Organophosphorus Ligands Research Articles

Phosphoramide-Based Metal-Organic Frameworks for Effective Gas Adsorption.

Cost-effective and facile synthetic routes to organic ligands, along with porous materials that exhibit exceptional gas-storage properties, promise significant industrial applications. Here, a two-step synthesis of novel organophosphorus ligands without metal catalysts is reported. These ligands serve as versatile linkers for the construction of metal-organic frameworks (MOFs) incorporating various metal ions, including zinc and copper. One of the zinc-based MOFs demonstrates remarkable gas-storage properties, with a hydrogen (H2) capacity exceeding 2.5 wt% at 77 K and 100 kPa as well as a carbon dioxide (CO2) capacity exceeding 20 wt% at 298 K and 100 kPa. Furthermore, this zinc-based MOF can be synthesized through a solvothermal process on the gram scale that yields high-quality single crystals.

Transforming Cobalt Nanospheres into Co2P Nanorods: The Key Roles of Oleylamine and Organophosphorus Ligands in a Co(I) Precursor Uncovered through X-ray Photoelectron Spectroscopy Analysis

Transforming Cobalt Nanospheres into Co₂P Nanorods: The Key Roles of Oleylamine and Organophosphorus Ligands in a Co(I) Precursor Uncovered through X-ray Photoelectron Spectroscopy Analysis

Crystal, Solution, and Computational Study of the Structure of Ortho-Lithium N,N-Diisopropyl-P,P-Diphenylphosphinothioic Amide.

The first crystal structure of an ortho-lithium phosphinothioic amide complexed with tetramethylethylenediamine 12 is reported. The complex consists of a spirane in which the spiro-lithium is N,N- and C,S-chelated by the diamine and organophosphorus ligands, respectively. The analogous ortho anion 14 obtained by Sn(IV)/Li transmetallation in THF has also been synthesized. Nuclear magnetic resonance study of both anions showed that they exist as monomers in solution and are involved in dynamic processes including the restricted rotation around the P-N bond. 14 is converted at room temperature by nucleophilic cyclization to the dearomatized anion 15, which evolves after a few hours to the benzophosphindole sulfide 16. Density functional theory calculations supported the aggregation state in solution and were used to explore the conformational space of anion 12, the mechanism of ortho-lithiation directed by P(X)-N (X=O, S) groups, and the mechanism of formation of 15.

Are 4f-Orbitals Engaged in Covalent Bonding Between Lanthanides and Triphenylphosphine Oxide? An Oxygen K-Edge X-ray Absorption Spectroscopy and Density Functional Theory Study.

The bonding covalency between trivalent lanthanides (Ln = La, Pr, Nd, Eu, Gd) and triphenylphosphine oxide (TPPO) is studied by X-ray absorption spectra (XAS) and density functional theory (DFT) calculations on the LnCl3(TPPO)3 complexes. The O, P, and Cl K-edge XAS for the single crystals of LnCl3(TPPO)3 were collected, and the spectra were interpreted based on DFT calculations. The O and P K-edge XAS spectra showed no significant change across the Ln series in the LnCl3(TPPO)3 complexes, unlike the Cl K-edge XAS spectra. The experimental O K-edge XAS spectra suggest no mixing between the Ln 4f- and the O 2p-orbitals in the LnCl3(TPPO)3 complexes. DFT calculations indicate that the amount of the O 2p character per Ln-O bond is less than 0.1% in the Ln 4f-based orbitals in all of the LnCl3(TPPO)3 complexes. The experimental spectra and theoretical calculations demonstrate that Ln 4f-orbitals are not engaged in the covalent bonding of lanthanides with TPPO, which contrasts the involvement of U 5f-orbitals in covalent bonding in the UO2Cl2(TPPO)2 complex. Results in this work reinforce our previous speculation that bonding covalency is potentially responsible for the extractability of monodentate organophosphorus ligands toward metal ions.

Chiral bisphosphine Ph-BPE ligand: a rising star in asymmetric synthesis.

