Cycloadditions of Diazoalkenes with P4 and tBuCP: Access to Diazaphospholes

Diazoalkenes readily react with tert-butylphosphaalkyne (tBuCP) and white phosphorus (P4) to afford novel phosphorus heterocycles, 3H-1,2,4-diazamonophospholes and 1,2,3,4-diazadiphospholes. Both species represent rare examples of neutral heterophospholes. The mechanism of formation and the electronic structures of these formal (3+2) cycloaddition products were analyzed computationally. The new phospholes form structurally diverse coordination compounds with transition metal and main group elements. Given the growing number of stable diazoalkenes, this work offers a straightforward route to neutral aza(di-)phospholes as a new ligand class.

Synthesis of Carbene-Stabilized PNPN Fragments and Their Carbene-Dependent Redox Properties

Herein, we report the synthesis of carbene-stabilized 1,3-diaza-2,4-diphosphabutenes CAACMePNPNCAACMe 4CAAC (CAACMe = 1-[2,6-bis(isopropyl)phenyl]-3,3,5,5-tetramethyl-2-pyrrolidinylidene) and IPrPNPNIPr 4NHC (IPr = 1,3-Bis(2,6-diisopropylphenyl)-imidazol-2-ylidene). The bonding in both systems is defined by a delocalized polar covalent π-system, with 4NHC exhibiting increased conjugation relative to 4CAAC. The nature of the stabilizing carbene also influences the redox properties of the compound, with 4CAAC undergoing potassium-mediated reduction to the closed-shell P-P bonded dimer K252, which upon treatment with Kryptofix-2,2,2 converts to the transient radical anion [Kcrypt][5], the formal one-electron reduction product of 4CAAC. In contrast, 4NHC undergoes reversible one-electron oxidation to the stable radical cation [6NHC][SbF6]. Computational and spectroscopic analyses of both radical species are suggestive of unevenly delocalized spin, with the bulk of the spin density residing on phosphorus in both cases.

Synthesis and reactivity of N-heterocyclic carbene (NHC)-supported heavier nitrile ylides

The synthesis and isolation of stable heavier analogues of nitrile ylide as N-heterocyclic carbene (NHC) adducts of phosphasilenyl-tetrylene [(NHC)(TerAr)Si(H)PE14(TerAr)] (E14 = Ge 1, Sn 2; TerAr = 2,6-Mes2C6H3, NHC = IMe4) are reported. The delocalized Si-P-E14 π-conjugation was examined experimentally and computationally. Interestingly, the germanium derivative 1 exhibits a 1,3-dipolar nature, leading to an unprecedented [3 + 2] cycloaddition with benzaldehyde, resulting in unique heterocycles containing four heteroatoms from group 14, 15, and 16. Further exploiting the nucleophilicity of germanium, activation of the P-P bond of P4 was achieved, leading to a [(NHC)(phosphasilenyl germapolyphide)] complex. Moreover, the [3 + 2] cycloaddition and the σ-bond activation by 1 resemble the characteristics of the classic nitrile ylide.

Direct Synthesis of Phosphoryltriacetates from White Phosphorus via Visible Light Catalysis

Organophosphorus compounds (OPCs) are widely used in many fields. However, traditional synthetic routes in the industry usually involve multistep and hazardous procedures. Therefore, it's of great significance to construct such compounds in an environmentally-friendly and facile way. Herein, a photoredox catalytic method has been developed to construct novel phosphoryltriacetates. Using fac-Ir(ppy)3 (ppy=2-phenylpyridine) as the photocatalyst and blue LEDs (456 nm) as the light source, white phosphorus can react with α-bromo esters smoothly to generate phosphoryltriacetates in moderate to good yields. This one-step approach features mild reaction conditions and simple operational process without chlorination.

