solution they display a one-electron reduction of pap near − 0.90 V vs SCE and a reversible ruthenium(II)-ruthenium(III) oxidation near 0.70 V vs SCE. The [Ru^III(PPh₃)₂(pap)Cl₂]⁺ complex cation, generated by coulometric oxidation of [Ru(PPh₃)₂(pap)Cl₂], shows two intense LMCT transitions in the visible region. It oxidizes N,N-dimethylaniline and [Ru^II(bpy)₂Cl₂] (bpy = 2,2′-bipyridine) to produce N,N,N′,N′-tetramethylbenzidine and [Ru^III(bpy)₂Cl₂]⁺ respectively. Reaction of [Ru(PPh₃)₂(pap)X₂] with Ag⁺ in ethanol produces [Ru(PPh₃)₂(pap)(EtOH)₂]²⁺ which upon further reaction with L (L = pap, bpy, acetylacetonate ion(acac⁻) and oxalate ion (ox²⁻)) gives complexes of type [Ru(PPh₃)₂(pap)(L)]ⁿ⁺ (n = 0, 1, 2). All these diamagnetic complexes show a weakdd transition and several intense MLCT transitions in the visible region. The ruthenium(II)-ruthenium(III) oxidation potential decreases in the order (of L): pap > bpy > acac⁻ > ox²⁻. Reductions of the coordinated pap and bpy are also observed.     

Ruthenium carbonyl derivatives of N-salicylidene-2-hydroxyaniline

The ruthenium tricarbonyl derivative [Ru(CO)₃(sha)] (1), was synthesized from reaction of [Ru₃(CO)₁₂] with N-salicylidene-2-hydroxyaniline (shaH₂) Schiff base. The corresponding reactions of the ruthenium cluster with shaH₂ in presence of a secondary ligand L,L?=?pyridine and triphenyl phosphine resulted in the formation of the dicarbonyl derivatives [Ru(CO)₂(shaH₂)(L)] (2, 3). In the presence of L?=?2-aminobenzimidazole or thiourea, two complexes [Ru(CO)₂(sha)(L)] (4, 5) were formed and the shaH₂ ligand bonded to ruthenium oxidatively. The bipyridine(bpy) derivative had the molecular formula [Ru(CO)₂(shaH)(bpy)] (6), with shaH coordinated bidentate. All complexes were characterized by elemental analysis and mass, IR, ¹H NMR and UV–Vis spectroscopy. The spectroscopic studies of these complexes revealed several structural arrangements and different tautomeric forms.     

Synthesis and properties of pentamethylmetallocene derivatives Cp*MCp (M = Ru, Fe). Crystal structure of the salt [CpRuC5Me4CH2+OC6H2(NO2)3-]

Photolysis of a solution of Cp*RuCp (1) in CF₃CO₂H generates salt [CpRu(C₅Me₄CH₂)]-(O₂CCF₃)(2 • O₂CCF₃). The reaction of compound 1 with oleum at 20 °C through the intermediate dication [η⁵-(CH₂C₅Me₄)Ru(μ:η⁵,ν⁵-C₅H₄C₅H₅)Ru(C₅Me₄CH₂)-η⁶]²⁺ leads to the triply charged cation η⁷CH₂)₂C₅Me₃Ru(μη⁵,η⁵-C₅H₄C₅H₄)Ru(C₅Me₄CH₂)-η⁶]³⁺. Synthesis of pentamethylmetallocene derivatives CpMC₅Me₄X (M = Ru, Fe; X = CHO, CH₂OH, CH₂An) has been accomplished. The reactions of 1-hydroxymethyl-2,3,4,5-tetramethylruthenocene with acids CF₃CO₂H, HBF₄, CF₃CO₂H/NaB[C₆H₃(CF₃)₂]₄, and picric acid C₆H₂(NO₂)₃OH afforded salts 2•X (X = CF₃CO₂, BF₄, B[C₆H₃(CF₃)₂]₄), and (2,3,4,5-tetram ethylruthenocenyl)methyl picrate [CpRu(C₅Me₄CH₂)-η⁶][(C₆H₂(NO₂)₃O] (2•C₆H₂(NO₂)₃O). Structure of the latter was characterized by single crystal X-ray diffraction.     

