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An efficient route for the chemoselective deoxygenation of benzylphenyl sulfones to the corresponding sulfides has been developed using a mixture of 1,2-bis(diphenylphosphino)ethane(dppe) and NBS as an effective promoter. This is the first development on the deoxygenation of diverse benzylphenyl sulfones under metal-free conditions. The mild reaction conditions, formation of the water soluble by-product and tolerance of a wide range of functional groups promote its broad applications in organic synthesis. [ABSTRACT FROM AUTHOR]

ABSTRACT The design, synthesis, and spectroscopic characterization of [Ag(P(o‐C6H4OCH3)3)(NO3)]2 (1) and [Ag(P(o‐C6H4OCH3)3)2][NO3] (2) were conducted to investigate the efficiency of the fabricated solar cell devices. The slow evaporation technique proved effective in growing the colorless crystals of the silver(I) complexes. Spectroscopic analyses including Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and ultraviolet–visible (UV–Vis) studies were carried out to elucidate the chemical structure and absorption properties of the compounds. The chemical composition and existence of intermolecular interactions in 1 and 2 were disclosed via the single‐crystal x‐ray diffraction method. The side‐to‐side arrangement of molecules in 1 and 2 was evident from the crystal packing analysis, in which the molecules in both compounds were linked together by C–H···O and C–H···π contacts. The silver(I) complexes exhibited maximum absorption wavelength (287–288 nm) within the ultraviolet region, where both compounds had comparable high energy band gap values ranging from 4.15 to 4.16 eV. Moreover, both compounds possess appropriate HOMO–LUMO energy levels that facilitate effective electron injection and dye regeneration processes in dye‐sensitized solar cell (DSSC) applications. Photophysical characterization techniques, field‐emission scanning electron microscopy (FESEM), and energy‐dispersive x‐ray (EDX) spectroscopy studies were employed to assess the morphological characteristics and elemental composition of the silver(I) complexes on TiO2. Compound 2 exceeded 1 in terms of solar cell efficiency, 2 (η = 3.34%) > 1 (η = 0.66%) due to the complex being in ionic form and composed of the mononuclear [Ag(P(o‐C6H4OCH3)3)2]+ cation [NO3]− anion. [ABSTRACT FROM AUTHOR]

Quantum chemical modeling of CO oxidation on the Cu12S6(PH3)8 and Cu12S6 clusters was performed in order to establish the general tendencies in the process on metal nanoclusters stabilized by ligands and to find out if the presence of a phosphine ligand is needed in the active site. The Langmuir–Hinshelwood mechanism was studied, which involves sequential oxidation of two CO molecules with oxygen. The calculated activation energies on Cu12S6(PH3)8 are lower than on Cu12S6 for all oxidation stages; therefore, the PH3 ligands have a positive effect on the catalytic properties of the copper sulfide cluster in the CO oxidation. A linear correlation was found between the energy of CO adsorption on various copper sulfide clusters and the activation energy of the oxidation stage: the lowest activation energy is observed for the cluster with a CO adsorption energy of 36 kJ/mol. [ABSTRACT FROM AUTHOR]

A class of novel chiral‐bridged biphenyl monophosphine ligands with a benzofuran moiety (He‐phos) has been successfully synthesized and reported. These ligands exhibited good performance in the gold‐catalyzed enantioselective cycloaddition reaction of 2‐(1‐alkynyl)‐2‐en‐1‐ones with nitrones, resulting in the successful preparation of a series of polyaryl‐substituted heterocyclic compounds with high enantioselectivities (up to 99% yield, 98% ee). The wide substrate adaptability (53 examples) and mild reaction conditions demonstrate the practicability of He‐phos in this reaction. [ABSTRACT FROM AUTHOR]

