101977-34-8

Basic information

• Product Name: 4-nitrostilbene
• CAS NO: 101977-34-8
• Molecular Weight: 225.247
• Mol File: 101977-34-8.mol
• Article Data: 216

Chemical Properties

• CAS DataBase Reference: 4-nitrostilbene(CAS DataBase Reference)
• NIST Chemistry Reference: 4-nitrostilbene(101977-34-8)
• EPA Substance Registry System: 4-nitrostilbene(101977-34-8)

Safety Data

• Hazardous Substances Data: 101977-34-8(Hazardous Substances Data)

Upstream product

• 100-42-5 styrene 
• 100-00-5 4-chlorobenzonitrile 
• 108-90-7 chlorobenzene 
• 591-50-4 iodobenzene 
• 1449-46-3 benzyltriphenylphosphonium bromide 
• 555-16-8 4-nitrobenzaldehdye 
• 72646-24-3 P-(benzylidene)methyldiphenylphosphorane 
• 329-98-6 phenylmethylsulphonyl fluoride 
• 26624-20-4 p-nitrostilbene dibromide 
• 140-10-3 (E)-3-phenylacrylic acid 
• 100-01-6 4-nitro-aniline 
• 79547-05-0 ethyl (4-nitrophenyl)pyruvate 
• 100-52-7 benzaldehyde 
• 20463-48-3 α-Phenyl-4-nitrozimtsaeure 

Downstream Products

• 134-81-6 benzil 
• 71845-20-0 4-(β-phenylethyl)aniline hydrochloride 
• 4336-57-6 trans-2-(4-nitrophenyl)-3-phenyloxirane 
• 37629-94-0 (E)-1-nitro-4-(2-nitro-2-phenylvinyl)benzene 
• 1144-74-7 4-nitrobenzophenone 
• 106797-81-3 4-Methylamino-stilben 
• 838-95-9 4-(N,N-dimethylamino)stilbene 
• 4336-57-6 cis-2-(4-nitrophenyl)-3-phenyl oxirane 
• 22711-24-6 4-nitrobenzil 
• 65-85-0 benzoic acid 
• 62-23-7 4-nitro-benzoic acid 
• 14310-29-3 1-nitro-4-phenethylbenzene 
• 13024-49-2 4-aminodibenzyl 
• 834-24-2 4-aminostilbene 

Relevant articles and documents

Magnetically-recoverable Schiff Base Complex of Pd (II) Immobilized on Fe3O4@SiO2 Nanoparticles: An Efficient Catalyst for Mizoroki-Heck and Suzuki-Miyaura Coupling Reactions

The activity of Pd(II)-Schiff base complexmolecules grafted on the surface of Fe3O4@SiO2 particles were investigated in the palladium-catalyzed coupling reactions of aryl halides with alkenes (Mizoroki-Heck reaction) and phenylboronic acids (Suzuki-Miyaura reaction) in the absence of phosphorous ligands. This method shows notable advantages such as heterogeneous nature of the catalyst, excellent yields, short reaction times, easy preparation, simplicity of operation, and cleaner reaction profiles. The catalyst can be separated from the reaction mixture by applying a permanent magnet externally and can be reused for several times without significant loss of activity. Also, the amount of palladium leaching has been determined by ICP analysis.

Green, cost-effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst

A novel heterogenized organometallic catalyst was synthesized by coordinating palladium with polyvinyl alcohol-functionalized Fe3O4@SiO2 nanospheres. This novel catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscope, field emission scanning electron microscope, dynamic light scattering, UV–vis spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, thermogravimetric analysis and inductively coupled plasma analysis. The prepared palladium nanoparticles supported on polyvinyl alcohol functionalized Fe3O4@SiO2 nanoparticles were successfully applied as a magnetically recyclable catalyst in Heck and Sonogashira coupling reactions in water. They showed remarkable activity toward aryl halides (I, Br, Cl) using very low palladium loading in excellent yields and demonstrated high TONs (mmol of product per mmol of catalyst). Also, the catalyst could be magnetically separated and reused seven times without any appreciable loss of catalytic activity.

