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.     

Chains,helices, sheets and unusual 3D nets: Diverse structures of the flexible,ditopic ligand 1,2-bis(3-(4-pyridyl)pyrazolyl)ethane

The flexible ditopic ligand 1,2-bis(3-(4-pyridyl)pyrazol-1-yl)ethane (L^4Et) displays remarkable versatility in the complexes that it forms with transition metals with products ranging from 1D chains to interpenetrating 3D networks. The L^4Et ligand itself crystallises in the space group P2₁, adopting a helical twist, although it is found in a variety of other conformations in its complexes. Coordination polymers containing the L^4Et ligand vary from almost straight, parallel 1D chains of [Ag₂(L^4Et)₂(ClO₄)₂(DMF)]·DMF (1), through interdigitating helical complexes containing tetrahedral Zn(II), [Zn(NCS)₂(L^4Et)]·DMF·H₂O (2) to 2D sheets of [Cu(L^4Et)₂(H₂O)₂](PF₆)₂·xH₂O (3) and the three-fold interpenetrating 3D network of [Co(L^4Et)₂(NCS)₂] (4). The 3D network adopts an unusual 3D 4-connected dmp (6⁵.8) topology. Dimensionality can be limited by the use of chelating co-ligands, demonstrated by the formation of the dinuclear complex [{Cu(py-2,6-CO₂)(H₂O)}₂(L^4Et)] (5).     

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].     

Syntheses of platinum(II) complexes of cyclo-octenyl group and isolation of a self-assembled oxo-bridged macrocyclic complex [Pt4(Spy)4(C8H12-O-C8H12)2]

Reactions of [Pt₂(μ-Cl)₂(C₈H₁₂OMe)₂] (1) (C₈H₁₂OMe = 8-methoxy-cyclooct-4-ene-1-yl) with various anionic chalcogenolate ligands have been investigated. The reaction of 1 with Pb(Spy)₂ (HSpy = pyridine-2-thiol) yielded a binuclear complex [Pt₂(Spy)₂(C₈H₁₂OMe)₂] (2). A trinuclear complex [Pt₃(Spy)₄(C₈H₁₂OMe)₂] (3) was isolated by a reaction between 2 and [Pt(Spy)₂]_n. The reaction of 1 with HSpy in the presence of NaOMe generated 2 and its demethylated oxo-bridged tetranuclear complex [Pt₄(Spy)₄(C₈H₁₂-O-C₈H₁₂)₂] (4). Treatment of 1 with ammonium diisopropyldithiophosphate completely replaced C₈H₁₂OMe resulting in [Pt(S₂P{OPrⁱ}₂)₂] (5), whereas non-rigid 5-membered chelating ligand, Me₂NCH₂CH₂E⁻, produced mononuclear complexes [Pt(ECH₂CH₂NMe₂)(C₈H₁₂OMe)] (E = S (6), Se (7)). These complexes have been characterized by elemental analyses, NMR (¹H, ¹³C{¹H}, ¹⁹⁵Pt{¹H}) and absorption spectroscopy. Molecular structures of 2, 3, 4, 5 and 7 were established by single crystal X-ray diffraction analyses. Thermolysis of 2, 6 and 7 in HDA gave platinum nanoparticles.     

Reactivity and improved synthesis of aquotris(dimethylsulfoxide)bis-(trifluoroacetato)ruthenium(II)

Reaction of [Ru(Me₂SO)₃(O₂CCF₃)₂(H₂O)] with triphenylphosphine and triphenylarsine gives complexes of the type [Ru(Me₂SO)(O₂CCF₃)₂(EPh₃)₂] (where E?=?P or As) in which there is a partial substitution of dimethylsulfoxide. Reaction with unidentate N donors resulted in [Ru(O₂CCF₃)₂L₄] (where L?=?pyridine, imidazole, benzimidazole); reaction with diimines yielded [Ru(L–L)₃](O₂CCF₃)₂ (where L–L?=?2,2′-bipyridyl, 1,10-phenanthroline). All complexes have been characterized by elemental analysis, conductivity measurements, IR and ¹H NMR spectroscopy.     