Phosphine@Pd@Fe3O4 nanomagnetic particles were synthesized through in situ or direct immobilization of the phosphine ligand on metal-coated Fe3O4. These separable heterogeneous nanoparticles were employed as highly efficient catalysts for the arylation of aldehydes using boron reagents, yielding up to 90% within 30 min. The synthesized catalysts were easily recovered through simple magnetic decantation and exhibited no significant decrease in activity upon reuse. The structure and morphology of the nanomagnetic particles were characterized using various techniques, including energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, differential thermal analysis, X-ray diffraction, vibrating-sample magnetometer analysis, and FT-IR spectroscopy. [ABSTRACT FROM AUTHOR]

Phosphine-stabilized gold clusters are an important subgroup of metalloid gold cluster compounds and are important model compounds for nanoparticles. Although there are numerous gold clusters with different phosphine ligands, the effect of phosphine on cluster formation and structure remains unclear. While the linear alkyl-substituted phosphine gold chlorides result in a Au32 cluster, the bulky tBu3P leads to a Au20 cluster. The reduction of (iPr2nBuP)AuCl, with the steric demand of the phosphine ligand between the mentioned phosphines, results in the successful synthesis and crystallization of a new metalloid gold cluster, Au30(PiPr2nBu)12Cl6. Its structure is similar to the Au32 cluster but with two missing AuCl units. The UV/Vis studies and quantum chemical calculations show the similarities between the two clusters and the influence of the phosphine ligand in the synthesis of metalloid gold clusters. [ABSTRACT FROM AUTHOR]

The reaction of Cu(NO3)2·3H2O with a potentially bidentate P,N-donor ligand, diphenyl-2-pyridylphosphine (PPh2Py), in 1:2 molar ratio resulted in formation of a κ2N,O-chelated complex, [Cu(κ2N,O-P(O)Ph2Py)2(NO3)2] (1). A single-crystal X-ray study confirmed the formation of a five-membered κ2N, O-chelate involving pyridyl nitrogen and phosphine oxide oxygen donor sites. A DFT study was carried out on 1 to understand the chelate ring expansion process upon oxidation with PPh2Py. DFT analysis revealed that 1 contains a relatively strong M-N bond compared to its M-P bond, facilitating the oxidation of the P atom followed by chelate ring expansion. [ABSTRACT FROM AUTHOR]

Simple nucleophilic aliphatic substitution gives access to mono- and diphosphine ligands with a CpC group in the backbone. The monophosphine ligand coordinates to gold(I) via the phosphine site, to thallium(I) via the cyclopentadienyl site and to ruthenium(II) via a combination of both, resulting in an ansa-type structure. Coordination with the cyclopentadiene site is not possible for the diphosphine ligand. In this case, monodentate coordination to gold(I) and bidentate coordination to the [PdCl(μ2-Cl)]2, the [Rh(CO)(μ2-Cl)]2, and the Rh(CO)Cl fragment is observed, showing the variability in coordination modes possible for the long-chain diphosphine ligand. Ligands and complexes were characterized by means of NMR and IR spectroscopy, elemental analysis and X-ray structure analysis.

Clusters combine the advantages of organic molecules and inorganic nanomaterials, which are promising alternatives for optoelectronic applications. Nonetheless, recently emerged cluster light‐emitting diodes require further excited state optimization of cluster emitters, especially to reduce population of the cluster‐centered triplet quenching state (3CC). Here we report that redox‐active ligands enhance reverse intersystem crossing (RISC) of Cu4I4 cluster for triplet‐to‐singlet conversion, and thermally activated delayed fluorescence (TADF) host can provide an external RISC channel. It indicates that the complementarity between TADF host and cluster in RISC transitions gives rise to 100 % triplet conversion efficiency and complete singlet exciton convergence, rendering 100‐fold increased singlet radiation rate constant and tenfold decreased triplet non‐radiation rate constant. We achieve a photoluminescence quantum yield of 99 % and a record external quantum efficiency of 29.4 %. [ABSTRACT FROM AUTHOR]

