Synthesis,characterization and anticancer activity of 3-aminopyrazine-2-carboxylic acid transition metal complexes

Synthetic procedures are described that allow access to the new complexes cis-[Mo₂O₅(apc)₂], cis-[WO₂(apc)₂], trans-[UO₂(apc)₂], [Ru(apc)₂(H₂O)₂], [Ru(PPh₃)₂(apc)₂], [Rh(apc)₃], [Rh(PPh₃)₂(apc)₂]ClO₄, [M(apc)₂], [M(PPh₃)₂(apc)]Cl, [M(bpy)(apc)]Cl (M(II) = Pd, Pt), [Pd(bpy)(apc)Cl], [Ag(apc)(H₂O)₂] and [Ir(bpy)(Hapc)₂]Cl₃, where Hapc, is 3-aminopyrazine-2-carboxylic acid. These complexes were characterized by physico-chemical and spectroscopic techniques. Both Hapc and several of its complexes display significant anticancer activity against Ehrlich ascites tumour cells (EAC) in albino mice.     

Hydrosilylation of n- and o-heterocyclic aldehydes in the presence of RhI,RuII, and PdII complexes

The hydrosilylation of 2-formylpyridine, 2-formyl-6-methylpyridine, 2-formylfuran, and 2-formyl-5-methylfuran with triethylsilane in the presence of Rh(PPh₃)₃Cl, Rh(PPh₃)₃(CO)H, Rh(PPh₃)₂(C0)Cl, Ru(PPh₃)₃Cl₂, Ru(PPh₃)₂(CO)₂Cl₂, and Pd(PPh₃)₂Cl₂ was studied. Silyl ethers of the corresponding hetarylcarbinols were obtained in high yields. The formation of products of dehydrocondensation of the silyl ethers is observed in the hydrosilylation of methyl-substituted aldehydes; this process does not occur in the presence of ruthenium complexes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1372–1380, October, 1988.     

Metal complexes of the diuretic drug furosemide

New complexes of the formulaeM(fur)₂·2H₂O (M = Mn, Cu, Zn),M(fur)₂·3H₂O (M = Co, Ni, Cd), Hg₂(fur)₃Cl₂·2H₂O, Pd(fur)Cl·H₂O and Rh(fur)₃·3H₂O, wherefurH = 4-chloro-N-(2-furfuryl)-5-sulfamoylanthranilic acid, have been prepared and characterized by conductivity measurements, X-ray powder patterns, thermal methods, effective magnetic moments as well as by IR, ligand field,¹H-NMR and ESR spectroscopic studies. The anionfur ^– shows a chelated bidentate O(carboxylato), N(imino)-coordinating behaviour.

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Metallkomplexe der diuretischen Droge Furosemid

Zusammenfassung Neue Komplexe der Verbindungen:M(fur)₂·2H₂O (M = Mn, Cu, Zn),M(fur)₂·3H₂O (M = Co, Ni, Cd), Hg₂(fur)₃Cl₂·2H₂O, Pd(fur)Cl·H₂O und Rh(fur)₃·3H₂O, wobeifurH 4-chlor-N-(2-furfuryl)-5-sulfamoylanthanilsäure ist, wurden dargestellt. Die Komplexe wurden durch Leitfähigkeitsmessungen, Röntgen-Pulver-Aufnahmen, thermogravimetrische Analysen, Messungen des effektiven magnetischen Dipolemomentes sowie durch spektroskopische Untersuchungen (IR,¹H-NMR und ESR) charakterisiert. Das Anionfur ^– zeigt das Verhalten einer Chelat-bidentat-O(carboxylato),N(imino)-Koordination.

