Reaction Of P4 Research Articles

Formation of a P162- Ink from Elemental Red Phosphorus in a Thiol-Amine Mixture.

A P162- polyphosphide dianion ink was produced by the reaction of red phosphorus with a binary thiol-amine mixture of ethanethiol (ET) and ethylenediamine (en). The polyphosphide was identified by solution 31P NMR spectroscopy and electrospray ionization mass spectrometry. This solute was compared to the reaction products of white phosphorus (P4) and other elemental pnictides in the same solvent system. The reaction of P4 with ET and en gives the same P162- polyphosphide; however, the easier handling and lower reactivity of red phosphorus highlights the novelty of that reaction. Elemental arsenic and antimony both give mononuclear pnictogen-sulfide-thiolate complexes upon reaction with ET and en under otherwise identical conditions, with this difference likely resulting from the greater covalency and tendency of phosphorus to form P-P bonds.

The Chemistry of Yellow Arsenic.

The generation and handling of the light-sensitive and metastable yellow arsenic (As4) is extremely challenging. In view of recent breakthroughs in synthesizing As4 storage materials and transfer reagents, the more intensive use of yellow arsenic as a source for further reactions can be expected. Given these aspects, the current stage of knowledge of the direct use of As4 is comprehensively summarized in the present review, which lists the activation of As4 by main group elements as well as transition metal compounds (including the f-block elements). Moreover, it also partly compares the reaction outcomes in relation to the corresponding reactions of P4. The possibility of using alternative sources for generating arsenic moieties and compounds is also discussed. The release of As4 molecules from precursor compounds and the use of transfer reagents for polyarsenic entities open up new synthetic pathways to avoid the direct generation of yellow arsenic solutions and to ensure its smooth usage for subsequent reactions.

Oligophosphine-thiocyanate Copper(I) and Silver(I) Complexes and Their Borane Derivatives Showing Delayed Fluorescence.

The series of chelating phosphine ligands, which contain bidentate P2 (bis[(2-diphenylphosphino)phenyl] ether, DPEphos; 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene, Xantphos; 1,2-bis(diphenylphosphino)benzene, dppb), tridentate P3 (bis(2-diphenylphosphinophenyl)phenylphosphine), and tetradentate P4 (tris(2-diphenylphosphino)phenylphosphine) ligands, was used for the preparation of the corresponding dinuclear [M(μ2-SCN)P2]2 (M = Cu, 1, 3, 5; M = Ag, 2, 4, 6) and mononuclear [CuNCS(P3/P4)] (7, 9) and [AgSCN(P3/P4)] (8, 10) complexes. The reactions of P4 with silver salts in a 1:2 molar ratio produce tetranuclear clusters [Ag2(μ3-SCN)(t-SCN)(P4)]2 (11) and [Ag2(μ3-SCN)(P4)]22+ (12). Complexes 7–11 bearing terminally coordinated SCN ligands were efficiently converted into derivatives 13–17 with the weakly coordinating –SCN:B(C6F5)3 isothiocyanatoborate ligand. Compounds 1 and 5–17 exhibit thermally activated delayed fluorescence (TADF) behavior in the solid state. The excited states of thiocyanate species are dominated by the ligand to ligand SCN → π(phosphine) charge transfer transitions mixed with a variable contribution of MLCT. The boronation of SCN groups changes the nature of both the S1 and T1 states to (L + M)LCT d,p(M, P) → π(phosphine). The localization of the excited states on the aromatic systems of the phosphine ligands determines a wide range of luminescence energies achieved for the title complexes (λem varies from 448 nm for 1 to 630 nm for 10c). The emission of compounds 10 and 15, based on the P4 ligand, strongly depends on the solid-state packing (λem = 505 and 625 nm for two crystalline forms of 15), which affects structural reorganizations accompanying the formation of electronically excited states.

