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Recrystallization of a palladium compound bearing bidentate H-spirophosporane [PdCl{P(OCH2CHi-PrNH)OCH2CHi-PrNH2}] from methanol in air atmosphere, gave rise to the palladium complex with tridentate NPN ligand [PdCl{P(O)(OCH2CHi-PrNH2)2}]. The structures of the complex and H-spirophosphorane ligand HP(OCH2CHi-PrNH)2 were determined using spectroscopic methods as well as by single-crystal X-ray diffraction.

A Pd complex with the H-spirophosphorane ligand, PdCl2{P(OCMe2CMe2O)OC6H4NH2} (Cat. 1), was used as the catalyst in the carbonylative Suzuki coupling of substituted iodobenzenes with arylboronic acids and with sodium tetraphenylborate. Substituted diarylketones were obtained in good to excellent yields and a selectivity over 95 % under 1 atm of CO with 1.5 mol % of the catalyst. The promoting role of the H-spirophosphorane ligand in the catalytic process was evidenced. We used X-ray photoelectron spectroscopy, TEM, and 31P NMR spectroscopy to reveal that during the reaction Cat. 1 undergoes transformation into Pd complexes that bear the spirophosphorane ligand or other P ligands formed by its dealkylation and to Pd nanoparticles. All these Pd species contribute to the high productivity of the system.

Two palladium complexes of the type [Pd(im)2Cl2] containing chiral imidazole ligands (im = 1-bornyloxymethylene imidazole, 1-fenchyloxymethylyne imidazole) were synthesized and structurally characterized. The square planar structure of one of the complexes was confirmed by the X-ray analysis. The new palladium complexes were tested as catalysts in various C C bond forming reactions, namely Suzuki–Miyaura, carbonylative Suzuki–Miyaura, asymmetric Heck-type coupling reactions and asymmetric conjugate addition of phenylboronic acid to heterocyclic acceptors. In all the reactions the cross-coupling products were obtained with high yield and selectivity under mild conditions. In case of coupling of 2,3-dihydrofuran with phenylboronic acid ee value ca. 10 was observed.

Two different kinds of Al 2 O 3 -ZrO 2 have been prepared by the alkoxide sol-gel process: bulky-shaped and formed into spherical granules with the diameter of 2–3 mm. The catalysts have been obtained either by impregnating the support with the metal precursor (Pd or Ni salt solution) or by simultaneous addition of the precursor during synthesis of the support (the co-precipitation technique). The catalysts have been characterized structurally with scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption studies and successfully applied in the Suzuki-Miyaura cross-coupling of phenylboronic acid with different kinds of aryl halides (2-bromotoluene, 4-bromotoluene, 4-bromoanisole or 4-iodoanisole). Our experiments have shown that nickel species supported on Al 2 O 3 -ZrO 2 can be successfully employed as the catalyst in the Suzuki-Miyaura process.

Palladium PEPPSI-type complexes with small NHC ligand were applied as catalyst precursors in cross-coupling reactions forming a wide range of non-symmetric biaryls with high yields. The recycling of the in situ formed palladium composite was successfully performed in 10 subsequent runs. Mechanistic studies confirmed a labile character of the N-ligands coordinated to palladium by ligand exchange monitored using 1H NMR. The formation of Pd(0) NPs during the catalytic process was evidenced by TEM.

Dimeric complexes of the type [Pd(μ-X)X(NHC)]2 were employed in the Suzuki–Miyaura cross-coupling leading to 2-methylbiphenyl. The excellent activity of the studied dimers is perfectly illustrated by a TOF of up to 106 h−1. Mechanistic investigations with the application of TEM, XPS, and mercury poisoning tests provided an insight into the nature of the catalytic process. Accordingly, the reduction of the dimeric palladium complex [Pd(μ-X)X(NHC)]2 resulted in the formation of a composite containing Pd(0) nanoparticles protected by a layer of a Pd(II) species such as anions [PdBr4]2− or [PdBr3(NHC)]−. The in situ formation of Pd(0)–Pd(II) composites resulted in the high stability of the catalytic system, which was active in ten subsequent recycles without any additional protection.

A series of trimeric palladium complexes of the [Pd3(μ-Cl)4(P–C)2] (P–C = orthometallated aryl phosphite) formula have been prepared and structurally characterized using 31P NMR and ESI-MS methods. The structure of [Pd3(μ2-Cl)4{k2-P,C–P(O–o-CH3C6H3)(O–o-CH3C6H4)2}2], 1c, was determined by X-ray diffraction. It is compared with the structure of the dimeric complex [Pd2(μ-Cl)2{k2-P,C–P(O–m-CH3C6H3)(O–m-CH3C6H4)2}2], 3b. The trimeric palladium complexes very efficiently catalyzed the Suzuki–Miyaura and Hiyama reactions in ethane-1,2-diol and the Sonogashira cross-coupling in ionic liquids. The mercury test confirmed the homogeneous pathway of the Suzuki–Miyaura reaction, although Pd(0) nanoparticles were observed by TEM in the post-reaction mixture.

