磷单质概念的新发展

自白磷与红磷相继被发现后,磷单质的概念初步形成。20世纪初期,黑磷的发现突破了人们对磷单质的认识。随后,紫磷、蓝磷、二磷分子以及环状磷的出现,使磷单质的概念有了新的发展。几种新的磷单质的发现,建立了磷单质概念的新范式,科学家在探索磷单质概念多元化的道路上还将继续前行。     

Determination of mineral phosphate species in sedimentary phosphate rock in Mardin, SE Anatolia, Turkey by sequential extraction

The importance of the effect of phosphate rock depends on the chemical form of phosphorus in which this element is combined. The paper presents the results of inorganic and organic forms of phosphorus in the phosphate rock from Mazidag-Derik, Semikan deposit located at Mardin city at SE Anatolia of Turkey. Total phosphorus concentration in the rock is an average 18.5%. The inorganic phosphorus mean % contents were 99.98% for studied sedimentary phosphate rock. Speciation of inorganic phosphorus was carried out using a method based on sequential extractions of the sedimentary phosphate rock each releasing four forms of inorganic phosphorus: loosely sorbed phosphorus, phosphorus bound to aluminium (P-Al), phosphorus bound to calcium (P-Ca) and phosphorus bound to iron (P-Fe). Calcium bound phosphorus is the dominant form of inorganic phosphorus in the studied sedimentary phosphate rock. Aluminium bound phosphorus is the second, iron bound phosphorus is the third most prevailing form. Loosely bound phosphorus is present in the lowest amounts. Analyses of phosphorus forms in sedimentary phosphate rock using a UV spectrophotometric method and ICP-AES are reported here. For the phosphorus the two methods give the same results and the concentrations are in good agreement with the reference values.     

Icosahedral and ring-shaped allotropes of phosphorus

The existence of two new allotropic forms of phosphorus, icosahedral cages and ring-shaped chains, is predicted. The cages and rings are nanostructural modifications of the black and the red phosphorus, respectively. The icosahedral and ring-shaped allotropes are compared with the experimentally known allotropic forms of phosphorus by quantum chemical methods. Both the cages and the rings are thermodynamically favored over the white phosphorus, the rings being comparable to the Hittorf's violet phosphorus and to the recently discovered fibrous red phosphorus. The stabilities of the icosahedral cages increase as a function of their size, having structural resemblance with the rhombohedral black phosphorus. The high thermodynamic stability of the phosphorus nanostructures suggests their experimental synthesis to be viable.     

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.     

黑磷的发现及其制备和应用发展史

1914年,美国物理学家布里奇曼无意间制得了黑磷并证明了这是磷的一种新的相变体,但在很长的一段时间内并没有引起人们的关注.20世纪中期以后,黑磷的制备方法得到了一定程度的发展.至2014年,研究者成功制备了二维黑磷场效应晶体管,随后人们发现黑磷在储能设备、光电子器件、光催化、生物传感等方面都有巨大的应用潜力.随着黑磷制...     

Reactions of Elemental Phosphorus with Electrophiles in Super Basic Systems: XVII. Phosphorylation of Arylalkenes with Active Modifications of Elemental Phosphorus

The example of the phosphorylation of styrene and 2-vinylnaphthalene with elemental phosphorus in the KOH-DMSO system at room or elevated temperature was used to show that the activated red phosphorus prepared from white phosphorus under ionizing radiation has a reactivity comparable with that of white phosphorus and significantly higher than that of ordinary technical red phosphorus.     

Determination of phosphorus in fertilizers by inductively coupled plasma atomic emission spectrometry

An inductively coupled plasma atomic emission spectrometry (ICP-AES) method was developed for the determination of phosphorus in fertilizers. Total phosphorus, direct extraction available phosphorus (EDTA), and water-soluble phosphorus, reported as phosphorus pentoxide (P205), in 15 Magruder check fertilizers were measured by ICP-AES, and the results were compared with those obtained by the AOAC official method. Five analytical wavelengths of phosphorus, 177.499, 178.287, 213.618, 214.914, and 253.565 nm, were tested for the determination of phosphorus in fertilizers, and their detection limits were obtained. Acid effects of perchloric acid and possible matrix effects of aluminum, calcium, magnesium, potassium, and sodium were negligible for phosphorus determination. Wavelength 213.618 nm was the best analytical wavelength for phosphorus determination by all 3 sample preparation methods for the selected Magruder fertilizers. The results demonstrated that the accuracy and precision of the ICP-AES method were comparable with those of the official methods.     