     

Synthesis of chloro-carbonyl derivatives of rhenium,ruthenium, rhodium,iridium and platinum via reaction of the metal atoms with oxalyl chloride

Co-condensation of atoms of Re, Ru, Rh, Ir and Pt with oxalyl chloride gives metal chloro-carbonyl derivatives which may be used as precursors to the compounds [Re(CO)₄Cl]₂, [Ru(PMe₃)₃(CO)Cl₂], α-[Ru(CO)₃Cl(μ-Cl)]₂, [Ru(PPh₃)₂(CO)₂Cl₂], [Rh(CO)₂(μ-Cl)]₂, [Rh(PPh₃)₂COCl], [Ir(PPh₃)(CO)₂Cl₃] and cis-Pt(CO)₂Cl₂. Molybdenum atoms with oxalyl chloride give molybdenum-chloro derivatives.     

Rh(III), Pd(II), Pt(IV) and Au(III) complexes of 2-thiopyrimidine derivatives

Some news thiopyrimidine derivatives and complexes [4-amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidine (TANH), its 2-methylthio derivative (MTH), the ammonium salt ofTANH (sTANH) and six new complexes of formulas: Rh(MT)₂Cl · 2H₂O, Pd(MTH)₂Cl₂, Pt(MTH)₂Cl₄, Au(MTH)Cl₃ Pd(TANH)₂Cl₂ and Au(TAN ^–)Cl] have been synthesized and characterized by elemental analysis, IR and¹H-NMR spectroscopy techniques. The thermal behaviour of all compounds has also been studied.

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Rh(III), Pd(II), Pt(IV) und Au(III) Komplexe von 2-Thiopyrimidin Derivaten

Zusammenfassung Es wurden einige neue Thiopyrimidinderivate und deren Komplexe synthetisiert und mittels Elementaranalyse, IR und¹H-NMR charakterisiert: 4-Amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidin (TANH), dessen 2-Methylthio-Derivat (MTH), das Ammoniumsalz vonTANH (sTANH) und sechs neue Komplexe der Formeln Rh(MT)₂Cl · 2H₂O, Pd(MTH)₂Cl₂, Pt(MTH)₂Cl₄, Au(MTH)Cl₃, Pd(TANH)₂Cl₂ und Au(TAN ^–)Cl. Das thermische Verhalten der Verbindungen wurde ebenfalls untersucht.

     

Synthesis and structural investigations of rhodium(I) complexes withN-phenylanthranilic acid

Summary The carbonyl-N-phenylanthranilatorhodium(I) complex [Rh(CO)₂(FA)] (1) was obtained by heating RhCl₃ · 3 H₂O withN-phenylanthranilic acid (HFA) in boiling dimethylformamide (DMF). Triphenylphosphine, PPh₃, can replace one carbonyl ligand in complex (1) to produce [Rh(CO)(PPh₃)(FA)] (2). Complexes (1) and (2) were characterized by analytical and physicochemical methods.     

Synthesis, Structure, and 31P NMR of Sulfur/Oxygen-Bridged Incomplete Cubane-Type Molybdenum and Tungsten Clusters with Triphenylphosphine Ligands

Sulfur/oxygen-bridged incomplete cubane-type triphenylphosphine molybdenum and tungsten-clusters [Mo₃S₄Cl₄(H₂O)₂(PPh₃)₃]·3THF (1A), [Mo₃S₄Cl₄(H₂O)₂(PPh₃)₃]·2THF (2A), [Mo₃OS₃Cl₄(H₂O)₂(PPh₃)₃]·2THF (1B), and [W₃S₄Cl₄(H₂O)₂(PPh₃)₃]·2THF (1C) were prepared from the corresponding aqua clusters and PPh₃ in THF/MeOH. On recrystallization from THF, procedures with and without addition of hexane to the solution gave 1A and 2A, respectively, while the procedures gave no effect on the formation of 1B and 1C. Crystallographic results obtained are as follows: 1A: monoclinic, P2₁/n, a=17.141(4) Å, b=22.579(5) Å, c=19.069(4) Å, =96.18(2)°, V=7337(3) ų, Z=4, R(R _w)=0.078(0.102); 1C: monoclinic, P2 ₁/c, a=12.635(1) Å, b=20.216(4) Å, c=27.815(3) Å, =96.16(1)°, V=7062(2) ų, Z=4, R(R _w)=0.071(0.083). If the phenyl groups are ignored, the molecule [Mo₃S₄Cl₄(H₂O)₂(PPh₃)₃] in 2A has idealized CS symmetry with the mirror plane perpendicular to the plane determined by the metal atoms, while the molecule in 1A does not have the symmetry. The tungsten compound 1C is isomorphous with the molybdenum compound 2A. ³¹P NMR spectra of 1A, 2A, and 1C were obtained and compared with similar clusters with dmpe (1,2-bis(dimethylphosphino)ethane) ligands.     

