Reaction Of PdCl Research Articles

Reaction of PdCl2 with Diphenylacetylene Revisited: Effect of Solvents and Ball Milling on Cyclization and Crystal Structures of Dimeric Cyclobutenylpalladium Chloride Complexes

AbstractIn an attempt to establish the structures of the product formed in the reaction of PdCl2 and diphenylacetylene in polar organic solvents, the reactions were carried out in alcohols, acetonitrile and tetrahydrofuran at room temperature. The reactions in protic solvents such as primary and secondary alcohols resulted in the cyclic dimerization of diphenylacetylene to yield the corresponding dimeric endo‐4‐alkoxy‐π‐1,2,3,4‐tetraphenylcyclobutenypalladium(II) chloride complexes 1–4 in good yields. In these complexes the tetraphenylcyclobutenyl moieties are coordinated to palladium atoms in η3‐mode and are bridged by two chlorides as confirmed by the single crystal X‐ray analysis of complexes 1, 2 and 4. In all these complexes, the coordination of cyclobutenyl moieties to palladium atoms are similar but a marked difference was observed for the Pd2Cl2 core which is planar in complex 1 but puckered in complexes 2 and 4 resulting in shorter Pd⋅⋅⋅Pd distances. The same reaction under solvent free ball milling condition yielded hexaphenylbenzene by the cyclic trimerization while that in the presence of ethanol and n‐butanol produced complexes 1 and 3, respectively, as major and hexaphenylbenzene as minor product. An efficient catalytic synthesis of hexaphenylbenzene using PdCl2 was developed using ball milling condition which has several advantages over the existing catalytic systems.

Synthesis of spherical porous Pd nanoparticle superstructure and its catalytic oxidation of formic acid

Spherical porous Pd nanoparticle superstructures with the diameter in the range of 30-50 nm were obtained by the reaction of PdCl₄^2- with hydrazine using hexadecylpyridinium chloride as a structure-directing agent in the mixed acetone/water solution. It was found that hexadecylpyridinium chloride had significant influence on the formation of the spherical porous Pd nanoparticle superstructure. Only solid spherical structure was formed in the absence of the surfactant. In addition, acetone had an effect on the size of the micelles modified. The electrocatalytic activity of the spherical porous Pd nanoparticle superstructure electrode for the formic acid oxidation in 0.5 mol/L H₂SO₄+0.5 mol/L HCOOH was also investigated. The results displayed that electrocatalytic activity and stability of the spherical porous Pd nanoparticle superstructure catalyst were better than that of the solid Pd catalyst.

First Palladium(II) and Platinum(II) Complexes from Employment of 2,6-Diacetylpyridine Dioxime: Synthesis, Structural and Spectroscopic Characterization, and Biological Evaluation

Employment of the monoanion of 2,6-diacetylpyridine dioxime (dapdoH(2)) as a tridentate chelate in palladium(II) and platinum(II) chemistry is reported. The syntheses, crystal structures, spectroscopic and physicochemical characterization, and biological evaluation are described of [PdCl(dapdoH)] (1) and [PtCl(dapdoH)] (2). Reaction of PdCl(2) with 2 equivs of dapdoH(2) in MeOH under reflux gave 1, whereas the same reaction with PtCl(2) in place of PdCl(2) gave 2 in comparable yields (70-80%). The divalent metal center in both compounds is coordinated by a terminal chloro group and a N,N',N"-tridentate chelating (η(3)) dapdoH(-) ligand. Thus, each metal ion is four coordinate with a distorted square planar geometry. Characterization of both complexes with (1)H and (13)C NMR and UV-vis and electrospray ionization mass spectroscopies confirmed their integrity in DMSO solutions. Interaction of the complexes with human and bovine serum albumin has been studied with fluorescence spectroscopy, revealing their affinity for these proteins with relatively high values of binding constants. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that they can bind to CT DNA, and the corresponding DNA binding constants have been evaluated. Cyclic voltammograms of the complexes in the presence of CT DNA solution have shown that the interaction of the complexes with CT DNA is mainly through intercalation, which has been also shown by DNA solution viscosity measurements. Competitive studies with ethidium bromide (EB) have revealed the ability of the complexes to displace the DNA-bound EB, suggesting competition with EB. The combined work demonstrates the ability of pyridyl-dioxime chelates not only to lead to polynuclear 3d-metal complexes with impressive structural motifs and interesting magnetic properties but also to yield new, mononuclear 4d- and 5d-metal complexes with biological implications.