Visible-light-mediated direct synthesis of phosphorotrithioates as potent anti-inflammatory agents from white phosphorus

The reaction of P4 with arylthiols in the presence of Na2–eosin Y under visible light gave phosphorotrithioites. Subsequent oxidation of phosphorotrithioites produced phosphorotrithioates. The phosphorotrithioate 3f presents good inflammation reducing characteristics.

Facile Activation of Homoatomic σ Bonds in White Phosphorus and Diborane by a Diboraallene.

Metal-free activation of homoatomic E-E σ bonds (E=P, B) in white phosphorus (P4 ) and bis(catecholato)diboron (B2 cat2 ) with a 1,2-diboraallene 1 is reported. The 1:1 and 1:2 reactions of P4 with 1 afford Bn P4 cages (2: n=2, 3: n=4), whereas a stoichiometric mixture of 1 and B2 cat2 undergoes homonuclear catenation through the addition of the B-B σ bond of B2 cat2 across the B=B double bond of 1 (i.e. diboration), which leads to the formation of a tetraborane (4) featuring a B4 chain.

Facile Activation of Homoatomic σ Bonds in White Phosphorus and Diborane by a Diboraallene

AbstractMetal‐free activation of homoatomic E−E σ bonds (E=P, B) in white phosphorus (P4) and bis(catecholato)diboron (B2cat2) with a 1,2‐diboraallene 1 is reported. The 1:1 and 1:2 reactions of P4 with 1 afford BnP4 cages (2: n=2, 3: n=4), whereas a stoichiometric mixture of 1 and B2cat2 undergoes homonuclear catenation through the addition of the B−B σ bond of B2cat2 across the B=B double bond of 1 (i.e. diboration), which leads to the formation of a tetraborane (4) featuring a B4 chain.

Selective chromo-fluorogenic detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) with a unique probe based on a boron dipyrromethene (BODIPY) dye.

A novel colorimetric probe (P4) for the selective differential detection of DFP (a Sarin and Soman mimic) and DCNP (a Tabun mimic) was prepared. Probe P4 contains three reactive sites; i.e. (i) a nucleophilic phenol group able to undergo phosphorylation with nerve gases, (ii) a carbonyl group as a reactive site for cyanide; and (iii) a triisopropylsilyl (TIPS) protecting group that is known to react with fluoride. The reaction of P4 with DCNP in acetonitrile resulted in both the phosphorylation of the phenoxy group and the release of cyanide, which was able to react with the carbonyl group of P4 to produce a colour modulation from pink to orange. In contrast, phosphorylation of P4 with DFP in acetonitrile released fluoride that hydrolysed the TIPS group in P4 to yield a colour change from pink to blue. Probe P4 was able to discriminate between DFP and DCNP with remarkable sensitivity; limits of detection of 0.36 and 0.40 ppm for DCNP and DFP, respectively, were calculated. Besides, no interference from other organophosphorous derivatives or with presence of acid was observed. The sensing behaviour of P4 was also retained when incorporated into silica gel plates or onto polyethylene oxide membranes, which allowed the development of simple test strips for the colorimetric detection of DCNP and DFP in the vapour phase. P4 is the first probe capable of colorimetrically differentiating between a Tabun mimic (DCNP) and a Sarin and Soman mimic (DFP).

An Actinide Zintl Cluster: A Tris(triamidouranium)μ3‐η2:η2:η2‐Heptaphosphanortricyclane and Its Diverse Synthetic Utility

An Actinide Zintl Cluster: A Tris(triamidouranium)μ₃‐η²:η²:η²‐Heptaphosphanortricyclane and Its Diverse Synthetic Utility

ChemInform Abstract: Chemistry of Functionalized Silylenes

AbstractReview: 194 refs.

