Ultra‐Long Crystalline Red Phosphorus Nanowires from Amorphous Red Phosphorus Thin Films

Heating red phosphorus in sealed ampoules in the presence of a Sn/SnI₄ catalyst mixture has provided bulk black phosphorus at much lower pressures than those required for allotropic conversion by anvil cells. Herein we report the growth of ultra‐long 1D red phosphorus nanowires (>1 mm) selectively onto a wafer substrate from red phosphorus powder and a thin film of red phosphorus in the present of a Sn/SnI₄ catalyst. Raman spectra and X‐ray diffraction characterization suggested the formation of crystalline red phosphorus nanowires. FET devices constructed with the red phosphorus nanowires displayed a typical I–V curve similar to that of black phosphorus and a similar mobility reaching 300 cm² V^?1 s with an I_on/I_off ratio approaching 10². A significant response to infrared light was observed from the FET device.     

Studies on the oxidation of red phosphorus by potassium permanganate in an acid medium

Summary Oxidation of red phosphorus by an acid solution of potassium permanganate has been studied and applied in the volumetric determination of red phosphorus. The kinetics of the oxidation-reduction process show that the reaction is of the bimolecular order. Influence of temperature on the velocity coefficient (K) as also the variation of (K) for different concentrations of the oxidant, observed, have been made use of in evaluating the activation energy of the reaction. Further the utilisability of this simple procedure for the volumetric determination of red phosphorus is emphasized.The nature of the above oxidation reaction in an alkaline medium is being investigated.Sincere thanks of the authors are due to Prof. S S. Joshi, for facilities and kind interest in the work.     

Reactions of Elemental Phosphorus and Phosphines with Electrophiles in Superbasic Systems: XIII. Phosphorylation of Phenylacetylene with Active Modifications of Elemental Phosphorus

Phosphorylation of phenylacetylene with white or activated red phosphorus (prepared from white phosphorus under the action of ionizing radiation) occurs in KOH-DMSO or KOH-HMPA systems with heat evolution and stereoselective formation of Z isomers of tristyrylphosphine and -phosphine oxide in yields of 48-49% and 10-15%, respectively. Under the comparable conditions the commercial red phosphorus is considerably less reactive toward phenylacetylene: The total yield of the above-mentioned products is 5%.     

Surface Synergistic Protections on Red Phosphorus Anode Material by Poly(3, 4-ethylenedioxythiophene) Coating and Electrolyte Strategy in Sodium Ion Batteries

Red phosphorus has attracted more attention as a promising sodium storage material due to its ultra-high theoretical capacity and suitable sodiation potential. However, the low intrinsic electrical conductivity and large volume change of pristine red phosphorus lead to high polarization and fast capacity fading during cycling. Herein, surface synergistic protections on red phosphorus composite are successfully proposed by conductive poly(3, 4-ethylenedioxythiophene) (PEDOT) coating and electrolyte strategy. Nanoscale red phosphorus is confined in porous carbon skeleton and the outside is packaged by PEDOT coating via in-situ polymerization. Porous carbon provides rich pathways for rapid Na⁺ diffusion and empty spaces accommodate the volume expansion of red phosphorus, PEDOT coating isolates the direct contact between electrolyte and active materials to form a stable solid electrolyte interphase. In addition, the reformulated electrolyte with 3 wt% SbF₃ additives can stabilize the electrode surface and thus enhance the electrochemical performance, especially cycling stability and rate capability (433 mA·h·g^-1 at high current density of 10 A/g).     