Complexes with metal-carbon bonds,part III(1). Preparation and properties of binuclear diarylplatinum(II) compounds

Summary Reaction ofcis-PtCl₂(R₂S)₂, where R=Et, n-Pr or i-Pr, with an excess of PhLi orp-tolylLi in ether yielded the dimeric [PtR₂(R₂S)]₂ complexes where R=Ph orp-tolyl. Usingtrans-PtCl₂(R₂S)₂ under the same conditions with PhLi, both [PtPh₂(Et₂S)]₂ and PtPh₂(Et₂S)₂ were isolated.The dimericcis-[PtR₂(Et₂S)]₂ complexes reacted with a range of neutral ligands to give PtR₂L₂ where L=Et₂S, Me₂S, PPh₃, t-BuNC, 0.5 (bipyridine) or pyridine. With CO, thecis-PtR₂(Et₂S)(CO) compounds were formed. Thecis-Pt(C₆F₅)₂(Et₂S)₂ complex reacted stepwise with PPh₃ and both Pt(C₆F₅)₂(Et₂S)(PPh₃) and Pt(C₆F₅)₂(PPh₃)₂ were isolated.     

Synthesis and study of Cu<Superscript>II</Superscript> complex with nitroxide,a jumping crystal analog

We synthesized 1-ethylimidazolyl-substituted nitronyl nitroxides, i.e., 2-(1-ethylimidazol-4-yl)- (L^4Et) and 2-(1-ethylimidazol-5-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole 3-oxide-1-oxyl (L^5Et). The stable radical L^5Et is an ethyl analog of 2-(1-methylimidazol-5-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole 3-oxide-1-oxyl (L^5Me) described earlier, the reaction of which with Cu(hfac)₂ (hfac is 1,1,1,5,5,5-hexafluoropentane-2,4-dionate) leads to the formation of the [Cu(hfac)₂(L^5Me)₂] jumping crystals. The reaction of Cu(hfac)₂ with L^5Et with reagent ratios 1: 2 and 1: 1 yields heterospin complexes [Cu(hfac)₂(L^5Et)₂] and [Cu(hfac)₂L^5Et]₂, respectively. X-ray diffraction study of the mononuclear complex [Cu(hfac)₂(L^5Et)₂] determined that the compound has a packing similar to that of jumping crystals studied earlier, with the only difference being that the O...O contacts between neigh- boring nitroxide groups were found to be 0.3—0.5 Å longer than in [Cu(hfac)₂(L^5Me)₂]. As a result of the lengthening of these contacts, [Cu(hfac)₂(L^5Et)₂] crystals lack chemomechanical activi- ty. We found that when cooling crystals of binuclear complex [Cu(hfac)₂L^5Et]₂ below 50 K, the antiferromagnetic exchange between unpaired electrons of the >N—?O groups of neighboring molecules leads to the full spin-pairing of the nitroxides, with only the Cu²⁺ ions contributing to the residual paramagnetism of the compound.     