Palladium-melamine complex anchored on magnetic nanoparticles: A novel promoter for C-C cross coupling reaction

A palladium-melamine complex deposited on Fe3O4@SiO2 nanoparticles (MNPs-Mel-Pd) was considered as an effective catalyst for C-C cross-coupling (Mirozoki-Heck) reaction. Surface and magnetic properties of the prepared core-shell hybrid nanocatalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, energy-dispersive X-ray, vibrating sample magnetometry, transmission and scanning electron microscopy techniques and ICP/OES analysis. It was found that the heterogeneous nanocatalyst could be recovered simply and reused numerous times without loss of its catalytic activity. The advantages of this new methodology are: isolation of highly pure products without chromatography techniques, reusability of the catalyst using a magnet, easy workup procedure and negligible leaching of palladium.

Solvent-free Mizoroki-Heck reaction catalyzed by palladium nano-particles deposited on gelatin as the reductant, ligand and the non-toxic and degradable natural product support

Gram-scale synthesis of uniform nano-particles of palladium supported on gelatin, as a reductant and ligand is described. These particles were prepared under green conditions without addition of any external reducing agent and ligand. No complicated work

Mesoporous Hierarchically Hollow Flower-Like CoAl-LDH@N,S-doped Graphene@Pd Nanoarchitectures for Heck Couplings

Abstract: A smart strategy for the synthesis of hierarchical CoAl-LDH hollow spheres assembled with nitrogen and sulfur co-doped graphene for high holding of palladium nanoparticles (CoAl-LDH@N,S-G@Pd) is reported. This architecture exhibited excellent activity in Heck reactions with TOF as high as 1633?h?1 due to a strong metal–support interaction, good electron transfers and high surface area. Graphic Abstract: [Figure not available: see fulltext.].

Engineered mesoporous ionic-modified γ-Fe2O3@hydroxyapatite decorated with palladium nanoparticles and its catalytic properties in water

A new mesoporous organic–inorganic nanocomposite was formulated and then used as stabilizer and support for the preparation of palladium nanoparticles (Pd NPs). The properties and structure of Pd NPs immobilized on prepared 1,4-diazabicyclo[2.2.2]octane (DABCO) chemically tagged on mesoporous γ-Fe2O3@hydroxyapatite (ionic modified (IM)-MHA) were investigated using various techniques. The synergistic effects of the combined properties of MHA, DABCO and Pd NPs, and catalytic activity of γ-Fe2O3@hydroxyapatite-DABCO-Pd (IM-MHA-Pd) were investigated for the Heck cross-coupling reaction in aqueous media. The appropriate surface area and pore size of mesoporous IM-MHA nanocomposite can provide a favourable hard template for immobilization of Pd NPs. The loading level of Pd in the nanocatalyst was 0.51?mmol?g?1. DABCO bonded to the MHA surface acts as a Pd NP stabilizer and can also lead to colloidal stability of the nanocomposite in aqueous solution. The results reveal that IM-MHA-Pd is highly efficient for coupling reactions of a wide range of aryl halides with olefins under green conditions. The superparamagnetic nature of the nanocomposite means that the catalyst to be easily separated from solution through magnetic decantation, and the catalytic activity of the recycled IM-MHA-Pd showed almost no appreciable loss even after six consecutive runs.

Palladium nanoparticles supported on poly (N-vinylpyrrolidone)-grafted silica as new recyclable catalyst for Heck cross-coupling reactions

Novel catalytic system based on palladium nanoparticles supported on poly (N-vinylpyrrolidone) (PVP) grafted silica was prepared. Aminopropylsilica was reacted with acryloyl chloride to form acrylamidopropylsilica, and onto this functionalized silica vinylpyrrolidone monomer was polymerized by free-radical polymerization. The complexation of PVP-grafted silica with PdCl2 was carried out to obtain the heterogeneous catalytic system. X-ray diffraction (XRD) technique and transmission electron microscopy (TEM) image showed that palladium dispersed through the support in nanometer size. This catalytic system exhibited excellent activity in cross-coupling reactions of aryl iodides, bromides and also chlorides with olefinic compounds in Heck-Mizoraki reactions in short reaction time and high yields. Elemental analysis of Pd by inductively coupled plasma (ICP) technique and hot filtration test showed low leaching of the metal into solution from the supported catalyst. The catalyst can be reused several times in repeating Heck reaction cycles without considerable loss in its activity.

Pd nanoparticles immobilized on magnetic chitosan as a novel reusable catalyst for green Heck and Suzuki cross-coupling reaction: In water at room temperature

A novel type of magnetically responsive chitosan nanocomposite was successfully synthesized as a green and high powerful palladium-based heterogeneous catalyst and its efficiency in Heck and Suzuki cross-coupling was evaluated. This catalyst promote a large library of functional substrates of these reactions under mild and sustainable conditions (water or ethanol as solvent, at room temperature, in significantly short reaction time (20?minutes)) and stand as recyclable, metal scavenging catalytic systems.

