Carbamoyl and alkoxycarbonyl complexes of palladium(II) and platinum(II)

Carbamoyl and alkoxycarbonyl complexes of palladium(II) and platinum(II) of the type M(pnp)(CONHR)Cl (pnp = 2,6-bis(diphenylphosphinomethyl)pyridine; M Pd, R  C₆H₅, p-CH₃C₆H₄, p-CH₃OC₆H₄, C₆H₁₁, t-Bu; M  Pt, R  C₆H₅), Pd(pnp)[CON(Pr)₂]Cl (Pr = propyl), M(pnp)(COOR)Cl (M  Pd, R  C₆H₅, CH₃; M  Pt, R  CH₃), Pd(pnp)(COOCH₃)₂ result from reaction of M(pnp)Cl₂ with carbon monoxide and amines or alkoxides at room temperature and atmospheric pressure.The carbamoyl complexes react with bases to give urethane or diphenylurea depending upon the experimental conditions.     

Synthesis and characterization of some trans-hydridomethylbis(phosphine)-platinum(II) and -palladium(II) complexes

Several trans-hydridomethylbis(phosphine)-platinum(II) and -palladium(II) complexes have been made by the reaction: trans-M(H)Cl(PR₃)₂ + CH₃MgBr → trans-M(CH₃)(PR₃)₂ + MgClBr and their structures determined by ¹H NMR and IR spectroscopy. The complexes in which M  Pt and R  Cy (cyclohexyl) or i-Pr (isopropyl) are very stable in the solid state and in solution, while the compounds in which M  Pt, R  Et (ethyl) and M  Pd, R  i-Pr slowly decompose either in the solid state or in solution. The compound in which M  Pd and R  Cy was not isolated but was identified in solution.     

New biimidazole and bibenzimidazole derivatives: mono and binuclear palladium(II) or platinum(II) complexes and heterobinuclear palladium(II)-rhodium(I) or platinum(II)-rhodium(I) complexes

Novel neutral biimidazolate or bibenzimidazolate palladium(II) and platinum(II) complexes of the type M(NN)₂(dpe) [M = Pd, Pt; (NN)₂^2? = BiIm^2?, BiBzIm^2?. dpe = 1,2-bis(diphenylphosphino) ethane] have been obtained by reacting MCl₂(dpe) with TI₂(NN)₂. Complexes M(NN)₂(dpe) which are Lewis bases react with HClO₄ or [M(dpe)(Me₂CO)₂](ClO₄)₂ to yield, respectively, mononuclear cationic complexes of general formula [M{H₂(NN)₂](dpe) (M = Pd, Pt; H₂(NN)₂ = H₂BiIm, H₂BiBzIm) and homobinuclear palladium(II) or platinum(II) cationic complexes of the type [M₂{μ - (NN)₂}(dpe)₂](ClO₄)₂. Reactions of M(BiBzIm)(dpe) with [Rh(COD) (Me₂CO)_X](ClO₄) render similar heterobinuclear palladium(II)-rhodium(I) and platinum(II)-rhodium(I) cationic complexes, of general formula [(dpe)M(μ-BiBzIm)Rh(COD)](ClO₄) (M = Pd, Pt; COD = 1,5-cyclooctadiene). Di- and mono-carbonyl derivatives [(dpe)M(μ-BiBzIm)Rh(CO)L](ClO₄) (M = Pd, Pt; L = CO, PPh₃) have also been prepared. The structures of the resulting complexes have been elucidated by conductance studies and IR spectroscopy.     

Preparation,NMR studies and crystal structure of mononuclear and dinuclear Pd(II) and Pt(II) complexes that contain 1,2-bis[3-(3,5-dimethyl-1-pyrazolyl)-2-thiapropyl]benzene