Nitridorhenium(V) Complexes with 1,3‐Dialkyl‐4,5‐dimethylimidazole‐2‐ylidenes

The nitridorhenium(V) complexes [ReNCl₂(PR₂Ph)₃] (R = Me, Et) react with the N‐heterocyclic carbenes (NHC) 1,3‐diethyl‐4,5‐dimethylimidazole‐5‐ylidene (L^Et) or 1,3,4,5‐tetramethylimidazole‐2‐ylidene (L^Me) in absolutely dry THF under complete replacement of the equatorial coordination sphere. The resulting [ReNCl(L^R)₄]⁺ complexes (L^R = L^Me, L^Et) are moderately stable as solids and in solution, but decompose in hot methanol under formation of [ReO₂(L^R)₄]⁺ complexes. With 1,3‐diisopropyl‐4,5‐dimethylimidazole‐5‐ylidene (L^i‐Pr), the loss of the nitrido ligand and the formation of a dioxo species is more rapid and no nitridorhenium intermediate could be isolated. The Re‐C bond lengths in [ReNCl(L^Et)₄]Cl of approximately 2.195Å are relatively long and indicate mainly σ‐bonding in the electron‐deficient d² system under study. The hydrolysis of the nitrido complexes proceeds via the formation of [ReO₃N]^2? anions as could be verified by the isolation and structural characterization of the intermediates [{ReN(PMe₂Ph)₃}{ReO₃N}]₂ and [{ReN(OH₂)(L^Et)₂}₂O][ReO₃N].     

Synthesis and structures of zirconium(IV) hydrogensulfato and carboxylato complexes with Kläui’s oxygen tripodal ligand

Interaction of [L_OEtZrF₃] ( = [Co(η⁵-C₅H₅){P(O)(OEt)₂}₃]⁻) (1) with 3 equivalents of bis(trimethylsilyl) sulfate afforded the Zr^IV hydrogensulfato complex [(L_OEt)₂Zr₂(SO₄)₂(HSO₄)₂] (2) that reacted with Et₃N to give [Et₃NH][L_OEtZr(H₂O)(SO₄)₂] (3). Treatment of complex 1 with 3 equivalents of trimethylsilyl acetate afforded [L_OEtZr(OCOCH₃)₃] (4), whereas that with 1 and 2 equivalents of trimethylsilyl trimethylsiloxyacetate yielded [L_OEtZrF(OCOCH₂O)]₂ (5) and [L_OEtZr(OCOCH₂OH)(OCOCH₂O)]₂ (6), respectively. The crystal structures of complexes 2 and 6 have been determined.     

Binuclear zinc(II) complexes with the anti-inflammatory compounds salicylaldehyde semicarbazone and salicylaldehyde-4-chlorobenzoyl hydrazone (H2LASSBio-1064)

Complexes [Zn₂(HL¹)₂(CH₃COO)₂] (1) and [Zn₂(L²)₂] (2) were synthesized with salicylaldehyde semicarbazone (H₂L¹) and salicylaldehyde-4-chlorobenzoyl hydrazone (H₂LASSBio-1064, H₂L²), respectively. The crystal structure of (1) was determined. Upon recrystallization of previously prepared [Zn₂(HL²)₂(Cl)₂] (3) in 1:9 DMSO:acetone crystals of [Zn₂(L²)₂(H₂O)₂]·[Zn₂(L²)₂(DMSO)₄] (3a) were obtained. The crystal structure of 3a was also determined. All crystal structures revealed the presence of phenoxo-bridged binuclear zinc(II) complexes.     

Octa- and hendecanuclear zinc(II) complexes of an acyclic diimine ligand derived from 1,4-diformyl-2,3-dihydroxybenzene

An acyclic diimine ligand, H₄L¹, formed in methanol from the condensation of 1,4-diformyl-2,3-dihydroxybenzene (1) with two equivalents of 2-aminoethanol, was reacted with two equivalents of solid zinc(II) acetate dihydrate. Diffusion of diethyl ether into the reaction solution yielded a mixture of orange crystals of an octanuclear complex, [Zn^II₈(H₂L¹)₄(OAc)₈] (2), and red crystals of a hendecanuclear complex, [Zn^II₁₁(H₂L¹)₆(OAc)₆(O)₂] (3).     

[Me8Pt4ReS4] and related PtMe2-containing clusters derived from tetrathiorhenate

The reactions of Pt₂Me₄(μ-SMe₂)₂ and [ReS₄]⁻ in MeCN solution have been investigated. The resulting polyalkylated clusters: Et₄N[ReS₄PtMe₂] (Et₄N[1]), Et₄N[ReS₄(PtMe₂)₂] (Et₄N[2]), and Et₄N[ReS₄(PtMe₂)₄] (Et₄N[4]), were characterized by ¹H, ¹³C, ¹⁹⁵Pt NMR spectroscopy and ESI mass spectrometry. The structure of Et₄N[1] was confirmed by single crystal X-ray diffraction, which demonstrated the expected square planar and tetrahedral coordination spheres bridged by a pair of sulfur atoms.     