Chiral 1,2-bis(2,5-diphenylphospholano)ethane (Ph-BPE) is a class of optimal organic bisphosphine ligands with C2-symmetry. Ph-BPE with its excellent catalytic performance in asymmetric synthesis has attracted much attention of chemists with increasing popularity and is growing into one of the most commonly used organophosphorus ligands, especially in asymmetric catalysis. Over two hundred examples have been reported since 2012. This review presents how Ph-BPE is utilized in asymmetric synthesis and how powerful it is as a chiral ligand or even a catalyst in a wide range of reactions including applications in the total synthesis of bioactive molecules.

Ligand-mediated manganese phosphonates with a variable morphological framework: efficient for energy storage application

Distinct morphological forms of manganese phosphonates were synthesized using multiple organophosphorus ligands which were explored for energy storage applications with the fabrication of interdigital in-plane micro-supercapacitors.

Highly efficient lithium extraction from magnesium-rich brines with ionic liquid-based collaborative extractants: Thermodynamics and molecular insights

Selective extraction of Li+ from high Mg2+/Li+ ratio brines with ionic liquid (IL) based collaborative extractants was investigated by experiments, thermodynamic analyses, and quantum chemical (QC) calculations. Effects of different IL cationic structures and organophosphorus ligands on extraction performances were studied. The results demonstrated that the system 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + trioctyl phosphate ([HOEMIM][Tf2N] + TOP) was considered as the best extractant, with the very high extraction efficiency of Li+ (83.16 %) and separation selectivity of Li+/Mg2+ (742.11), which is higher than values reported in literature. The thermodynamic model ePC-SAFT was first extended to quantitatively predict the phase equilibria of the so-called “organic–inorganic complex strong electrolyte system” presented in this work. The molecular-level extraction mechanism was explored by QC calculation, indicating that the strong multi-site intermolecular interactions between Li+ and [HOEMIM][Tf2N] + TOP break the Li+ hydration. This work provides guidance to rationally design novel IL-based extractants for efficient extraction of Li+.

Theoretical insights into the extraction behaviors of neptunium(VI) and plutonium(IV) based on the structure of organophosphorus ligands

Organophosphorus ligands such as TBP, TiAP, and DMHMP have exhibited excellent performance in recovering actinides from spent fuel. In this work, the molecular geometries and properties of TBP, TiAP and DMHMP were investigated using density functional theory calculations. Furthermore, the extraction mechanism of ligands for actinides (Np(Ⅵ), Pu(Ⅳ)) was further elucidated by simulating the microstructures and extraction reactions of metal–ligand complexes. The results demonstrate that the complexation ability of the three ligands on actinide cations (NpO22+ and Pu4+) follows the order of DMHMP > TiAP > TBP. The electrostatic potential (ESP) analysis indicates that the nucleophilic ability of DMHMP is stronger than that of the other two ligands. The frontier molecular orbital analysis of the three ligands represents that DMHMP has the highest HOMO energy, suggesting that it has the strongest electron-donating capability and is more likely to bond with metal ions. The values of Wiberg bond indices (WBI) suggest that the MO bonds in DMHMP complexes have more covalency. According to the QTAIM analysis, the interactions between actinide cations and the ligands are predominantly ionic in nature. The molecular orbital analysis of the complexes shows that the M(NO3)n·2DMHMP (MNpO22+ and Pu4+) complexes are more stable, which is supported by thermodynamic energy analysis. This work has clarified the complexing properties of actinide cations with three ligands, shedding light on the extraction mechanisms of organophosphorus ligands for actinide cations. It is anticipated to lay the theoretical foundation for the efficient recovery of critical actinide elements in spent fuel reprocessing, which will also provide innovative approaches for the design and development of related separation processes.

