PCl3 Research Articles

Synthesis of Adamantyl H‐Phosphinate Esters

AbstractAdamantyl H‐phosphinate esters have been described by Leclaire, Giordano, and coworkers as “universal precursors of P‐stereogenic compounds” after resolution by chiral HPLC, because these esters resist racemization during displacement with organometallics. In that work, the racemic esters were prepared from phosphorus trichloride or dichlorophosphines (RPCl2). We decided to investigate alternative methods for the preparation of these important precursors. Esterification methods included EDC, PivCl, and T3P. A protocol to avoid chromatographic purification was also developed and used for multigram‐scale synthesis. Finally, adamantyl hypophosphite 1‐AdOP(O)H2 was also prepared and used in the synthesis adamantyl H‐phosphinate esters, thereby providing an alternative to the esterification of H‐phosphinic acids, although 1‐AdOP(O)H2 was much less reactive than other hypophosphite esters.

Molecular Dynamics Simulation of Phosphorus Trichloride (PCl3) and Phosphorus Triiodide (PI3) Liquids by Using the Force-fields Derived from a Quantum Chemical Approach

In this study, phosphorus trichloride (PCl3) and phosphorus triiodide (PI3) as the condensed inorganic materials were investigated based on the molecular dynamics simulation. To this purpose, molecular dynamics simulations were performed by applying force field parameters derived from the quantum chemistry approach. The potential energy data were computed at the B3LYP/6-31+G (d) and B3LYP/dgdzvpd levels of theory for different configurations of PCl3 and PI3, respectively. To determine force field parameters, a four-site all-atom force field model was used to correlate the potential energy data. Therefore, the force field parameters were applied to perform the molecular dynamics simulations. The MD simulations were performed to obtain the atomic number density, enthalpy, heat capacity, and radial distribution function in the NPT and NVT ensembles for PCl3 and PI3 dimers. There is a good consistency between the experimental data and simulation results over a wide range of experimental conditions.

Environmental cost and impacts of chemicals used in agriculture: An integration of emergy and Life Cycle Assessment

Modern intensive agriculture worldwide is generating increasing environmental pressure, which prevents its sustainable development. A number of agricultural sustainability assessment approaches and methodological frameworks have been developed by research worldwide to assess the environmental costs and impacts of resources used in agricultural production. A joint use of Life Cycle Assessment (LCA, to assess a process' performance and environmental impacts) and Emergy Accounting (EMA, to estimate environmental support to resource generation and provision) is proposed in this study. The goal is not only to ascertain the environmental ‘cost’ of production of selected chemical resources used in agricultural processes, but also to develop a reliable calculation procedure capable to integrate the two approaches (LCA and EMA), while considering their different allocation algebra and space-time scales of application. Specifically, the UEVs of glyphosate and urea, which are respectively the most used herbicide and nitrogen fertilizer used in worldwide agriculture, are calculated, yielding values of 2.47E+13 sej/kg and 7.07E+12 sej/kg, respectively. In order to do so, UEVs of intermediate process chemicals such as ammonia, acetic anhydride, chlorine gas, formaldehyde, phosphorous chloride, and sodium hydroxide have also been calculated or updated, thus providing at the same time a procedure and a set of values potentially useful for future studies. The LCA impacts of agro-chemicals in China are compared to worldwide averages from the Ecoinvent database, and the UEVs for several chemicals are also compared to previous estimates from published emergy literature.

Access to cationic polyhedral carboranes via dynamic cage surgery with N-heterocyclic carbenes

Polyhedral boranes and heteroboranes appear almost exclusively as neutral or anionic species, while the cationic ones are protonated at exoskeletal heteroatoms or they are instable. Here we report the reactivity of 10-vertex closo-dicarbadecaboranes with one or two equivalents of N-heterocyclic carbene to 10-vertex nido mono- and/or bis-carbene adducts, respectively. These complexes easily undergo a reaction with HCl to give cages of stable and water soluble 10-vertex nido-type cations with protonation in the form of a BHB bridge or 10-vertex closo-type cations containing one carbene ligand when originating from closo-1,10-dicarbadecaborane. The reaction of a 10-vertex nido mono-carbene adduct with phosphorus trichloride gives nido-11-vertex 2-phospha-7,8-dicarbaundecaborane, which undergoes an oxidation of the phosphorus atom to P = O, while the product of a bis-carbene adduct reaction is best described as a distorted C2B6H8 fragment bridged by the (BH)2PCl2+ moiety.