The reaction between 1,2-bis[3-(3,5-dimethyl-1-pyrazolyl)-2-thiapropyl]benzene (bddf) and [MCl₂(CH₃CN)₂] (M = Pd(II), Pt(II)) in a 1:1 M/L ratio in CH₂Cl₂ or acetonitrile solution, respectively, gave the complexes trans-[MCl₂(bddf)] (M = Pd(II) (1), Pt(II) (4)), and in a 2:1 M/L ratio led to [M₂Cl₄(bddf)] (M = Pd(II) (2), Pt(II) (5)). Treatment of 1 and 4 with AgBF₄ and NaBPh₄, respectively, gave the compounds [Pd(bddf)](BF₄)₂ (3) and [Pt(bddf)](BPh₄)₂ (6). When complexes 3 and 6 were heated under reflux in a solution of Et₄NBr in CH₂Cl₂/CH₃OH (1:1) for 24 h, analogous complexes to 1 and 4 with bromides instead of chlorides bonded to the metallic centre were obtained. These complexes were characterised by elemental analyses, conductivity measurements, infrared, ¹H, ¹H{¹⁹⁵Pt}, ¹³C{¹H}, ¹⁹⁵Pt{¹H} NMR, HSQC and NOESY spectroscopies. The X-ray crystal structure of the complex [Pd(bddf)](BF₄)₂ · H₂O has been determined. The metal atom is tetracoordinated by the two azine nitrogen atoms of the pyrazole rings and two thioether groups.     

Some transition metal complexes of new terdentate ligands: Bis[2-(diphenylphosphino)ethyl]benzylamine and bis[2-(diphenylarsino)ethyl)benzylamine

Complexes of the terdentate ligands bis[2-diphenylphosphino)ethyl]benzylamine (DPBA) and bis[2-(diphenylarsino)ethyl]benzylamine (DABA) with Co(II), Ni(II), Pd(II), Pt(II), Rh(III), Ir(III), Rh(I) and Ir(I) are reported. The ligand DPBA reacts with Co(II) ion to form two types of complexes: a high-spin, paramagnetic, tetrahedral Co(II) complex of composition [CoCl(DPBA)]Cl and a low-spin, paramagnetic, square-planar complex of composition [CoBr(DPBA)]B(C₆H₅)₄. The reaction of DPBA with Ni(II) ion in methanol yields low-spin, diamagnetic, square-planar complexes of type [NiX(DPBA)]Y [X = Cl, Br or I; Y = Cl or B(C₆H₅)₄]. Four-coordinate, square-planar, cationic complexes of type [MY(L⁺[M = Pd(II), Pt(II), Rh(I) or Ir(I); Y = Cl or P(C₆H₅)₃; L = DPBA or DABA], were obtained on reaction of L with various starting materials containing these metal ions. Reaction of DPBA and DABA with rhodium and iridium trichlorides gave octahedral, neutral complexes of general formula [MCl₃(L)] (M = Rh or Ir, L = DPBA or DABA). All the complexes were characterized on the basis of their elemental analysis, molarconductance data, magnetic susceptibilities, electronic spectra, IR spectral measurements, and¹H and³¹P-{¹H} NMR spectral data.     

Synthesen und Charakterisierungen der ersten Tris‐ und Tetrakis(trifluormethyl)palladate(II) und ‐platinate(II), [M(CF3)3(PPh3)]— und [M(CF3)4]2— (M = Pd,Pt)

Syntheses and Characterizations of the First Tris and Tetrakis(trifluoromethyl) Palladates(II) and Platinates(II), [M(CF₃)₃(PPh₃)]^— and [M(CF₃)₄]^2— (M = Pd, Pt) Tris(trifluoromethyl)(triphenylphosphino)palladate(II) and platinate(II), [M(CF₃)₃PPh₃]^—, and the tetrakis(trifluoromethyl)metallates, [M(CF₃)₄]^2— (M = Pd, Pt), are prepared from the reactions of [MCl₂(PPh₃)₂] and Me₃SiCF₃ / [Me₄N]F or [I(CF₃)₂]^— salts in good yields. [Me₄N][M(CF₃)₃(PPh₃)] crystallize isotypically in the orthorhombic space group Pnma (no. 62) with Z = 4. The NMR spectra of the new compounds are described.     

