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。     

Vibrational spectra and structures of a number of oxaazaphospholanes

The Raman and IR spectra of six 1,3,2-oxaazaphospholanes with a tri- and tetracoordinated phosphorus atom were obtained. The bands were assigned, and the spectroscopic features of the oxaazaphospholane ring were noted. Assumptions regarding the peculiarities of the three-dimensional structure of the molecules were made on the basis of the change in the characteristic frequencies on passing from trivalent phosphorus compounds to tetracoordinated phosphorus compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1612–1615, December, 1971.     

Phosphorus halides complexes with 4-dimethylaminopyridine and <Emphasis Type="Italic">N</Emphasis>-methylimidazole

Formation of complexes between phosphorus halides and 4-dimethylaminopyridine or N-methylimidazole was studied. The following phosphorus halides: trichloride, oxychloride, and sulfochloride, were found to form equilibrium mixtures of the complexes containing different numbers of the ligand molecules. Among the studied phosphorus halides only pentachloride and tribromide form stable complexes with a constant composition.     

The Correlation of Structure Features and Valent Phosphorus State with NMR Parameters of Some Five-Membered Heterocycles

Abstract

NMR parameters of the phosphorus-containing molecules are known to be affected by the phosphorus coordination number. Very little has been published about the theory proper and about the correlation characteristics of this influence. In order to obtain some information about this problem we have synthesized a number of phospholene and oxaphospholene derivatives containing phosphorus in various valent states.     

CNDO CI calculations on second-row molecules

The CNDO/S method is extended to second-row molecules and parametrized for phosphorus and sulphur. Both sp and spd basis sets are considered. The method is applied to the aromatic molecules phosphorin and thiophen. The uv transitions, ionization potentials and dipole moments of these molecules are satisfactorily explained.     

Chain and Ring Phosphorus Compounds—Analogies between Phosphorus and Carbon Chemistry

Up to about 15 years ago compounds with a skeleton of phosphorus chains or rings were regarded as “exotic” in the field of nonmetal chemistry. Aside from a number of examples of molecules with two P atoms directly bonded to each other and a few sporadically discovered monocyclic ring compounds, only solids of undefined composition and structure were known. Since then the state of our knowledge in this sector has made considerable progress: between PH₃ and its derivatives on the one hand, and the high-molecular modifications of elementary phosphorus on the other, an unexpected variety of well defined compounds have been discovered, showing many similarities to the analogous compounds of carbon. However, surprises can still occur even with “small” phosphorus-containing molecules, as shown by the likewise recently discovered field of phosphorus three-membered ring compounds.     

The quantum-chemical estimation of the effect of phosphorus atoms on the electron acceptor properties of aluminum- and boron-containing zeolite clusters

The effect of a phosphorus atom introduced in a zeolite cluster involving ten silicon and aluminum atoms on the state of active catalytic structure sites is estimated. Zeolite clusters modified with boron are also considered. The effect of the electron density redistribution upon zeolite modification with boron and phosphorus, as well as the effect upon the coordination of probe water and ammonia molecules to the clusters, is analyzed. The bond energies of water or ammonia molecules coordinated to acceptor sites of phosphorus-containing zeolites are estimated. Experimentally discovered changes in the acidic properties of zeolites resulting from their modification with boron and phosphorus are interpreted.     

Thermal Behaviour of Some Organ0 Phosphorus Compounds

Abstract

So far organophosphorus chemists have been interested in synthesizing low coordinated phosphorus compounds and in studying them in solution at temperatures rarely above 300 °C. As a matter of fact there are few reports on the behaviour of dicoordinated phosphorus molecules at temperatures above 500 °C under low pressure. Another interesting point is that such a study would allow to assess the correla- tion between mass spectral processes and thermal ones.     