Iron Cobalt Phosphonate Derived Heteroatom Doped Metal Oxides as Superior Electrocatalysts for Water Oxidation Reaction

AbstractThe development of low cost‐effective and highly efficient heterogeneous electrocatalysts is most appreciable in the research community. A newly designed microporous organic‐inorganic hybrid iron cobalt phosphonate (FeCoDPAM) is synthesized using diphenylphosphinamide as an organophosphorus ligand through a hydrothermal pathway without any template. To synthesize N, P‐codoped bimetallic oxides (NP/FeCoO350, NP/FeCoO550, and NP/FeCoO750), the as‐synthesized material FeCoDPAM has undergone pyrolysis at three different temperatures, i. e., 350, 550, 750 °C, respectively. The high specific surface area and a regular microporous array of N, P‐codoped iron cobalt oxide (NP/FeCoO350) material provide excellent oxygen evolution reaction (OER) activity. The NP/FeCoO350 material catalyzes OER with the overpotential of 331 mV at a current density of 10 mAcm−2 and Tafel slope of 56.7 mV dec−1 in 1.0 M KOH solution. The inclusion of iron in the cobalt phosphonate framework can change the electronic structure, and electron transfer can be feasible to the d‐orbital of cobalt. Due to the doping of heteroatoms such as N and P into the bimetallic oxide matrix, a synergistic effect can occur, which is the driving force for the efficient electrocatalytic OER activity. Also, the FeCoO350 displays stability with outstanding oxidative current up to 50 h time in chronoamperometry measurement.

Isocyanide Cycloaddition and Coordination Processes at Trigonal Phosphinidene-Bridged MoRe and MoMn Complexes

Heterometallic phosphinidene complexes are appealing species for the construction of novel organophosphorus ligands thanks to the high reactivity expected from the combination of M-P multiple bonding and the intrinsically different electronic and coordination preferences of the distinct metals. In a preliminary study, we found that the heterobimetallic complex [MoReCp(μ-PMes*)(CO)6] (Mes* = 2,4,6-C6H2tBu3) reacted with CN(p-C6H4OMe) via [2+1]-cycloaddition to form a novel azaphosphallene complex. We have now examined in detail the reactions of the above complex and those of its MoMn analogue with different isocyanides, which turned out to be strongly dependent on experimental conditions and on the size of the substituent at the isocyanide. All the products formed follow from one or several of the following reaction pathways: (i) CO substitution by CNR; (ii) addition of CNR at the group 7 metal centre; and (iii) [2+1] cycloaddition of isocyanide at a Mo=P bond to form azaphosphallene groups, with the former process being dominant in reactions at room temperature and for the Mn system. In contrast, low-temperature reactions of the Re system favoured the addition processes, with the [2+1] cycloaddition at Mo=P bonds only taking place at substrates without metal-metal bonds and when the size of the CNR group does not cause unbearable steric clashes when placed in between the Cp and Mes* groups.

Synthesis, characterization, DFT/M06 studies, NBO, QTAIM and RDG analyses of new copper (II) complexes with bis-phosphonamide obtained under microwave irradiation

We have devised a novel one-step approach for synthesizing bis-phosphonamides utilizing primary amines and phenylphosphonic dichloride (PPDC) under ultrasound irradiation. The bis-phosphonamides obtained were used as organophosphorus ligands for the synthesis of new copper (II) complexes with metal ions. The synthesis of these complexes was accomplished via a novel eco-friendly method employing microwave irradiation. The desired complex obtained, as a green powder in 65% yield, which were fully characterized by spectroscopic methods (FT-IR, UV–vis, XDR). To gain and further insights into structure and properties of studied complexes, several calculations such as Natural Atomic Orbitals (NAO), Natural Bond orbitals(NBO), Quantum Theory of Atoms in Molecules (QTAIM) analysis were performed at M06/6-311++g(d, p) level. Using the Reduced electron Density Gradient (RDG) approach, the non-covalent interactions were explored and visualized in two and three-dimensional spaces.