中国煤中磷的分布特征

以“中国煤种资源数据库”为基础,结合新采集煤样,对中国不同煤田1117个煤层煤样的磷含量数据进行了统计分析.结果表明,中国煤中磷可采储量加权平均质量分数为224x10-6,大约90％的煤中磷质量分数低于500x10-6,为特低磷煤或低磷煤,全国总体上呈“北低南高”的趋势.按不同聚煤区、不同成煤时代和不同煤炭类别讨论了中...     

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。     

Structural Principles of Polyhedral Allotropes of Phosphorus

We derive the structural principles of polyhedral allotropes of phosphorus, introducing three distinct families of black phosphorus nanostructures. The predicted tetrahedral, octahedral, and icosahedral phosphorus cages can also be considered as phosphorus fullerenes. Phosphorus cages up to P₈₈₈ are systematically investigated by quantum chemical methods, and their thermodynamic stabilities are compared with the experimentally known allotropic forms of phosphorus. The tetrahedral cages are thermodynamically favored over the octahedral and icosahedral structures, although large octahedral structures become nearly as stable as the tetrahedral ones. The stability trends of the studied polyhedral families can be rationalized on the basis of their structural characteristics. The phosphorus polyhedra can be further stabilized by fitting smaller structures inside larger ones, resulting in multilayered, bulk‐like cages. The synthesis of the predicted black phosphorus nanostructures is suggested to be viable from the thermodynamic point of view, and several approaches for their experimental preparation can be envisaged.     

污泥与煤共热解过程中磷元素的挥发规律研究

污泥灰分中磷元素含量明显高于煤,其中主要的晶体态含磷化合物为磷酸铁钙和少量的磷酸铝。利用高频加热反应装置考察了污泥-神府煤混合物快速热解过程中磷元素挥发规律。结果表明,污泥-神府煤混合物热解后磷元素主要存在于热解焦中。磷元素挥发比例随污泥添加比例的增加先升高后降低,随热解温度的升高而增加。热解温度不高于1 100 ℃时,混合物中以有机磷的挥发为主,磷元素挥发比例不高于3.2%。热解温度高于1 200 ℃后无机磷中磷元素挥发明显,1 300 ℃下最高有33.0%的磷元素随热解气体挥发出。     

灰化法磷测定中不同灰化助剂的效果比较

以磷酸二氢钠和磷酸氢二钠与脱氧腺苷三磷酸（dATP)的混合溶液为磷标样,比较了MgSO4,Mg(NO3)2和MgCl2等灰化助剂的作用效果。结果发现,磷标样中加入MgSO4经500℃灼烧后用0.2mol/L HCl于80℃浸提残渣0.5h不能使磷全部回收;而MgCl2、Mg(NO3)2、MgAc2、CaCl2等助剂,却都能使灼烧后的磷完全回收。在采用MgSO4高温灰化法分析海水中的颗粒磷和总磷或有机体中的磷时,应当用MgCl2作为灰化助剂取代MgSO4。尽管Mg(NO3)2也是高效的灰化辅助剂,但其应用的危险性有较多的手工操作限制了它的广泛应用。     

Synthesis of crowded triarylphosphines carrying functional sites

4,4′-Diphosphinobiaryls and 1,3- and 1,4-borylphosphinobenzenes carrying crowded triarylphosphine moieties were synthesized by reaction of the corresponding diarylchlorophosphine with an arylcopper(I) reagent. Intramolecular interaction of the phosphorus redox center with the other phosphorus or the boron redox center was investigated by cyclic voltammetry. 4,4′-Diphosphinobiaryls displayed two-step reversible redox waves with slight differences of the oxidation potentials due to weak interaction between two phosphorus redox centers across 4,4′-biarylene linkage. Borylphosphinobenzenes showed two step redox waves corresponding to oxidation at the phosphorus and reduction at the boron. Although significant interaction between the phosphorus and boron redox centers was not observed in the cyclic voltammograms due to large difference of the redox potentials between phosphorus and boron redox centers, an absorption due to weakly interacting phosphorus and boron was observed in the UV-Vis spectrum of the 1,4-borylphosphinobenzene.     

Phosphorus Post-Functionalization of Diphosphahexaarenes

Diphosphahexaarenes are highly stable π-extended frameworks containing two six-membered phosphorus heterocycles that have emerged recently. Herein, we present a detailed investigation on the post-functionalization reactions of their phosphorus centers with special emphasis on the selectivity of the processes and the impact of the phosphorus functionalizations into the physicochemical properties. These studies reveal that indeed the phosphorus atoms of the diphosphahexaarenes are readily available to be functionalized with quaternizing and oxidizing agents as well as borane groups without compromising the stability of the system. In addition, the optoelectronic properties of the diphosphahexaarenes are impacted by the phosphorus post-modifications.     