Simulant molecules with trivalent or pentavalent phosphorus atoms: bond dissociation energies and other thermodynamic and structural properties from quantum chemical models

The CBS-QB3 and G4 thermochemical models have been used to generate energetic, structural, and spectroscopic data on a set of molecules with trivalent or pentavalent phosphorus atoms that can serve as simulants of chemical warfare agents. Based on structural data, the conformational stabilities of these molecules are explained in terms of the anomeric interaction within the OPOC and OPSC fragments. For those cases where experimental data are available, comparisons have been made between calculated and previously reported vibrational frequencies. All varieties of bond dissociation energies have been examined except those for C-H and P═O bonds. In trivalent phosphorus molecules, the O-C and S-C bonds have the lowest dissociation energies. In the pentavalent phosphorus set, the S-C bonds, followed by P-S bonds, have the lowest dissociation energies. In the fluorinated simulant molecules, the P-F bond is strongest, and the P-C or O-C bonds are weakest.     

Some INDO calculations of 1J(PC) and 1J(PF) values

INDO parameterized calculations, employing phosphorus s, p and d valence orbitals, are reported for values of ¹J(PC) and ¹J(PF) relating to phosphorus in formal tri- and pentavalent states. The ¹J(PC), interactions are mainly controlled by the contact term. Thus, trivalent phosphorus compounds have negative values for ¹J(PC), whereas those for pentavalent phosphorus are positive due to the s lone-pair effect. The inclusion of phosphorus 3d orbitals is shown to be important for an understanding of the processes contributing to ¹J(PF) interactions. ¹J(PF) values are shown to be negative for both tri- and pentavalent phosphorus compounds. The contact and orbital interactions are significant for the trivalent phosphorus molecules, whereas in the pentavalent phosphorus case ¹J(PF) is dominated by the orbital term.     

Superconducting Phases of Phosphorus Hydride Under Pressure: Stabilization by Mobile Molecular Hydrogen

At 80 GPa, phases with the PH₂ stoichiometry, which are composed of simple cubic like phosphorus layers capped with hydrogen atoms and layers of H₂ molecules, are predicted to be important species contributing to the recently observed superconductivity in compressed phosphine. The electron–phonon coupling in these phases results from the motions of the phosphorus atoms and the hydrogen atoms bound to them. The role of the mobile H₂ layers is to decrease the Coulomb repulsion between the negatively charged hydrogen atoms capping the phosphorus layers. An insulating PH₅ phase, the structure and bonding of which is reminiscent of diborane, is also predicted to be metastable at this pressure.     

Reactivity of white phosphorus with compounds of the p-block

This review covers the activation, aggregation and degradation of white phosphorus by molecules containing reactive p-block centers. The chemistry has been divided into a number of reaction types and possible mechanisms are used to aid in the understanding of these reactions.     

Stereochemistry of base-induced cleavage of methoxide ion on cis- and trans-1,4-diphenylphosphorinanium salts. A different behavior with a phenyl substituent

The synthesis and characterization of pure cis- and trans-1,4-diphenyl-1-methoxy-phosphorinanium tetrafluoroborate salts 11a and 11b, molecules designed to evaluate the effect of a phenyl substituent at C-4 on the stereochemical course of base-induced nucleophilic displacement of the methoxy group at phosphorus, was accomplished. The presence of a phenyl substituent at C-4 changes the stereochemical course of these reactions, from complete inversion with alkyl groups to products where retention of configuration at phosphorus predominates. We suggest a mechanism involving Berry pseudorotations and provide evidence that the hydroxide ion attacks the phosphorus atom through experiments with NaOH enriched with ¹⁷O.     

超分子有机膦大环化合物研究进展

有机膦大环化合物是伴随着大环化学的出现而发展起来的．它们不仅具有多变的结构而且非常稳定;不仅能够包结客体分子,还可以与许多过渡金属形成稳定的配位化合物,在主客体化学以及金属有机催化领域中受到人们的广泛关注．由于其独特的性质,有机膦大环化合物在超分子化学的发展中具有重要的地位．本文主要介绍了近些年有机膦大环化合物研究的新进展及其在超分子化学中的应用．     

Principles of Phosphorus Chemistry: Molecular States of Phosphorus Compounds - A Report on Gasphase Investigations 1-3