Reactivity of [Cp*Fe(η5 -As5 )] towards Carbenes, Silylenes and Germylenes

The reaction behavior of [Cp*Fe(η5 -As5 )] (I) (Cp*=C5 Me5 ) towards carbenes and their heavier analogs was investigated. The reaction of I with NHCs (NHCs=N-heterocyclic carbenes) results in the first substitution products of polyarsenic ligand complexes by NHCs [Cp*Fe(η4 -As5 NHC)] (1 a: NHC=IMe=1,3,4,5-tetramethylimidazolin-2-ylidene, 1 b: NHC=IMes=1,3-bis(2,4,6-trimethylphenyl)-imidazolin-2-ylidene). In contrast, the reaction of I with Et CAAC (Et CAAC=2,6-diisopropylphenyl)-4,4-diethyl-2,2-dimethyl-pyrrolidin-5-ylidene) leads to a fragmentation and the formation of an unprecedented As6 -sawhorse-type compound [As2 (AsEt CAAC)4 ] (2). The reaction of (LE)2 (L=PhC(Nt Bu)2 ; E=Si, Ge) with I resulted in a rearrangement and an insertion of LE fragments, forming unique silicon- (4: [Cp*Fe(η4 -As4 SiL)], 5 a: [Cp*Fe(η4 -As6 SiL)) and germanium-containing (5 b: [Cp*Fe(η4 -As6 GeL)) cyclic polyarsenic ligand complexes.

Photochemical Benzylation of White Phosphorus

Organophosphorus compounds (OPCs) have wide application in organic synthesis, material sciences, and drug discovery. Generally, the vast majority of phosphorus atoms in OPCs are derived from white phosphorus (P4). However, the large-scale preparation of OPCs mainly proceeds through the multistep and environmentally toxic chlorine route from P4. Herein, we report the direct benzylation of P4 promoted by visible light. The cheap and readily available benzyl bromide was used as a benzylation reagent, and tetrabenzylphosphonium bromide was directly synthesized from P4. In addition, the metallaphotoredox catalysis strategy was applied to functionalize P4 for the first time, which significantly improved the application range of the substituted benzyl bromide.

Counterintuitive Chemistry: Carbene Stabilization of Zero-Oxidation State Main Group Species

Carbenes have evolved from transient laboratory curiosities to a robust, diverse, and surprisingly impactful ligand class. A variety of different carbenes have significantly contributed to the development of low-oxidation state main group chemistry. This Perspective focuses upon advances in the chemistry of carbene complexes containing main group element cores in the formal oxidation state of zero, including their diverse synthetic strategies, unusual bonding and structural motifs, and utility in transition metal coordination chemistry and activation of small molecules.

Binding, Release and Functionalization of Intact Pnictogen Tetrahedra Coordinated to Dicopper Complexes

The bridging MeCN ligand in the dicopper(I) complexes [(DPFN)Cu2 (μ,η1  : η1 -MeCN)][X]2 (X=weakly coordinating anion, NTf2 (1 a), FAl[OC6 F10 (C6 F5 )]3 (1 b), Al[OC(CF3 )3 ]4 (1 c)) was replaced by white phosphorus (P4 ) or yellow arsenic (As4 ) to yield [(DPFN)Cu2 (μ,η2  : η2 -E4 )][X]2 (E=P (2 a-c), As (3 a-c)). The molecular structures in the solid state reveal novel coordination modes for E4 tetrahedra bonded to coinage metal ions. Experimental data and quantum chemical computations provide information concerning perturbations to the bonding in coordinated E4 tetrahedra. Reactions with N-heterocyclic carbenes (NHCs) led to replacement of the E4 tetrahedra with release of P4 or As4 and formation of [(DPFN)Cu2 (μ,η1  : η1 -Me NHC)][X]2 (4 a,b) or to an opening of one E-E bond leading to an unusual E4 butterfly structural motif in [(DPFN)Cu2 (μ,η1  : η1 -E4 Dipp NHC)][X]2 (E=P (5 a,b), E=As (6)). With a cyclic alkyl amino carbene (Et CAAC), cleavage of two As-As bonds was observed to give two isomers of [(DPFN)Cu2 (μ,η2  : η2 -As4 Et CAAC)][X]2 (7 a,b) with an unusual As4 -triangle+1 unit.

Unexpected White Phosphorus (P4 ) Activation Modes with Silylene-Substituted o-Carboranes and Access to an Isolable 1,3-Diphospha-2,4-disilabutadiene

New types of metal-free white phosphorus (P4 ) activation are reported. While the phosphine-silylene-substituted dicarborane 1, CB-SiP (CB=ortho-C,C'-C2 B10 H10 , Si=PhC(tBuN)2 Si, P=P[N(tBu)CH2 ]2 ), activates white phosphorus in a 2 : 1 molar ratio to yield the P5 -chain containing species 2, the analogous bis(silylene)-substituted compound 3, CB-Si2 , reacts with P4 in the molar ratio of 2 : 1 to furnish the first isolable 1,3-diphospha-2,4-disilabutadiene (Si=P-Si=P-containing) compound 4. For the latter reaction, two intermediates having a CB-Si2 P4 and CB-Si2 P2 core could be observed by multinuclear NMR spectroscopy. The compounds 2 and 4 were characterized including single-crystal X-ray diffraction analyses. Their electronic structures and mechanisms were investigated by density functional theory calculations.