Platinum(II) and Palladium(II) Bis(chelate) Complexes Containing both Tri(1‐cyclohepta‐2, 4, 6‐trienyl)phosphane,P(C7H7)3, and Dichalcogenolato Ligands

Tri(1‐cyclohepta‐2, 4, 6‐trienyl)phosphane, P(C₇H₇)₃ ([P] when coordinated to a metal atom), was used to stabilize complexes of platinum(II) and palladium(II) with chelating dichalcogenolato ligands as [P]M(E∩E) [E = S, ∩ = CH₂CH₂, M = Pt ( 3a ); E = S, ∩ = 1, 2‐C₆H₄, M = Pt ( 5a ), Pd ( 6a ); E = S, ∩ = C(O)C(O), M = Pt ( 7a ), Pd ( 8a ); E = S, Se, ∩ = 1, 2‐C₂(B₁₀H₁₀), M = Pt ( 9a, 9b ), Pd ( 10a, 10b ); E = S, ∩ = Fe₂(CO)₆, M = Pt ( 11a ), Pd ( 12a )]. Starting materials in all reactions were [P]MCl₂ with M = Pt ( 1 ) and Pd ( 2 ). Attempts at the synthesis of [P]M(ER)₂ with non‐chelating chalcogenolato ligands were not successful. All new complexes were characterized by multinuclear magnetic resonance spectroscopy in solution (¹H, ¹³C, ³¹P, ⁷⁷Se and ¹⁹⁵Pt NMR), and the molecular structures of 5a and 12a were determined by X‐ray analysis. Both in the solid state and in solution the ligand [P] is linked to the metal atom by the P‐M bond and by η²‐C=C coordination of the central C=C bond of one of the C₇H₇ rings. In solution, intramolecular exchange between coordinated and non‐coordinated C₇H₇ rings is observed, the exchange process being markedly faster in the case of M = Pd than for M = Pt.     

Zweikernige Palladium(II)‐, Platin(II)‐ und Iridium(III)‐Komplexe von Bis[imidazol‐4‐yl]alkanen

Dinuclear Palladium(II), Platinum(II), and Iridium(III) Complexes of Bis[imidazol‐4‐yl]alkanes The reaction of bis(1,1′‐triphenylmethyl‐imidazol‐4‐yl) alkanes ((CH₂)_n bridged imidazoles L(CH₂)_nL, n = 3–6) with chloro bridged complexes [R₃P(Cl)M(μ‐Cl)M(Cl)PR₃] (M = Pd, Pt; R = Et, Pr, Bu) affords the dinuclear compounds [Cl₂(R₃P)M–L(CH₂)_nL–M(PR₃)Cl₂] 1 – 17 . The structures of [Cl₂(Et₃P)Pd–L(CH₂)₃L–Pd(PEt₃)Cl₂] ( 1 ), [Cl₂(Bu₃P)Pd–L(CH₂)₄L–Pd(PBu₃)Cl₂] ( 10 ), [Cl₂(Et₃P)Pd–L(CH₂)₅L–Pd(PEt₃)Cl₂] ( 3 ), [Cl₂(Et₃P)Pt–L(CH₂)₃L–Pt(PEt₃)Cl₂] ( 13 ) with trans Cl–M–Cl groups were determined by X‐ray diffraction. Similarly the complexes [Cl₂(Cp*)Ir–L(CH₂)_nL–Ir(Cp*)Cl₂] (n = 4–6) are obtained from [Cp*(Cl)Ir(μ‐Cl)₂Ir(Cl)Cp*] and the methylene bridged bis(imidazoles).     

The Coordination Chemistry of 1,2-Bis[(diphenylphosphino)methyl]benzene with Nickel(II), Palladium(II), Platinum(II), and Platinum(0) and the X-Ray Crystals Structure of [Pt{1,2-bis[(diphenylphospino)methyl]benzene}(C2H4)]

The preparation of complexes [MX₂( 1 )] (M = Ni, Pd, and Pi; X - Cl, Br, and I; 1 = 1,2-bis[(diphenylphosphino)methyl]benzene). [Pt(OSO₂CH₃)Et( 1 )], [Pt(alkene)( 1 )] (alkene - C₂H₂, and CH₂ = CHCN), and [( 1 )Pt-(μ-H)₂PtH( 1 )][BPh₄] is reported. Their ¹H- and ³¹P-NMR spectra were recorded and used lor structural assignments. The X-ray crystal structure of [Pt(C₂H₄)( 1 )] was determined. It is shown that the P? Pt? P bond angle in this complex differs significantly from those found in related compounds with monodentate phosphines, and that this difference is likely to be due to intramolecular contacts.     