Study of the Structure and Reactions of Bis(μ-Oxalato)tetramminediplatinum(II) in Aqueous Chloride Solutions

A comparison study of the bis(-oxalato)tetramminediplatinum(II) dimer [Pt₂(NH₃)₄(-C₂O₄)₂] and the oxalatodiammineplatinum(II) chelate [Pt(NH₃)₂C₂O₄] is performed. The kinetics and mechanism of substitution of C₂O^2– ₄ for Cl^– in aqueous chloride solutions are studied by photoelectronic spectroscopy, gravimetry, and chemical phase analysis within the 1.0–6.7 pH range at 75°C. The rate constants of substitution and the equilibrium constants for a two-step protonation for the dimeric and chelate complexes are calculated. Their solubility in 1 M KCl at 75°C; is determined. The unit cell parameters for [Pt₂(NH₃)₄(-C₂O₄)₂] are determined: a = 3.858 Å, b = 10.704 Å, c = 6.795 Å, = 94.35°. The IR spectra of [Pt(NH₃)₂C₂O₄], [Pt₂(NH₃)₄(-C₂O₄)₂], and their deuterated analogs are studied.     

Synthesis, crystal structure and spectroscopic properties of some cadmium(II) complexes with three polyamine and corresponding macroacyclic Schiff base ligands

Three Cd(II) macroacyclic Schiff base complexes [CdL⁴(NO₃)₂] (4), [CdL⁵(NO₃)₂] (5), [CdL⁶(NO₃)₂] (6) were prepared by template condensation of 2-pyridinecarboxaldehyde with N1-(2-nitrobenzyl)-N1-(2-aminoethyl)ethane-1,2-diamine (L¹), N1-(2-nitrobenzyl)-N1-(2-aminoethyl)propane-1,3-diamine (L²) or N1-(2-nitrobenzyl)-N1-(3-aminopropyl)propane-1,3-diamine (L³), in the presence of cadmium metal ion, respectively. Three Cd(II) complexes with L¹, L² and L³ were also synthesized. All complexes have been studied with IR, ¹H NMR, ¹³C NMR, DEPT, COSY, HMQC and microanalysis. Two of these complexes, [CdL⁴(NO₃)₂] (4) and [CdL¹(NO₃)₂] (1) have been characterized through X-ray crystallography. In complex 4, the Cd is in a six-coordinate environment comprised of the ligand N₄-donor set and two oxygen atoms of two nitrate groups. In the polyamine complexes (1, 2 and 3) Cd and ligand are in a ratio of 1:1. Supporting ab initio HF-MO calculations have been undertaken using the standard 3-21G^∗ and 6-31G^∗ basis sets.     

Redox Properties of Rhodium(III) Oxo-Bridged Carboxylate Complexes

Chemical and electrochemical oxidation of rhodium (III) oxo-bridged carboxylate complexes was studied. The chemical [with O₃ and Ce(IV) salts] or electrochemical (at potentials of 1.00-1.20 V) oxidations of the binuclear complexes [Rh₂(-O)(-O₂CCH₃)₂(H₂O)₆]^{2 +} and [Rh₂(-O)(-O₂CCF₃)₂(H₂O)₆]^{2 +} leads to the superoxo complexes [Rh₂(-O)(O₂-)(-O₂CCH₃)₂(H₂O)₅]⁺ and [Rh₂(-O)(O₂ ^-)(-O₂CCF₃)₂(H₂O)₅]⁺ with terminal coordination of O₂-. The trinuclear acetate [Rh₃(₃-O)(-O₂CCH₃)₆(H₂O)₃]⁺, unlike its trifluoroacetate analog [Rh3(₃-O)(-O₂CCF₃)₆(H₂O)₃]⁺, is oxidized only electrochemically at a potential of 1.38 V. The oxidation of [Rh₃(₃-O)(-O₂CCH₃)₆(H₂O)₃]⁺ is reversible and involves formation of an unstable superoxo group O₂ ^- between two Rh₃III(₃-O) cores.     