Spent automotive three-way catalysts, containing Rh, Pd and Pt nanoparticles supported on oxide-based ceramic materials, catalyze the Heck cross-coupling of iodobenzene with butyl acrylate and unsaturated alcohols at 140 °C. Under Suzuki reaction conditions, biphenyl was formed with high yield when the same catalysts were applied. Successful hydroformylation of 1-hexene was performed in the presence of PPh 3 . The catalytic activity of spent automotive three-way catalysts was compared with that of airborne matter collected in the city of Wroclaw.

This review focuses on the underlying pathways of gender-dependent renal diseases and presents specific examples of diseases influenced by gender. In the literature it has been shown, in many clinical and experimental observations, that the incidence and the rate of progression of renal disease are influenced by many gender-dependent factors, such as kidney and glomerular size, differences in glomerular hemodynamics, and direct effects of sex hormones on renal tissue and signal pathways such as the renin-angiotensin-aldosterone system and signal molecules (e.g. nitric oxide, reactive oxygen species, cytokines and growth factors). It has been shown that the main female hormone, 17 β estradiol, is capable of inhibiting inflammatory and pro apoptotic processes and protects the renal tissue. In contrast, the male hormones, testosterone and dehydroepiandrosterone, have the opposite effect. Hormonal manipulation by male or female castration changes the course of renal disease progression and confirms the influence of the sex hormones. Female gender is therefore considered a protective factor in many kidney diseases, such as primary glomerulonephritis, autosomal dominant polycystic kidney disease (ADPKD) and hypertensive nephropathy. Similarly, women are more predisposed to autoimmune diseases with secondary glomerulonephritis, e.g. systemic lupus erythematosus, as the female sex hormones have the ability of autoimmune process activation. After menopause the protective effect of female gender is not observed, which confirms the role of the female sex hormones.

Three monomeric triphenylphosphite palladacycles of the formula [PdCl(P–C)(im)], where P–C = P(OC6H4)(OC6H5)2, im = 1-methylimidazole, 2, 1,2-dimethylimidazole, 3, and 1-butylimidazole, 4, were obtained in reaction of [PdCl(P–C)]2, 1, with the respective imidazoles. These complexes exhibited high catalytic activity in the Suzuki–Miyaura reaction in ethane-1,2-diol and in the Sonogashira reaction in ionic liquids, [bmim]BF4 and [bmim]PF6. While the application of two imidazoles per palladium caused improvement of the reaction yield, an inhibiting effect was found in both reactions when 1-methylimidazole or 1-butylimidazole was used in 20-fold excess relative to palladium.

We have investigated the reactivity of the unsymmetrical H-spirophosphorane (HSP) ligand HP(OCMe2CMe2O)(OCH2CMe2NH) 1 towards different palladium(II) precursors and synthesised the mononuclear complexes [PdCl2{P(OCMe2CMe2O)OCH2CMe2NH2}] 2 and [PdCl(C3H5){P(OCMe2CMe2O)OCH2CMe2NH2}] 3. The structural features of the compounds are characterised by spectroscopic methods as well as single crystal X-ray diffraction studies. The complexes are shown to be remarkably active precatalysts for the Heck and Hiyama cross-coupling reactions. The products of the C–C bond formation reactions were obtained with high conversion and stereoselectivity. Mechanistic studies of the Heck reaction reveal that, besides homogenous precatalysts, also heterogeneous Pd(0) nanoparticles are involved in the catalytic process.

Palladium catalysts containing Pd(0) or Pd(II) supported on alumina-based mixed oxides prepared by alkoxide sol–gel method (Al 2 O 3 , Al 2 O 3 –ZrO 2 , Al 2 O 3 –ZrO 2 –Eu 2 O 3 , Al 2 O 3 –MgO, Al 2 O 3 –CeO 2 , Al 2 O 3 –Fe 2 O 3 ) are very effective in the Heck coupling of bromobenzene with butyl acrylate in DMF solvent. In the presence of an excess of bromobenzene, butyl cinnamate (1) was formed as the main product after 4 h. With the same catalysts, good results, up to 97% yield of ethyl β-phenylcinnamate (3), were also obtained in the coupling of bromobenzene with ethyl cinnamate. The three most active catalysts, Pd(0)/Al 2 O 3 , Pd(II)/Al 2 O 3 , and Pd(II)/Al 2 O 3 –Fe 2 O 3 , were applied in the Heck cross-coupling of cinnamates with different bromobenzene and iodobenzene derivatives, leading to β-arylcinnamate products. The highest yield was observed when iodoanisole and cinnamic aldehyde were used as substrates. The formation of Pd(0) nanoparticles in the Heck reaction carried out with supported Pd(II) catalyst precursors was confirmed by TEM measurements.