One‐step Conversion of Amides and Esters to Acid Chlorides with PCl3

AbstractA general and efficient iodine‐promoted chlorination of amides and esters with phosphorus trichloride is described. For the first time. Various inactivated amides including secondary and tertiary amides were directly converted to the corresponding acid chlorides in one‐step. The substrate scope of methyl esters including aromatic and aliphatic esters was also explored under this system. This method is simple, scalable and wide in scope, which provides an approach to preparation of these acid chlorides.

Nucleophilic Substitution at Tetracoordinate Phosphorus. Stereochemical Course and Mechanisms of Nucleophilic Displacement Reactions at Phosphorus in Diastereomeric cis- and trans-2-Halogeno-4-methyl-1,3,2-dioxaphosphorinan-2-thiones: Experimental and DFT Studies.

Geometrical cis- and trans- isomers of 2-chloro-, 2-bromo- and 2-fluoro-4-methyl-1,3,2-dioxaphosphorinan-2-thiones were obtained in a diastereoselective way by (a) sulfurization of corresponding cyclic PIII-halogenides, (b) reaction of cyclic phosphorothioic acids with phosphorus pentachloride and (c) halogen–halogen exchange at PIV-halogenide. Their conformation and configuration at the C4-ring carbon and phosphorus stereocentres were studied by NMR (1H, 31P) methods, X-ray analysis and density functional (DFT) calculations. The stereochemistry of displacement reactions (alkaline hydrolysis, methanolysis, aminolysis) at phosphorus and its mechanism were shown to depend on the nature of halogen. Cyclic cis- and trans-isomers of chlorides and bromides react with nucleophiles (HO−, CH3O−, Me2NH) with inversion of configuration at phosphorus. DFT calculations provided evidence that alkaline hydrolysis of cyclic thiophosphoryl chlorides proceeds according to the SN2-P mechanism with a single transition state according to the potential energy surface (PES) observed. The alkaline hydrolysis reaction of cis- and trans-fluorides afforded the same mixture of the corresponding cyclic thiophosphoric acids with the thermodynamically more stable major product. Similar DFT calculations revealed that substitution at phosphorus in fluorides proceeds stepwise according to the A–E mechanism with formation of a pentacoordinate intermediate since a PES with two transition states was observed.

Phosphorylation of glycoluryl derivatives with phosphorus pentachloride

The paperpresents the research results on the synthesis and study of new organophosphorus derivatives of glycoluril, obtained on the basis of pentavalent phosphorus. New organoelement phosphorus derivatives synthesized on the basis of N-acyl-substituted glycolurilhave been obtained.They are of considerable interest due to the presence of effective reaction centers. Tetraacetyl-substituted glycoluril —2,4,6,8-tetraacetyl-2,4,6,8-tetraazabicyclo[3,3,0]octane-3,7-dione was chosen as theinitial synthon. Theuse of unsubstituted glycoluril in the reaction of direct phosphorylation by the action of phosphorus trichloride or pentachloride is not possible due to the absence of active phosphorylation centers. It was experimentally shown that the reaction proceeds with prolonged heating for at least 48 hours in an argon. Theinitial acyl derivative of glycoluril and phosphorus pentachloride in theratio of 1:6 and leads to the formation of diphosphonic complex of tetraacetylglycoluril —dihexachlorophosphorate 2,6-diacetyl-(4,8-diacetyl-2,4,6,8-tetraaza-bicyclo[3.3.0]octane-3,7-dione)-2,6-di(chloroethenyltrichlorophosphonium). The obtained compoundis a white crystalline substance unstable in air. Decomposition of the diphosphonic complex was carried out using benzaldehyde and proceeds with the formation of the corresponding dichlorophosphate derivative, also unstable in air and rapidly decomposing at room temperature.

