Dual Functionalization of White Phosphorus: Formation, Characterization, and Reactivity of Rare-Earth-Metal Cyclo -P3 Complexes

Recent progress on the functionalization of white phosphorus in China

Direct synthesis of organophosphorus compounds from white phosphorus represents a significant but challenging subject, especially in the context of ongoing efforts to comprehensively improve the phosphorus-derived chemical industry driven by sustainability and safety concerns. China is the world's largest producer of white phosphorus, creating a significant demand for the green transformation of this crucial feedstock. This review provides an overview of advancements in white phosphorus activation by Chinese research teams, focusing on the direct construction of P‒C/N/O/S/M bonds from white phosphorus. Additionally, we offer some insights into prospective directions for the activation and transformation of white phosphorus in the future. This review paper aims to attract more researchers to engage in this area, stimulating follow-up exploration and fostering enduring advances.

Cobalt-Mediated [3+1] Fragmentation of White Phosphorus: Access to Acylcyanophosphanides

Despite the accessibility of numerous transition metal polyphosphido complexes through transition-metal-mediated activation of white phosphorus, the targeted functionalization of Pn ligands to obtain functional monophosphorus species remains challenging. In this study, we introduce a new [3+1] fragmentation procedure for cyclo-P4 ligands, leading to the discovery of acylcyanophosphanides and -phosphines. Treatment of the complex [K(18c-6)][(Ar*BIAN)Co(η4 -P4 )] ([K(18c-6)]3, 18c-6=[18]crown-6, Ar*=2,6-dibenzhydryl-4-isopropylphenyl, BIAN=1,2-bis(arylimino)acenaphthene diimine) with acyl chlorides results in the formation of acylated tetraphosphido complexes [(Ar*BIAN)Co(η4 -P4 C(O)R)] (R=tBu, Cy, 1-Ad, Ph; 4 a-d). Subsequent reactions of 4 a-d with cyanide salts yield acylated cyanophosphanides [RC(O)PCN]- (9 a-d- ) and the cyclo-P3 cobaltate anion [(Ar*BIAN)Co(η3 -P3 )(CN)]- (8- ). Further reactions of 4 a-d with trimethylsilyl cyanide (Me3 SiCN) and isocyanides provide insight into a plausible mechanism of this [3+1] fragmentation reaction, as these reagents partially displace the P4 C(O)R ligand from the cobalt center. Several potential intermediates of the [3+1] fragmentation were characterized. Additionally, the introduction of a second acyl substituent was achieved by treating [K(18c-6)]9b with CyC(O)Cl, resulting in the first bis(acyl)monocyanophosphine (CyC(O))2 PCN (10).

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.

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.

Molecular cyclo-P3 complexes of the rare-earth elements via a one-pot reaction and selective reduction

Synthesis of new organo-lanthanide polyphosphides with an aromatic cyclo-[P₄]^2- moiety and a cyclo-[P₃]^3- moiety is presented. For this purpose, the divalent Ln^II-complexes [(NON)Ln^II(thf)₂] (Ln = Sm, Yb) ((NON)^2- = 4,5-bis(2,6-diisopropylphenyl-amino)-2,7-di-tert-butyl-9,9-dimethylxanthene) and trivalent Ln^III-complexes [(NON)Ln^IIIBH₄(thf)₂] (Ln = Y, Sm, Dy) were used as precursors in the reduction process of white phosphorus. While using [(NON)Ln^II(thf)₂] as a one-electron reducing agent the formation of organo-lanthanide polyphosphides with a cyclo-[P₄]^2- Zintl anion was observed. For comparison, we investigated a multi-electron reduction of P₄ by a one-pot reaction of [(NON)Ln^IIIBH₄(thf)₂] with elemental potassium. As products molecular polyphosphides with a cyclo-[P₃]^3- moiety were isolated. The same compound could also be obtained by reducing the cyclo-[P₄]^2- Zintl anion within the coordination sphere of Sm^III in [{(NON)Sm^III(thf)₂}₂(μ-η⁴:η⁴-P₄)]. Reduction of a polyphosphide within the coordination sphere of a lanthanide complex is unprecedented. Additionally, the magnetic properties of the dinuclear Dy^III-compound bearing a bridging cyclo-[P₃]^3- moiety were investigated.