Several palladium complexes of the type [Pd(im)2Cl2], [Pd(im)3Cl]Cl, and [Pd(im)4]Cl2 (im = imidazole 1, 1-methylimidazole 2, 1,2-dimethylimidazole 3, 1-butylimidazole 4, 4a, 1-phenylimidazole 6, 1-phenylimidazoline 7, and 1-methylimidazoline 8) were prepared and structurally characterized. The square planar structure of two new complexes with the composition [Pd(im)4]Cl2 (2b, 4b) was confirmed by X-ray analysis. In solution, exchange of imidazole ligands leading to heteroleptic products was evidenced by ESI-MS studies. Two bis-ligated complexes, bearing 1-methylimidazole (2a) and 1-propoxymethylimidazole (5) ligands, were obtained in the reaction of palladium with imidazoles formed by deprotection of one nitrogen atom in the respective imidazolium halides. Catalytic Suzuki–Miyaura reactions were carried out using the obtained palladium complexes in isopropanol–water solution. High yields of the cross-coupling products were obtained at 40 and 60 °C when 2-bromotoluene, 4-bromotoluene, and 4-bromoanizole were used as substrates.

PdII anionic, square planar complexes of the type [IL]2[PdX4], where IL = imidazolium cations, X = Cl, Br, have been applied for the first time as catalyst precursors for the Suzuki–Miyaura (S–M) reaction carried out in alcohols at 40 °C. Depending on the structure of the catalyst precursor used, different yields of 2-methylbiphenyl (2-MePh–Ph) were obtained in a test reaction of 2-bromotoluene (2-MePhBr) with phenyl boronic acid (PhB(OH)2). The highest yield, ca. 95%, was obtained for [dmiop]2[PdCl4] (dmiop-1,2-dimethyl-3-propoxymethylene imidazolium cation) in methanol in the presence of KOH as a base. It was found that during the reaction Pd0 nanoparticles of 4–7 nm have been formed in situ from the palladium(II) precursor. In the first stage of this process, [(IL)3Pd(OH)2]+-type species have been formed from [IL]2[PdX4] precursors. Small Pd0 clusters, [(IL)5Pd3(H2O)]+ and [(IL)3Pd3(H2O)7]+, were also identified by ESI-MS. These species reacted with ArB(OH)2 forming palladium aryl complexes of the type [(IL)2PdAr]+, key intermediates in the catalytic process. The first experimental evidence of the IL stabilized Pd0 species in S–M reaction is presented.

Alumina-based oxides Al 2 O 3 , Al 2 O 3 –ZrO 2 (A, B, C) and Al 2 O 3 –ZrO 2 –Eu 2 O 3 (D) were prepared by alkoxide sol–gel method and used as supports for palladium nanoparticles obtained by reduction of PdCl 2 by methanol or hydrazine. As confirmed by XRD and TEM methods, such catalysts are composed of palladium nanoparticles well dispersed on the surface of the alumina matrix. The Suzuki coupling of 2-bromotoluene with phenylboronic acid, used as the test reaction, revealed that the obtained catalysts were quite efficient even at 40 °C and that their catalytic activity increased at 60 and 80 °C. Very good results (95% yield after 1 h) also were obtained when PdCl 2 supported on mixed oxides was used without earlier palladium reduction. It was confirmed that under the reaction conditions, Pd(0) nanoparticles of ca. 5 nm in diameter were formed on the support. Under the same conditions ( i PrOH + H 2 O used as a solvent, KOH as a base), a Pd(0)/PVP colloid exhibited slightly lower catalytic activity.