Abstract

An up-to-date concept of bonding in phosphorus compounds has to be based on the reality of molecular states. Molecules, which change their structure with energy, at present are best rationalized in terms of topology and symmetry, effective nuclear potentials and charge distribution. To reduce the complexity of the resulting manifold, comparison of equivalent states of chemically related molecules, based advantageously on quantum chemical calculations, is strongly recommended. Adding the time-scale, molecular dynamics within the numerous degrees of freedom become important, also as a basis to gain some understanding of the rather complex microscopic reaction pathways of medium-sized molecules. Examples are presented to illustrate the use of spectroscopic ‘fingerprints’ for the analysis and optimization of gasphase reactions as well as the benefit of inherent information on molecular states for the preparative phosphorus chemist. The catalytic dehydrochlorination of alkyldichlorophosphanes RH₂C-PCl₂ → RHC = PCI → R-C ≡ P and their dechlorination on magnesium metal surface are discussed in some detail as well as the generation of other unsaturated phosphorus molecules like Cl-P = O, Cl-P = S, Cl-P(= O)₂, Cl-P(= S)₂ or H₃C-P =CH₂. Approximate energy hypersurface calculations for the gasphase equilibrium P₄ ? 2 P₂ or for the unexpected dehydration (H₃C)₂HP=O → H₂O + H₃C-P = CH₂, which includes chemical activation, provide some insight into microscopic reaction pathways of phosphorus compounds.     

An ICR study of ion—molecule reactions of PHn+ ions

The reaction of PH_n⁺ ions (n = 0–3) were examined with a number of neutrals using ion cyclotron resonance techniques. The reactions examined have significance for the distribution of phosphorus in interstellar molecules. The results indicate that interstellar molecules containing the PO bond are likely to be more abundant than those containing the PH bond.     

Highly strained tricyclic molecules: tricyclo[p.q.0.0]alkanes and phosphatricyclo[m.1.0.0]alkanes

We theoretically investigate ring strains of tricyclic molecules or tricyclo[p.q.0.0^1,f]alkanes by calculating the strain energies as heat of the homodesmotic reactions. The strain energies are well correlated with the deformation from the tetrahedral configuration of the C₁ atom. We theoretically design less strained tricyclic molecules by replacing some carbon atoms with phosphorus atoms.     

A New Synthetic Route to Diastereomerically Pure Cyclopropane-Phosphorus Derivatives Utilizing the Chiron 5-L-Men-thyloxy-3-bromo-2(5H)-furanone and Racemic Dialkyl α-Hydroxyalkanephosphonate

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Simulation of the electronic and vibrational structure of hydrogenated amorphous silicon using cluster models

A set of simple models of hydrogenated amorphous silicon (a-Si:H) consisting of hypothetical silane molecules with diamond or similar lattices was studied by the semiempirical AM1 method. Densities of states and infrared spectra were calculated for the silane molecules and similar molecules with dangling bonds disorder, and with boron or phosphorus substitution to simulate doping. Some examples are presented, and a comparison is made with experimental properties of a-Si:H. It is proposed to use these models in a study of the Staebler–Wronski photodegradation of a-Si:H and other aspects of amorphous silicon technology. © John Wiley & Sons, Inc.     

Investigations of reactions involved in electro-thermal atomic absorption procedures : Part 8. A theoretical and experimental study of factors influencing the determination of phosphorus

Ideal conditions for the determination of phosphorus by graphite-furnace atomic absorption spectrometry are investigated by the use of high-temperature equilibrium calculations. All reasonable reaction products resulting from the reaction between P, C, O, H, N, Ca and Ar are considered. The calculations show that phosphorus forms the volatile monoxide and dioxide molecules below 1800 K (P_o2? 10^-13 atm.). At higher temperatures the relative amount of atomic phosphorus is mainly controlled by the equilibrium between monatomic and diatomic phosphorus. The significance of the theoretical ' study was investigated experimentally. The relative amounts of P₂ and PO were monitored by molecular absorption using vaporization under isothermal conditions; the interfering effects of Ca, N₂, H₂, and O₂ on the atomic absorption signal for phosphorus were also studied. The sensitivity was greatly dependent on graphite tube conditions as well as the heating rate of the furnace. For CaHPO₄ the sensitivity for phosphorus was 4.5 × lO^-8 g. If samples were introduced into a preheated tube, this value was improved to 2 × 10^-9 g.