N-Heterocyclic carbene palladium complex supported on ionic liquid-modified SBA-16: an efficient and highly recyclable catalyst for the Suzuki and Heck reactions

By grafting an N-heterocyclic carbene palladium complex and ionic liquid on the mesoporous cage-like material SBA-16, an efficient and highly recyclable heterogeneous catalyst for the Suzuki and Heck reactions was prepared. This catalyst afforded a fast c

A highly active nickel-fibre complex as a catalyst for the Heck reaction

A new amidoxime fibre-nickel catalyst (AOFs-Ni(0)) was synthesised by a coordination and reduction reaction. The X-ray diffraction patterns indicated that the Ni(II) ions were reduced to Ni(0). The scanning electron microscope image showed that the Ni(0) particles which were reduced in situ had a diameter of about 300 nm. This catalyst demonstrated high activity in the Heck coupling reaction of aryl iodine and conjugated alkenes without the protection of an inert atmosphere.

Easy-separable magnetic nanoparticle-supported Pd catalysts: Kinetics, stability and catalyst re-use

A series of novel palladium-based catalysts supported on magnetic nanoparticles with diameters of 7- 17 nm have been prepared and evaluated in C-C coupling, hydrogenation and amination reactions. One type of catalyst used palladium complexes containing phosphine and/or acetate ligands for applications in Suzuki and Heck reactions. The second type consisted of Pd(0)-functionalised magnetic cores for use in hydrogenation and C-C coupling. Each type was effective for a range of reactions and was easily recoverable from the reaction mixture due to the superparamagnetic behaviour of the support. Detailed rate studies, found to correspond to pseudo-first-order kinetics, were conducted to assist in determining the mechanism of the reactions and showed that, during Heck reactions, Pd leaching is critically dependent on the presence of the aryl halide. The catalysts were found to retain their activity for several cycles although the rate of reaction was markedly reduced on re-use. Crown Copyright

Pd/Cu-free Heck and Sonogashira cross-coupling reaction by Co nanoparticles immobilized on magnetic chitosan as reusable catalyst

Chitosan (CS) is a porous, self-standing, nanofibrillar microsphere that can be used as a metal carrier. Amino groups on CS enable to modulate cobalt coordination using a safe organic ligand (methyl salicylate). This catalyst efficiently promotes Heck cross-coupling of a large library of functional substrates under mild and sustainable conditions (polyethylene glycol as solvent at 80 °C in a short time (1 h)). The cobalt complex was also used as a heterogeneous, efficient, inexpensive, and green catalyst for Sonogashira cross-coupling reactions. The reactions of various aryl halides and phenylacetylene provided the corresponding products in moderate to good yields. More importantly, this phosphine, copper, and palladium-free catalyst was stable under the reaction conditions and could be easily reused using an external magnet for at least five successive runs without a discernible decrease in its catalytic activity.

Dramatic effect of the gelling cation on the catalytic performances of alginate-supported palladium nanoparticles for the Suzuki-Miyaura reaction

This work describes the preparation and characterization of a library of alginate-supported palladium nanoparticles together with their catalytic capabilities to promote the Suzuki-Miyaura reaction. Using the chelating properties of the carboxylate functions of the alginate matrix a series of Ca, Ba, Mn, Zn, Ni, Ce, Cu, and Co alginate gels were first prepared and then reacted with Pd2+ salts. Partial exchange of metal cations followed by Pd reduction into palladium nanoparticles and supercritical CO2 drying generated a panel of bimetallic alginate aerogels. Physical characterizations of these materials showed a significant influence of both the gelling metal nature and the Pd loading on surface areas and nanoparticles size. A comparative study of the catalytic performances of these heterogeneous catalytic systems is then reported for the Suzuki-Miyaura reaction. This study highlighted the superior performances of palladium nanoparticles supported on copper-alginate aerogels. This heterogeneous catalyst showed high catalytic activities as illustrated by a TOF value of 10 s-1 and a TON value close to 106. The robustness of the catalyst allowed several reuses with no significant loss of activity or metal leaching.