Aminocarbonylation of aryl iodides with aromatic and aliphatic amines, leading to formation of the corresponding amides, was efficiently carried out in water under 1 atm of CO using palladium nanoparticles (Pd NPs) formed in situ from [PdCl2(Ar2-BIAN)] complexes. The role of Ar2-BIAN ligands in the stabilization of Pd NPs was evidenced. The nature of the catalytically active species was confirmed by poisoning experiments, which highlighted that the catalyst is actually in the form of Pd NPs rather than soluble palladium complexes. In the aminocarbonylation of iodobenzene with substituted anilines good yields of amides were obtained, although the activity was depleted by the presence of substituents in the ortho positions of the aniline. On the other hand, in the reaction with aliphatic amines α-ketoamides were formed in addition to the amides. The selectivity towards α-ketoamides was increased by increasing the CO pressure to 10 atm, at equimolar amounts of PhI and amine. Pd NPs were successfully recovered after the catalytic reaction and recycled in five subsequent runs with only a marginal loss of activity after the fourth cycle.

Pd(II)/Al2O3 and Pd(0)/Al2O3, containing 0.6% of palladium were characterized by EDX, SEM and XRD methods and used as catalysts of the Heck coupling of bromobenzene with butyl acrylate at 140 °C in molten [Bu4N]Br salt. Monoarylated (trans-PhCH = CHC(O)OBu) (1) and diarylated (Ph2C = CHC(O)OBu) (2) products were obtained in amounts dependent on kind of base present in the system (Scheme 1). During the reaction palladium was partially leached from the support forming [Bu4N][PdBr4] complex that catalyze Heck reaction or undergo readsorption on Al2O3. These soluble palladium complexes are partially reduced to Pd soluble nanoparticles which can also be anchored on Al2O3 giving active catalyst of Pd(0)/Al2O3 type. Reduction of Pd(II) to Pd(0) during catalytic process at the presence of bases (NaHCO2, NaHCO3, NaOAc, Cs2CO3) was studied by XPS method and the total reduction was observed in reactions of PdCl2(PhCN)2 with NaHCO2 or with NaHCO3 and [Bu4N]Br. It was experimentally proved that heterogenized catalyst, Pd(0)/Al2O3, after oxidative addition of aryl halides, serve as a source of soluble palladium species and colloidal nanoparticles that are active as homogeneous catalysts.

The title compound, [Pd2(C12H10O3P)2Cl2(C12H11O3P)2], consists of a dinuclear mu-chloro-bridged palladium unit with two diphenoxyphosphinite groups per Pd atom, linked together by a hydrogen bond. The asymmetric unit contains one half of the molecule, with the other half generated by an inversion centre. The geometry around the P atoms may be described as distorted tetrahedral. Adjacent molecules of the complex are linked by weak C-H...O and C-H...Cl hydrogen bonds. The structure is additionally stabilized by pi-pi stacking interactions between the aryl rings. These interactions form a herring-bone pattern in the crystal structure.

Palladium colloids were prepared by chemical reduction of an aqueous solution of palladium dichloride with the reducing agents pyrogallol, chromium(II) acetate, and hydrazine in the presence of polyvinylpyrrolidone (PVP) as a stabilizing agent. The colloids thus obtained were characterized by means of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy-dispersive X-ray microanalysis (EDX). Their catalytic activity was studied in a test reaction, methoxycarbonylation of iodobenzene. The choices of reducing agent and reduction conditions enables to synthesize colloids with various mean nanoparticle sizes (ranging from 1.9 to 19.8 nm) and nanoparticle morphologies. These two factors play a decisive role from the standpoint of catalytic activity of the systems under study.

Pd-PVP colloid (stabilized with polyvinylpyrrolidone) with a diameter of 19.8 nm in [Bu4N]Br medium catalyzes Heck coupling of bromobenzene with butyl acrylate and methoxycarbonylation of iodobenzene reactions. Oxidative addition of PhI or PhBr to Pd-PVP as the first step of a catalytic reaction was confirmed by TEM and XPS measurements. TEM studies showed significant reduction of Pd nanoparticle size after their reaction with PhX (X = I, Br) and [Bu4N]X (X = Cl, Br, I). The biggest shift of the center of nanoparticle size distribution, from 19.8 nm to 7.6 nm, was found when Pd-PVP reacted with PhI and [Bu4N]Br. The formation of [Bu4N]2[Pd(Ph)Br3]- and [Bu4N]2[PdBr4]-type complexes in that system was evidenced by XPS and UV–vis spectra.

In this paper we describe application of liquid crystals in optical imaging and processing. Electrically and optically addressed liquid crystal spatial light modulators are key elements in real-time holographic devices. Their implementation for beam steering and hologram formation is briefly discussed. The Joint Fourier transform optical correlator for pattern recognition is presented as well as the use of liquid crystals for the adaptive optics purposes is discussed.