Improving stability and efficiency of three-dimensional perovskite solar cells with organophosphorus ligands

The core density of the defects in perovskite thin films will directly affect the properties of perovskite solar cells. On the other hand, interface engineering is usually being used to effectively improve the quality of perovskite thin films. In this sought of work, MAPbI3 perovskite thin films were modified by an antisolvent process using trioctylphosphine as a passivator. Trioctylphosphine is a kind of Lewis base and from the experimental results, it is noticed on being contribute to MAPbI3 grain growth and grain boundary passivation. Due to the grain boundary passivation and grain size increase, the intense defect density inside the grain and at the grain boundary of the MAPbI3 films is gradually reduced, thereby improving the carrier lifetime, while the hydrophobic property of octyl alkane makes the perovskite thin films less susceptible to air, water and oxygen degraded by the influence. The solar cell which are using the proposed films with the device structure configuration as ITO/SnO2/MAPbI3/spiro-OMeTAD/Ag and the perovskite layers were modified with trioctylphosphine. Among them, the perovskite thin films showcased to have a best performance when the trioctylphosphine chlorobenzene solution was about 0.15% and the PCE of the device reached for about 12.17%, an increase of 10% was compared with the standard device. In addition, the modified device exhibits good environmental stability, retaining about 90% of the initial efficiency for 100 h in a 70% humidity environment.

Direct and chlorine-free synthesis of phosphafluorenes or their oxides from white phosphorus

The known methods for the preparation of acylphosphine oxides and polyfluorobenzene-substituted triarylphosphines need to utilize PCl3, while the chlorine-free methods are not reported. In this work, we report a chlorine-free method by one-pot three-component reaction of white phosphorus (P4), dilithio reagents, and acyl chlorines or polyfluorobenzenes for the synthesis of biphenyl-based acylphosphine oxides and phosphines. This reaction is green and environmentally friendly compared with the traditional method, because it avoids the use of Cl2 and the discharge of a large amount of waste gas and waste acid. These two products have potential applications as photoinitiators in photopolymerization or as organophosphorus ligands in catalytic reactions.

Palladacycle versus coordination complex of palladium(II) with a bulky organophosphorus (P,N) ligand: Application in catalysis of allylation of aldehydes

Palladacyclic complex 1 [Pd(L1)Cl] [L1: anthracene–9-yl–CH = N(CH2)2–PPh2 behaving as (P, N, C−) ligand] has been prepared, and characterized using multi-nuclei NMR spectroscopic, high resolution mass spectrometric (HRMS) and single-crystal X-ray diffraction (SC-XRD) techniques. This palladacycle 1 and the 2 [i.e., Pd(L1)Cl2, a square planar Pd(II) complex of the same ligand] have anthracene core, imine functionality and P,N donors. Both the 1 and 2 have been explored as potential catalysts for allylation of aldehydes with allyltributylstannnane. Both the complexes show good efficiency towards this CC coupling reaction. Various aldehydes such as 4–bromobenzaldehyde, 4–chlorobenzaldehyde, 2–bromobenzaldehyde, 2–chlorobenzaldehyde, 4–methoxybenzaldehyde, 4–methylbenzal dehyde, 4–nitrobenzaldehyde pyridine–2–carboxaldehyde and furfural have been explored for this reaction. Effect of presence of Pd–C bond is noticed on the catalytic performance. The palladacyclic complex 1 is more efficient than coordination complex 2 as the Pd-C bond of metallacyclic complex increases the rate of dissociation of Pd-Cl bond and therefore helping in easy participation and increased efficiency of complex 1 in catalysis.

Assessment of the Equilibrium Constants of Mixed Complexes of Rare Earth Elements with Acidic (Chelating) and Organophosphorus Ligands

A survey of the experimental equilibrium constants in solution for the mixed complexes of 4f ions with acidic (chelating) and O-donor organophosphorus ligands published in the period between 1954 and 2022 is presented. These data are widely used in both analytical and solvent extraction chemistry. Important data evaluation criteria involved the specification of the essential reactions, process conditions and the correctness of techniques and calculations used, as well as appropriate equilibrium analysis of experimental data. Higher-quality data have been evaluated, compiled and presented herein, providing a synoptic view of the unifying theme in this area of research, i.e., synergism.

The Backbone of Success of P,N-Hybrid Ligands: Some Recent Developments.