Heck and Sonogashira cross-coupling reactions using recyclable Pd-Fe 3O4 heterodimeric nanocrystal catalysts

We have developed a convenient Pd-Fe3O4 heterodimeric nanocrystal catalyst system for Heck and Sonogashira reactions. This catalyst offers an environment-friendly, atom-efficient, and robust catalytic system for both reactions. Furthermore the nanocrystal catalyst could be easily separated by an external magnet and recycled six times without losing its catalytic activity.

Palladium catalyst supported on N-aminoguanidine functionalized magnetic graphene oxide as a robust water-tolerant and versatile nanocatalyst

A novel heterogeneous Pd catalyst has been developed by decorating palladium onto the surface of N-aminoguanidine functionalized magnetic graphene oxide nanosheets (denoted as Pd@AGu-MGO), while the diethylene glycol (DEG) group has been applied as an organic spacer. The usefulness of the Pd@AGu-MGO nanocatalyst was investigated in palladium catalyzed organic reactions including Heck/Suzuki couplings of aryl halides and reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The nanocatalyst showed high efficiency and thermal stability (up to 300 °C). The catalyst recovery test was performed using an external magnet device, and showed that this catalyst can be reused several times without a significant decrease in its performance and catalytic activity. The loading level of Pd in the Pd@AGu-MGO catalyst was assessed as 0.9 mmol g-1 by ICP-AES and elemental analysis. This catalyst is more remarkable from the environmental and economic points of view because of its key properties such as high efficiency and turnover frequency (TOF), mild reaction conditions, utilization of green solvent, simple product work-up, and easy catalyst recovery.

Multifunctional and robust covalent organic framework-nanoparticle hybrids

Highly dispersed Pd(0) nanoparticles were successfully immobilized into a stable, crystalline and porous covalent organic framework (COF), TpPa-1, by a solution infiltration method using NABH4 as a reducing agent. High resolution and dark field TEM images confirmed the uniform loading of the Pd(0) nanoparticles into the TpPa-1 matrix without aggregation. This hybrid material exhibited excellent catalytic activity towards the Cu free Sonogashira, Heck and sequential one pot Heck-Sonogashira cross-coupling reactions under basic conditions, and with superior performance compared to commercially available Pd supported on activated charcoal (i.e., 1, 5 and 10 wt%). Additionally, the precursor Pd(ii)-doped COF also displayed competitive catalytic activity for the intramolecular oxidative biaryl synthesis under acidic conditions. Both catalysts were found to be highly stable under the reaction conditions showing negligible metal leaching, non-sintering behavior, and good recyclability. To the best of our knowledge, the organic support used in this work, TpPa-1, constitutes the first COF matrix that can hold both Pd(0) nanoparticles and Pd(ii) complex without aggregation for catalytic purposes under both highly acidic and basic conditions. This journal is the Partner Organisations 2014.

Pd(II) complexes with mono- and bis-chelate carbene ligands tagged with pyridinium cation: Synthesis, structures, and their catalytic activities toward Heck reaction

Homoleptic Pd(II) complexes with one and two chelating di-N-heterocyclic carbene (NHC) ligands tagged with pyridinium cation, [Pd2( PyBuCCme)2Cl2](PF6) 6 and [Pd (PyBu

Enhancement in the catalytic activity of Pd/USY in the Heck reaction induced by H2 bubbling

Pd was loaded on ultra stable Y (USY) zeolites prepared by steaming NH 4-Y zeolite under different conditions. Heck reactions were carried out over the prepared Pd/USY. We found that H2 bubbling was effective in improving not only the catalytic activity of Pd/USY, but also that of other supported Pd catalysts and Pd(OAc)2. Moreover, the catalytic activity of Pd/USY could be optimized by choosing appropriate steaming conditions for the preparation of the USY zeolites; Pd loaded on USY prepared at 873 K with 100% H2O gave the highest activity (TOF = 61,000 h-1), which was higher than that of Pd loaded on other kinds of supports. The prepared Pd/USY catalysts were applicable to the Heck reactions using various kinds of substrates including bromo-and chlorosubstituted aromatic and heteroaromatic compounds. Characterization of the acid properties of the USY zeolites revealed that the strong acid site (OHstrong) generated as a result of steaming had a profound effect on the catalytic activity of Pd.

Aryl-Pd covalently bonded palladacycles, novel amino and oxime catalysts {di-μ-chlorobis(benzaldehydeoxime-6-C,N)dipalladium(II), di-μ-chlorobis(dimethylbenzylamine-6-C,N)dipalladium(II)} for the Heck reaction

Amine and oxime palladacycles with an aryl-Pd covalent bond were found to be robust catalysts for the Heck reaction of aryl iodides, bromides and even chlorides. High TONs and TOFs were obtained with these palladacycles. (C) 2000 Elsevier Science Ltd.