Hitting Two Birds with One Stone: Crystal Containing Both Disproportionation Products of the Mixed-Valence Ruthenium(II,III) Carboxylate

The disproportionation of the mixed-valence diruthenium(II, III) trifluoroacetate, [Ru₂(O₂CCF₃)₅] (1), is reported. The overall conversion leads to the triruthenium(II, III, III) and diruthenium(II, II) species according to the scheme: 4 Ru₂ ⁵⁺ 2 Ru₃ ⁸⁺ + Ru₂ ⁴⁺. Both disproportionation products have been isolated and structurally characterized as they cocrystallize in a 2:1 ratio in the form of the acetone adducts to give the complex [Ru₃O(O₂CCF₃)₆·(OCMe₂)₃]₂ [Ru₂(O₂CCF₃)₄·(OCMe₂)₂] (2). Compound 2 conforms to the triclinic space group, P 1 (No. 2), with the parameters a = 9. 9238(5) Å, b = 12. 8388(7) Å, c = 20. 1188(10) Å, = 103. 1390(10)°, = 103. 1210(10)°, = 98. 1650(10)°, V = 2379. 8(2) ų, and Z = 1. The refinement of 747 parameters and 90 restraints resulted in the final R ₁ value of 0. 0454 and wR ₂ = 0. 0971 for 8003 reflections with I 2(I), and R ₁ value of 0. 0697 and wR ₂ = 0. 1071 for all 10, 755 data. The oxidized form is represented by a mixed-valence trinuclear ruthenium complex, [Ru₃O(O₂CCF₃)₆·(OCMe₂ )₃] (2a). This neutral complex possesses a ³-oxo-centered Ru₃O unit with peripheral ligands provided by bridging carboxylates and terminal acetone groups. The core dimensions of 2a indicate a valence-detrapped state in the range of temperatures 295–90 K. The central unit consists of a nearly equilateral triangular array with the Ru–O_(oxo) bond distances of 1. 909(3), 1. 905(3), and 1. 910(3) Å. The reduced form, [Ru₂(O₂CCF₃)₄·(OCMe₂)₂] (2b), is a typical tetrabridged diruthenium(II, II) carboxylate having coordinated acetone molecules at both axial sites. The Ru–Ru double bond in the paddlewheel unit is measured at 2. 2858(8) Å. The mechanistic aspects of the disproportionation and the core conversion in 1 as well as in similar metal trifluoroacetates are discussed.     

Synthesis and characterization of dinuclear pyrazolato bridged platinum(IV) complexes

Reactions of [PtMe₃(OCMe₂)₃](BF₄) and [(PtMe₃I)₄] with pyrazole (pzH) afforded mononuclear pyrazole platinum(IV) complexes [PtMe₃(pzH)₃](BF₄) (1) and [PtMe₃I(pzH)₂] (2), respectively. The formation of dinuclear pyrazolato bridged platinum(IV) complexes (PPN)[(PtMe₃)₂(μ-pz)₃] (3), (PPN)[(PtMe₃)₂(μ-I)(μ-pz)₂] · 1/2Et₂O (4) and [K(18C6)][(PtMe₃)₂(μ-I)(μ-pz)₂] (5) was achieved by the reaction of each 1 and 2 with [PtMe₃(OCMe₂)₃](BF₄) in the presence of KOAc followed by reaction with (PPN)Cl (PPN⁺ = bis(triphenylphosphine)iminium cation) and 18C6, respectively. The reaction of complex 4 with AgO₂CCF₃ followed by addition of RSR′ (R/R′ = Me/Me, Me/Ph) resulted in the formation of complexes [(PtMe₃)₂(μ-pz)₂(μ-RSR′)] (R/R′ = Me/Me, 6; Me/Ph, 7). All complexes were characterized unambiguously by microanalysis and NMR (¹H, ¹³C) spectroscopic investigations. Additionally, crystal structures of complexes 3 and 4 as well as DFT calculation are presented. Furthermore, in vitro studies on the anti-proliferative activity of complexes 2 and 5 were carried out.     