31P-, 119Sn- and 195Pt-NMR. Studies of Trichlorostannate Complexes of Pt(II) and Pd(II). 2J(119Sn, 117Sn)-Values

The synthesis and solution structures of new four- and five-coordinate phosphine and arsine complexes of Pt and Pd containing the trichlorostannate ligand are described. Complexes containing two and three SnCl^?₃-ligands have been identified from their ³¹P-, ¹¹⁹Sn- and ¹⁹⁵Pt-NMR. spectra. The complexes trans-[M (SnCl₃)₂L₂] (M = Pt, L-PEt₃, PPr₃, AsEt₃; M = Pd, L = AsEt₃) show unexpectedly large ²J(¹¹⁹Sn, ¹¹⁷Sn)-values (34,674–37,164 Hz) with the trans-orientation of these spins playing an important role. The heteronuclear coupling constant ²J(¹¹⁹Sn, ³¹P) in the five-coordinate cationic complexes [Pt(SnCl₃)(P(o-AsPh₂? C₆H₄)₃)]⁺ and [Pt(SnCl₃)(As(o-PPh₂? C₆H₄)₃)]⁺ also shows a geometric dependence. New five-coordinate anionic complexes of type [M (SnCl₃)₃L₂]^? (M = Pd, Pt; L = PEt₃, AsEt₃) may be prepared via addition of three mol-equiv. of SnCl₂ and one mol-equiv. of (PPN)Cl to [MCl₂L₂] in acetone.     

Cyclopentadienyl ruthenium and osmium complexes : II. The reactivity of π-cyclopentadienyl(triphenylphosphine)-ruthenium(II) and -osmium(II) complexes

Ruthenium and osmium complexes of the type CpMX(PPh₃)L (M = Ru; X = Cl, H, S₂COC₁₀H₁₉, S₂COMe; L & PPh₃ and PHPh₂; M = Os, X = Cl, Br, I, H, D, xanthogenate, dithiocarbamate, BPh₄, L = PPh₃). The compound CpOsCl(PPh₃)₂ is readily soluble in MeOH and in the solution the cation [CpOs(PPh₃)₂]⁺ is present. Upon addition of NaBPh₄ a white compound CpOs(PPh₃)₂BPh₄ immediately precipitates, which can not be solved in MeOH, contrary to the behaviour of the corresponding ruthenium compound.     

Synthese und Struktur der Kronenetherkomplexe von Kaliumhexachlorodipalladat(II) und -diplatinat(II)

Synthesis and Structure of Crown Ether Complexes of Potassium Hexachlorodipalladate(II) and -diplatinate(II) K₂[MCl₄] (M ? Pd, Pt) reacts with an excess of crown ether 18-crown-6 in water to give the crown ether complexes of potassium hexachlorodipalladate(II) and -diplatinate(II) [K(18-cr-6)]₂[M₂Cl₆] (M ? Pd, 1 ; M ? Pt, 3 ), respectively, and in methylene chloride to give those of potassium tetrachloropalladate(II) and -platinate(II) [K(18-cr-6)]₂[MCl₄] ( 1 ) (M ? Pd, 2 ; M ? Pt, 4 ), respectively. 1 - 4 are characterized by microanalysis, NMR (¹H, ¹³C), and vibrational spectroscopy. The X-ray structure analyses of the isotypic complexes 1 (P2₁/c; a = 10,9678(8), b = 8,2991(7), c = 22,469(2) Å, β = 98,523(5)°; Z = 2) and 3 (P2₁/c; a = 10,934(3), b = 8.376(3), c = 22,410(5) Å, β = 98,77(3)°; Z = 2) reveal [M₂Cl₆]^2? anions of nearly D_2h symmetry and [K(18-cr-6)]⁺ cations, in which the distance of K⁺ to the mean plane of the crown ether defined by its six oxygen atoms amounts to 0,830(4) Å in 1 and 0,821(2) Å in 3 , respectively. There are tight contacts between cations and anions (d(K-Cl): 3,341(2)/3,260(2) Å ( 1 ); 3,348(4)/3,259(4) Å ( 3 )).     