Simple nucleophilic aliphatic substitution gives access to mono- and diphosphine ligands with a CpC group in the backbone. The monophosphine ligand coordinates to gold(I) via the phosphine site, to thallium(I) via the cyclopentadienyl site and to ruthenium(II) via a combination of both, resulting in an ansa-type structure. Coordination with the cyclopentadiene site is not possible for the diphosphine ligand. In this case, monodentate coordination to gold(I) and bidentate coordination to the [PdCl(μ2-Cl)]2, the [Rh(CO)(μ2-Cl)]2, and the Rh(CO)Cl fragment is observed, showing the variability in coordination modes possible for the long-chain diphosphine ligand. Ligands and complexes were characterized by means of NMR and IR spectroscopy, elemental analysis and X-ray structure analysis. [ABSTRACT FROM AUTHOR]

Trisphosphines, in which two phenylene or vinylene backbones connect three phosphine atoms, belong to an emerging class of ligands in metal-catalyzed organic synthesis and materials applications. However, these ligands were previously known only in a small variety because of the synthetic limitations. We report herein two versatile synthetic routes to a hitherto unavailable variety of trisphosphines. The compounds bearing phenylene backbones were synthesized by sequential addition of two different organolithium reagents to triphenyl phosphite and that with vinylene backbones by stereoretentive addition of lithium diarylphosphide to a cis -bromoalkene. The new trisphosphine compounds will serve as valuable tools for the development of transition-metal-catalyzed reactions and functional materials. [ABSTRACT FROM AUTHOR]

Phosphine-stabilized gold clusters are an important subgroup of metalloid gold cluster compounds and are important model compounds for nanoparticles. Although there are numerous gold clusters with different phosphine ligands, the effect of phosphine on cluster formation and structure remains unclear. While the linear alkyl-substituted phosphine gold chlorides result in a Au32 cluster, the bulky tBu3P leads to a Au20 cluster. The reduction of (iPr2nBuP)AuCl, with the steric demand of the phosphine ligand between the mentioned phosphines, results in the successful synthesis and crystallization of a new metalloid gold cluster, Au30(PiPr2nBu)12Cl6. Its structure is similar to the Au32 cluster but with two missing AuCl units. The UV/Vis studies and quantum chemical calculations show the similarities between the two clusters and the influence of the phosphine ligand in the synthesis of metalloid gold clusters.

The optoelectronic applications of clusters emerged rapidly. Cluster light‐emitting diodes (CLED) as representative hold promise as a new generation of displays and lightings. However, as one of the main challenges in electroluminescence (EL) field, until present, no deep‐blue CLEDs were reported, due to the strict requirements on excited‐state characteristics of clusters. Herein, two phosphine‐stabilized Au3 triangle and Au3Ag pyramid named [O(Audppy)3]BF4 and [O(Audppy)3Ag](BF4)2 were chosen to demonstrate efficient deep‐blue CLEDs. The ligand‐incorporated charge transfer transitions of the clusters contribute to both singlet and triplet excited states of the clusters, giving rise to phosphorescence at 460 nm and EL emissions at 436 nm. Based on device engineering, the maximum luminescence beyond 8000 nits and the chromatic coordinates with y <0.1 in deep‐blue region verify the competence of CLEDs for high‐resolution displays. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed direct arylation of α,β-unsaturated carbonyl compounds is an efficient and attractive strategy to access arylated α,β-unsaturated carbonyl compounds through the construction of carbon–carbon bonds. This reaction has several challenges, especially in terms of the control of regioselectivity between α- and γ-arylation and the selectivity for monoarylation and multiple arylation. Herein, we discuss the recent development of γ-arylation of α,β-unsaturated carbonyl compounds and present the ligand-controlled, site-selective α- and γ-arylation of α,β-unsaturated carbonyl ketones with (hetero)aryl halides. The site selectivity of the reaction is switchable by simply changing the phosphine ligand. 1 Introduction 2 Reaction Development and Mechanistic Investigation 3 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Herein, a strategy has been executed to reduce the trap states in as‐synthesized CsPbBr3 perovskite quantum dots (PQDs) by using the capping of trioctylphosphine (TOP) which is further evident by the ultrafast spectroscopic technique. Moreover, the excitation source powers and unvarying excitation energy‐dependent studies were carried out to compare the hot carrier (HC) cooling dynamics in the PQDs and TOP‐capped CsPbBr3 PQDs (TOP‐PQDs) to explain the diminution of trap states in TOP‐PQDs. The HC cooling time has been calculated and found that 469.2 fs for PQDs whereas 394.8 fs is for TOP‐PQDs, respectively. From these HC cooling times, it can be concluded that TOP‐PQDs is more capable to intensify the process of HC relaxation from the higher energy states to the conduction band and contribute to suppress the charge trappings that supports the radiative recombination, which demonstrates the enhancement in the PL intensity and PLQY (i. e. 98.8 %). Likewise, and simultaneously at the excitation wavelength e.g. (λexcitation=410nm,3.02eV) , TOP‐PQDs show an improved ground state bleaching (GSB) intensity signal than PQDs at three excitation source powers (e.g.P=300μW,200μW,and100μW) in the following order: TOP‐PQDs P=300μW> PQDs P=300μW , TOP‐PQDsP=200μW> PQDsP=200μW , and TOP‐PQDs P=100μW> PQDs P=100μW , respectively. [ABSTRACT FROM AUTHOR]