Palladium nano-particles supported on agarose as efficient catalyst and bioorganic ligand for CC bond formation via solventless Mizoroki-Heck reaction and Sonogashira-Hagihara reaction in polyethylene glycol (PEG 400)

In this study, abundant naturally occurring agarose has been used as a support and ligand for palladium nanoparticles. In the presence of this catalytic system, Mizoroki-Heck and Sonogashira-Hagihara coupling reactions were performed successfully. The catalyst exhibits high activity in Mizoroki-Heck reaction under phosphane and solvent-free conditions for the reaction of iodo- and bromoarenes with butyl acrylate and styrene. This catalytic system also showed high catalytic activity for Sonogashira-Hagihara coupling reaction of various aryl halides (I, Br, Cl) under copper and ligand-free conditions in polyethylene glycol (PEG 400) as an ecofriendly and non-poisonous media. The catalyst can be separated from the reaction mixture and reused for the similar batches of the reaction. High efficiency of the catalyst along with its recycling ability and the rather low Pd-loading which are demonstrated in both Mizoroki-Heck and Sonogashira-Hagihara reactions are the merits of the presented catalyst system.

Iron-catalyzed cross-coupling reaction: Heterogeneous palladium and copper-free Heck and Sonogashira cross-coupling reactions catalyzed by a reusable Fe(III) complex

An interesting silica-supported iron catalyst was successfully prepared and demonstrated as an efficient heterogeneous catalyst for cross-coupling reactions of aryl halides. The as-prepared nanocatalyst was well characterized and found to be highly efficient in Heck reaction under mild and sustainable conditions (water as solvent at 80?°C in short reaction time). Furthermore, the obtained catalyst was used as an efficient, inexpensive and green heterogeneous catalyst for Sonogashira cross-coupling reactions of various aryl iodides and provided the corresponding products with moderate to good yields. This phosphine, copper and palladium-free catalyst was simply recovered from the reaction mixture and recycled five times without substantial decrease in its catalytic activity.

Application of an air-and-moisture-stable diphenylphosphinite cellulose-supported nanopalladium catalyst for a Heck reaction

A diphenylphosphinite cellulose-supported nanopalladium (Cell-OPPh 2-Pd0) was conveniently prepared from cellulose and chlorodiphenylphosphine in pyridine, followed by treatment of an ethanol solution of palladium chloride. The prepared catalysis was found to be air- and moisture-stable and have significant catalytic activities in Heck coupling under mild operating conditions. Various phenyl halides were coupled with alkenes in DMF under air, to afford the corresponding products in good yields. Furthermore, the catalyst can be easily recovered by simple filtration and reused for up to six cycles without losing its activity. Springer Science+Business Media B.V. 2012.

Magnetically recyclable Pd/γ-AlOOH@Fe3O4 catalysts and their catalytic performance for the Heck coupling reaction

Novel magnetically recyclable Pd/γ-AlOOH@Fe3O4 catalysts were prepared using γ-AlOOH@Fe3O4 as a magnetic supporter and nano-Pd particles as the active catalytic component. The structure of the catalysts was characterized by XRD (X-ray diffraction), TEM (transmission electron microscopy), N2 adsorption-desorption, and a VSM (vibration sample magnetometer). The catalytic activity and recyclability for the Heck coupling reaction were investigated. Results showed that the magnetic γ-AlOOH@Fe3O4 possessed a core-shell structure, as well as that the nano-Pd particles were 6-8 nm and had been well dispersed in the γ-AlOOH shell. In the Heck coupling reactions, the magnetic Pd/γ-AlOOH@Fe3O4 catalysts exhibited good catalytic activity and recyclability. For the (0.021 mol%)Pd/γ- AlOOH@Fe3O4 catalyst, the bromobenzene conversion and product yield reached about 100% and 96.3%, respectively, under a 120°C reaction temperature and 12 h reaction time. After being recycled 8 times, the conversion of bromobenzene and the recovery of the catalyst were about 90% and 93%, respectively. The nano-Pd particles were kept well dispersed in the used Pd/γ-AlOOH@Fe3O4 catalyst.