Chemistry of functionalized silylenes

Recent years have witnessed important developments in organosilicon chemistry, courtesy to the high yield access of stable monomeric chlorosilylene (LSiCl, L = PhC(NtBu)2) and N-heterocyclic carbene (NHC) stabilized dichlorosilylene (L1SiCl2, L1 = 1,3-bis(2,6-iPr2C6H3)imidazol-2-ylidene) by dehydrochlorination technique using strong bases such as N-heterocyclic carbenes or LiN(SiMe3)2 as HCl scavenger. The chemistry of functionalized silylenes is markedly different from the previously reported dicoordinate silylenes. Their utility as synthons is well documented which paves the way for several striking compounds, e.g. monosilaoxiranes, CSi2P derivative, CSi3P cation, a dimer of silaisonitrile (Si2N2) with dicoordinate Si atoms etc. This study also unravels that these functionalized silylenes are proficient at activating phosphorus, and the functional group attached to the α-position of the silicon(II) centre plays a key role to determine the final product. The reaction of P4 with LSiCl affords a zwitterionic Si2P2 ring, while with LSiN(SiMe3)2 it gives an acyclic Si2P4 derivative. Another recent achievement in this field is the successful isolation of a valence isomer of disilyne known as the inter-connected bis-silylene. This perspective portrays the chemistry of functionalized silylenes which will attract great attention, heading for the further development of organosilicon chemistry.

Solvent-free mesityllithium: solid-state structure and its reactivity towards white phosphorus

The donor-free mesityllithium was prepared from the reaction of MesBr with n-BuLi in diethyl ether at -78 degrees C. The solid-state structure of unsupported mesityllithium consists of C(2)Li(2)-rings composed of two LiMes units, which interact with adjacent dimers [LiMes](2), forming a polymeric infinite chain along the crystallographic c-axis (monoclinic space group, P2(1)/n). The structure of donor-free mesityllithium reveals short contacts between the C atoms of the mesityl rings and the lithium atoms of neighbouring [LiMes](2) units. The structure determination of LiMes was performed by X-ray powder diffraction. In addition we have investigated the reaction of LiMes with Me(3)SnCl and P(4) for our understanding of the reactivity of donor-free mesityllithium. The heterogeneous reaction of donor-free mesityllithium with Me(3)SnCl produces conveniently the stannylated mesitylene Me(3)SnMes (triclinic, space group P1). White phosphorus reacts with three equivalents of unsupported mesityllithium in benzene to give Li(3)P(4)Mes(3). In this context it should be noted that a tetraphosphide with an identical LiP-core as in Li(3)P(4)Mes(3) had been formed in the 1:3 reaction of P(4) with the silanide Li[SitBu(3)]. The tetraphosphide Li(3)P(4)Mes(3) was analyzed using X-ray crystallography (monoclinic, space group C2/c).

Supersilylated Tetraphosphene Derivatives M2[t-Bu3SiPPPPSi-t-Bu3] (M = Li, Na, Rb, Cs) and Ba[t-Bu3SiPPPPSi-t-Bu3]: Reactivity and Cis−Trans Isomerization