Recent Advances in the Domain of Cyclic (Alkyl)(Amino) Carbenes

Isolation of cyclic (alkyl) amino carbenes (cAACs) in 2005 has been a major achievement in the field of stable carbenes due to their better electronic properties. cAACs and bicyclic(alkyl)(amino)carbene (BicAAC) in essence are the most electrophilic as well as nucleophilic carbenes are known till date. Due to their excellent electronic properties in terms of nucleophilic and electrophilic character, cAACs have been utilized in different areas of chemistry, including stabilization of low valent main group and transition metal species, activation of small molecules, and catalysis. The applications of cAACs in catalysis have opened up new avenues of research in the field of cAAC chemistry. This review summarizes the major results of cAAC chemistry published until August 2021.

Fragmentation, catenation, and direct functionalisation of white phosphorus by a uranium(IV)-silyl-phosphino-carbene complex

Room temperature reaction of the uranium(iv)-carbene [U{C(SiMe3)(PPh2)}(BIPMTMS)(μ-Cl)Li(TMEDA)(μ-TMEDA)0.5]2 (1, BIPMTMS = C(PPh2NSiMe3)2) with white phosphorus (P4) produces the organo-P5 compound [P5{C(SiMe3)(PPh2)}2][Li(TMEDA)2] (2) and the uranium(iv)-methanediide [U{BIPMTMS}{Cl}{μ-Cl}2{Li(TMEDA)}] (3). This is an unprecedented example of cooperative metal-carbene P4 activation/insertion into a metal-carbon double bond and also an actinide complex reacting with P4 to directly form an organophosphorus species. Conducting the reaction at low temperature permits the isolation of the diuranium(iv) complex [{U(BIPMTMS)([μ-η2:η2-P2]C[SiMe3][PPh2])}2] (4), which then converts to 2 and 3. Thus, surprisingly, in contrast to all other actinide P4 reactivity, although this reaction produces catenation overall it proceeds via P4 cleavage to functionalised P2 units. Hence, this work establishes a proof of concept synthetic cycle for direct fragmentation, catenation, and functionalisation of P4.

Bicyclic and tricyclic phosphanes with p-block substituents

This review summarises the experimental and structural knowledge on polycyclic phosphanes, with a focus on bicyclic and tricyclic phosphanes, as they have not only been the most studied in the last 25 years, but also show the greatest diversity in terms of constitutional isomerism and structural motifs. Moreover, only polycyclic phosphanes that have p-block substituents at all free valences are discussed.

Di-tert-butyldiphosphatetrahedrane as a building block for phosphaalkenes and phosphirenes

The remarkable 'mixed' diphosphatetrahedrane (tBuCP)2 (1) - which is both the elusive dimeric form of the phosphaalkyne tBuCP and an isolobal analogue of the important industrial feedstock P4 - was recently isolated for the first time; however, its chemistry remains unexplored. Herein we report that treatment of 1 with various N-heterocyclic carbenes readily yields unusual, unsaturated organophosphorus motifs. These results demonstrate the significant potential of 1 as a building block for the synthesis of previously unknown organophosphorus compounds.

Fragmentation Mechanism of White Phosphorus: A Theoretical Insight into Multiple Cleavage/Formation of P-P and P-C Bonds

Molecular-level understanding of metal-mediated white phosphorus (P₄ ) activation is meaningful but challenging because of its direct relevance to the conversion of P₄ into useful organophosphorus compounds as well as the complicated and unforeseeable cleavage process of P-P bonds. The related study, however, has still rarely been achieved to date. Here, a theoretical insight into the step-by-step process of three P-P bond cleavage/four P-C bond formation for [P₃ +P₁ ]-fragmentation of P₄ mediated by lutetacyclopentadienes is reported. The unique charge-separated intermediate and the intermolecular cooperation between two lutetacyclopentadienes play a vital role in the subsequent P-P/P-C bond breaking/forming. It is found that, although the first P-C formation is involved in the assembly of the cyclo-P₃ [R₄ C₄ P₃ ]^- unit, the construction of the aromatic five-membered P₁ heterocycle [R₄ C₄ P]^- is completed prior to the cyclo-P₃ formation. The reaction mechanism has been carefully elucidated by analyses of the geometric structure, frontier molecular orbitals, bond index, and natural charge, which greatly broaden and enrich the general knowledge of the direct functionalization of P₄ .