Mechanism of flame retardant action of red phosphorus in polyacrylonitrile

The mechanism of flame retardant (FR) action of red phosphorus in polyacrylonitrile combustion was investigated by thermogravimetry, flash-pyrolysis GC-MS, and combustion methods. Red phosphorus was found to increase the thermal stability in air of polyacrylonitrile and to induce a char residue increment on this substrate. Both these effects disappeared when pyrolysis was carried out under nitrogen flow. Flash-pyrolysis GC-MS experiments showed that red phosphorus does not alter the pyrolysis product distribution of polyacrylonitrile, which implies that there is no specific interaction between polyacrylonitrile and red phosphorus. These data also showed that polymeric red phosphorus decomposes to volatile white phosphorus (P₄) during pyrolysis. These observations allow us to propose a simple model for the mechanism of FR action of red phosphorus on polyacry-lonitrile at the molecular level. Combustion data for polyacrylonitrile-red phosphorus mixtures are in agreement with the proposed mechanism of FR action.     

Covalent Structures of Phosphorus: A Comprehensive Theoretical Study

Starting from earlier work by Baudler we introduce a chemical heuristic for the systematic deduction and classification of covalent partial structures of phosphorus in polycyclic phosphanes, phosphorus-rich polycyclic phosphides, and allotropes of phosphorus except the black forms. This approach is used to direct ab initio techniques (which also confirm the rules) in the quest for as yet unknown forms of molecular or macromolecular phosphorus. Based on calculated stabilities of systematically generated structural alternatives we rationalize the stabilities of Hittorf's phosphorus and of molecular P₄, confirm the possible existence of at least one other crystalline allotropic form of phosphorus, and provide insight into the probable structure of amorphous red phosphorus. In total, the combined approach of chemical heuristics and large scale ab initio calculations presented in this work supplies a coherent chemical understanding of covalent polyphosphorus structures.     

Laser desorption ionization of red phosphorus clusters and their use for mass calibration in time‐of‐flight mass spectrometry

Phosphorus clusters P_n (n = 1–89) are easily formed from red phosphorus by laser desorption ionization (LDI) and they cover a range of up to approx. m/z 3000 in both positive and negative ion mode. The clusters are singly charged and the spectra are simple because phosphorus is monoisotopic. The mass spectra can be measured with an acceptable resolution and intensity. The use of positively charged P_n clusters for calibration in mass spectrometry was examined and it was demonstrated that in external calibration a standard deviation of ±0.04 m/z units can be achieved even when using a common commercial matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) instrument. When used as internal standards the P_n clusters react with some analytes – C₆₀ and C₇₀ fullerenes and cucurbituril[8], for example. It was also found that red phosphorus is a suitable MALDI matrix for peptides and proteins, illustrated by the examples of a Calmix mixture of bradykinin, angiotensin, renin, adrenocorticotropic hormone ACTH fragment 18‐359 and insulin, and of insulin alone. Copyright © 2009 John Wiley & Sons, Ltd.     

热裂解气相色谱质谱法分析聚合物中红磷

采用单击热裂解(PY)模式和逸出气体分析(EGA)程序升温两种热裂解模式对红磷样品进行定性分析,利用气相色谱分离技术对红磷进行分离,根据红磷的特征质谱31,62,93,124及特征丰度比,质谱法分析不同材料中的红磷含量。单击热裂解模式下,材质和添加剂有可能对红磷造成干扰,改进后的EGA热裂解模式能排除红磷检测中材质和添加剂的干扰,并采用改进后的EGA裂解程序测定自制阳性样品中红磷的含量。结果表明:通过优化裂解温度和气相色谱条件可以有效改善红磷的分析结果,红磷质量浓度在100~500 mg/kg范围内具有良好线性,加标回收率在90.7%~97.7%,相对标准偏差(RSD)为1.6%~2.3%,定量限为81.27 mg/kg。     

Reactions of elemental phosphorus and phosphine with electrophiles in superbasic systems: XVIII. Phosphorylation of 1-(chloromethyl)naphthalene with the elemental phosphorus

1-Chloromethylnaphthalene reacts with white and red phosphorus, and also with the “activated red phosphorus,” the complex organophosphorus polymer of unknown structure obtained by irradiation of a solution of white phosphorus in benzene by the ⁶⁰Co source, in a system including KOH water solution, dioxane or benzene, and a phase transfer catalyst (22–98°C, argon), to form bis(1-naphthylmethyl)-and tris-(1-naphthylmethyl)phosphine oxides, and also (1-naphthylmethyl)phosphonous-and bis(1-naphthylmethyl)-phosphinic acids. The yield and the ratio of the reaction products depend on reaction conditions as well as on the nature of phosphorylating agent. It is shown that the reactivity of the “activated red phosphorus” is not worse than that of the white phosphorus and significantly exceeds the reactivity of the usual technical red phosphorus.     