The role of organonickel reagents in organophosphorus chemistry

Organonickel reagents are widely used for the obtaining of the organophosphorus compounds from different phosphorus sources including elemental white phosphorus, phosphorus trichloride and phosphine PH 3 . In particular, new highly efficient and environmentally friendly methods for preparation of organophosphorus compounds bearing phosphorus–carbon bonds have been elaborated using the electrochemically generated organonickel complexes. The synthetic application of the developed techniques towards the formation of wide range of practically important primary, secondary and tertiary organophosphines, with a special focus on unsymmetrical PH phosphines, is disclosed. The mechanistic pathways and the structure of the assumed intermediates formed on some key stages of the overall process are presented for discussion. The elaborated methods operate on the electrochemical techniques with combination of coordination chemistry principles and are considered as an efficient alternative to the more common methods.

On Pyridopyrazinol Chemistry: Synthesis of Chemiluminescent Substances

AbstractOur work on new chemiluminescent substances related to the marine luciferin coelenterazine (λmax = 465 nm) led us to attempt the synthesis of four nitrogen-rich pyridopyrazine-bearing analogues. Accordingly, the preparation of the corresponding benzyl-bearing pyridopyrazinols is studied. By varying the conditions for the condensation of phenylpyruvic acid with 1,2-diaminopyridine or 3,4-diaminopyridine, all the possible pyridopyrazin-2-ol regioisomers are isolated and properly characterized, including by means of crystallographic studies. The ensuing syntheses of the halogenated pyridopyrazines are fraught with difficulties ranging from extensive decomposition to an unexpected ring contraction. In one instance, the inherently reductive mixture of phosphorus oxychloride and phosphorus trichloride provides 2-benzyl-3-chloropyrido[2,3-b]pyrazine. This precursor is then transformed into the target O-acetylated luciferin (6,8-dibenzylimidazo[1,2-a]pyrido[3,2-e]pyrazin-9-yl acetate). The ‘benzo’ derivative of this analogue (i.e., 2,12-dibenzylimidazo[1′,2′:1,6]pyrazino[2,3-c]isoquinolin-3-yl acetate) is also prepared and the chemiluminescence emission spectra of these compounds are determined in a phosphate buffer (λmax = 546 and 462 nm).

Vapor Phosphorylation of Cellulose by Phosphorus Trichlo-Ride: Selective Phosphorylation of 6-Hydroxyl Function-The Synthesis of New Antimicrobial Cellulose 6-Phosphate(III)-Copper Complexes.

This research is focused on a synthesis of copper-cellulose phosphates antimicrobial complexes. Vapor-phase phosphorylations of cellulose were achieved by exposing microcrystalline cellulose to phosphorus trichloride (PCl3) vapors. The cellulose-O-dichlorophosphines (Cell-O-PCl2) formed were hydrolyzed to cellulose-O-hydrogenphosphate (P(III)) (Cell-O-P(O)(H)(OH)), which, in turn, were converted into corresponding copper(II) complexes (Cell-O-P(O)(H)(OH)∙Cu2+). The analysis of the complexes Cell-O-P(O)(H)(OH)∙Cu2+ covered: scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), atomic absorption spectrometry with flame excitation (FAAS), and bioactivity tests against representative Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). The antimicrobial tests of synthesized Cell-O-P(O)(H)(OH)∙Cu2+ revealed their potential applications as an antibacterial material.

Polydentate Phosphane Ligands Featuring N,N,N’‐Trialkylformamidines

AbstractA set of novel polydentate phosphanes featuring one, two and three formamidine substituents was prepared by the reaction of C‐trimethylsilyl N,N,N’‐trialkylformamidines with P(III) chlorides. Chloro‐ and dichlorophosphanes gave tertiary phosphanes. More sterically congested adamantyldichlorophosphane reacted only with the least sterically congested silylformamidine. With phosphorus trichloride, five‐membered heterocycles, namely 1,4,2‐diazaphosphol‐4‐ium chlorides were formed in most cases. A mechanism for the formation of diazaphospholes was proposed and corroborated by DFT calculations. A key chlorophosphane underwent 1,2‐phosphorus shift giving the corresponding carbene that readily cyclized into diazaphospholium salts. The key compounds were studied by X‐ray diffractometry. Analysis of molecular structures of 1,4,2‐diazaphosphol‐4‐ium chloride 13 c and 1H‐1,4,2‐diazaphosphole 14 c revealed that the N‐Cring bonds for the orthogonally oriented i‐propylamino groups are unusually short. Only in the case of N,N‐dimethyl‐N’‐isopropyltrimethylsilylformamidine, we managed to isolate trisphosphane, albeit in a low yield.