The tetraphosphenediides M2[t-Bu3SiPPPPSi-t-Bu3] (M = Li, Na, K) were accessible by the reaction of P4 with the silanides M[Si-t-Bu3] (M = Li, Na, K), whereas M2[t-Bu3SiPPPPSi-t-Bu3] (M = Rb, Cs) were obtained from the reaction of RbCl and CsF with Na2[t-Bu3SiPPPPSi-t-Bu3]. 31P NMR experiments revealed that, in tetrahydrofuran, Na2[t-Bu3SiPPPPSi-t-Bu3] adopts a cis configuration. However, treatment of Na2[t-Bu3SiPPPPSi-t-Bu3] with 18-crown-6 led to the formation of [Na(18-crown-6)(thf)2]2[t-Bu3SiPPPPSi-t-Bu3] that possesses a trans configuration in the solid state. The ion-separated tetraphosphenediide [Na(18-crown-6)(thf)2]2[t-Bu3SiPPPPSi-t-Bu3] was analyzed using X-ray crystallography (monoclinic, space group P2(1)/n). The reaction of Na2[t-Bu3SiPPPPSi-t-Bu3] with BaI2 gave, conveniently, the corresponding barium derivative Ba[t-Bu3SiPPPPSi-t-Bu3]. However, addition of AuI to the tetraphosphenediide Na2[t-Bu3SiPPPPSi-t-Bu3] yielded 1,3-diiodo-2,4-disupersilyl-cyclotetraphosphane (monoclinic, space group C2/c), which is an isomer of disupersilylated diiodotetraphosphene. A further isomeric derivative of disupersilylated tetraphosphene, the 3,5-disupersilyl-2,2-di-tert-butyl-2-stanna-bicyclo[2.1.0(1,4)]pentaphosphane, which possesses a phosphanylcyclotriphosphane structure, was obtained by the reaction of Na2[t-Bu3SiPPPPSi-t-Bu3] with t-Bu2SnCl2. Calculations revealed that the acyclic cis and trans isomers of the dianions [HPPPPH]2- and [H3SiPPPPSiH3]2- are thermodynamically more stable than the cyclic isomers with a phosphanylcyclotriphosphane or a cyclotetraphosphane structure. However, the neutral cyclic isomers of H4P4 and H2(H3Si)2P4 represent more stable structures than the cis- and trans-tetraphosphenes H2P-P=P-PH2 and (H3Si)HP-P=P-PH(SiH3), respectively. In addition, the molecular orbitals (MOs) of the silylated cis- and trans-tetraphosphene dianions of [H3SiPPPPSiH3]2-, which are comparable with those of the ion-separated supersilylated tetraphosphenediide [t-Bu3SiPPPPSi-t-Bu3]2-, show the highest occupied antibonding pi*MO (HOMO). The HOMO is represented by the (p(z)-p(z)+p(z)-p(z)) pi* MO.

New Routes for the Functionalization of P4

New Routes for the Functionalization of P₄

Reaction of Elemental Phosphorus (P4) with Thiophenol in the Presence of Amines

Elemantal phosphorus (P4) reacts with thiophenol and amines at elevated temperature in acetonitrile to give ammonium or acetimidamidium S,S-diphenyl phosphorodithioates, depending on the nature of the amine. Analogous salts were isolated in the reaction of triphenyl phosphorotrithioite with thiophenol and corresponding amines in acetonitrile. The molecular and crystal structures of the acetimidamidium salt was confirmed by X-ray diffraction. With two different types of intermolecular interactions taken into account, a 1D supramolecular structure formed by infinite cylinders, rather that 0D structures, dimers of anion-cation pairs formed by classical hydrogen bonds exclusively, was obtained. S,S,S-Triphenyl phosphorotrithioate is formed by the reactions of P4 with thiophenol and a catalytic amount of an amine or in the presence of diphenyl disulfide.

Nucleophilic Degradation of White Phosphorus with tBu3SiK: Synthesis and X-ray Crystal Structure Analysis of the Potassium Triphosphide (tBu3Si)2P3K

The potassium phosphides (tBu3Si)2P4K2 and (tBu3Si)4P8K4 can be synthesized from the reaction of P4 with 2 equiv of the potassium silanide tBu3SiK in tetrahydrofuran at −78 °C. The potassium silanide tBu3SiK slowly transforms the tetraphospide (tBu3Si)2P4K2 and the octaphosphide (tBu3Si)4P8K4 into (tBu3Si)2P3K and (tBu3Si)3P5K2. X-ray quality crystals of the triphosphide, tBu3SiKP−PPSitBu3, have been obtained from a tetrahydrofuran solution at −25 °C.

Reactions of P4 and I2 with Ag[Al(OC(CF3)3)4]: from elusive polyphosphorus cations to subvalent P3I6+ and phosphorus rich P5I2+