Improved syntheses of Ru(CO)2 (O3SCF3)2 (bidentate) complexes and their conversion into new [Ru(CO)2 (bidentate)2]2+ complexes

Reaction of the complexes Ru(CO)₂Cl₂L [L = 2,2′-bipyridyl (bpy) or 1,10-phenanthroline (phen)] with trifluoromethanesulphonic acid under carefully controlled conditions yields Ru[cis-(CO)₂] [cis-(O₃SCF₃)₂] (bidentate complexes. From reactions of the trifluoromethanesulphonates with the appropriate bidentate ligands, the new complexes [cis-Ru(CO)₂-L(L′)]²⁺ (L as above; L′ = 4,4′-dimethyl-2,2′-bipyridyl or 4,4′-diisopropyl-2,2′-bipyridyl) as well as the known [_cis-Ru(CO)₂L₂]²⁺ and [cis-Ru(CO)₂bpy(phen)]²⁺ have been prepared.     

Synthesis and characterization of transition metal complexes of a new bidentate ligand {2-(diphenylphosphino)ethyl}benzylamine

A new bidentate ligand {2-(diphenylphosphino)ethyl}benzylamine(DPEBA) was synthesized and characterized based on the IR, mass and ¹H, ¹³C and ³¹P NMR spectra. Various complexes of platinum group metal ions and Ni(II) and Co(II) ions with the ligand were synthesized. Reaction of RuCl₂(PPh₃)₃ or RuCl₂(Me₂SO)₄ with the ligand DPEBA, resulted in formation of a penta-coordinate, Ru(II) species of the composition [RuCl(DPEBA)₂]Cl. Carbonylation of [RuCl(DPEBA)₂]Cl gave an octahedral carbonyl complex of the type [RuCl(CO)(DPEBA)₂]Cl. The reaction of RuCl₃·3H₂O or RuCl₃(AsPh₃)₂MeOH with a twofold excess of the ligand gave an octahedral Ru(III) cationic species [Ru(DPEBA)₂Cl₂]Cl. Carbonylation of the Ru(III) complex gave rise to a carbonyl complex [RuCl(CO)(DPEBA)₂]Cl₂. The ligand DPEBA reacts with cobalt(II) chloride in methanol to give the 1 : 1 complex [Co(DPEBA)Cl₂]. A series of Rh(I) complexes [Rh(DPEBA)₂Cl], [ RhCl(CO)(DPEBA)] and [Rh(DPEBA)₂]Cl were synthesized by the reaction of DPEBA with RhCl(PPh₃)₃, RhCl(CO)(PPh₃)₂ and [Rh(COD)Cl]₂, respectively. Reaction of [Ir(COD)Cl]₂ and IrCl(CO)(PPh₃)₂ with the ligand DPEBA, gave the square-planar complexes [Ir(DPBA)₂]Cl and [Ir(DPEBA)(CO)Cl], respectively. Octahedral cationic complexes of the type [M(DPEBA)₂Cl₂]Cl (M = Rh(III), Ir(III)) were synthesized by the reaction of the ligand DPEBA and rhodium and iridium trichlorides. Reaction of NiCl₂·6H₂O with DPEBA in 1 : 2 molar equivalents, in boiling butanol gave an octahedral neutral complex [Ni(DPEBA)₂Cl₂] which readily rearranges to the square-planar complex [Ni(DPEBA)₂]Cl₂ in methanol. Reaction of Pd(II) and Pt(II) chlorides with DPEBA gave square-planar, cationic complexes of the type [M(DPEBA)₂Cl]Cl (M = Pd, Pt). All the complexes were characterized on the basis of their analytical and spectral data.