Structural Flexibility and Role of Vicinal 2-Thienyl Rings in 2,3-Dicyano-5,6-di(2-thienyl)-1,4-pyrazine, [(CN)2Th2Pyz], Its Palladium(II) Complex [(CN)2Th2Pyz(PdCl2)2], and the Related Pentametallic Pyrazinoporphyrazines [(PdCl2)4Th8TPyzPzM] (M = MgII(H2O), ZnII)

The solid state and solution structure of 2,3-dicyano-5,6-di(2-thienyl)-1,4-pyrazine, [(CN)(2)Th(2)Pyz], and its Pd(II) derivative, [(CN)(2)Th(2)Pyz(PdCl(2))(2)]·H(2)O, formed by reaction of [(CN)(2)Th(2)Pyz] with [(C(6)H(5)CN)(2)PdCl(2)] were characterized by X-ray, UV-visible, (1)H and (13)C NMR, and extended X-ray absorption fine structure (EXAFS) spectral measurements. The X-ray crystal structure of [(CN)(2)Th(2)Pyz] shows the presence of one thienyl ring positioned orthogonal to the rest of the molecule, with the two vicinal thienyl rings lying orthogonal to each other in a rare arrangement. NMR studies of [(CN)(2)Th(2)Pyz] in the solid state and in solutions of dimethylformamide or dimethyl sulfoxide confirm a nonequivalence of the thienyl rings in the solid state and also in solution. EXAFS results indicate that two distinct Pd(II) coordination sites are formed at the di(2-thienyl)pyrazino moiety of [(CN)(2)Th(2)Pyz(PdCl(2))(2)]·H(2)O, with identical Pd-N(pyz) (2.03(3) Å) and Pd-Cl (2.36(3) Å) bond lengths but with different Pd-S1 (2.25(4) Å) and Pd-S2 (3.21(5) Å) bond distances in an overall asymmetric molecular framework. Density functional theory (DFT) and time-dependent DFT (TDDFT) theoretical studies also provide information about the structure and spectral behavior of the precursor and its metalated Pd(II) derivative. (1)H/(13)C NMR and UV-visible spectral measurements were also carried out on two heteropentametallic porphyrazine macrocycles which were prepared by a reaction of PdCl(2) with [Th(8)TPyzPzM] where Th(8)TPyzPz = tetrakis-2,3-[5,6-di-(2-thienyl)-pyrazino]porphyrazinato dianion and M = Mg(II)(H(2)O) or Zn(II). Spectroscopic data on the newly synthesized [(PdCl(2))(4)Th(8)TPyzPzM] compounds suggest that the binding of PdCl(2) involves coordination sites of the type S(2(th))PdCl(2) with the two thienyl rings of each di(2-thienyl)pyrazino fragment bound to Pd(II) in an equivalent manner ("th-th" coordination). This is similar to what was found for the corresponding octapyridinated analogues ("py-py" coordination).

Reusable functionalized polysiloxane-supported palladium catalyst for Suzuki–Miyaura cross-coupling

Palladium catalyst, obtained in the reaction of PdCl 2(cod) with poly[(3-N-imidazolopropyl)methylsiloxane-co-dimethylsiloxane], was used in the Suzuki–Miyaura cross-coupling of aryl bromides with phenylboronic acid. Catalytic reactions, performed at 40–80 °C in water or 2-propanol/water mixture, led to high yields of 2-methylbiphenyl with TOF up to 25,000 h −1. In recycling experiments, excellent results were obtained in eight subsequent runs. With application of microwave heating, more than 95% of product was formed under mild conditions and short time. XRD, TEM, and XPS methods evidenced the presence of Pd(0) nanoparticles bonded to the polysiloxane support. Their important role in the catalytic process was indicated by the results of mercury poisoning test.

Cyclopalladation of indole-3-carboxaldehyde aroylhydrazones

Reactions of PdCl 2, LiCl, indole-3-carboxaldehyde 4- R-benzoylhydrazones (H 2L n ; n = 1, 2, 3 and 4 for R = H, Cl, OMe and NMe 2, respectively) and CH 3COONa·3H 2O in 1:2:1:1 mol ratio in methanol produce the cyclopalladated species of general formula [Pd(HL n )Cl] in 65–85% yields. The complexes have been characterized with the help of elemental analysis and spectroscopic (infrared, electronic and NMR) measurements. The proton NMR spectra of the complexes suggest palladation at the peri position of the indole moiety in (HL n ) −. Molecular structure of a representative complex determined by X-ray crystallography confirms the peri-palladation and formation of a distorted CNOCl square-plane around the metal centre by the tridentate (HL n ) − and the chloride.