Selective [2+1+1] Fragmentation of P4 by heteroleptic Metallasilylenes

Small-molecule activation by low-valent main-group element compounds is of general interest. We here report the synthesis and characterization (1 H, 13 C, 29 Si NMR, IR, sc-XRD) of heteroleptic metallasilylenes L1 (Cl)MSiL2 (M=Al 1, Ga 2, L1 =HC[C(Me)NDipp]2 , Dipp=2,6-i Pr2 C6 H3 ; L2 =PhC(Nt Bu)2 ). Their electronic nature was analyzed by quantum chemical computations, while their promising potential in small-molecule activation was demonstrated in reactions with P4 , which occurred with unprecedented [2+1+1] fragmentation of the P4 tetrahedron and formation of L1 (Cl)MPSi(L2 )PPSi(L2 )PM(Cl)L1 (M=Al 3, Ga 4).

Rare Earth Starting Materials and Methodologies for Synthetic Chemistry

The number of rare earth (RE) starting materials used in synthesis is staggering, ranging from simple binary metal-halide salts to borohydrides and "designer reagents" such as alkyl and organoaluminate complexes. This review collates the most important starting materials used in RE synthetic chemistry, including essential information on their preparations and uses in modern synthetic methodologies. The review is divided by starting material category and supporting ligands (i.e., metals as synthetic precursors, halides, borohydrides, nitrogen donors, oxygen donors, triflates, and organometallic reagents), and in each section relevant synthetic methodologies and applications are discussed.

Facile Synthesis of the Dicyanophosphide Anion via Electrochemical Activation of White Phosphorus: An Avenue to Organophosphorus Compounds

Organophosphorus compounds (OPCs) have gained tremendous interest in the past decades due to their wide applications ranging from synthetic chemistry to materials and biological sciences. We describe herein a practical and versatile approach for the transformation of white phosphorus (P₄) into useful OPCs with high P atom economy via a key bridging anion [P(CN)₂]^-. This anion can be prepared on a gram scale directly from P₄ through an electrochemical process. A variety of OPCs involving phosphinidenes, cyclophosphanes, and phospholides have been made readily accessible from P₄ in a two-step manner. Our approach has a significant impact on the future preparation of OPCs in laboratory and industrial settings.

Reactivity Studies on Lanthanum and Cerium Hydrido Metallocenes

The alkyl complexes [5-1,3-(Me3C)2C5H3]2Ln(CH2C6H4-o-NMe2) (Ln = La 1, Ce 2) react with 9-borabicyclo[3.3.1]nonane (9-BBN) in THF to afford the lanthanum boroxide complex [5-1,3-(Me3C)2C5H3]2La(µ-OBC8H14)(THF) (3) and cerium boroxide complex [5-1,3-(Me3C)2C5H3]2Ce(µ-OBC8H14)(THF) (4)....

Conversion of E4 (E4 =P4 , As4 , AsP3 ) by Ni(0) and Ni(I) Synthons - A Comparative Study

The reactivity of white phosphorus and yellow arsenic towards two different nickel nacnac complexes is investigated. The nickel complexes [(L1 Ni)2 tol] (1, L1 =[{N(C6 H3 i Pr2 -2,6)C(Me)}2 CH]- ) and [K2 ][(L1 Ni)2 (μ,η1 : 1 -N2 )] (6) were reacted with P4 , As4 and the interpnictogen compound AsP3 , respectively, yielding the homobimetallic complexes [(L1 Ni)2 (μ-η2 ,κ1 :η2 ,κ1 -E4 )] (E=P (2 a), As (2 b), AsP3 (2 c)), [(L1 Ni)2 (μ,η3 : 3 -E3 )] (E=P (3 a), As (3 b)) and [K@18-c-6(thf)2 ][L1 Ni(η1 : 1 -E4 )] (E=P (7 a), As (7 b)), respectively. Heating of 2 a, 2 b or 2 c also leads to the formation of 3 a or 3 b. Furthermore, the reactivity of these compounds towards reduction agents was investigated, leading to [K2 ][(L1 Ni)2 (μ,η2 : 2 -P4 )] (4) and [K@18-c-6(thf)3 ][(L1 Ni)2 (μ,η3 : 3 -E3 )] (E=P (5 a), As (5 b)), respectively. Compound 4 shows an unusual planarization of the initial Ni2 P4 -prism. All products were comprehensively characterized by crystallographic and spectroscopic methods.