Multi walled carbon nanotubes supported N-heterocyclic carbene-cobalt (II) as a novel, efficient and inexpensive catalyst for the Mizoroki-Heck reaction

In this paper, an N-heterocyclic carbene-cobalt complex (NHC-Co2+) was immobilized onto the surface of multi-walled carbon nanotubes (MWCNTs) via direct grafting amination approach for the first time. The resultant composite (Co - NHC@MWCNTs) was characterized by FT-IR, TGA, XRD, ICP-OES, FE-SEM, TEM and CHN analyses. It was demonstrated that Co-NHC@MWCNTs can act as an efficient and inexpensive catalyst for Heck reactions in normal conditions which provided the corresponding products in moderate to good yields. More importantly, this phosphine and palladium-free catalyst can be reused for at least six successive runs without any discernible decrease in its catalytic activity and no remarkable changes were observed in catalyst structure.

Palladium supported aminobenzamide modified silica coated superparamagnetic iron oxide as an applicable nanocatalyst for Heck cross-coupling reaction

An applicable palladium-based nanocatalyst was constructed through the immobilization of palladium onto 2-aminobenzamide functionalized silica coated superparamagnetic iron oxide magnetic nanoparticles. The nanocatalyst (named as Pd@ABA@SPIONs@SiO2) was characterized by several characterization methods, including scanning electron microscope (SEM), transmission electron microscopy (TEM), vibrating-sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma (ICP), and X-ray photoelectron spectroscopy (XPS) analyses. Microscopy results showed that the nanoparticles are spherical in shape with 20–25 nm size. The size of the nanoparticles was confirmed by the DLS method. The superparamagnetic nature of the catalyst was confirmed by the VSM method. The successful functionalization of SPIONs@SiO2 was confirmed by FT-IR spectroscopy. The presence of palladium in the structure of the nanocatalyst was illustrated by XRD and EDS analysis. Also using XPS technique, the oxidation state of palladium in Pd@ABA@SPIONs@SiO2 was determined zero before and after the catalyst was applied in Mizoroki-Heck reaction. Several aryl halides and alkenes were reacted in the presence of the nanocatalyst and formed the corresponding products in high isolated yields. The nanocatalyst showed very good reusability and did not decrease its activity after 10 sequential runs. Density functional theory (DFT) calculation was performed to provide a mechanism for the reaction and confirmed the role of the palladium catalyst in the reaction function.

Effect of the Linking Group on the Thermoelectric Properties of Poly(Schiff Base)s and Their Metallopolymers

As polymer-based thermoelectric (TE) materials possess attractive features such as light weight, flexibility, low toxicity and ease of processibility, an increasing number of conducting polymers and their composites with high TE performances have been developed in recent years. Up to date, however, the research focusing on the structure-performance relationship remains rare. In this paper, two series of poly(Schiff base)s with either C=C or C≡C linker and their metallopolymers were synthesized and doped with single-walled carbon nanotubes to evaluate how the linking groups affected the TE properties of the resulting composites. Apart from the effect exerted by the morphology, experimental results suggested that the linkers played a key role in determining the band gaps, preferred molecular conformation and extent of conjugation of the polymers, which became key factors that influenced the TE properties of the resulting materials. Additionally, upon coordination with transition metal ions, the TE properties could be tuned readily.

Green and sustainable palladium nanomagnetic catalyst stabilized by glucosamine-functionalized Fe3O4@SiO2 nanoparticles for Suzuki and Heck reactions

A novel magnetic and heterogeneous palladium-based catalyst stabilized by glucosamine-functionalized magnetic Fe3O4@SiO2 nanoparticle was synthesized. The strategy relies on the covalently bonding of glucosamine to cyanuric chloride-functionalized magnetic nanoparticles followed by complexation with palladium. The structure of magnetic nanocatalyst was fully determined by FT-IR, XRD, DLS, FE-SEM, TEM, ICP, UV-Vis, TGA, VSM, and EDX. The obtained results confirmed that the palladium nanoparticles stabilized by glucosamine immobilized onto the magnetic support exhibited high activity in cross-coupling reactions of Suzuki-Miyaura and Mizoroki-Heck. Various aryl halides were coupled with arylboronic acid (Suzuki cross-coupling reaction) and olefins (Heck reactions) under the green conditions to provide corresponding products in high to excellent yields. Interestingly, the catalyst can be easily isolated from the reaction media by magnetic decantation and can subsequently be applied for consecutive reaction cycles (at least seven times) with no notable reduction in the catalytic activity.