Direct functionalization of white phosphorus with anionic dicarbenes and mesoionic carbenes: facile access to 1,2,3-triphosphol-2-ides

A series of unique C₂P₃-ring compounds [(ADC^Ar)P₃] (4) are readily accessible in an almost quantitative yield by the direct functionalization of white phosphorus (P₄) with appropriate anionic dicarbenes [Li(ADC^Ar)].

A series of unique C₂P₃-ring compounds [(ADC^Ar)P₃] (ADC^Ar = ArC{(DippN)C}₂; Dipp = 2,6-iPr₂C₆H₃; Ar = Ph 4a, 3-MeC₆H₄4b, 4-MeC₆H₄4c, and 4-Me₂NC₆H₄4d) are readily accessible in an almost quantitative yield by the direct functionalization of white phosphorus (P₄) with appropriate anionic dicarbenes [Li(ADC^Ar)]. The formation of 1,2,3-triphosphol-2-ides (4a–4d) suggests unprecedented [3 + 1] fragmentation of P₄ into P₃⁺ and P^–. The P₃⁺ cation is trapped by the (ADC^Ar)^– to give 4, while the putative P^– anion reacts with additional P₄ to yield the Li₃P₇ species, a useful reagent in the synthesis of organophosphorus compounds. Remarkably, the P₄ fragmentation is also viable with the related mesoionic carbenes (iMICs^Ar) (iMIC^Ar = ArC{(DippN)₂CCH}, i stands for imidazole-based) giving rise to 4. DFT calculations reveal that both the C₃N₂ and C₂P₃-rings of 4 are 6π-electron aromatic systems. The natural bonding orbital (NBO) analyses indicate that compounds 4 are mesoionic species featuring a negatively polarized C₂P₃-ring. The HOMO–3 of 4 is mainly the lone-pair at the central phosphorus atom that undergoes σ-bond formation with a variety of metal-electrophiles to yield complexes [{(ADC^Ar)P₃}M(CO)_n] (M = Fe, n = 4, Ar = Ph 5a or 4-Me-C₆H₄5b; M = Mo, n = 5, Ar = Ph 6; M = W, n = 5, Ar = 4-Me₂NC₆H₄7).

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.

[P4H]+[Al(OTeF5)4]-: protonation of white phosphorus with the Brønsted superacid H[Al(OTeF5)4](solv)

A sustainable transformation of white phosphorus (P4) into chemicals of higher value is one of the key aspects in modern phosphorus research. Even though the chemistry of P4 has been investigated for many decades, its chemical reactivity towards the simplest electrophile, the proton, is still virtually unknown. Based on quantum-chemical predictions, we report for the first time the successful protonation of P4 by the Brønsted acid H[Al(OTeF5)4](solv). Our spectroscopic results are in agreement with acid-mediated activation of P4 under protonation of an edge of the P4-tetrahedron and formation of a three-center two-electron P-H-P bond. These investigations are of fundamental interest as they permit the activation of P4 with the simplest electrophile as a new prototype reaction for this molecule.

NHCs in Main Group Chemistry

Since the discovery of the first stable N-heterocyclic carbene (NHC) in the beginning of the 1990s, these divalent carbon species have become a common and available class of compounds, which have found numerous applications in academic and industrial research. Their important role as two-electron donor ligands, especially in transition metal chemistry and catalysis, is difficult to overestimate. In the past decade, there has been tremendous research attention given to the chemistry of low-coordinate main group element compounds. Significant progress has been achieved in stabilization and isolation of such species as Lewis acid/base adducts with highly tunable NHC ligands. This has allowed investigation of numerous novel types of compounds with unique electronic structures and opened new opportunities in the rational design of novel organic catalysts and materials. This Review gives a general overview of this research, basic synthetic approaches, key features of NHC-main group element adducts, and might be useful for the broad research community.