Remarks on the process of homogeneous carbonylation of rhodium compounds by N,N-dimethylformamide

Reductive carbonylation of rhodium(III) chloride complexes, commercial RhCl₃ · nH₂O neutralized with BaCO₃, (Me₂NH₂)₂[RhCl₅(DMF)], (PPh₄)[RhCl₄(H₂O)₂], RhCl₃(DMF)₃, RhCl₃(CH₃CN)₃, RhCl₃(CH₃CN)₂(DMF), [Rh(CO)₂Cl₃]₂, and rhodium(I) complex, Rh(PPh₃)₃Cl, by N,N-dimethylformamide (DMF) is studied. The data obtained support the conception of direct carbonyl group transfer from DMF molecule to the Rh metal center. The mechanistic scheme of carbonylation process is refined and discussed with regard of new experimental results.     

Derivate des borols: IX. (η5-borol)metall-komplexe von ruthenium,osmium und rhodium

Dehydrogenating complexation of borolenes with carbonyls (Ru₃(CO)₁₂, Os₃(CO)₁₂), Wilkinson's catalyst (RhCl(PPh₃)₃) and related compounds (RuCl₂(PPh₃)₃, RuHCl(PPh₃)₃, OSCl₂(PPh₃)₃), and (η⁶-arene)ruthenium complexes (Ru(η-C₆H₆)(η⁴-C₆H₈), [Ru(η-C₆H₆)Cl₂]₂, [Ru(η-C₆-Me₆)Cl₂]₂) leads to the (η⁵-borole)metal complexes of Ru, Os, and Rh. Inter alia, the preparation of the complexes Ru(CO)₃(η⁵-C₄H₄BF) (R = Ph, OMe, Me), Os(CO)₃L (L = η⁵-C₄H₄BPh), MHClL(PPh₃)₂ (M = Ru, Os), RhClL(PPh₃)₂, and RuL(η-C₆R₆) (R = H, Me) is described. The structures of RuHClL(PPh₃)₂ and RhClL(PPh₃)₂ have been determined by X-ray diffraction analysis.     

Synthesis,characterization and antineoplastic activity of 5-chloro-2,3-dihydroxypyridine transition metal complexes

Synthetic procedures are described that allow access to cis-[Mo₂O₅(cdhp)₂]^2?, cis-[W₂O₅(Hcdhp)₂], trans-[OsO₂(cdhp)₂]^2?, trans-[UO₂(Hcdhp)₂], [ReO(PPh₃)(Hcdhp)₂]X (X =?Cl, I), [ReO₂(cdhp)₂]^?, [M(PPh₃)₂(cdhp)], [M(bpy)(cdhp)] (M(II) =?Pd, Pt), [Ru(YPh₃)₂(Hcdhp)₂] (Y =?P, As), [Rh(Hcdhp)₂Cl(H₂O)], [Rh(PPh₃)₂(Hcdhp)₂]ClO₄ and [Ir(bpy)(cdhp)Cl₂], where Hcdhp, cdhp are the deprotonated monoanion of 5-chloro-3-hydroxypyrid-2-one and dianion of 5-chloro-2,3-dihydroxypyridine, respectively. These complexes were characterized by their Raman, IR, ¹H NMR, electronic and mass spectra, conductivity, magnetic and thermal measurements. H₂cdhp, cis-K₂[Mo₂O₅(cdhp)₂], [Pd(bpy)(cdhp)] display a significant antineoplastic activity against Ehrlich ascites tumor cells (EAC).     

