Reaktion von Diphosphan(4) mit flüssigem Ammoniak und mit Aminen – ein neuer Weg zu Polyphosphiden und Hydrogenpolyphosphiden

Contributions to the Chemistry of Phosphorus. 241. On the Reaction of Diphosphane(4) with Liquid Ammonia and with Amines – a New Route to Polyphosphides and Hydrogen Polyphosphides Diphosphane(4), P₂H₄, reacts with liquid ammonia in the temperature range –76 °C to –40 °C to furnish a mixture of the ammonium polyphosphides (NH₄)₂H₂P₁₄, (NH₄)₂P₁₆, (NH₄)₃P₁₉, and (NH₄)₃P₂₁, in addition to PH₃. The first intermediate product detectable by NMR spectroscopy is the bicyclic compound NH₄H₄P₇, which reacts further with P₂H₄ to afford the more phosphorus‐rich polycyclic phosphides. On removal of the ammonia the hydrogen polyphosphide (NH₄)₂H₂P₁₄ decomposes with formation of PH₃ and hydrogen‐free, more phosphorus‐rich polyphosphides. When the reaction of diphosphane(4) with liquid ammonia is performed in the presence of tetrahydrofuran the final products are the hydrogen polyphosphides NH₄H₄P₇ and NH₄H₅P₈ together with PH₃; the hydrogen‐rich, open‐chain heptaphosphide NH₄H₈P₇ has been identified as a precursor. An investigation of the behavior of diphosphane(4) towards amines using the primary amine ethylenediamine as an example at +10 °C in the absence of a solvent or in the presence of tetrahydrofuran resulted in the formation of a polyphosphide mixture consisting of (C₂H₄N₂H₅)₂P₁₆, (C₂H₄N₂H₅)₃P₂₁, and (C₂H₄N₂H₅)₃P₁₉ as well as some PH₃. No reaction occurred with the secondary and tertiary amines diethylamine and tetramethylethylenediamine (TMEDA), respectively, even at room temperature.     

Crystal Structures of [Cu2(bpy)2(H2O)(OH)2(SO4)]·4H2O and [Cu(bpy)(H2O)2]SO4 with bpy = 2, 2′‐Bipyridine

Two sulfato Cu^II complexes [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)]· 4H₂O ( 1 ) and [Cu(bpy)(H₂O)₂]SO₄ ( 2 ) were synthesized and structurally characterized by single crystal X—ray diffraction. Complex 1 consists of the asymmetric dinuclear [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)] complex molecules and hydrogen bonded H₂O molecules. Within the dinuclear molecules, the Cu atoms are in square pyramidal geometries, where the equatorial sites are occupied by two N atoms of one bpy ligand and two O atoms of different μ₂—OH groups and the apical position by one aqua ligand or one sulfato group. Through intermolecular O—H···O and C—H···O hydrogen bonds and intermolecular π—π stacking interactions, the dinuclear complex molecules are assembled into layers, between which the hydrogen bonded H₂O molecules are located. The Cu atoms in 2 are octahedrally coordinated by two N atoms of one bpy ligand and four O atoms of two H₂O molecules and two sulfato groups with the sulfato O atoms at the trans positions and are bridged by sulfato groups into ¹[Cu(bpy)(H₂O)₂(SO₄)_2/2] chains. Through the interchain π—π stacking interactions and interchain C—H···O hydrogen bonds, the resulting chains are assembled into bi—chains, which are further interlinked into layers by O—H···O hydrogen bonds between adjacent bichains.     