Substoichiometric extraction of phosphorus

A study of the substoichiometric extraction of phosphorus is described. Phosphorus was extracted in the form of ternary compounds such as ammonium phosphomolybdate, 8-hydroxyquinolinium phosphomolybdate, tetraphenylarsonium phosphomolybdate and tri-n-octylamine phosphomolybdate. Consequently, phosphorus was extracted substoichiometrically by the addition of a substoichiometric amount of molybdenum for all four phosphomolybdate compounds. On the other hand, phosphorus could be separated substoichiometrically with a substoichiometric amount of tetraphenylarsonium chloride or tri-n-octylamine. Stoichiometric ratios of these ternary compounds obtained substoichiometrically were 1∶12∶3 for phosphorus, molybdenum and organic reagent. Applicability of these compounds to phosphorus determination was also discussed.     

Microwave-assisted synthesis of cyclopentanones using the relevant phosphorus ylides

A one-pot synthesis of cyclopentanone derivatives from phosphorus ylide under lab-type microwave assisted methodology was described. The phosphorus ylides were obtained via the reaction of activated acetylenic compounds, ethyl 4-chloroacetoacetate and triphenylphosphine. The structure of phosphorus ylides was assigned by 1H, 13C and 31PNMR. The phosphorus ylides as precursor were crystallized as two enantiomers (R,R) and (S,S) and one of the phosphorus ylide structures was confirmed by single X-ray crystallography.     

A mechanistic study of flame retardance of novel copolyester phosphorus containing linked pendant groups by TG/XPS/direct Py-MS

The flame retardant mechanism of the copolyester phosphorus containing linked pendant groups was investigated by thermogravimetric （TG）, X-ray photoelectron spectroscopy （XPS） and direct insertion probe pyrolysis mass spectrometry （DP-MS） technique. TG results show that the incorporation of phosphorus containing unit linked pendant groups can destabilize the copolyester due to the cleavage of P-CH2 bond, and phosphorus containing units cannot promote the char-formation of the copolyester during the thermal degradation of the copolyester. XPS spectra indicate that with the increase of the temperature, the P-CH2 bonds of the copolyester break down gradually, the concentration of phosphorus in the condensed phase products decrease gradually and the chemical state of phosphorus does not change in the temperature of 250-380 ℃. Direct pyrolysis MS suggests that the P-CH2 bonds cleavage occurs at pendant groups and species containing phosphorus can volatilize into the gas phase. A flame retardant mechanism is proposed for the gas phase mode of action of the halogen-free copolyester phosphorus containing linked pendant groups.     

Type-II Red Phosphorus: Wavy Packing of Twisted Pentagonal Tubes

Elemental phosphorus exhibits fascinating structural varieties and versatile properties. The unique nature of phosphorus bonds can lead to the formation of extremely complex structures, and detailed structural information on some phosphorus polymorphs is yet to be investigated. In this study, we investigated an unidentified crystalline phase of phosphorus, type-II red phosphorus (RP), by combining state-of-the-art structural characterization techniques. Electron diffraction tomography, atomic-resolution scanning transmission electron microscopy (STEM), powder X-ray diffraction, and Raman spectroscopy were concurrently used to elucidate the hidden structural motifs and their packing in type-II RP. Electron diffraction tomography, performed using individual crystalline nanowires, was used to identify a triclinic unit cell with volume of 5330 ų, which is the largest unit cell for elemental phosphorus crystals up to now and contains approximately 250 phosphorus atoms. Atomic-resolution STEM imaging, which was performed along different crystal-zone axes, confirmed that the twisted wavy tubular motif is the basic building block of type-II RP. Our study discovered and presented a new variation of building blocks in phosphorus, and it provides insights to clarify the complexities observed in phosphorus as well as other relevant systems.     

磷纳米材料的光学、光电子和光催化应用

碳纳米结构的研究和发现鼓励科学家们寻找下一代多功能材料.过去几年中磷纳米材料吸引了人们的广泛注意.尽管对磷纳米材料的结构和性质的研究仍处于起步阶段,但预期磷纳米材料有许多独特的性质.在这篇综述中,我们总结了黑磷和红磷纳米材料的一些光学和光电子应用,以及磷在光催化剂材料方面的作用.