Trichloro-bridged diruthenium (III,III) complexes: X-ray isomorphous structures of [Ph3X=O···H···O=XPh3][Ru2Cl7(XPh3)2]·0.5(CH2Cl2)(H2O)(X = As or P)

The triply chloro-bridged binuclear complexes [Ph₃X=O···H···O=XPh₃][Ru₂Cl₇(XPh₃)₂]·0.5(CH₂Cl₂)(H₂O) (X = As or P) were obtained from [RuCl₃(XPh₃)₂DMA]·DMA (DMA = dimethylacetamide) CH₂Cl₂/Et₂O solution. The structures were characterized by X-ray diffraction studies. The complexes are formed from two Ru atoms bridged by three chloride anions. The two ruthenium atoms are also coordinated to two non-bridging Cl atoms and an AsPh₃ or PPh₃ ligand respectively. As an interesting feature, the cations of these complexes are protons, trapped in a very short hydrogen bond between two triphenylarsine or triphenylphosphine oxide molecules.     

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.     

Structurally characterized acylruthenium organometallics bearing a pendant aldehyde function

By reacting [Ru(RL¹)(PPh₃)₂(CO)Cl], (1) (R = C₆H₄Me, Et) with an excess of CNBu^t in the presence of NH₄PF₆, organometallics of the type [Ru(RL²)(PPh₃)₂(CNBu^t)₂]PF₆, (2) have been isolated in excellent yield [RL¹ = C₆H₂O-2-CHNHR(p)-3-Me-5, RL² = C₆H₂(CO)-O-2-CHNHR(p)-3-Me-5]. These organometallics, on controlled hydrolysis, produce [Ru(L³)(PPh₃)₂(CNBu^t)₂], (3) in very good yield (L³ = C₆H₂(CO)-O-CHO-3-Me-5). In both ([2(C₆H₄Me)] · 2H₂O) and ([3] · 2CH₂Cl₂) the two phosphine ligands lie in trans positions. In ([2(C₆H₄Me)] · 2H₂O) the Ru(C₆H₄MeL²) fragment, excluding the pendant tolyl ring, is a near perfect plane (mean dev ~ 0.02Å) which makes a dihedral angle of 5.2° with the tolyl plane. The acyl chelate ring in ([2(C₆H₄Me)] · 2H₂O) is excellently planar with a mean deviation of 0.006°. In ([3] · 2CH₂Cl₂) the Ru(L³) fragment defines a crystallographic plane of symmetry, the coordinates of the atom being of the type x, 1/4z. The complex ([2C₆H₄Me)] · 2H₂O) displays N–HȮFO (iminium-phenolato) hydrogen bonding while in ([3] · 2CH₂Cl₂) C–H...O hydrogen bonding is present. Characteristic spectral data (u.v.–vis, i.r. and ¹H n.m.r.) of the complexes are reported. A notable feature is that an allowed band near 500 nm due to the t_2g → π^*(azomethine) charge transfer transition, which is diagnostic of the coordinated iminium-phenolato function, is present in (3) but this band is absent in the aldehydic acyl complex (2). In the ¹H n.m.r. spectrum the N⁺–H signal in (2) (near 13.5 ppm) is split into a doublet due to transcoupling with the azomethine proton. The aldehydic proton of (3) resonates as a sharp singlet near 10 ppm. In CH₂Cl₂ solution (2) and (3) display quasireversible a Ru^III/Ru^IIcyclic voltammetric response with E_1/2 near 0.9 and 0.5 V versuss.c.e. The conversion (2) → (3) is accompanied by the nucleophilic attack of water. The complex (3) is also obtained directly from (1) by reaction with CNBu^t in the presence of H₂O. The aldehyde function in (3) is deactivated by the existing acyl moiety; as a result further decarbonylation does not take place.     