Computational Study on the Unconventional Hydrogen‐Bonded F–H···C Systems

The F–H···YZ₂ (Y = C, Si, BH, A1H;Z = H, PH₃) systems were examined using density functional theory calculations. The main focus of this work is to demonstrate that the chemistry of Y(PH₃)₂ exhibits a novel feature which is a central Y atom with unexpected high basicity. Further, the hydrogen bond strength can be adjusted by the substitution of H atoms of YH₂ by PH₃ groups. The FH···C(PH₃)₂ system has the strongest hydrogen bond interaction, which is larger than a conventional hydrogen bond. In addition to electrostatic interaction, donor‐acceptor interaction also plays an important role in determining the hydrogen bond strength. Therefore, a carbon atom can not only be the hydrogen bond acceptor but also can create an unusual stabilized hydrogen bond complex. Also, X₃B–YZ₂ (X = H, F; Y = C, Si, BH, A1H;Z = PH₃, NH₃) systems were examined, and it was found that the bond strength is controlled predominately by the HOMO‐LUMO gap (ΔIP). The smaller the ΔIP, the larger the bond dissociation energy of the B–Y bond. In addition, NH₃ is a better electron‐donating group than PH₃, and thus forms the strongest donor‐acceptor interaction between X₃B and Y(NH₃)₂.     

Quantitative characterization of the P?C bonds in ylides of phosphorus

The nature of the carbon–phosphorus bond in trivalent and pentavalent carbon phosphorus compounds is currently a matter of some dispute. These compounds contain unusual bonds, unusual in the sense that the behavior of electrons in the compounds does not conform to that expected solely on the basis of carbon–carbon and carbon–hydrogen bonds. Quantitative measures of how a single electron, as a wave, is shared between any two spatial points are given by means of the sharing amplitude and the sharing index. 1 These quantities are orbital independent, rooted in the single particle density matrix, and do not depend on arbitrary localization procedures. The quantitative characterization of the P? C bonds in molecules such as PHCH₂, PH₃CH₂, PF₃CH₂, and PH₃CHF was carried out by means of the sharing indices. On the basis of interbasin sharing indices, the P? C bonds are: (mostly) double in PHCH₂, and single in PH₃CH₂, PF₃CH₂, and PH₃CHF. On the basis of the group basin charges and intergroup sharing indices between the CH₂ (or CHF) groups and the PH_1,3 (or PF₃) groups, the molecules are ionic with double bonds between the groups (in line with an ylene form). The sharing indices between atoms, which are not directly linked (secondary sharing indices), indicate that the electrons are quite delocalized over the basins of the following groups: CPH in PHCH₂, CPH₃ in PH₃CH₂, CPF₃ in PF₃CH₂, and CPH₃ in PH₃CHF. The sharing indices and the sharing amplitude offer the needed tools to put our understanding of the chemistry of a large number of compounds on a rigorous basis by elucidating the behavior of a single electron in a many electron system. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1387–1395, 2001     

Beiträge zur Chemie des Phosphors. 240 [1]. Zum reaktiven Verhalten von Diphosphan-boran,P2H4 · BH3

Contributions to the Chemistry of Phosphorus. 240. On the Reactive Behaviour of Diphosphane-borane, P₂H₄ · BH₃ Under mild temperature conditions, the thermal decomposition of diphosphane-borane ( 1 ) gives rise to the formation of phosphane-borane, PH₃ · BH₃, and triphosphane-2-borane, PH₂? PH(BH₃)? PH₂ ( 2 ). In the presence of diphosphane-1,2-bis(borane), triphosphane-1,3-bis(borane), BH₃? PH₂? PH? PH₂? BH₃ ( 3 ), is formed additionally. The thermolysis product at room temperature is a polymeric solid of varying composition which contains phosphorus, boron, and hydrogen. Compound 1 reacts with metalating agents such as n-BuLi, LiBH₄, and NaBH₄ to furnish the borane-trihydrogendiphosphide ion, [PH₂? PH? BH₃]^?, which immediately disproportionates to give the corresponding mono-and triphosphane derivatives. In the presence of an excess of THF-borane and in the case of a 1 : 1 molar ratio of 1 : NaBH₄, the disproportionation does not occur and the new diphosphide derivative sodium-1,1,2-tris(borane)-1,2,2-trihydrogendiphosphide, Na[(BH₃)₂PH? PH₂BH₃] ( 4 ) can be obtained. The action of additional NaBH₄ yields the diphosphide dianion with four coordinated BH₃ groups.     