Reactions of X2 (X = Br, I), P4 and Ag(CH2Cl2)[Al(OR)4] [R = C(CF3)3] in suitable ratios to prepare naked polyphosphorus cations were carried out and led to products which suggested the presence of these elusive cations as intermediates. At temperatures above −30 °C to rt the initially formed cations decomposed the Al(OR)4− anion giving, in two cases, the more stable fluoride bridged (RO)3Al–F–Al(OR)3− anion. When Br2 was used as the oxidising agent the proposed intermediate phosphorus cation (P5+?) reacted with the solvent CDCl3 by double insertion of a P+ unit into the C–Cl bond giving Cl2P(CDCl2)2[(RO)3Al–F–Al(OR)3], 1. When I2 was used as the oxidiser the reaction led to the marginally stable P3I6[(RO)3Al–F–Al(OR)3], 2 (X-ray). By using very mild conditions throughout (−80 °C) the primary product of the reaction of Ag(P4)2[Al(OR)4] and I2 was isolated: P5I2[Al(OR)4], 3, containing the P5I2+ cation with a hitherto unknown C2v-symmetric P5 cage as structural building block. P3I6[Al(OR)4], 4, was directly synthesised in quantitative yield starting from P2I4, PI3 and Ag(CH2Cl2)[Al(OR)4] in CH2Cl2 solution. P3I6+ is formed through the P2I5+ stage (31P-NMR). P3I6+ (av.: P2.33) is the first subvalent P–X cation (X = H, F, Cl, Br, I). P5I2+ (av.: P0.6) is the first phosphorus rich binary P–X cation. They are the third and fourth example of a binary P–X cation after the known PX4+ and P2X5+ cations. The observed reactions were fully accounted for by thermochemical Born–Haber cycles based on (RI-)MP2/TZVPP ab initio, COSMO solvation and lattice enthalpy calculations (all phases). The gaseous enthalpies of formation of several species were calculated to be (in kJ mol−1): P5+ (913), P3I6+ (694), P5I2+ (792), P2I5+ (733), Ag(P4)2+ (784).

Supersilylverbindungen des Phosphors, V [1]. Darstellung, Struktur und Reaktivität des Pentaphosphids (tBu3Si)3P5Na2 und des Pentaphosphans (tBu3Si)3P5[2] / Supersilyl Compounds of Phosphorus, V [1]. Preparation, Structure, and Reactivity of the Pentaphosphide (tBu3Si)3P5Na2 and the Pentaphosphane (tBu3Si)3P5 [2

The orange THF adduct (tBu3Si)3P5Na2 (THF)4 of the pentaphosphide (tBu3Si)3P5Na2 (3) has been prepared, (i) by protolysis of the tetraphosphide (tBu3Si)2P4Na2(THF)n (2) with CF3CO2H in THF (molar ratio 2 : 1 ) , (ii) by dissolving crystalline 2 in toluene, and (iii) by the reaction of P4 with tBu3SiNa(THF)2 in benzene (molar ratio 1 : 4). According to an X-ray structural analysis, the THF adduct of 3 contains a P3 ring with two PNa(SitBu3) substituents in cis position and one SitBu3 substituent in trans position to the former groups. The protolysis of 3 with CF3CO2H leads to the pentaphosphane P5H2(SitBu3)3 (9), the silylation of 3 with Me2SiCl2 to the pentaphosphane P5 (SiMe2)(SitBu3)3 (10), and the oxidation of 3 with C2(CN)4 to the pentaphosphane P5(SitBu3)3 (5). The structures of 3,5,9, and 10 have been assigned from 31P and 29Si NMR data. The pentaphosphane 5 contains a hitherto unknown P5 backbone of a P3 ring anellated with a P4 ring.

Bildung und Charakterisierung des Dinatrium‐tetraphosphendiids (tBu3Si)NaP–PP–PNa(SitBu3) und seines Dimeren

AbstractReaction of P4 in THF or DME with 2 R*Na (R* = SitBu3) at –78°C leads quantitatively to deep red THF or DME adducts of R*NaP–PP–PNaR* (3). According to 31P NMR, the P4 skeleton 3 is cis‐configurated. On the other hand, reaction of P4 in TBME with 2 R*Na at ‐78°C leads quantitatively to (R*NaP)4 (4), a [2+2] cycloadduct of 3, the Na4P8 skeleton of which according to X‐ray structure analysis forms a double cube with four P atoms in the second layer and two P and two Na atoms in alternating positions in the first and in the third layer (the Na atoms are coordinated with donors). By resolving the THF adduct 3 in TBME (the TBME adduct of 4 in THF) the compound 4 (the compound 3) is rapidly formed under reversal of the P–PP–P configuration by way of [2+2] cycloaddition (by way of [2+2] cycloreversion). 3 and 4 are sensitive to oxidation and to protolysis. With TCNE, 3 is oxidized to R*2P4 (bicyclic P4 skeleton), with CF3SO3H, 3 may be transformed into R*3P5Na2 X 4 THF or in (R*P3)3 and R*PH2.