Ruthenium(II,III,III) μ<Subscript>3</Subscript>-oxotrifluoroacetate with dimethyl sulfoxide: Synthesis,structure, and DTF quantum-chemical calculations

The reaction of [Ru ₃ ^III (μ₃-O)(μ-O₂CCF₃)₆(H₂O)₃](O₂CCF₃) in methanol gives two solvates, [Ru₃O(O₂CCF₃)₆(DMSO)₃] · 1/2H₂O (I) and [Ru₃O(O₂CCF₃)₆(DMSO)₃] · H₂O (II), of a novel trinuclear mixedvalence Ru(II,III,III) trifluoroacetate complex, where two DMSO molecules are coordinated to the Ru atoms through the O atom, while the third DMSO molecule is coordinated through the S atom. According to the X-ray diffraction data, the complex can crystallize in two crystal systems: triclinic (I) (space group P \(\overline 1 \)) and monoclinic (II) (space group P2₁/m). The unit cell parameters for I are: a = 9.354, b = 11.005, c = 20.846 Å, α = 99.10, β = 96.38, γ = 92.17, Z = 2; R = 7.27%; for I are: a = 9.186, b = 17.044, c = 13.091 Å, β = 101.10, Z = 2; R = 14.18%.     

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).     

The Synthesis of Mono- and Bi-Metallic Platinum(II) and/or (IV) Complexes Containing the Ligand Bis(diphenylphosphino) Methylamine

Complexes of the type [Pt R₂ (dppma-PP′)] (R─Me, Et, Ph, CH₂Ph, C₆H₄ Me-p, C₆H₄OMe-2, CH₂CMe₃, 1-naphthyl, C₆H₄Me-o, dppma = Ph₂PNMe PPh₂) have been prepared from [PtCl₂, (dppma-PP′)] and the corresponding alkyl-lithium or Grignard reagents. Equilibrium constants, k, for the conversion of [PtR₂ (dppma-PP′)] into cis-[PtR₂(dppma-P)₂] with dppma were studied using ³¹P NMR spectroscopy at room temperature. Equilibrium is rapidly established for R─C₆H₄-Me-o, at 20°C. Complex of the type cis-[PtR₂ (dppma-P)₂] was isolated R─C₆H₄ Me-o. The complexes [PtMe₂(dppma-P)₂] and [Pt(o-methoxyphenyl)₂(dppma-P)₂] were prepared, but unfortunately decomposed once isolated, the only evidence for its formation being from ³¹P-{¹H} NMZR spectroscopy. The o-tolyl or 1-naphthyl complexes exist as syn-anti mixtures in solution, due to restricted rotation around the platinum aryl bonds. Treatment of several complexes of the type [PtR₂(dppma-PP′)] with MeI gives [PtR₂Me(I)(dppma-PP′)] with trans addition of MeI. Treatment of [PtR₂(dppma-PP′)] with HCl gives [Pt Cl (R) (dppma-PP′)] for R─C₆H₂Me₃-2,4,6, C₆H₄-CH₃-2, C₆H₄-Me-4, Me, 1-naphthyl. The ¹H, ³¹P NMR parameters for these complexes are discussed. Attempted preparation of complexes of the type [PtR₂ (dppma-P)₂M] (R─C₆H₄-Me-2, Me CN-C₆H₄-Me-4); M─Pd, Pt, Au,) are reported.