Sur quelques réactions par décharge électrique dans les systèmes phosphine-eau,phosphine-eau-ammoniac et phosphine-eau-ammoniac-méthane

Electric discharge reactions in the systems PH₃ + H₂O, PH₃ + H₂O + NH₃ and PH₃ + H₂O + NH₃ + CH₄ have been studied. In the system PH₃ + H₂O, they produce polyphosphines (insoluble in water) and hypophosphorous, phosphorous and orthophosphoric acids. In the system PH₃ + H₂O + NH₃, besides the above products, hypophosphate, pyrophosphate, polyphosphates and possibly polyhyphosphates are also present. In the system PH₃ + H₂O + NH₃ + CH₄, besides all the above inorganic P compounds, organic phosphorus derivatives such as aminoalkyl phosphates and aminoalkanephosphonates are also formed, as well as other non-phosphorus containing organic products (amino acids, ethanolamine, etc.). The presence of phosphine (or its transformation products), seems to promote condensation reactions in this system since the ratio of amino acids found after hydrolysis (in 6N HCl) to amino acids found before hydrolysis is greater in this system. than in the system (CH₄+ H₂O+ NH₃)iiot containing phosphine.     

Über die Reaktion von weißem Phosphor mit Jodwasserstoff

White phosphorus and hydrogen iodide quantitatively form PH₃ and P₂J₄ in anhydrous carbon disulfide. Besides PJ₃ the hitherto unknown iodophosphines PH₂J and PHJ₂ are formed during the reaction as intermediates.     

Oxidative addition of dihydrogen as the key step of the active center formation in the HDS sulfide bimetallic catalysts: ab initio MO/MP2 study

The electronic structure of Ni in the sulfide bimetallic species (SBMS), which is the active component of the sulfide HDS catalysts, is studied with the ab initio molecular orbital calculations. In the previous paper [I.I. Zakharov, A.N. Startsev, G.M. Zhidomirov, J. Mol. Catal. 119 (1997) 437], we have shown that the d⁸ Ni(II) electronic state in the SBMS composition cannot be active in HDS reaction because of the lack of possibility to coordinate S-containing molecule. Therefore, this paper deals with the study of the possibility to stabilize d⁶ electron configuration with the formal Ni(IV) oxidation state. With this in mind, the reaction of oxidative addition of dihydrogen to square–planar complex Ni(II)Cl₂(PH₃)₂ has been studied, which allowed to predict a stabilization of the octahedral complex Ni(IV)H₂Cl₂(PH₃)₂ with d⁶ configuration. This allows us to assume a possibility of an oxidative adsorption of dihydrogen to the Ni atom entering the SBMS composition. Ab initio calculations have shown that such type of oxidative addition is thermodynamically favorable resulting in stabilization of the Ni(IV) d⁶ electronic state. Consequently, the dihydrogen molecule is assumed to dissociate on the Ni atom resulting in the formation of `surface' H<sub>s</sub> and `occluded' H_o hydrogen, which is located under the Ni atom in the center of the trigonal sulfur prism. The structure of the active centers is optimized and the stretching modes of the hydrogen atoms are calculated, which appear to be close to the literature data. The H₂S adsorption on the active center was also investigated and it was shown that the hydrogen disulfide molecule benefits to stabilization of the active Ni(IV) d⁶ state. The conclusion is drawn that the deciding factor in the formation of the active centers of sulfide HDS catalysts is the `occluded' hydrogen.     