Lanthankomplexe mit 2,2′-Bipyridin-N,N′-dioxid

Compounds of the composition La(bpyO₂ ^*)₄Cl₃·4H₂O, La(bpyO₂)₃Cl₃·5H₂O, La(bpyO₂)₂Cl₃·3H₂O, La(bpyO₂)Cl₃·3H₂O, La(bpyO₂)₄Br₃·4H₂O, La(bpyO₂)₃Br₃·8H₂O, La(bpyO₂)₂Br₃·7H₂O, La(bpyO₂)Br₃·4H₂O, La(bpyO₂)₄I₃·3H₂O, La(bpyO₂)₃(NO₃)₃·2H₂O, La(bpyO₂)₂(NO₃)₃·2H₂O, La(bpyO₂)₄(SCN)₃·3H₂O, La(bpyO₂)₃(SCN)₃·2H₂O, La(bpyO₂)₂(SCN)₃·2H₂O were isolated. They were investigated by means of thermoanalysis, I.R. spectroscopy, X-ray diffraction and molar conductivity.     

Reduction of nitrobenzene in the liquid phase by carbon monoxide (II) in the presence of palladium complexes

Conclusions We investigated the transformations of catalysts based on palladium complexes under the conditions of the catalytic reduction of nitrobenzene by carbon monoxide (II). We established that the reduced forms of the catalyst are Pd₂(PPh₃),₄(CO)·H₂SO₄ and Pd₂PPh₃)₄CO)· HClO₄, while the reduced forms are Pd(PPh₃)₂SO₄ and Pd(PPh₃)₃(H₂O)(ClO₄)₂ in the sulfate and the perchlorate media, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 998–1002, May, 1989.     

Aerobic alcohol oxidation catalyzed by a new, oxygen-bridged heterometallic compound [PPh4][Ru(N)Me2(μ2-O)2Pd((−)-sparteine)]

The reaction between the new hydroxy compound [PPh₄][Ru(N)(OH)₂Me₂] and Pd(OSiMe₃)₂((−)-sparteine) produces (Me₃Si)₂O, H₂O and a new heterobimetallic compound [PPh₄][Ru(N)Me₂(μ₂-O)₂Pd((−)-sparteine)] in good yield. The Ru/Pd bimetallic compound catalyzes the oxidation of aryl and allyl alcohols to the corresponding carbonyl compound in air and the rearrangement of allylic alcohols unsaturated aldehydes. It also oxidizes PPh₃ to O-PPh₃ under O₂.     

Cyclopentadienyl-ruthenium and -osmium chemistry : XXXIX. Syntheses of novel alkynyl-ruthenium complexes. X-Ray structures of two forms of {Ru(PPh3)2(η-C5H5)}2(μ-C4) and of Ru{CCC(O)Me}(PPh3)2(η-C5H5)

Reactions between [Ru(thf)(PPh₃)₂(η-C₅H₅)]⁺ and lithium acetylides have given further examples of substituted ethynylruthenium complexes that are useful precursors of allenylidene and cumulenylidene derivatives. From Li₂C₄, mono- and bi-nuclear ruthenium complexes were obtained: single-crystal X-ray studies have characterised two rotamers of {Ru(PPh₃)₂(η-C₅H₅)}₂(μ-C₄), which differ in the relative cis and trans orientations of the RuL_n groups. Protonation of Ru(CCCCH)(PPh₃)₂(η-C₅H₅) afforded the butatrienylidene cation [Ru(C=C=C=CH₂)(PPh₃)₂(η-C₅H₅)]⁺, which reacted readily with atmospheric moisture to give the acetylethynyl complex Ru{CCC(O)Me}(PPh₃)₂(η-C₅H₅), also fully characterised by an X-ray structural study.     

Synthesis,crystal structure and electrochemical properties of three isocloso eleven‐vertex ferrocenecarboxylate ruthenaborane clusters