Catalytic Synthesis of N-Aryladamantane-1-carboxamides Using Phosphorus Trichloride

N-Aryl(benzyl)adamantane-1-carboxamides were synthesized in 54–87% yields by reaction of adamantane-1-carboxylic acid with aromatic amines in the presence of phosphorus trichloride, 4-dimethylaminopyridine, and triethylamine on heating at 80°C for 8 h.

Reaction of Phosphorus Trihalides with Methyl Triflate. Molecular and Supramolecular Structure of Methyltrichloro- and Methyltribromophosphonium Triflates

Prolonged (~4 years) keeping of mixtures of phosphorus trichloride or tribromide with methyl triflate in dark at 20–25°C has led to the formation of crystalline methyltrichloro- and methyltribromophosphonium triflates with a content of 10–11% in the reaction mixture and yield of 5–6%. Structure of the triflates has been elucidated by means of X-ray diffraction analysis.

Флуоресцирующая и рострегулирующая активность производных 2-фенилэтенилфосфоновой кислоты

The paper provides data on an improved method for the synthesis of 2-phenylethenylphosphonic acid dichloride by interacting of carbamide derivatives with 2-phenylethenyltrichlorophosphonium hexachloro-phosphate, which is an intermediate adduct of the reaction of styrene and phosphorus pentachloride. Readily available urea, biuret, and acetylurea have been used as transformers of the adduct. It has been shown that carbamide derivatives are not only donors of the oxygen atom, but they also bind hydrogen chloride released at the stage of complexation into the corresponding hydrochlorides. This allows obtaining the target 2-phenyl-ethenyldichlorophosphonate without admixture of the hydrochlorination by-product. The phenomenon of induced fluorescence of 2-phenylethenylphosphonic acid and its esters in the solid phase and in solution was revealed. The growth-regulating activity of 2-phenylethenylphosphonic acid and O,O-di(p-nitrophenyl)-2-phenylethenyl-phosphonate on the seed germination energy, laboratory and field germinations of grain and vegetable crops was established. It is shown that pre-sowing treatment of the Prokhorovka spring wheat seeds with a 0.0005% aqueous solution of O,O-di(p-nitrophenyl)-2-phenylethenylphosphonate leads to an increase in wheat yield by 21%, which expands the range of products for this purpose. A study of the acute toxicity of 2-phenylethenylphosphonic acid according to LeBlanc on male rats kept on a standard vivarium diet showed that it has a two-phase effect. In the first phase, there are symptoms of damage to the motor part of the peripheral nervous system in the form of local seizures and the central nervous system in the form of the general suppression of motor activity and moderate relaxation of skeletal muscles, and in the second phase, the acid manifests itself in a general toxic effect. Determination of the LD50 of 2-phenylethenylphosphonic acid showed that it belongs to the third class of toxicity – low-hazard substances.

P⋯N type pnicogen bonding in phosphorus trichloride–pyridine adduct: A matrix isolation infrared, DFT and ab initio study

Matrix isolation infrared spectroscopy in low temperature N2 matrices with the support of Density Functional Theory (DFT) and ab initio computations have been employed to investigate noncovalent forces formed between phosporous trichloride (PCl3) and hetero cyclic Pyridine (C5H5N) molecules. The possible geometries of PCl3–C5H5N adducts were optimized by computations performed at B3LYP/6–311++G(d,p) and MP2/6–311++G(d,p) levels of theory. Two minima, a global minimum and a local minimum, on the potential energy surface have been obtained for PCl3–C5H5N adduct system and the main force of interaction for their stabilization is pnicogen bonding (phosphorus bonding). The global minimum is stabilized by Cl–P⋯N interaction whereas local minimum is stabilized by Cl–P···π interaction. Interestingly, experiments revealed large red shift of 48.5 cm−1 for P–Cl stretching vibrational mode (ν3) in N2 matrix and this magnitude of shift is in good agreement with computational shift for PCl3–C5H5N adduct which is stabilized by Cl–P⋯N interaction. Moreover, computations predicted that P⋯N interacting adduct is stronger than the P···π interacting adduct by 2.02 kcal/mol at MP2/6–311++G(d,p) levels of theory. To understand the nature of interactions and the effect of charge transfer interaction on the stability of the adducts, Atoms In Molecules (AIM) and Natural Bond Orbital (NBO) analysis were performed.