Dynamic electron transfers in B2H6 and Cu(PH3)2(BH4)

In order to investigate the coupling of molecular vibrations and electron distribution, dynamic electron transfers in B₂H₆ and Cu(PH₃)₂(BH₄) are lated by using a new variational method. In both molecules, the dynamic electron density near bridging hydrogen atoms decreases to form the density valley by exciting specific vibrational modes. On the other hand, in both sides of the valley density hills grow up. For these molecules, similar contour maps are given by the modes with different symmetry which have large contribution of the bridging ligands. While the dynamic electron transfer of B₂H₆ arises in symmetric form, the vibrational modes of the Cu complex gives the asymmetric redistribution of the dynamic electron density. This is attributed to the difference of the symmetry between the two molecules.     

Thermolysis of Noble Metal Nanoparticles into Electron‐Rich Phosphorus‐Coordinated Noble Metal Single Atoms at Low Temperature

Noble metal single atoms coordinated with highly electronegative atoms, especially N and O, often suffer from an electron‐deficient state or poor stability, greatly limiting their wide application in the field of catalysis. Herein we demonstrate a new PH₃‐promoted strategy for the effective transformation of noble metal nanoparticles (MNPs, M=Ru, Rh, Pd) at a low temperature (400 °C) into a class of thermally stabilized phosphorus‐coordinated metal single atoms (MPSAs) on g‐C₃N₄ nanosheets via the strong Lewis acid–base interaction between PH₃ and the noble metal. Experimental work along with theoretical simulations confirm that the obtained Pd single atoms supported on g‐C₃N₄ nanosheets exist in the form of PdP₂ with a novel electron‐rich feature, conceptionally different from the well‐known single atoms with an electron‐deficient state. As a result of this new electronic property, PdP₂‐loaded g‐C₃N₄ nanosheets exhibit 4 times higher photocatalytic H₂ production activity than the state‐of‐art N‐coordinated PdSAs supported on g‐C₃N₄ nanosheets. This enhanced photocatalytic activity of phosphorus‐coordinated metal single atoms with an electron‐rich state was quite general, and also observed for other active noble metal single atom catalysts, such as Ru and Rh.     

Crystal structure,thermal behavior,and infrared absorption spectrum of cesium hydrogen selenite-selenious acid (12) CsHSeO3 · 2H2SeO3

The present work describes the crystal structure, thermal behavior, and infrared absorption spectrum of cesium hydrogen selenite-selenious acid (12), CsHSeO₃ · 2H₂SeO₃. This compound crystallizes in the monoclinic crystal system withP2₁c-C⁵_2b (Z = 4) as the space group. The unit cell dimensions are as follows:a = 8.9897(20), b = 8.5078(21), c = 12.6476(31)A˚, and β = 95.141(19)°. The crystal structure consists of discrete H₂SeO₃ molecules which are weakly hydrogen bonded to form layers which are further connected by (HSeO₃)⁻ ions with much stronger hydrogen bonds. The hydrogen atoms show no disorder within the hydrogen bonds. The Cs⁺ ions are coordinated to oxygens from both selenious acid molecules and hydrogen selenite ions. The thermal decomposition of CsHSeO₃ · 2H₂SeO₃ in air starts with incongruent melting due to rupture of hydrogen bonds at 310 K and is followed later by the formation of cesium diselenite phase. At higher temperatures (700 K) this compound decomposes with oxidation of selenium to yield cesium selenate. Both deformation and stretching vibrations of SeOH groups from both (HSeO₃)⁻ ions and H₂SeO₃ molecules can be found in the IR absorption spectrum of CsHSeO₃ · 2H₂SeO₃. This confirms the ordered position of hydrogen atoms in hydrogen bonds. The OH vibrations corresponding to hydrogen bonded species can be found also.     

Poly[[tetraaquatris(μ3‐2,2‐dimethylmalonato)dilanthanum(III)] monohydrate]

In the title complex, {[La₂(C₅H₆O₄)₃(H₂O)₄]·H₂O}_n, the La atoms are connected by bridging O atoms from carboxylate groups to build, through centres of inversion, two‐dimensional layers parallel to the ac plane containing decanuclear 20‐membered rings. The coordinated water molecules are involved in intralayer hydrogen‐bond interactions. Adjacent layers are linked via hydrogen bonding to the solvent water molecules. This work represents the first example of a new substituted malonate–lanthanide complex.     