Pn‐Liganden mit maximaler Elektronendonorfähigkeit, 7. Dreikomponentenreaktion von P4‐Phosphor mit [CpxRh(CO)2] in Gegenwart von [Cr(CO)5THF] oder [CpMn(CO)2THF]. – Eine Methode zum Studium des Transformationsweges vom P4‐Tetraeder zum planaren cyclo‐P4‐Liganden

Pn Ligands with Maximum Electron‐Donor Capacity, 7. – Three‐Component Reaction of P4‐Phosphorus with [CpxRh(CO)2] in the Presence of [Cr(CO)5THF] or [CpMn(CO)2THF]. – A Method of Studying the Pathway from Tetrahedral P4 to the Planar cyclo‐P4 LigandHerrn Professor Gerhard Fritz zum 75. Geburtstag gewidmet. The reaction of P4 with [CpxRh(CO)2] (Cpx = Cp′, Cp′′; Cp′ = η5‐C5H4tBu, Cp′′ = η5‐C5H3tBu2‐1,3) in the presence of [Cr(CO)5THF] leads to [CpxRh(CO)(η1:1‐P4){Cr(CO)5}4] (1a, b), [Cp′′Rh(η4‐P4){Cr(CO)5}3] (2b), and [Cp′Rh(η4‐P4){Cr‐(CO)5}4] (3a). In the corresponding reaction with [CpMn‐(CO)2THF] no P4 takes part, and [(Cp′′RhCO)(CpMnCO)(μ‐CO)2] (4) is formed. An X‐ray structure determination of [CpxRh(CO)(η1:1‐P4){Cr(CO)5}4] (1) and [Cp′Rh(η4‐P4)‐{Cr(CO)5}4] (3a) indicates a stepwise (PP) bond cleavage as the transformation pathway from the P4 tetrahedron to the cyclo‐P4 ligand by passing a bicyclotetraphosphane. In the cyclo‐P4 ligand complex 3a all P atoms are able to coordinate to [Cr(CO)5] groups. However, in [Cp′′Rh(η4‐P4){Cr(CO)5}3] (2b) the additional tBu group at the Cpx ligand sterically influences the coordination behavior of the P atoms, and only three of them are able to coordinate to [Cr(CO)5] units. In these syntheses the [Cr(CO)5] moieties promote the reaction and stabilise intermediates along the reaction pathway. Variable‐temperature 31P{1H}‐NMR measurements indicate for 2b the freezing of the Cp′′ rotation at low temperature and reveals a ΔG (at the coalescence temperature) of 36 kJ mol−1. Surprisingly, in [(Cp′′RhCO)(CpMnCO)(μ‐CO)2]‐(Rh‐Mn) (4) the Cpx ligands are cis‐oriented whereas in [(Cp*RhCO)(CpMnCO)(μ‐CO)2](Rh‐Mn) a trans arrangement is observed. This indicates the unusual behavior of the Cp′′ ligand as a “rod” and not as an “enlarged disk” like Cp* in the crystal lattice of these compounds.

Cyclo-P4Ligands with a Maximum of Electron-Donating Ability

The reactions of P4 with metal carbonyls of chromium, tungsten and iron lead to square planar cyclo-P4 ligand complexes and to a rectangular distorted P4 ligand complex, respectively. Furthermore the study of the transformation pathway of tetrahedral P4 to the corresponding Px ligands reveals a stepwise (PP) bond cleavage with a bicyclotetraphosphine intermediate to give a cyclo-P4 containing product.