We have succeeded in the synthesis of various tetrasilatetrathia[8]circulenes with alkyl and aryl groups on the silicon atoms. We also disclosed the effect of phosphine ligands on palladium-catalyzed silylation of tetraiodotetrathienylene and rhodium-catalyzed intramolecular silylation of tetrasilyltetrathienylenes. Experimental and theoretical analysis revealed the effect of the substituents on the silicon atoms on their electronic property. [ABSTRACT FROM AUTHOR]

Biomimics for the active site of [FeFe]-hydrogenases, have been synthesized and characterized. Treatment of [Fe2(CO)6{μ-SCH2CH(CH3)S}] (1) and phosphine ligands tris(2-furyl)phosphine, tri(m-tolyl)phosphine, bis(diphenylphosphino)methane (dppm), or 1,2-bis(diphenylphosphino)benzene (dppbz) with Me3NO·2H2O as the decarbonylation agent afforded the corresponding phosphine-containing derivatives [Fe2(CO)5(L){μ-SCH2CH(CH3)S}] (L = P(2-C4H3O)3, 2; P(3-C6H4CH3)3, 3; Ph2PCH2PPh2, 4) and [Fe2(CO)4{κ2-(Ph2P)2(1,2-C6H4)}{μ-SCH2CH(CH3)S}] (5) in moderate to good yields. The new complexes 2‒5 have been structurally characterized by elemental analysis, IR, NMR spectroscopy, and further confirmed by X-ray diffraction analysis. The electrochemistry of complexes 2‒5 have been investigated by cyclic voltammetry, showing that they can catalyze the reduction of protons to H2 in the presence of HOAc. [ABSTRACT FROM AUTHOR]

In this paper, the DFT method was applied at the B3LYP/6–311+G (d,p) level of theory to investigate the [2 + 4] Diels−Alder cycloaddition reactions of HSi≡Si(para‐C6H4X); X = NH2, OH, Me, H, F, CCH, OCF3 with benzene. It was attempted to show how the substituent affects the barrier height and thermodynamic parameters of these reactions. To illustrate the interaction between two fragments at transition states Activation Strain Model (ASM) and Energy Decomposition Analysis (EDA) were utilized. The Wiberg bond indices were used to check the progress of the reactions. The rate constant of the reaction was computed at 300 K, in the gas phase. Also, the synchronicity values of this reaction were determined. [ABSTRACT FROM AUTHOR]