Palladium(II)-, Platin(II)-, Ruthenium(II)-, Rhodium(III)- und Iridium(III)-Komplexe von Desoxyfructosazin

Metal Complexes of Biologically Important Ligands. CIII. [1] Palladium(II), Platinum(II), Ruthenium(II), Rhodium(III), and Iridium(III) Complexes of Desoxyfructosazine The reactions of the pyrazine derivative desoxyfructosazin(pz) with K₂PtCl₄ and with the chlorobridged [M(PR₃)Cl₂]₂ (M = Pd, Pt), [(η⁵-C₅Me₅)MCl₂]₂ and [(η⁶-p-Cymol)RuCl₂]₂ give the watersoluble complexes cis-Cl₂Pt(pz)₂, (R₃P)(Cl)M(pz)M(Cl)(PR₃) (M = Pd, Pt), (η⁵-C₅Me₅)(Cl)₂M(pz)M(Cl)₂(η⁵-C₅Me₅) (M = Rh, Ir), (η⁶-p-Cymol)(Cl₂)Ru(pz)Ru(Cl)₂(η⁶-p-Cymol).     

Acyl-platinum(II) and -palladium(II) complexes derived from 2-hydroxybenzaldehyde derivatives. X-ray structure of [Pt(OC6H4CO) (P(p-CH3C6H4)3)2]

Platinum(II) and palladium(II) complexes containing chelating acyl ligands have been synthesized from salicylaldehyde, 2-hydroxynaphthaldehyde and 2-hydroxy-3-methoxybenzaldehyde. The platinum(II) complexes [Pt(acyl)L₂], acyl  OC₆H₄CO, OC₁₀H₆CO, O(m-CH₃OC₆H₃CO), L  tertiary phosphine, 1/2 diphenylphosphinoethane, can be isolated with both monodentate and chelating diphosphines, whereas for palladium only the compounds with chelating phosphines are readily obtainable. The reactions of [Pt(OC₆H₄CO)L₂] with HCl afford trans-[PtCl(OHC₆H₄CO)L₂], L  monodentate tertiary phosphine and cis-[PtCl(OHC₆H₄CO)L₂], L2  1,2-bis-diphenylphosphinoethane, in which the metal—carbon bond remains intact. The structure of [Pt(OC₆H₄CO)-(P(p-CH₃C₆H₄)₃)₂] has been determined by X-ray diffraction methods and found to have the expected square planar structure. Some relevant bond lengths and angles are: PtP; 2.271(4) and 2.348(5) Å; PtC; 1.96(2) Å and PtO; 2.07(1) Å; PPtP  101°, CPtO  82°.     

Palladium(II)‐ und Platin(II)‐Komplexe mit dem Antimalariamittel Mefloquin als Liganden

Metal Complexes of Biologically Important Ligands. CXXVI. Palladium(II) and Platinum(II) Complexes with the Antimalarial Drug Mefloquine as Ligand The coordination sites of the antimalarial drug mefloquine (L) were studied. Reactions of the chloro bridged complexes (allyl)Pd(μ‐Cl)₂Pd(allyl) and (R₃P)(Cl)M(μ‐Cl)₂M(Cl)(PR₃) (M = Pd, Pt) with racemic mefloquine give the compounds (allyl)(Cl)Pd(L) ( 1 ), Cl₂(Et₃P)Pt(L) ( 2 ) and Cl₂(Et₃P)Pd(L) ( 3 ) with coordination of the piperidine N atom of mefloquine. In the presence of NaOMe the N,O‐chelate complexes Cl(Et₃P)Pt(L–H⁺) ( 4 ) and Cl(R₃P)Pd(L–H⁺) ( 5 , 6 , R = Et, nBu) were obtained. Protection of the piperidine N atom of mefloquine by protonation allows the synthesis of the complexes Cl₂(Et₃P)Pt(L + H⁺) ( 7 ) in which mefloquine is coordinated via the quinoline N atom. The structures of 2 , 3 and 4 were determined by X‐ray diffraction analysis. In the crystal of 4 pairs of enantiomers are found which are linked by two hydrogen bridges between the amine group and the chloro ligand.     

Synthesis and reactivity of novel cationic organonickel(II) compexes. X-ray structure of [bis(2-diphenylphosphinoethyl)phenylphosphinenickel-O-methylsulfinate]tetraphenylborate