Structure and Bonding in Amorphous Red Phosphorus**

Amorphous red phosphorus (a-P) is one of the remaining puzzling cases in the structural chemistry of the elements. Here, we elucidate the structure, stability, and chemical bonding in a-P from first principles, combining machine-learning and density-functional theory (DFT) methods. We show that a-P structures exist with a range of energies slightly higher than those of phosphorus nanorods, to which they are closely related, and that the stability of a-P is linked to the degree of structural relaxation and medium-range order. We thus complete the stability range of phosphorus allotropes [Angew. Chem. Int. Ed. 2014 , 53, 11629] by now including the previously poorly understood amorphous phase, and we quantify the covalent and van der Waals interactions in all main phases of phosphorus. We also study the electronic densities of states, including those of hydrogenated a-P. Beyond the present study, our structural models are expected to enable wider-ranging first-principles investigations—for example, of a-P-based battery materials.     

High Electron Mobility of Amorphous Red Phosphorus Thin Films

Black phosphorus (BP) has been gathering great attention for its electronic and optoelectronic applications due to its high electron mobility and high I_ON/OFF current switching ratio. The limitations of this material include its low synthetic yield and high cost. One alternative to BP is another type of phosphorus allotrope, red phosphorus (RP), which is much more affordable and easier to process. Although RP has been widely used in industry for hundreds of years and considered as an insulating material, in this study, we demonstrate through field‐effect transistors (FET) measurements that amorphous red phosphorus (a‐RP) films are semiconductive with a high mobility of 387 cm² V^?1 s^?1 and a current switching ratio of ≈10³, which is comparable to the electronic characteristics previously reported for BP. The films were produced via a thermal evaporation method or a facile drop‐casting approach onto Si/SiO₂ substrates. We also report a study of the oxidation process of the films over time and a method to stabilize the films via doping a‐RP with metal oxides. The doped films retain stability for one thousand I–V cycles, with no signs of degradation.     

t-Butyl Alcohol-Assisted Fission of the P-P Bonds in Red Phosphorus with Lithium in Liquid Ammonia

Abstract

A new method of the selective generation of mono- or diphosphide anions from red phosphorus by the system Li/NH₃ liq in the presence of t-BuOH has been developed.     

Reactions of elemental phosphorus and phosphine with electrophiles in superbasic systems: XX. Phosphorylation of 4-vinylbenzyl chloride with elemental phosphorus

4-Vinylbenzyl chloride reacts with white and red phosphorus, as well as with nanostructured “activated” red phosphorus (complex organophosphorus polymer prepared from white phosphorus under ionizing radiation) in the system concentrated aqueous KOH-dioxane-phase-transfer catalyst (20–50°C, argon) to form tris(4-vinylbenzyl)phosphine oxide, along with (4-vinylbenzyl)- and bis(4-vinylbenzyl)phosphinic acids, the yield and product ratio being dependent on both the reaction conditions and the nature of the phosphorylating agent. The nanostructured “activated” red phosphorus is more reactive than ordinary commercial red phosphorus.     

Structure and properties of bis{[2-(4-<Emphasis Type="Italic">tert</Emphasis>-butyl)phen]ethyl}phosphine sulfide

Previously unknown bis[2-(4-tert-butyl)phen]ethylphosphine sulfide is obtained with a high yield from 4-tert-butyl styrene, red phosphorus, and elemental sulfur. Using single crystal XRD, multinuclear NMR, IR, and UV spectroscopy, it is found that the phosphorus atom is four-coordinated in the bis[2-(4-tert-butyl)phen]ethylphosphine sulfide molecule (regardless of the phase state of the compound: crystal, solution). By the example of phosphorylation of bis[2-(4-tert-butyl)phen]ethylphosphine sulfide acetylene in the KOH-DMSO system it is shown that the reaction proceeds by double addition with the participation of phosphorus-centered nucleophiles.     