Synthesis and characterization of amide-functionalized N-heterocyclic carbene–Pd complexes

Amide-functionalized N-heterocyclic carbene (NHC) precursors such as azolium compounds have been designed and synthesized. Reaction of PdCl 2(CH 3CN) 2 with the NHC–Ag complex derived from the azolium salt gave [(NHC)PdCl 2] 2 or (NHC) 2PdCl 2, whereas PdCl 2(PPh 3) 2 reacted with the Ag complex to afford a mixed carbene/phosphine complex such as (NHC)(PPh 3)PdCl 2 together with a cationic [(NHC)(PPh 3) 2PdCl] +Cl − whose structure was characterized by X-ray crystallographic studies. Thus, the library of NHC–Pd complexes with a tethered amide group has been successfully expanded.

Diethanolamine Pd(II) complexes in bioorganic modeling as model systems of metallopeptidases and soybean lipoxygenase inhibitors

The reaction of PdCl 2 with diethanolammonium chloride (DEAxHCl), in the molar ratio 1:2, affords the [HDEA] 2[PdCl 4] complex ( 1). The hydrolytic activity of the novel Pd(II) complex 1 was tested in reaction with N-acetylated L-histidylglycine dipeptide (AcHis-Gly). Complex 1, as well as earlier prepared trans-[PdCl 2(DEA) 2] complex ( 2), and DEA, as their precursor, were tested for their in vitro free radical scavenging activity. UV absorbance-based enzyme assays were done in order to evaluate their inhibitory activity of soybean lipoxygenase (LOX). Also, assays with superoxide anion radical were done. The scavenging activities of the complexes were measured and compared with those of their precursors and caffeic acid. Complex 2 exhibits the highest antioxidant activity and the highest inhibitory effect against the soybean LOX.

Palladium and platinum complexes of chiral and achiral calix[4]arene bisphosphite ligands

Chiral and achiral p- tert-butyl-calix[4]arene bisphosphites ( L 1– L 3) have been synthesized by the reaction of p- tert-butyl-calix[4]arene and the phosphorodichloridites, ROPCl 2 [R = (1 S,2 R,5 R)-(+)- iso-menthyl ( L 1), (1 R,2 S,5 R)-(−)-menthyl ( L 2) or C 6H 4Bu t -4 ( L 3)]. These bisphosphites function as chelating ligands in palladium(II) and platinum(II) complexes which are formed in good yields by the reaction of PdCl 2(PhCN) 2, MCl 2(COD) (M = Pd or Pt) or PdMeCl(COD) with the respective calix[4]arene bisphosphite. Single crystal X-ray diffraction studies performed on the complexes [PdCl 2( L 1)], [PdCl 2( L 2)], [PdCl 2( L 3)] and [PtCl 2( L 3)] reveal a near square planar geometry around the metal with the two chloride ligands in a cis disposition. The crystal packing in the complexes [PdCl 2( L 1)] and [PdCl 2( L 2)], which crystallize in the chiral ( P6 122) space group, shows different hydrophobic channels with intermolecular C–H⋯Cl hydrogen bonding. The complexes [PdCl 2( L 3)] and [PtCl 2( L 3)] are isostructural and the molecules in the crystal lattice are linked by intermolecular C–H⋯Cl and C–H⋯O hydrogen bonds.

New Pd(II)–mechlorethamine complex: Synthesis, NMR study of hydrolytic activity and in vitro evaluation of antiradical property of new complex and its alkylating precursor

The reaction of PdCl 2 with anticancer-alkylating agent mechlorethamine hydrochloride (CH 3NH(C 2H 4Cl) 2 = HN2 x HCl), in the molar ratio 1:2, affords the complex [CH 3NH(C 2H 4Cl) 2] 2[PdCl 4] ([H2N2] 2[PdCl 4]). Novel Pd(II) complex and the complex precursor mechlorethamine hydrochloride were tested for their antiradical property. Both present weak interaction with 2, 29-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS). Assays with soybean lipoxygenase and with superoxide anion radicals in vitro showed very high radical scavenging activity of the complex, whereas the complex precursor mechlorethamine hydrochloride presents lower inhibition. Hydrolytic activity of new complex with N-acetylhistidylglycine (AcHis–Gly) was also studied. It was established that regioselective cleavage of the amide bond of the investigated dipeptide had occurred after heating at 60 °C and at pH = 1.5 for 36 h.