This study examined the effects of phosphine ligand on the structure and electronic properties of (C5H4)Re(PX3)3Cl rhenabenzyne complexes (X = H, F, Cl, Me) using the hybrid density functional MPW1PW91. Variations in the structure, dipole moment, electronic spatial extent (ESE), and aromaticity of the title complex were studied. In addition, adiabatic and vertical ionization potential and electron affinity values of these complexes were calculated. Correlations between the calculated parameters and Tolman cone angles (θ), Tolman's Electronic Parameter (TEP), as well as the Crabtree's DFT Electronic Parameter (CEP) of the phosphine ligands were illustrated. The para‐delocalization index (PDI) was used to investigate aromaticity in these systems. Natural bond orbital analysis (NBO) was employed for a comprehensive insight into the nature of the bonds in these complexes. [ABSTRACT FROM AUTHOR]

A copper-catalyzed hydroamination of styrenes using piv ZPhos as ligand is reported. Enantioselectivities up to 94% are achieved under optimized conditions with aryl and heteroaryl styrenes. A variety of electrophilic O -benzoylhydroxylamines are well tolerated. [ABSTRACT FROM AUTHOR]

Herein, we report the preparation and characterization of two diiron carbonyl complexes with ethyldiphenylphosphine or dicyclohexylphenylphosphine. Me3NO-driven decarbonylation of complex [Fe2(CO)6(µ-SCH2CH2CH2S)] (1) with the corresponding phosphine ligands afforded the products [Fe2(CO)5(Ph2PCH2CH3)(µ-SCH2CH2CH2S)] (2) and [Fe2(CO)5PhP(C6H11)2(µ-SCH2CH2CH2S)] (3) in 91% and 84% yields, respectively. The structures of complexes 2 and 3 have been identified by spectroscopy, elemental analysis, and X-ray diffraction analysis. Moreover, the electrochemistry was investigated by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Treatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested. [ABSTRACT FROM AUTHOR]

The solid-state structures of compounds PPh2CH2SPh (1) and PPh2C6H4SMe (2) were determined by single crystal X-ray diffraction. Experimental results on the molecular structures of compounds 1 and 2 were supported by Hirshfeld surface analysis and Density Functional Theory (DFT). The computed values calculated at DFT level using B3LYP function with 6-311++G (3df, 3pd) (P, S) and 6-31G* (C, H) basis sets are in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Treatment of [RuCl2(PPh3)3] with N-(β-aminoethyl)-γ-aminopropylmethylbimethoxysilane (L1) in tetrahydrofuran at room temperature gave a mononuclear ruthenium(II) complex [Ru(PPh3)2Cl2 (κ2-N,N-L1)] (1). Condensation of γ-aminopropyltriethoxysilane and potassium diphenylphosphine in the molar ratio of 1:1 in tetrahydrofuran afforded phosphine (PPh2)(CH2)3Si(OEt)3 (L2) with ethoxysilane groups. Reaction of [Ru(η6-p-cymene)Cl2]2 with L2 in refluxing tetrahydrofuran afforded a ruthenium(II) phosphine complex [Ru(η6-p-cymene)Cl2(κ-P-L2)] (2). Complexes 1 and 2 were systematically characterized by microanalyses, FT-IR, and NMR spectroscopies. Their structures have been unambiguously established by single-crystal X-ray diffraction. Immobilization of 1 and 2 on SBA-15 and characterization of these hybrid heterogeneous catalysts were studied by transmission electron microscopy (TEM), FT-IR, and low-pressure N2 adsorption/desorption measurements. Transfer hydrogenation of acetophenone was also briefly investigated with the heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