One‐Pot Halogen‐Free Synthesis of 2,3‐Dihydro‐1H‐inden‐2‐yl‐phosphinic Acid from 1H‐indene and Elemental Phosphorus via the Trofimov–Gusarova Reaction

1H‐Indene reacts with red phosphorus in the superbasic KOH/DMSO(H₂O) suspension at 120°C for 2.5 h to give (after acidification) 2,3‐dihydro‐1H‐inden‐2‐yl‐phosphinic acid in 55% isolated yield.     

Efficient One-Pot Procedures for the Preparation of Secondary Phosphines

Secondary phosphines R₂PH or RR'PH (R and R' = alkyl, cycloalkyl) have been obtained in good yields by preparing lithium phosphide from lithium, red phosphorus and t-butylalcohol in liquid ammonia and subsequent alkylation in the presence of alkali amide, prepared in the same flask.     

Novel Effectively Carbonaceous and Sulfurated Hydrogen Corrosion Inhibitors on the Basis of Organosulfurphosphorus Compounds

Abstract

Novel ammonium salts of O,O-dialkyl dithiophosphoric acids were obtained by one-pot synthesis from white phosphorus, elemental sulfur, industrial alcohols or phenols, and amines. Long-chain S-alkyl O,O-dialkyldithiophosphonates were prepared by the reaction of red phosphorus with elemental sulfur, alcohols, and the cheap industrial fractions of С₁₆–С₁₈ and С₂₀–С₂₆ of higher α-olefins in the presence of Lewis acid catalyst. The dithiophosphates obtained possess the high anticorrosion activities toward mild steel.     

Analysis of red phosphorus in resins using pyrolysis-gas chromatography/mass spectrometry.

Although red phosphorus is used as a flame retardant for polymer materials, no analysis methods for it in resins has been established. Analysis methods for red phosphorus in resins were investigated using pyrolysis-gas chromatograpy/mass spectrometry (Py-GC/MS) by paying attention to the fact that it has a sublimation property. We found that the mass spectrum of red phosphorus shows a series of ions at m/z=62, 93 and 124, and a fragment pattern indicating that red phosphorus (P4=124, P=31) was pyrolytically decomposed. The coefficient of the correlation between the content of red phosphorus in the resin and the peak intensity in Py-GC/MS was 0.9781. The relative standard deviations of this analysis method was 6.29% (n=5). Py-GC/MS was applicable not only to qualitative analysis but also to the quantitative analysis of red phosphorus.     

Hydrostannylation of Red Phosphorus: A Convenient Route to Monophosphines

The preparation of valuable and industrially relevant organophosphorus compounds currently depends on indirect multistep procedures involving difficult-to-handle white phosphorus as a common P atom source. Herein, we report a practical and versatile method for the synthesis of a variety of monophosphorus compounds directly from the bench-stable allotrope red phosphorus (P_red). The relatively inert P_red was productively functionalised by using the cheap and readily available radical reagent tri-n-butyltin hydride, and subsequent treatment with electrophiles yields useful P₁ compounds. Remarkably, these transformations require only modest inert-atmosphere techniques and use only reagents that are inexpensive and commercially available, making this a convenient and practical methodology accessible in most laboratory settings.     

Transport of Phosphorus in a low Pressure Hydrogen Plasma

Using a hydrogen low pressure discharge, red phosphorus has been evaporated, transported and deposited in a plasma gradient. At a pressure of 1 Torr and temperatures of about 370°C and 200°C in the charge and deposition zone respectively, several grams of phosphorus are transported in one hour. The red phosphorus is deposited as compact, X-ray amorphous layers, and also considerably purified by the transport.