Highly active Pd(II) catalysts with pyridylbenzoimidazole ligands for the Heck reaction

The air-, and thermo-stable palladium(II) complexes C1– C10 are prepared by the reaction of PdCl 2(CH 3CN) 2 with pyridylbenzoimidazole. With various substituents on the pyridine ring, palladium atom was coordinated by two pyridylbenzoimidazole molecules via nitrogen atoms of benzoimidazole. The structure of complexes C3, C4, C6, and C7 has been confirmed by X-ray diffraction analysis. Without substituents on the pyridine ring, palladium atom was directly coordinated with two nitrogen atoms of pyridine and benzoimidazole nitrogen via intramolecular chelation ( C10). These complexes performed the Heck olefination of aryl bromides in a good to high yield under phosphine-free conditions.

Synthesis, structure and reactivity of cuboidal-type cluster aqua complexes with W3PdS44+core

The reaction of PdCl(2) with [W3S4(H2O)9]4+ in the presence of hypophosphorous acid in 2 M HCl gives cuboidal cluster [W3(PdCl)S4(H2O)9]3+ (1) which undergoes condensation and crystallises from Hpts solutions as edge-linked double cubane cluster [{W3PdS4(H2O)9}2](pts)(8).19H2O (pts = p-toluenesulfonate) (1'). The substitution of Cl- in (1) by different ligands was explored. The Pd atom in the cluster shows an exceptionally high reactivity in the isomerisation of the hydrophosphoryl H2P(O)(OH), HP(O)(OH)2, HPPh(O)(OH) and HPPh2(O) molecules into the corresponding hydroxo tautomers HP(OH)2, P(OH)3, PhP(OH)2 and Ph2P(OH) stabilised by coordination at Pd. The reactions were followed by UV-Vis spectrophotometry and 31P NMR. Formation constants of the 1 : 1 coordination of [M3(PdCl)S4(H2O)9]3+ (M = Mo, W) with HP(OH)2 and As(OH)3 were obtained. The structures of cucurbit[6]uril (C36H36N24O12, CUC[6]) adducts [W3(PdP(OH)3)S4(H2O)8Cl]-(C36H36N24O12)Cl3.12.5H2O (2), and [W3Pd(PhP(OH)2)S4(H2O)7Cl2]2(C36H36N24O12)Cl4.9H2O (3) were determined by single-crystal X-ray diffraction.

Synthesis, characterization and assessment of the cytotoxic properties of cis and trans-[Pd(L) 2Cl 2] complexes involving 6-benzylamino-9-isopropylpurine derivatives

A series of square-planar Pd(II) complexes of the composition cis-[Pd(L n ) 2Cl 2] {L 1 = 2-chloro-6-benzylamino-9-isopropylpurine ( 1), L 2 = 2-chloro-6-[(4-methoxybenzyl)amino]-9-isopropylpurine ( 2), L 3 = 2-chloro-6-[(2-methoxybenzyl)amino]-9-isopropylpurine ( 3) and 2-[(chloropropyl)amino]-6-benzylamino-9-isopropylpurine ( 6)} has been synthesized by the reaction of PdCl 2 with L n in a 1:2 molar ratio. In contrast, the same reaction followed by recrystallization of the product from N, N′-dimethylformamide (DMF) leads to trans-[Pd(L n ) 2Cl 2] · nDMF {L 3, n = 0 ( 4), n = 1( 4 ∗ DMF); L 4 = 2-chloro-6-[(2,3-dimethoxybenzyl)-amino]-9-isopropylpurine, n = 0 ( 5), n = 1.5 ( 5 ∗ DMF). The compounds have been characterized by elemental analyses, conductivity measurements, electrospray mass spectra in the positive ion mode (ES + MS), FTIR, 1H and 13C NMR spectra, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Moreover, the complexes 2 and 6 have been also investigated by 15N NMR spectroscopy. The molecular structures of L 5, {(H 2+L 5)(Cl −) 2} · H 2O, i.e. the protonated form of L 5, trans-[Pd(L 3) 2Cl 2] ( 4) and trans-[Pd(L 4) 2Cl 2] ( 5) have been determined by single crystal X-ray analysis. NMR data and X-ray structures revealed that the organic molecules are coordinated to Pd via N7 atom of a purine moiety. All the complexes and the corresponding ligands have been tested in vitro for their cytotoxicity against four human cancer cell lines: breast adenocarcinoma (MCF7), malignant melanoma (G361), chronic myelogenous leukaemia (K562) and osteogenic sarcoma (HOS). Promising in vitro cytotoxic effect has been found for cis-[Pd(L 2) 2Cl 2] ( 2), having the IC 50 values of 12, 10, 25, and 14 μM against MCF7, G361, K562, and HOS, respectively, and for trans-[Pd(L 3) 2Cl 2] · DMF ( 4) with the IC 50 value of 15 μM against G361.