Synthesis, Spectroscopic Characterization, and Redox Reactivity of a Cyclic (Alkyl) Amino Carbene-Derived Arsamethine Cyanine Dye

In our efforts to prepare a diarsenic allotrope supported by two cyclic alkyl amino carbene (CAAC) ligands we stumbled upon the synthesis of the first carbene-supported chloroarsinidene 3, which has been fully characterized by a combination of NMR spectroscopic and XRD methods. Although further reduction of 3 was not possible, we found that addition of a second equivalent of CAAC in refluxing toluene afforded the first example of a crystallographically characterized arsamethine cyanine dye (4). The arsenic(I) dye is structurally similar to phosphorus analogues, and contains an arsenide anion with two stereochemically active lone pairs supported by two iminium ligands. The UV/Visible spectrum and redox chemistry of 4 were also explored. Upon reduction with one equivalent of KC₈ , 3 is reduced to the originally targeted CAAC₂ As₂ allotrope 6, whereas oxidation provides access to the first example of an arsenic(II) radical dication (5).

The bismuth tetramer Bi4: the ν3 key to experimental observation

The spectroscopic identification of Bi₄ has been very elusive. Two constitutional Bi₄ isomers of T_d and C_2v symmetry are investigated and each is found to be a local energetic minimum.

A direct route from white phosphorus and fluorous alkyl and aryl iodides to the corresponding trialkyl- and triarylphosphines

The title reaction is effected with samarium(ii) reductants that generate fluorous radicals that add to P₄ with phosphorus–phosphorus bond cleavage.

Functionalization of P4 through Direct P-C Bond Formation

Research on chlorine-free conversions of P4 into organophosphorus compounds (OPCs) has a long track record, but methods that allow desirable, direct P-C bond formations have only recently emerged. These include the use of metal organyls, carbenes, carboradicals, and photochemical approaches. The versatile product scope enables the preparation of both industrially relevant organophosphorus compounds, as well as a broad range of intriguing new compound classes. Herein we provide a concise overview of recent breakthroughs and outline the acquired fundamental insights to aid future developments.

NHC adducts of tantalum amidohalides: the first example of NHC abnormally coordinated to an early transition metal

The first abnormally coordinated NHC complex of an early transition metal, [(aIMes)TaCl₂(NMe₂)₃], is prepared.

Transition-Metal-like Behavior of Main Group Elements: Ligand Exchange at a Phosphinidene

(Phosphino)phosphaketenes (>P-P═C═O) behave as (phosphino)phosphinidene-carbonyl adducts (>P-P←:C═O). CO scrambling was observed using ¹³C labeled CO, and exchange reactions with phosphines afford the corresponding (phosphino)phosphinidene-phosphine adducts (>P-P←:PR₃). The latter react with isonitriles and singlet carbenes giving (phosphino)phosphinidene-isonitrile (>P-P←:CNR) and -carbene adducts (>P-P←:C<). Based on experimental results and DFT calculations, it is shown that these "ligand" exchange reactions occur via an associative mechanism as classically observed with transition metal complexes.

Selective [3+1] Fragmentations of P4 by "P" Transfer from a Lewis Acid Stabilized [RP4 ]- Butterfly Anion

Two [3+1] fragmentations of the Lewis acid stabilized bicyclo[1.1.0]tetraphosphabutanide Li[Mes*P₄ ⋅ BPh₃ ] (Mes*=2,4,6-tBu₃ C₆ H₂ ) are reported. The reactions proceed by extrusion of a P₁ fragment, induced by either an imidazolium salt or phenylisocyanate, with release of the transient triphosphirene Mes*P₃ , which was isolated as a dimer and trapped by 1,3-cyclohexadiene as a Diels-Alder adduct. DFT quantum chemical computations were used to delineate the reaction mechanisms. These unprecedented pathways grant access to both P₁ - and P₃ -containing organophosphorus compounds in two simple steps from white phosphorus.