Poly[[aqua(μ7‐ethylenediaminetetraacetato)dicadmium(II)] monohydrate]

The title compound, {[Cd₂(C₁₀H₁₂N₂O₈)(H₂O)]·H₂O}_n, consists of two crystallographically independent Cd^II cations, one ethylenediaminetetraacetate (edta) tetraanion, one coordinated water molecule and one solvent water molecule. The coordination of one of the Cd atoms, Cd1, is composed of five O atoms and two N atoms from two tetraanionic edta ligands in a distorted pentagonal–bipyramidal coordination geometry. The other Cd atom, Cd2, is six‐coordinated by five carboxylate O atoms from five edta ligands and one water molecule in a distorted octahedral geometry. Two neighbouring Cd1 atoms are bridged by a pair of carboxylate O atoms to form a centrosymmetric [Cd₂(edta)₂]⁴⁻ unit located on the inversion centre, which is further extended into a two‐dimensional layered structure through Cd2—O bonds. There are hydrogen bonds between the coordinated water molecules and carboxylate O atoms within the layer. The solvent water molecules occupy the space between the layers and interact with the host layers through O—H...O and C—H...O interactions.     

Poly[[aqua‐μ3‐2,2‐dimethylmalonato‐copper(II)] monohydrate] and poly[aqua‐μ3‐2,2‐dimethylmalonato‐copper(II)]

The coordination mode of the dimethylmalonate ligand in the two title Cu^II complexes, {[Cu(C₅H₃O₄)(H₂O)]·H₂O}_n, (I), and [Cu(C₅H₃O₄)(H₂O)]_n, (II), is the same, with chelated six‐membered, bis‐monodentate and bridging bonding modes. However, the coordination environment of the Cu^II atoms, the connectivity of their metal–organic frameworks and their hydrogen‐bonding interactions are different. Complex (I) has a perfect square‐pyramidal Cu^II environment with the aqua ligand in the apical position, and only one type of square grid consisting of Cu^II atoms linked via carboxylate bridges to three dimethylmalonate ligands, with weak hydrogen‐bond interactions within and between its two‐dimensional layers. Complex (II) has a coordination geometry that is closer to square pyramidal than trigonal bipyramidal for its Cu^II atoms with the aqua ligand now in the basal plane. Its two‐dimensional layer structure comprises two alternating grids, which involve two and four different dimethylmalonate anions, respectively. There are strong hydrogen bonds only within its layers.     

catena‐Poly[[[triaquazinc(II)]‐μ‐2‐nitroterephthalato‐κO1:κ2O4,O4′] monohydrate]

The title complex, {[Zn(C₈H₃NO₆)(H₂O)₃]·H₂O}_n, has a one‐dimensional chain structure. The two carboxylate groups of the dianionic 2‐nitroterephthalate ligand adopt mono‐ and bidentate chelating modes. The Zn atom shows distorted octahedral coordination, bonded to three O atoms from two carboxylate groups and three O atoms of three non‐equivalent coordinated water molecules. The one‐dimensional chains are aggregated into two‐dimensional layers through inter‐chain hydrogen bonding. The whole three‐dimensional structure is further stabilized by inter‐layer hydrogen bonds.     