Cationic tetracoordinate nickel(II) compounds containing a nickelcarbon σ bond with general formula [NiR(etp)]Y, (etp  bis(2-diphenylphosphinoethyl)phenylphosphine, PhP(CH₂CH₂PPh₂)₂; R = CH₃, CH₂C₆H₅, C₆H₅; Y = BPh₄, PF₆) were synthesized by reaction of the complexes [NiX(etp)]Y (X = halogen) with appropriate Grignard reagents.This type of organometallic complexes undergo insertion of sulfur dioxide into the NiC bond with formation of tetracoordinate O-sulfinate derivatives of nickel(II). The structure of [NiOS(O)CH₃(etp)]BPh₄ has been determined from three dimensional X-ray data collected by counter methods. The compound crystallized in the triclinic group P$\text{1}$ with cell dimensions a 16.726(4), a 15.350(4), c 11.632(3) Å, α 66.55(4), β 73.37(4), γ 74.75(4)°, Z = 2. The structure was refined by full matrix least-squares methods to a conventional R factor of 0.076. The coordination polyhedron has a distorted square planar geometry. The sulfinate group is linked to the metal through an oxygen atom.     

Synthesis and characterization of cyclometallated palladium(II) and platinum(II) complexes with amide-thiolate ligands

The redox reaction of bis(2-benzamidophenyl) disulfide (H₂L-LH₂) with [Pd(PPh₃)₄] in a 1:1 ratio gave mononuclear and dinuclear palladium(II) complexes with 2-benzamidobenzenethiolate (H₂L⁻), [Pd(H₂L-S)₂(PPh₃)₂] (1) and [Pd₂(H₂L-S)₂ (μ-H₂L-S)₂(PPh₃)₂] (2). A similar reaction with [Pt(PPh₃)₄] produced only the corresponding mononuclear platinum(II) complex, [Pt(H₂L-S)₂(PPh₃)₂] (3). Treatment of these complexes with KOH led to the formation of cyclometallated palladium(II) and platinum(II) complexes, [Pd(L-C,N,S)(PPh₃)]⁻ ([4]⁻) and [Pt(L-C,N,S) (PPh₃)]⁻ ([5]⁻). The molecular structures of 2, 3 and [4]⁻ were determined by X-ray crystallography.     

The coordination chemistry of simple phospholes: Complexes of nickel(II), palladium(II) and platinum(II)

The reactions between four very simply substituted phospholes and the chlorides of Ni(II), Pd(II) and Pt(II) are described. The phospholes 1-phenylphosphole, 3-methyl-1-phenyl-phosphole and 3,4dimethyl-1-phenylphosphole all readily form bis-complexes of formula L₂MCl₂ [L = phosphole ligand and M = Ni(II), Pd(II) or Pt(II)] or tris-complexes of formula L₃MCI₂. 1-n-Butyl-3,4-dimethylphosphole appears to form stable complexes only with Ni(II). Evidence is put forward which indicates that the L₂MCl₂ complexes exist in a four-coordinate, square-planar monomeric/five coordinate equilibrium while the L₃MCl₂ complexes are primarily the ionic species [L₃MCl]⁺ Cl^? in solution. Comparisons are made with the behaviour of other simple phospholes which do not form Ni(II) complexes and the results are discussed briefly in terms of both aromatic and non-aromatic phosphole models.     

Heterodinukleare Cobalt(II)‐, Nickel(II)‐, Kupfer(II)‐, Zink(II)und Palladium(II)‐Komplexe mit einem makrocyclischen Liganden vom Schiff‐Basen‐Typ: Synthesen und Strukturen

Complexes with Macrocyclic Ligands. IV. Heterodinuclear Cobalt(II), Nickel(II), Copper(II), Zinc(II) and Palladium(II) Complexes with a Macrocyclic Ligand of Schiff‐Base Type: Syntheses and Structures The synthesis and properties of nickel(II), copper(II), and palladium(II) complexes, [ML^Ph] ( 3 ; L^Ph = N,N′‐phenylene‐bis(3‐formyl‐5‐tert.‐butyl‐salicylaldimine)), are described. These neutral mononuclear complexes react with metal(II) perchlorate and 1,3‐propylenediamine to form heterodinuclear, macrocyclic, cationic complexes of the type [MM′(L^Ph,3)]²⁺ ( 4 ; M = Ni, Cu, Pd; M′ = Co, Cu, Zn). The structures of the five new compounds [NiCo(L^Ph,3)](ClO₄)₂, [NiCu(L^Ph,3)](ClO₄)₂, [CuCu(L^Ph,3)](ClO₄)₂, [CuZn(L^Ph,3)](ClO₄)₂, and [PdCu(L^Ph,3)](ClO₄)₂ were determined by X‐ray diffraction.     

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.