N,N'-Diamidocarbenes: Isolable Divalent Carbons with Bona Fide Carbene Reactivity

Since the first reported isolation of a carbene just over a quarter century ago, the study of such compounds-including stable derivatives-has flourished. Indeed, N-heterocyclic carbenes (NHCs), of which imidazolylidenes and their derivatives are the most pervasive subclass, feature prominently in organocatalysis, as ligands for transition metal catalysts, and as stabilizers of reactive species. However, imidazolylidenes (and many other NHCs) typically lack the reactivity characteristic of electrophilic carbenes, including insertion into unactivated C-H bonds, participation in [2 + 1] cycloadditions, and reaction with carbon monoxide. This has led to debates over whether NHCs are truly carbenic in nature or perhaps better regarded as ylides. The fundamental and synthetic utility of transformations that involve electrophilic carbenes has motivated our group and others to expand the reactivity of NHCs and other stable carbenes to encompass electrophilic carbene chemistry. These efforts have led to the development of the diamidocarbenes (DACs), a stable and unique subset of the NHCs that feature carbonyl groups inserted into the N-heterocyclic scaffold. To date, crystalline five-, six-, and seven-membered DACs have been prepared and studied. Unlike imidazolylidenes, which are often designated as prototypical NHCs, the DACs exhibit a reactivity profile similar to that of bona fide carbenes, reactive species that are less "tamed" by heteroatom π conjugation. The DACs engage in [2 + 1] cycloadditions with electron-rich or -poor alkenes, aldehydes, alkynes, and nitriles, and doing so in a reversible manner in some cases. They also react with isonitriles, reversibly couple to CO, and mediate the dehydrogenation of hydrocarbons. Such rich chemistry may be rationalized in terms of their ambiphilicity: DACs are nucleophilic, as required for some of the reactions above, yet also have electrophilic character, as evidenced by their insertions into unactivated N-H and C-H bonds, including nonacidic derivatives. As will become clear, such reactivity is unique among isolable carbenes. DAC chemistry is expected to find applications in synthesis, dynamic covalent chemistry, and catalysis. For example, the hydrolysis of DAC-derived diamidocyclopropanes and -propenes affords carboxylic acids and cyclopropenones, respectively. These new hydrocarboxylation and carbonylation methodologies are significant in that they represent alternatives to processes that typically involve precious metals and gaseous carbon monoxide. Future efforts in this area may involve modifications that transform the stoichiometric conversions facilitated by DACs into catalytic variants. In this context, the reversible binding of CO to DACs is an indication that the latter may serve as a blueprint for the development of more electrophilic, stable carbenes with the capacity to activate other challenging small molecules.

Direct Synthesis of Phospholyl Lithium from White Phosphorus

The selective construction of P-C bonds directly from P4 and nucleophiles is an ideal and step-economical approach to utilizing elemental P4 for the straightforward synthesis of organophosphorus compounds. In this work, a highly efficient one-pot reaction between P4 and 1,4-dilithio-1,3-butadienes was realized, which quantitatively affords phospholyl lithium derivatives. DFT calculations indicate that the mechanism is significantly different from that of the well-known stepwise cleavage of P-P bond in P4 activation. Instead, a cooperative nucleophilic attack of two Csp2 Li bonds on P4 , leading to simultaneous cleavage of two P-P bonds, is favorable. This mechanistic information offers a new view on the mechanism of P4 activation, as well as a reasonable explanation for the excellent yields and selectivity. This method could prove to be a useful route to P4 activation and the subsequent production of organophosphorus compounds.

Formation of the spirocyclic, Si-centered cage cations [ClP(NSiMe3)2Si(NSiMe3)2P5](+) and [P5(NSiMe3)2Si(NSiMe3)2P5](2)

On account of our interest in P4 activation by phosphenium ion insertion into P-P bonds we have developed synthetic routes to bicyclic N-P-Si-heterocycle 7 and probed its reactivity towards GaCl3 and P4. A GaCl3-induced rearrangement of 7 leads to the in situ formation of spirocyclic, Si-centered phosphenium ions. Their insertion into P-P bonds of one or two P4 tetrahedra yields polyphosphorus cages [ClP(NSiMe3)2Si(NSiMe3)2P5](+) (19(+)) and [P5(NSiMe3)2Si(NSiMe3)2P5](2+) (13(2+)).

P4functionalization by hydrides: direct synthesis of P–H bonds

Functionalization of white phosphorus (P₄) by hydride sources MBH₄and LiBEt₃H leads to the formation of HP₄M and LiPH₂(BEt₃)₂respectively.

Functionalization of P4 in the coordination sphere of coinage metal cations

Selective functionalization of white phosphorus is achieved by addition of ArLi to unique cationic coinage metal η²–P₄ complexes.