The electrochemical properties of two complexes, [RuII(η3‐(N,N,N)‐OMePDI)Cl2(PPh3)]0 (1) and [RuII(η2‐(C,N)‐OMePDI‐H)Cl (PPh3)2]0 (2), were studied. In octahedral complex 1, bis(imino)pyridine (PDI) is a tridentate η3‐N,N,N‐coordinated ligand, whereas in trigonal‐bipyramidal complex 2, the deprotonated PDI ligand adopts the unusual bidentate binding mode η2‐C,N to coordinate to the central Ru(II) ion. Bulk electrolysis in two electrolyte solutions of acetonitrile (MeCN) and tetrahydrofuran (THF) suggests that complexes 1 and 2 have very different electrocatalytic CO2 reduction activities. In MeCN solution, complex 1 can selectively electrocatalytic CO2 reduction to CO with a Faradaic efficiency of about 50% and a turnover frequency (TOF) of 4.4 s−1, whereas complex 2 can perform electrocatalytic of CO2 reduction with a Faraday efficiency of ~22% and a TOF of 0.3 S−1. The electrocatalytic CO2 reduction selectivity and activity of the two complexes are poor when the solvent is changed to THF. Combined with the results of the density functional theory calculation, we propose that the binding pattern of the redox‐active ligand OMePDI has a significant effect on the electrocatalytic activity for the two Ru(II)PDI complexes. [ABSTRACT FROM AUTHOR]

A series of new heteromultinuclear FeI/RuII clusters are described. The complexes (η6‐arene)RuFe2S2(CO)6 (arene = p‐cymene 1, C6Me62) and Fe2[μ‐S (Cp*Ru)(CO)2]2(CO)6 (Cp* = η5‐C5Me5) (3) were prepared by the reduction reactions of (μ‐S)2Fe2(CO)6 with 2 equiv of LiHBEt3, followed by treatment (μ‐SLi)2Fe2(CO)6 with ruthenium‐arene complexes Ru2(μ‐Cl)2Cl2(η6‐arene)2 or Cp*Ru (CO)2Cl in 22–33% yields. Further reactions of 1 and 2 with 1 equiv of triphenylphosphine in the presence of the decarbonylating agent Me3NO·2H2O, afforded the corresponding monophosphine‐substituted FeI/RuII complexes (η6‐arene)RuFe2S2(CO)5(Ph3P) (arene = p‐cymene 4, C6Me65) in 75% and 78% yields. While treatment of parent complex 1 or 2 with 1 equiv of diphosphine Ph2PCH2PPh2 (dppm) in xylene at reflux temperature resulted in the formation of the diphosphine‐bridged RuFe2S2(CO)9 derivate RuFe2S2(CO)7(dppm) (6). The possible pathway for the formation was proposed. Two isomers of novel macrocyclic complexes involve the (η6‐arene) Ru‐bridged quadruple‐butterfly Fe/S clusters [{μ‐S (CH2)3S‐μ}{(μ‐CS2)Fe2(CO)6}2]2[(η6‐arene)Ru]2 (arene = p‐cymene 7a and 7b, C6Me68a and 8b) were isolated by reactions of two μ‐CS2‐containing dianion [{μ‐S (CH2)3S‐μ}{(μ‐S=CS)Fe2(CO)6}2]2− with [Ru2(μ‐Cl)2Cl2(η6‐arene)2], in which the propylene groups are attached to two S atoms by ee and ea types of bonds respectively. All the new complexes 1–8 have been characterized by elemental analysis, spectroscopy, and particularly for 1–6, 7b and8a by X‐ray crystallography. In addition, the electrochemical properties of representative complexes 1–4 and 6 have been investigated. [ABSTRACT FROM AUTHOR]