The title compound, trans-[Pd(C6H4I)I(C18H15P)2], has been crystallized from dichloro­methane. The crystal structure of this complex reveals a slightly distorted square-planar coordination geometry of the Pd atom, which lies on a twofold rotation axis. The P atoms in the triphenyl­phosphine ligands lie slightly out of the planes of the phenyl rings. The crystal structure is stabilized by short inter­molecular I⋯I contacts, weak C—H⋯π(arene) hydrogen bonds and π–π stacking inter­actions.

The title compound, (C10H16N)2[PdCl4], has been crystallized from acetonitrile. The asymmetric unit contains two 1-butyl-4-methylpyridinium cations in general positions and two halves of tetrachloropalladate(II) anions, with the metal atoms lying on inversion centers. The Pd atoms are four-coordinated in a slightly distorted square-planar geometry. The crystal structure is stabilized by numerous weak C—H...Cl interactions.

The Pd atom in the title compound, [Pd(C(18)H(14)O(3)P)Cl(C(5)H(8)N(2))], adopts a slightly distorted square-planar coordination geometry, with the metallated carbon positioned trans to the Cl atom. The crystal structure is stabilized by several weak C-H⋯O and C-H⋯Cl hydrogen-bond inter-actions. One of the phenyl rings is disordered over two almost equally occupied sites.

A series of PEPPSI-type palladium(II) complexes was synthesized that contain 3-chloropyridine as an easily removable ligand and a triazolylidene as a strongly donating mesoionic spectator ligand. Catalytic tests in Suzuki–Miyaura cross-coupling reactions revealed the activity of these complexes towards aryl bromides and aryl chlorides at moderate temperatures (50 °C). However, the impact of steric shielding was the inverse of that observed with related normal Nheterocyclic carbenes (imidazol-2-ylidenes) and sterically congested mesityl substituents induced lower activity than small alkyl groups. Mechanistic investigations, including mercury poisoning experiments, TEM analyses, and ESI mass spectrometry, provide evidence for ligand dissociation and the formation of nanoparticles as a catalyst resting state. These heterogeneous particles provide a reservoir for soluble palladium atoms or clusters as operationally homogeneous catalysts for the arylation of aryl halides. Clearly, the substitution of a normal N-heterocyclic carbene for a more basic triazolylidene ligand in the precatalyst has a profound impact on the mode of action of the catalytic system. European Research Council Science Foundation Ireland

The mononuclear palladium complexes (I) and (II), prepared from the title ligand, catalyze the Heck and Hiyama coupling reactions.

The title compound, cis-[Re(C(12)H(24)O(4)P)Cl(2)O(C(18)H(15)P)], was prepared from the analogous trans isomer [Głowiak et al. (2000 ▶). Polyhedron, 19, 2667-2672] by a trans-cis isomerization reaction. The Re(V) atom adopts a distorted octa-hedral coordination geometry. Besides being coordinated by the oxide and the butano-late O atoms, the Re(V) atom is coordinated by a pair of chloride ligands and two P atoms in cis positions with respect to each other. In the crystal, adjacent mol-ecules are linked by weak C-H⋯Cl inter-actions, forming a three-dimensional network.

The Pd atom in the title compound, [Pd(C18H14O3P)Cl(C5H8N2)], adopts a slightly distorted square-planar coordination geometry, with the metallated carbon positioned trans to the Cl atom. The crystal structure is stabilized by several weak C—H⋯O and C—H⋯Cl hydrogen-bond inter­actions. One of the phenyl rings is disordered over two almost equally occupied sites.

The five-membered ring in the title compound, C(6)H(13)O(3)P, exists in an envelope conformation with one of the ring C atoms at the flap position. The coordination geometry around the P atom is a distorted tetra-hedron. The crystal structure is stabilized by several weak C-H⋯O and P-H⋯O hydrogen bonds, forming a three-dimensional network.

Rhodium colloids have been prepared by chemical reduction of an aqueous solution of rhodium trichloride with different aliphatic alcohols (from methanol to pentanol) in the presence of polyvinylpyrrolidone (PVP) as the stabilizing agent. The obtained Rh(0) nanoparticles have been characterized structurally by means of X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. Catalytic activity of the synthesized Rh/PVP colloids has been evidenced in the Suzuki–Miyaura coupling reaction of phenylboronic acid with bromobenzaldehyde. The choice of the reducing agent and reduction conditions enabled to obtain Rh(0) colloids showing various mean nanoparticle diameters (ranging from 3.8 to 6.0 nm) and different nanoparticle morphologies. These two factors play the decisive role from point of view of catalytic activity of the presented systems. The most active Rh/PVP catalyst, prepared using ethanol as the reducing agent, have also been applied in hydrogenation of benzene to cyclohexane, showing very high activity in this process.