Synthesis, structure, and hydrolytic reaction of trans-dichlorobis(diethanolamine- N)palladium(II) with N-acetylated L-histidylglycine dipeptide

The reaction of PdCl 2, or K 2PdCl 4, with diethanolamine (DEA), in the molar ratio 1:2, affords the trans-[PdCl 2(DEA) 2] complex. X-ray structure analysis of this complex confirmed the formation of the trans-isomer. The complex crystallizes in the space group P4 2 bc. The central Pd(II) ion is coordinated in an almost ideal square-planar fashion with a small deformation of the Cl–Pd–Cl angle (175.6(7)°) due to N–H⋯Cl hydrogen bonding. The N–H group participates in a bifurcated interaction with the two symmetry related Cl − anions. The hydroxyl groups of the diethanolamine ligand form very strong hydrogen bonds between the complex units, thus leading to infinite zigzag (O–H⋯O–H⋯O–H ··) chains in the crystal packing. The complex units are further connected by weaker intermolecular hydrogen bonds of the N–H⋯Cl type in a way to form layers parallel to the crystallographic (001) plane. The reaction between the trans-[PdCl 2(DEA) 2] or trans-[Pd(H 2O) 2(DEA) 2] 2+ complex and MeCOHis-Gly dipeptide at 1.5 < pH < 2.0 and at 25 °C leads to the regioselective cleavage of the amide bond involving the carboxylic group of the histidine. The cleavage of the substrate was fast and went almost to completion within less than one hour.

Synthesis of palladium complexes containing 2-methoxycarbonyl-6-iminopyridine ligand and their catalytic behaviors in reaction of ethylene and norbornene

A series of palladium complexes ( C1– C7) have been prepared by the reaction of PdCl 2(CH 3CN) 2 with 2-methoxycarbonyl-6-iminopyridines, L1– L7. The 2-methoxycarbonyl-6-iminopyridines and their complexes were fully characterized by FT-IR, NMR spectra and elemental analysis. Structures of C1, C2, C4, C5 and C6, C7 were determined by X-ray crystallography, and these complexes fold slightly distorted square planar structures around palladium coordinated with two nitrogen atoms and two chlorides. These palladium complexes exhibited moderate catalytic activities for ethylene dimerization and/or polymerization in the presence of methylaluminoxane, and showed remarkable catalytic activity for norbornene polymerization. The catalytic behaviors of these complexes were highly affected by both the ligand employed and reaction conditions.

Chemistry of palladium phosphinite (PPh2(OR)) and phosphonite (P(OPh)2(OH)) complexes: catalytic activity in methoxycarbonylation and Heck coupling reactions

The new phosphinite and phosphonite complexes (1-8) are very efficient catalysts for the methoxycarbonylation of iodobenzene and Heck cross-coupling of bromobenzene with butyl acrylate. High catalytic activity of these complexes can be explained by their in situ transformations during the reaction, stimulated by the presence of water, acid (HCl) or base (NEt(3)). Hydrolysis of phosphinite palladium complexes of the form trans-PdCl(2)[PPh(2)(OR)](2) (R = C(6)F(5), 2, (t)Bu 3, or O-menthyl 4) results in the formation of the dimeric complex [mu-ClPd(PPh(2)OH)(PPh(2)O)](2) 5, which is deprotonated by NEt(3), producing a polymeric complex of formula [Pd(P(O)PPh(2))(2)](n) 8. The reverse reaction, protonolysis of 8 with HCl, leads back to 5 and the monomeric complex 5a. The phosphinite complex PdCl(2)[PPh(2)(OBu)](2)1 with a more lipophilic ligand, PPh(2)(OBu), does not undergo hydrolysis under the same conditions. In the reaction of PdCl(2)(cod) with P(OPh)(2)(OH), the new dimer [mu-ClPd(P(OPh)(2)OH)(P(OPh)(2)O)](2) 6 was obtained, whereas reaction of Pd(OAc)(2) with P(OPh)(2)(OH) leads to the polymeric complex [Pd[P(O)(OPh)(2)](2)](n) 7. Protonolysis of 7 with HCl results in the formation of 6.