Insertion Chemistry of Lutetacyclopropene toward Unsaturated C-O/C-N Bonds

Although the reaction chemistry of transition metallacyclopropenes has been well-established in the last decades, the reactivity of rare-earth metallacyclopropenes remains elusive. Herein, we report the reaction of lutetacyclopropene 1 toward a series of unsaturated molecules. The reaction of 1 with one equiv. of PhCOMe, Ar¹ CHO (Ar¹ =2,6-Me₂ C₆ H₃ ), W(CO)₆ , and PhCH=NPh provided oxalutetacyclopentenes, metallacyclic lutetoxycarbene, and azalutetacyclopentene via 1,2-insertion of C=O, C≡O, or C=N bonds into Lu-C_sp2 bond, respectively. However, the reaction between 1 and Ar² N=C=NAr² (Ar² =4-MeC₆ H₄ ) gave an acyclic lutetium complex with a diamidinate ligand by the coupling of one molecule of 1 with two carbodiimides, irrespective of the amount of carbodiimide employed. More interestingly, when 1 was treated with two equiv. of Ar¹ CHO, the reductive coupling of two C=O bonds was discovered to give a lutetium pinacolate complex along with the release of tolan. Remarkably, the reactivity of 1 is significantly different from that of scandacyclopropenes; these metallacycles derived from 1 all represent the first cases in rare-earth organometallic chemistry.

A Structural Diversity of Molecular Alkaline-Earth-Metal Polyphosphides: From Supramolecular Wheel to Zintl Ion

A series of molecular group 2 polyphosphides has been synthesized by using air-stable [Cp*Fe(η5 -P5 )] (Cp*=C5 Me5 ) or white phosphorus as polyphosphorus precursors. Different types of group 2 reagents such as organo-magnesium, mono-valent magnesium, and molecular calcium hydride complexes have been investigated to activate these polyphosphorus sources. The organo-magnesium complex [(Dipp BDI-Mg(CH3 ))2 ] (Dipp BDI={[2,6-i Pr2 C6 H3 NCMe]2 CH}- ) reacts with [Cp*Fe(η5 -P5 )] to give an unprecedented Mg/Fe-supramolecular wheel. Kinetically controlled activation of [Cp*Fe(η5 -P5 )] by different mono-valent magnesium complexes allowed the isolation of Mg-coordinated formally mono- and di-reduced products of [Cp*Fe(η5 -P5 )]. To obtain the first examples of molecular calcium-polyphosphides, a molecular calcium hydride complex was used to reduce the aromatic cyclo-P5 ring of [Cp*Fe(η5 -P5 )]. The Ca-Fe-polyphosphide is also characterized by quantum chemical calculations and compared with the corresponding Mg complex. Moreover, a calcium coordinated Zintl ion (P7 )3- was obtained by molecular calcium hydride mediated P4 reduction.

Synthesis of a carborane-substituted bis(phosphanido) cobaltate(i), ligand substitution, and unusual P4 fragmentation

Oxidative addition of the P-P single bond of an ortho-carborane-derived 1,2-diphosphetane (1,2-C2(PMes)2B10H10) (Mes = 2,4,6-Me3C6H2) to cobalt(-i) and nickel(0) sources affords the first heteroleptic complexes of a carborane-bridged bis(phosphanido) ligand. The complexes also incorporate labile ligands suitable for further functionalisation. Thus, the cobalt(i) complex [K([18]crown-6)][Co{1,2-(PMes)2C2B10H10}(cod)] (cod = 1,5-cyclooctadiene) bearing a labile cyclooctadiene ligand undergoes facile ligand exchange reactions with isonitriles and tert-butyl phosphaalkyne with retention of the bis(phosphanido) ligand. However, in the reaction with one equivalent of P4, the electron-rich bis(phosphanido) moiety abstracts a single phosphorus atom with formation of a new P3 chain, while the remaining three P atoms derived from P4 form an η3-coordinating cyclo-P3 ligand. In contrast, when the same reaction is performed with two equivalents of the cobalt(i) complex, a dinuclear product is formed which features an unusual P4 chain in its molecular structure.