The reaction of [RuCl₂(PPh₃)₃] with closo‐[B₁₀H₁₀]^2? and C₅H₅FeC₅H₄COOH (FcCO₂H) in refluxing CH₂Cl₂ solution affords three ruthenaborane clusters: [PPh₃(H₂O)(FcCO₂)RuB₁₀H₈Cl] (1), [(PPh₃)₂ClRu(PPh₃)(FcCO₂)RuB₁₀H₉]·0.5CH₂Cl₂ (2 × 0.5CH₂Cl₂) and [PPh₃(FcCO₂)₂RuB₁₀H₈] (3). All of these compounds are characterized by FT‐IR, NMR spectroscopic techniques, elemental analysis and single‐crystal X‐ray analysis. They are all based on a closo‐type 1:2:4:2:2 {RuB₁₀} stack with the metal occupying the unique six‐connected apical position and can be considered as having isocloso structures derived from the complete capping of the open face of an arachano geometry to give a completely closed deltahedral cluster. Compounds 1 and 2 both have an exo‐polyhedral ferrocenecarboxylate that is attached with one {Ru? O} and one {B? O} bond each, resulting in one exo‐cyclic five‐membered Ru? O? C? O? B ring. There is in addition one exo‐polyhedral ruthenium atom bonded to the center {RuB₁₀} cluster via one {Ru? Ru} linkage and two {RuH_µB} bridges, which forms a closed exo‐polyhedral tetrahedron configuration in compound 2. Compound 3 has two exo‐polyhedral ferrocenecarboxylates to form two five‐membered Ru? O? C? O? B rings engendering a symmetrical conformation. All of these new 11‐vertex ruthenaboranes can be considered as having isocloso structures derived from the complete capping of the open face of an arachano geometry to give a completely closed deltahedral cluster. Copyright © 2006 John Wiley & Sons, Ltd.     

Metal complexes of some 5-nitrosopyrimidine derivatives

M(ADNU) ₂ complexes [whereM=Cu(II), Ni(II), Pd(II) and Pt(II); HADNU=6-amino-1,3-dimethyl-5-nitroso-uracil], Co(ADNU)₃·5H₂O, Pt(ADNU)₂Cl₂·0.5H₂O, Pd(ADU)₂ and Pt(ADU)₂Cl₂ (where HADU=1,3-dimethyl violuric acid) have been synthesized and characterized by elemental analysis, IR, magnetic measurements and thermal analysis (TG and DSC). All the isolated complexes of formulasM(ADNU)₂ orM(ADU)₂ show a square planar geometry, whereas the others are octahedral. Both ligands coordinate in bidentate form through the nitrogen and oxygen atoms of the 5-nitroso and 6-oxide groups.

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Metall-Komplexe einiger 5-Nitrosopyrimidine

Zusammenfassung Komplexe des TypesM(ADNU)₂ [M=Cu(II), Ni(II), Pd(II), Pt(II); HADNU=6-Amino-1,3-dimethyl-5-nitroso-uracil], Co(ADNU)₃·5H₂O, Pt(ADNU)₂Cl₂·0.5H₂O, Pd(ADU)₂ und Pt(ADU)₂Cl₂ (mit HADU=1,3-dimethylviolursäure) wurden synthetisiert und mittels Elementaranalysen, IR, magnetischen Messungen und Thermoanalyse (TG und DSC) charakterisiert. Alle isolierten Komplexe der allgemeinen FormelnM(ADNU)₂ oderM(ADU)₂ waren von quadratisch planarer Geometrie, während die anderen sich als octaedrisch erwiesen. Beide Liganden komplexieren zweizähnig über die Stickstoff- und Sauerstoffatome der 5-Nitroso- und 6-Oxo-Gruppen.

     

Preparation of Pd(PPh<Subscript>2</Subscript>H)<Subscript>2</Subscript>(PPh<Subscript>3</Subscript>)<Subscript>2</Subscript> and its Role as a Precursor of a Dinuclear Complex with Bridging Phosphide Ligands

Reaction of PPh₂H with Pd(PPh₃)₄ in a 4:1 molar ratio produced the Pd complex with two diphenylphosphine ligands, Pd(PPh₂H)₂(PPh₃)₂ (1). Complex (1) was characterized by n.m.r. (¹H and ³¹P{¹H}) spectra as well as by elemental analysis. Reaction of (1) with RhCl(PPh₃)₃ yielded a Pd–Rh heterobimetallic complex with bridging phosphide ligands, formulated as [(Ph₃P)₂Pd(μ-PPh₂)₂Rh(PPh₃)₂]Cl (2).