Phenoxide-assisted P–C bond cleavage in PdCl 2(PPh 3) 2 under very mild conditions

PdCl 2(PPh 3) 2 reacted with NaOAr (Ar = Ph, p-tolyl) at 0 °C to afford PdCl(Ph)(PPh 3) 2, instead of PdCl(OAr)(PPh 3) 2, in 12–16% isolated yields based on Pd. The structure was confirmed by NMR and X-ray crystallography. GC–MS analysis of the reaction solution revealed that OPPh 2(OAr), OPPh(OAr) 2, and OP(OAr) 3 are formed, while NMR studies indicated that PdCl(Ph)(PPh 3) 2 is produced when PdCl(OAr)(PPh 3) 2 decomposes. The reaction of PdCl 2(PPh 3) 2 with Bu 3Sn(OC 6H 4- p-OMe) also gave PdCl(Ph)(PPh 3) 2 in 8% isolated yield. These results suggest that PdCl(OAr)(PPh 3) 2 is highly labile and the aryloxy ligand exchanges with the phenyl groups in triphenylphosphine even under very mild conditions.

Synthesis and characterization of new palladium–clotrimazole and palladium–chloroquine complexes showing cytotoxicity for tumor cell lines in vitro

New palladium complexes of chloroquine (CQ) and clotrimazole (CTZ) have been prepared, characterized, and evaluated against four tumor cell lines in vitro. [Pd (CQ) 2Cl 2] ( 1) was synthesized by the reaction of PdCl 2(CH 3CN) 2 with CQ, and the [Pd (CTZ) 2Cl 2] ( 2) complex by a similar reaction. The new compounds were characterized by a combination of FAB-MS (fast atom bombardment-mass spectrum), elemental analysis, molar conductivity, IR, and NMR spectroscopy. The solid-state structure of 2 has been determined by X-ray crystallography. 2 crystallizes in the monoclinic space group P(2 1/ c), with a = 21.100(4) Å, b = 13.408(3) Å, c = 22.642(5) Å. The structure refinement converged at R 1 = 0.0728, wR 2 = 0.1918. The cytotoxicity of these two complexes for the tumor cell lines, PANC-1, SKBR-3, MDA-MB231 and HT-29, was compared with that of the original ligands. Ligation of palladium to CTZ led to an increase in the IC 50, although a three-fold reduction in the IC 50 of CQ was observed on ligation to the metal when tested against the MDA-MB231 cell line.

Coordination of (aminoalkyloxymethyl)dimethylphosphine oxides with palladium(II). Crystal structure of trans-bis[2-(dimethylphosphinoylmethoxy-1,1-dimethylethylamine)]palladium(II) dichloride

The synthesis, structure and spectroscopic properties of novel palladium(II) chloro complexes with a series of (aminoalkyloxymethyl)dimethylphosphine oxides (AOPO) are reported. The complexes with general formula PdCl 2( N, N′-AOPO 2) were obtained by the reaction of PdCl 2(CH 3CN) 2 with the ligands in dry ethanol. The crystal structure of the trans-bis[2-(dimethylphosphinoylmethoxy-1,1-dimethylethylamine)]palladium(II) dichloride has been determined from single-crystal X-ray diffraction data. The compound crystallizes in monoclinic crystal system with P2 1/ n space group. The square-planar coordination sphere of palladium consists of two N atoms from two aminoalkyldimethylphosphine ligands and two Cl atoms in trans-arrangement. The AOPO ligand has monodentate coordination through the NH 2 group. The Pd–N and Pd–Cl distances are 2.0610(14) and 2.3225(4) Å, respectively. The preparation of complexes with a composition PdCl 2(AOPO) 2 in chloroform solution are also reported.

Suzuki cross-coupling in aqueous media catalyzed by a 1,1 ′- N-substituted ferrocenediyl Pd(II) complex

Reaction of PdCl 2(MeCN) 2 with Fe[η-C 5H 4NC(H)Ph–N] 2 ( 1) at MeOH at r.t. gives air-stable PdCl 2Fe[η-C 5H 4NC(H)Ph–N] 2 ( 2; yield 84%). X-ray single-crystal diffraction analyses show that 2 is a Pd(II) square planar complex with N, N ′ chelation of the ferrocenediyl ligand, without Fe–Pd bond. It effectively catalyzes Suzuki cross-coupling reactions of aryl iodides and bromides with aryl boronic acids in aqueous media under non-homogeneous conditions in which the products can be easily isolated. The reaction conditions including choice of base, catalytic load and catalyst recoverability have been investigated and reported.