Organophosphorus ligands are an invaluable family of compounds that continue to underpin important roles in disciplines such as coordination chemistry and catalysis. Their success can routinely be traced back to facile tuneability thus enabling a high degree of control over, for example, electronic and steric properties. Diphosphines, phosphorus compounds bearing two separated PIII donor atoms, are also highly valued and impart their own unique features, for example excellent chelating properties upon metal complexation. In many classical ligands of this type, the backbone connectivity has been based on all carbon spacers only but there is growing interest in embedding other donor atoms such as additional nitrogen (–NH–, –NR–) sites. This review will collate some important examples of ligands in this field, illustrate their role as ligands in coordination chemistry and highlight some of their reactivities and applications. It will be shown that incorporation of a nitrogen-based group can impart unusual reactivities and important catalytic applications.

Coordination and extraction properties of new bis- and tetrakis(diphenylphosphoryl)-substituted pyrazines towards f-block elements

2,3-Bis- and 2,3,5,6-tetrakis(diphenylphosphoryl)-substituted pyrazines have been synthesized from the corresponding polychloropyrazines and ethyl diphenylphosphinite. They may serve as new N,O-bidentate organophosphorus ligands for extraction and recovery of f-block metal ions from nitric acid solutions.

New ionic [{2-(Me2NCH2)C6H4}(R)Sn{(EPPh2)2N}][(EPPh2)2N] (R = 2-(Me2NCH2)C6H4, nBu; E = O, S, Se) compounds. Solution behaviour and solid state structure

The new compounds [{2-(Me2NCH2)C6H4}(R)Sn{(EPPh2)2N}][(EPPh2)2N] [R = 2-(Me2NCH2)C6H4, E = O (1), S (2), Se (3) and R = nBu, E = O (4), S (5), Se (6)] were prepared by salt metathesis reactions between [2-(Me2NCH2)C6H4](R)SnCl2 and the potassium salt of the corresponding tetraorganodichalcogenoimidodiphosphinic acid in a 1:2 molar ratio. The multinuclear NMR studies (1H, 13C, 31P, 119Sn, and 77Se where appropriate) showed the equivalence of the 2-(Me2NCH2)C6H4 groups in 1 - 3 and non-equivalent organophosphorus ligands in 1 - 6. The compounds behave as 1:1 electrolytes in solution, with [{2-(Me2NCH2)C6H4}(R)Sn{(EPPh2)2N}]+ cations and [(EPPh2)2N]− anions. The single-crystal X-ray diffraction studies revealed an ionic structure for 2 and 3. An octahedral coordination environment is realized about tin by two C,N-coordinated 2-(Me2NCH2)C6H4 groups and a κ2-E,E'-chelating organophosphorus [(EPPh2)2N]ˉ anionic ligand. We found a dimeric structure with bridging OHˉ groups and monodentate S-organophosphorus ligands for the hydrolysis product [{2-(Me2NCH2)C6H4}(nBu)Sn(OH){(SPPh2)2N}]2 (5h).

A Comprehensive Discovery Platform for Organophosphorus Ligands for Catalysis.

The design of molecular catalysts typically involves reconciling multiple conflicting property requirements, largely relying on human intuition and local structural searches. However, the vast number of potential catalysts requires pruning of the candidate space by efficient property prediction with quantitative structure-property relationships. Data-driven workflows embedded in a library of potential catalysts can be used to build predictive models for catalyst performance and serve as a blueprint for novel catalyst designs. Herein we introduce kraken, a discovery platform covering monodentate organophosphorus(III) ligands providing comprehensive physicochemical descriptors based on representative conformer ensembles. Using quantum-mechanical methods, we calculated descriptors for 1558 ligands, including commercially available examples, and trained machine learning models to predict properties of over 300000 new ligands. We demonstrate the application of kraken to systematically explore the property space of organophosphorus ligands and how existing data sets in catalysis can be used to accelerate ligand selection during reaction optimization.

Improving Stability and Efficiency of Three-Dimensional Perovskite Solar Cells with Organophosphorus Ligands

Improving Stability and Efficiency of Three-Dimensional Perovskite Solar Cells with Organophosphorus Ligands