A Simple Way to Stabilize Li and Na Metallic Electrodes Surfaces

Post Li-ion technologies such as Li-air, lithium sulphur or all-solid-state batteries have in common the use of lithium metal as negative electrode. Known from decades, dissolution and deposition of lithium induce the growth of inactive lithium moss or more critically the dendritic growth that can lead to short circuit phenomenon. Therefore, researchers try to tackle this problem by adding functional layers at the Li surface that may generate an improvement in capacity, lifetime and performances at high current rates.There are different ways to protect lithium such as ALD inorganic coating1,2, grafting of organic materials3,4,5, polymers6 or deposition of inorganic alloys7,8. In this work, by dip coating (a simple and cheap process) a lithium foil into a solution of glyme with phosphorus trichloride (DME-PCl3), we succeeded in obtaining a thin and protective phosphorus-based layer.Through electrochemical characterization techniques (EIS, GITT in 2 or 3 electrodes) and surface characterization techniques (SEM, and more importantly XPS), we were able to determine its morphology and chemical composition, its influence on the lithium plating and stripping processes and the mechanism of lithium diffusion through the protective layer. Cycling results in lithium symmetric cells but also full cells (Li-ion, Li-S) will be presented.Finally, since our results were very promising with lithium, we extended this type of protection to sodium since the reactivity of this metal with electrolyte is ever more pronounced. With the same methodology, we will demonstrate that our protection nicely improves the use of Na metal in liquid cells. 1 A. C. Kozen and al., Next-generation lithium metal anode engineering via Atomic Layer Deposition, acsnano, 2015, 9, 6, 5884-5892 2 C-F Lin, and al., ALD protection of Li-metal anode surfaces – Quantifying and preventing chemical and electrochemical corrosion in organic solvent, Adv. Mater. Interfaces, 2016, 3, 1600426 3 F. Marchioni and al., Protection of lithium metal surfaces using chlorosilanes, Langmuir, 2007, 23, 11598 - 11602 4 S. Neuhold and al., Effect of surface preparation and R-group size on the stabilization of lithium metal anode with silanes, Journal of Power Sources, 2012, 206, 295 -300 5 S. Neuhold and al., Enhancement in cycle life of metallic lithium electrodes protected with Fp-silanes, Journal of Power Sources, 2014, 254, 241-248 6 Y. Liu and al., Lithium-coated polymeric matrix as a minimum volume-change and dentrite-free lithium metal anode, Nature communications, 2016, 7, 10992 7 X. Liang and al., A facile surface chemistry route to a stabilized lithium metal anode, Nature Energy, 2017, 2, 17119 8 L-L. Kong and al., Lithium-Magnesium alloy as a stable anode for Lithium-sulfur battery, Adv. Funct. Mater., 2019, 29, 1808756 9 L. Lin and al., Lithium phosphide/lithium chloride coating on lithium for advanced lithium metal anode, J. Mater. Chem. A, 2018, 6, 15859

Dichlorophosphoranides Stabilized by Formamidinium Substituents

Dichlorophosphoranides featuring N,N-dimethyl-N′-arylformamidine substituents were isolated as individual compounds. Dichlorophosphoranide 9 was prepared by the multicomponent reaction of C-trimethylsilyl-N,N-dimethyl-N′-phenylformamidine and N,N-dimethyl-N′-phenylformamidine with phosphorus trichloride. Its molecular structure derived from a single-crystal X-ray diffraction was compared to the analogous dibromophosphoranide prepared previously by us by the reaction of phosphorus tribromide with N,N-dimethyl-N′-phenylformamidine. It was shown that a chlorophosphine featuring two N,N-dimethyl-N′-mesitylformamidine substituents reacted with hydrogen chloride to form dichlorophosphoranide 11. Its molecular structure was also determined by X-ray analysis and compared with that of closely related dichlorophosphoranide C.