• Challenge: control of chemoselectivity in multiple (pseudo)halides coupling. • The reaction shows the reactivity order of C−Br > C−Cl > C−OTf. • Low Pd catalyst loading achieves C−Br > C−OTf selectivity. • One-pot sequential coupling allows simple polyfunctionalized arene synthesis. This paper presents general examples of the palladium-catalyzed chemoselective Suzuki–Miyaura cross-coupling reaction of polyhalogenated aryl triflates with a reactivity order of C–Br > C–Cl > C–OTf. A diverse array of bromo(hetero)aryl triflates was successfully coupled with (hetero)aryl boronic acids, achieving excellent reactivity and chemoselectivity. This was accomplished using a catalyst system composed of Pd(OAc) 2 and SelectPhos (L1), with catalyst loadings reducible to as low as 0.02 mol% Pd. The sequential double functionalization of bromochloroaryl triflates was also demonstrated successfully, paving the way for the synthesis of terphenyl derivatives. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, five diiron propane-1,3-dithiolate complexes containing substituted phosphine ligands were prepared and structurally characterized. Treatment of [Fe2(CO)6(μ-SCH2CH2CH2S)] (1) with a monophosphine ligand methyl diphenylphosphinite, ethyl diphenylphosphinite, 4-(dimethylamino)phenyldiphenylphosphine, tris(2-methoxyphenyl)phosphine, or tris(4-chlorophenyl)phosphine in the presence of Me3NO·2H2O as the decarbonylating agent gave the corresponding phosphine-substituted analogues [Fe2(CO)5(L)(μ-SCH2CH2CH2S)] [L = Ph2POCH3, 2; Ph2POCH2CH3, 3; Ph2P(4-C6H4 NMe2), 4; P(2-C6H4OCH3)3, 5; P(4-C6H4Cl)3, 6] in 73–93% yields. Complexes 2–6 have been characterized by elemental analysis, spectroscopy, and X-ray crystallography. Additionally, electrochemical studies have shown that 2–6 can catalyze the reduction of protons to H2 in the presence of HOAc. [ABSTRACT FROM AUTHOR]

The reactions of the starting complex, [Fe2(CO)6{μ-SCH2CH (CH2CH3)S}] (1), with the phosphine ligands tris(4-methylphenyl)phosphine, diphenyl-2-pyridylphosphine, tris(4-fluorophenyl)phosphine, 2-(diphenylphosphino)benzaldehyde, or benzyldiphenylphosphine in the presence of the decarbonylating agent Me3NO·2H2O yielded the corresponding phosphine-substituted diiron butane-1,2-dithiolate complexes [Fe2(CO)5(L){μ-SCH2CH(CH2CH3)S}] (L = P(4-C6H4CH3)3, 2; Ph2P(2-C5H4N), 3; P(4-C6H4F)3, 4; Ph2P(2-C6H4CHO), 5; Ph2PCH2Ph, 6) in 75%–87% yields. The complexes have been characterized by elemental analysis, IR, 1H, and 31P{1H} NMR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Moreover, the electrochemistry of 2–4 was studied by cyclic voltammetry, suggesting that they can catalyze the reduction of protons to H2 in the presence of HOAc. [ABSTRACT FROM AUTHOR]