Heavier element-containing aromatics of [4n+2]-electron systems

While the implication of the aromaticity concept has been dramatically expanded to date since its emergence in 1865, the classical [4n+2]/4n-electron counting protocol still plays an essential role in evaluating the aromatic nature of compounds. Over the last few decades, a variety of heavier heterocycles featuring the formal [4n+2] π-electron arrangements have been developed, which allows for assessing their aromatic nature. In this review, we present recent developments of the [4n+2]-electron systems of heavier heterocycles involving group 13-15 elements. The synthesis, spectroscopic data, structural parameters, computational data, and reactivity are introduced.

Diphenyl Diselenide-Catalyzed Synthesis of Triaryl Phosphites and Triaryl Phosphates from White Phosphorus

Industrially important triaryl phosphites, traditionally prepared from PCl₃, have been synthesized by a diphenyl diselenide-catalyzed one-step procedure involving white phosphorus and phenols, which provides a halogen- and transition metal-free way to these compounds. Subsequent oxidation of triaryl phosphites produces triaryl phosphates and triaryl thiophosphates. Phosphorotrithioates are also prepared efficiently from aromatic thiols and aliphatic thiols.

Redox Chemistry of Heterobimetallic Polypnictogen Triple-Decker Complexes - Rearrangement, Fragmentation and Transfer

The redox chemistry of the heterobimetallic triple‐decker complexes [(Cp*Fe)(Cp′′′Co)(μ,η⁵:η⁴‐E₅)] (E=P (1), As (2), Cp*=1,2,3,4,5‐pentamethyl‐cyclopentadienyl, Cp′′′=1,2,4‐tri‐tertbutyl‐cyclopentadienyl) and [(Cp′′′Co)(Cp′′′Ni)(μ,η³:η³‐E₃)] (E=P (10), As (11)) was investigated. Compound 1 and 2 could be oxidized to the monocations 3 and 4 and further to the dications 5 and 6, while the initially folded cyclo‐E₅ ligand planarizes upon oxidation. The reduction leads to an opposite change in the geometry of the middle deck, which is now folded stronger into the direction of the other metal fragment (formation of monoanions 7 and 8). For the arsenic compound 8, a different behavior is found since a fragmentation into an As₆ (9) and As₃ ligand complex occurs. The Co and Ni triple‐decker complexes 10 and 11 can be oxidized initially to the heterometallic monocations 12 and 13, which are not stable in solution and convert selectively into the homometallic nickel complexes 14 and 15 and the cobalt complexes 16 and 17. This behavior was further proven by the oxidation of [(Cp′′′Co)(Cp′′Ni)(μ,η³:η²‐P₃)] (19, Cp′′=1,3‐di‐tertbutyl‐cyclopentadienyl) comprising two different Cp ligands. The transfer of {Cp^RM} fragments can be suppressed when a {W(CO)₅} unit is coordinated to the P₃ ligand (20) prior to the oxidation and the mixed cobalt and nickel cation 21 can be isolated. The reduction of 10 and 11 yields the heterometallic monoanions 22 and 23, where no transfer of the {Cp^RM} fragments is observed.

FeCl2 Catalyzed Three-Component Reactions of Phospholes, Pyrrolidine, and Ketones (Aldehydes): Chemoselective Synthesis of 1-Phosphafulvenes

We have developed an unprecedented approach for the synthesis of transient 1-phosphafulvenes through three component reactions of phospholes. The generation of 1-phosphafulvenes was demonstrated by in situ [6 + 4] cycloaddition with 2H-phospholes and [6 + 6] self-dimerization. The [6 + 4] and [6 + 6] reaction pathway could be modulated by the starting ketones and aldehydes. The construction of 1-phosphafulvenes is illustrated by a proposed mechanism combining nucleophilic addition of phospholide to the iminium or isomerized azomethine ylide and a [1,5]-shift of phosphole.