New crystal structures of fluorinated α-aminophosphonic acid analogues of phenylglycine

The four novel phosphonic acid analogues of phenylglycine with various substituents in phenyl ring (mostly fluorine atoms) have been synthesized by using procedure of amidoalkylation of phosphorus trichloride with aromatic aldehydes and acetamide. The NMR, ESI-MS spectroscopy, and single-crystal X-Ray diffraction methods were used to characterize unusual structures: the amino-(4-trifluoromethylbenzyl)-(1), amino-(3,4-difluorobenzyl)-(2), amino-(2,4,6-trifluorobenzyl)-(3), and amino-(2-fluoro-4-hydroxybenzyl)-(4) phosphonic acids. Since the α-aminophosphonates have a potential for biological activity and could be used as building blocks in medicinal chemistry, it is important to know their detail crystal structures and properties which, in turn, may extend the knowledge on their interaction with physiologic receptors.

Identification of Water-Soluble Sulfonic Acids Isolated from Acid Tars by Gas Chromatography–Mass Spectrometry

We determined the nature of water-soluble sulfonic acids in acid tars taken from two storage ponds: one located at the 21 km of the M-7 Moscow–Nizhny Novgorod federal highway and another in the Kozinskoe forestry of the Balakhninsky district of Nizhny Novgorod oblast. Water-soluble compounds were extracted from acid tar with water; sulfuric acid was precipitated from acidic water as barium sulfate; the precipitate of barium sulfate was separated by filtration; the filtrate was neutralized with sodium carbonate and evaporated to dryness. The dry residue was treated with phosphorus pentachloride to convert sulfonic acid salts to volatile chlorides, which were analyzed by gas chromatography–mass spectrometry.

A quantum chemical perspective on the potency of electron donors and acceptors in pnicogen bonds (AS...N, P...N, N...N).

A quantum chemical perspective of 31 structures contains electron acceptors: ASCl3 (arsenic trichloride), PCl3 (phosphorous trichloride) and NCl3 (nitrogen trichloride); forming non-covalent bond with various nitrogen-based electron donors that resulted in pnicogen bonds, AS...N, P...N and N...N were calculated at M062X/def2-QZVP level of theory. Besides the above method, MP2/def2-QZVP and CCSD(T)/def2-QZVP level of theories have also been analysed to have in depth knowledge about the bonds formed. The nature of the bonds was assumed from the electrostatic potential evaluated for all the monomers, where σ hole is positive for all the monomers. The strongest pnicogen bonds are ASCl3-NF2H, PCl3-NCH3CH3CH3 and NCl3-NCH3CH3CH3 having interaction energies as -4.15, -11.58 and -3.25 kcal/mol, respectively, at MP2/def2-QZVP level of theory. Further at CCSD(T)/def2-QZVP level of theory, ASCl3-NF2H and NCl3-NCH3CH3CH3 are found to be the most stable with interaction energies as -3.53 and -2.45 kcal/mol, respectively. The potential energy surface scan was performed for all the stable complexes in order to confirm the existences of energies are true minima. Moreover to confirm the halogen and pnicogen bonds, AIM analysis was carried out. The results from the above factors of pnicogen bond will help crystal growth, material science and engineering community to explore novel materials, which abide for modernization. Graphical abstract PCl3-NCH3CH3CH3 complex with 2.61 Å and pnicogen angle of 178.54° is strong, and interaction energy is -11.58 kcal/mol. Electron donors - ASCl3, PCl3 and NCl3 and electron acceptors -NCH3CH3CH3, NH3C2 and NHCO have strong electrostatic contribution. High and low values of (ρ) ∇2(ρ) reveal the strong and weak pnicogen bond. Schematic representation of acceptors surrounded by its donors and Electrostatic Potential map.