Graphical abstract The bis(phosphino)ethane chelate demonstrates remarkable coordination weakness in a series of dinickel(II) tetrachloride complexes based on a binucleating racemic- and meso -tetraphosphine ligands. Addition of water to these complexes results in loss of chloride and formation of a hydroxide-bridged dinickel species. This is followed by facile loss of one nickel center at room temperature for the meso -P4 diastereomer forming several monometallic complexes that ultimately dimerize to form a new tricationic dinickel(II) species with a bridging chloride and two coordinated tetraphosphine ligands. This new bimetallic complex is also quite susceptible to fragmentation reactions. Comparisons with a far more strongly chelating P4 ligand are presented. Abstract NMR studies demonstrate that rac - and meso -Ni 2 Cl 4 (P4), P4 = (Et 2 PCH 2 CH 2)(Ph)PCH 2 P(Ph)(CH 2 CH 2 PEt 2), bimetallic complexes readily react with water in different organic solvents (acetone, acetonitrile, DMSO) to dissociate a chloride and most likely form a hydroxide-bridged bimetallic complex, [Ni 2 (μ-OH)Cl 2 (P4)]+. The meso bimetallic complex is very susceptible to dissociation of one of the external chelated phosphines, which leads to loss of one of the nickel atoms. The tetraphosphine ligand recoordinates to the remaining nickel center to form [NiCl(κ3- meso -P4)]+, which can, in turn, react with chloride to produce NiCl 2 (κ2- meso -P4). The meso diastereomers of these monometallic complexes then react with one another to form a double P4-coordinated bimetallic complex, [Ni 2 (μ-Cl)(meso -P4) 2 ]3+, which has been crystallographically characterized. Despite the presence of four bis-phosphino(ethane) chelates around two nickel centers, [Ni 2 (μ-Cl)(meso -P4) 2 ]3+ readily fragments and can be converted back to the precursor mono- and bimetallic complexes by heating in the presence of chloride and NiCl 2 ·6H 2 O. The racemic dinickel diastereomer, Ni 2 Cl 4 (rac -P4), also reacts with water to produce [Ni 2 (μ-OH)Cl 2 (rac -P4)]+, but does not fragment further at room temperature unless oxygen is present. The rac- or meso- Ni 2 Cl 4 (P4-Ph) complexes based on the much stronger chelating tetraphosphine ligand with 1,2-phenylene chelate rings also react readily with water to form a hydroxide-bridged bimetallic complex, but further reaction and fragmentation chemistry is inhibited by the much stronger chelate effect present. [Ni 2 (μ-OH)Cl 2 (meso -P4-Ph)]+ has been crystallographically and spectroscopically characterized along with some intermediate monometallic rac - and meso -P4-Ph nickel complexes from cyanolysis attempts. [ABSTRACT FROM AUTHOR]

Commercial use of H2 production catalysts requires a repeated use/stop/store and reuse of the catalyst. Ideally, this cycle should be possible under ambient O2. Herein we exemplify the concept of Use-Store-Reuse (USR) of a (Ru-phosphine) catalyst in a biphasic catalytic system, for H2 production via dehydrogenation of HCOOH. The catalytic system can operate uninterrupted for at least four weeks, including storage and reuse cycles, with negligible loss of its catalytic efficiency. The catalytic system consisted of a RuP(CH2CH2PPh2)3 (i.e. RuPP3) in (tri-glyme/water) system, using KOH as a cocatalyst, to promote HCOOH deprotonation. In a USR cycle of 1 week, followed by storage for three weeks under ambient air and reuse, the system achieved in total TONs > 90,000 and TOFs > 4000 h−1. Thus, for the first time, a USR concept with a readily available stable ruthenium catalyst is presented, operating without any protection from O2 or light, and able to retain its catalytic performance.

Stereodynamic ligands offer intriguing possibilities in enantioselective catalysis. “NU-BIPHEPs” are a class of stereodynamic diphosphine ligands which are easily accessible via rhodium-catalyzed double [2 + 2 + 2] cycloadditions. This study explores the preparation of differently functionalized “NU-BIPHEP(O)” compounds, the characterization of non-covalent adduct formation and the quantification of enantiomerization barriers. In order to explore the possibilities of functionalization, we studied modifications of the ligand backbone, e.g., with 3,5-dichlorobenzoyl chloride. Diastereomeric adducts with Okamoto-type cellulose derivatives and on-column deracemization were realized on the basis of non-covalent interactions. Enantioselective dynamic HPLC (DHPLC) allowed for the determination of rotational barriers of ΔG‡298K = 92.2 ± 0.3 kJ mol−1 and 99.5 ± 0.1 kJ mol−1 underlining the stereodynamic properties of “NU-BIPHEPs” and “NU-BIPHEP(O)s”, respectively. These results make the preparation of tailor-made functionalized stereodynamic ligands possible and give an outline for possible applications in enantioselective catalysis.