Synthesis and Crystal Structures of Novel Copper(I) Complexes of a Phosphanylborane

The novel copper iodide clusters [Cu₃(μ‐I)(μ₃‐I)₂(PH₂BH₂·NMe₃)₃] ( 2 ) and [Cu₄(μ‐I)₂(μ₃‐I)₂(PH₂BH₂·NMe₃)₃] ( 3 ) were synthesized by treating CuI with the primary phosphine (H₂PBH₂·NMe₃). The novel features of both compounds, which have been characterized by X‐ray crystallography, are the unsymmetrical constitution of the copper iodide core due to the influence of the monodentate phosphorus ligand. This results in copper atoms with different coordination numbers within the compound. Complex 2 , the major product of the reaction, contains a distorted octahedral Cu₃I₃‐core, in which one vertex is missing. Complex 3 was isolated as a by‐product and is composed of a Cu₄I₄‐core in a distorted octahedral coordination.     

Polymeric bis(phosphonomethyl­carboxylato)calcium(II) at 85 K

In the crystal structure of the title compond, alternatively called poly[calcium(II)‐di‐μ‐carboxymethylphosphonato], [Ca(C₂H₄O₅P)₂]_n or [Ca(H₂AP)₂]_n, one of the phosphonate O atoms of the phosphonocarboxylate monoanion lies nearly antiperiplanar (ap) to the carboxylic acid C atom. The phosphonate P atom is located −sc and +ac relative to the carboxylic acid O atoms. The overall structure has a layered architecture. The Ca²⁺ cations lie on a twofold axis and are bridged by the phosphonate O atoms to form chains along the c axis, giving layers parallel to (100). There are medium‐strength O—H⃛O and C—H⃛O hydrogen‐bonding interactions stabilizing the layers, and O—H⃛O hydrogen bonds connect adjacent layers.     

Intramolecular Communication in Anionic Oxidized Phosphanes through a Chelated Proton

Oxidation of the 1,2‐(PR₂)₂‐1,2‐closo‐C₂B₁₀H₁₀ (R=Ph, iPr) platform with hydrogen peroxide in acetone is a two‐step procedure in which partial deboronation of the closo cluster and oxidation of the phosphorus atoms occur. Based on NMR spectroscopic and kinetic data, we demonstrate that the phosphorus atoms are oxidized in the first step, followed by cluster deboronation. DFT calculations and natural‐bond orbital (NBO) analysis were used to obtain insight into the electronic structures of diphosphane ortho‐carborane derivatives.     

Poly[[tetraaquabis(μ2‐2‐nitroterephthalato‐κ3O1:O4,O4′)(μ2‐piperazine‐κ3N:N′)dicadmium(II)] dihydrate]

In the title complex, {[Cd₂(C₈H₃NO₆)₂(C₄H₁₀N₂)(H₂O)₄]·2H₂O}_n, the Cd^II atoms show distorted octahedral coordination. The two carboxylate groups of the dianionic 2‐nitroterephthalate ligand adopt monodentate and 1,2‐bridging modes. The piperazine molecule is in a chair conformation and lies on a crystallographic inversion centre. The Cd^II atoms are connected via three O atoms from two carboxylate groups and two N atoms from piperazine molecules to form a two‐dimensional macro‐ring layer structure. These layers are further aggregated to form a three‐dimensional structure via rich intra‐ and interlayer hydrogen‐bonding networks. This study illustrates that, by using the labile Cd^II salt and a combination of 2‐nitroterephthalate and piperazine as ligands, it is possible to generate interesting metal–organic frameworks with rich intra‐ and interlayer O—H...O hydrogen‐bonding networks.     

Some CNDO/S parameterized calculations of intramolecular effects on nuclear shielding

Some shielding calculations, using Pople's SOS model, are reported for B, C, N, F, P and Si as a function of changes in bond length and pyramidal bond angle. In all cases considered, the shielding is predicted to decrease as the bond length increases, which is in line with the available experimental data. The observed temperature variation of the nitrogen and phosphorus shieldings of NH₃, PH₃ and PF₃ could be accounted for by a decrease in the pyramidal angle at higher temperatures. A similar angular variation for NF₃ is predicted to cause a shielding variation, with temperature, in the same sense as that reported for NH₃ and PH₃, but opposite to that for PF₃.