Nonbenzenoid aromaticity of 1-phosphafulvenes: synthesis of phosphacymantrenes

The coordination chemistry of 1-phosphafulvenes was investigated by employing their [6 + 4] adducts or α-C₂-bridged biphospholes as a precursor. Unbridged phosphacymantrenes arise from 1-phosphafulvenes via proton abstraction. α-C₂-bridged biphosphacymantrenes are probably yielded by the reductive coupling of 1-phosphafulvene with Mn₂(CO)₁₀. The coordination behavior of 1-phosphafulvenes is comparable to that of pentafulvenes, which again demonstrates the phosphorus-carbon analogy in low-coordinate organophosphorus chemistry.

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 .

The Butterfly Complex [{Cp*Cr(CO)3 }2 (μ,η1:1 -P4 )] as a Versatile Ligand and Its Unexpected P1 /P3 Fragmentation

The versatile coordination behavior of the P4 butterfly complex [{Cp*Cr(CO)3 }2 (μ,η1:1 -P4 )] (1) towards Lewis acidic pentacarbonyl compounds of Cr, Mo and W is reported. The reaction of 1 with [W(CO)4 (nbd)] (nbd=norbornadiene) yields the complex [{Cp*Cr(CO)3 }2 (μ3 ,η1:1:1:1 -P4 ){W(CO)4 }] (2) in which 1 serves as a chelating P4 butterfly ligand. In contrast, reactions of 1 with [M(CO)4 (nbd)] (M=Cr (a), Mo (b)) result in the step-wise formation of [{Cp*Cr(CO)2 }2 (μ3 ,η3:1:1 -P4 ){M(CO)5 }] (3 a,b) and [{Cp*Cr(CO)2 }2 -(μ4 ,η3:1:1:1 -P4 ){M(CO)5 }2 ] (4 a,b) which contain a folded cyclo-P4 unit. Complex 4 a undergoes an unprecedented P1 /P3 -fragmentation yielding the cyclo-P3 complex [Cp*Cr(CO)2 (η3 -P3 )] (5) and the as yet unknown phosphinidene complex [Cp*Cr(CO)2 {Cr(CO)5 }2 (μ3 -P)] (6). The identity of 6 is confirmed by spectroscopic methods and by the in situ formation of [{Cp*Cr(CO)2 (tBuNC)}P{Cr(CO)5 }2 (tBuNC)] (7). DFT calculations throw light on the bonding situation of the reported products.

Transformations of the cyclo-P4 ligand in [Cp'''Co(η4-P4)]

The reactivity of the cyclo-P₄ ligand complex [Cp′′′Co(η⁴-P₄)] (1) (Cp′′′ = 1,2,4-tri-tert-butyl-cyclopentadienyl) towards reduction and main group nucleophiles was investigated. By using K[CpFe(CO)₂], a selective reduction to the dianionic complex [(Cp′′′Co)₂(μ,η³:η³-P₈)]²⁻ (2) was achieved. The reaction of 1 with ^tBuLi and LiCH₂SiMe₃ as carbon-based nucleophiles yielded [Cp′′′Co(η³-P₄R)]⁻ (R = ^tBu (4), CH₂SiMe₃ (7)), which, depending on the reaction conditions, undergo subsequent reactions with another equivalent of 1 to form [(Cp′′′Co)₂(μ,η³:η³-P₈R)]⁻ (R = ^tBu (5), CH₂SiMe₃ (8)). In the case of 4, a different pathway was observed, namely a dimerisation followed by a fragmentation into [Cp′′′Co(η³-P₅^tBu₂)]⁻ (6) and [Cp′′′Co(η³-P₃)]⁻ (3). With OH⁻ as an oxygen-based nucleophile, the synthesis of [Cp′′′Co(η³-P₄(O)H)]⁻ (9) was achieved. All compounds were characterized by X-ray crystal structure analysis, NMR spectroscopy and mass spectrometry. Their electronic structures and reaction behavior were elucidated by DFT calculations.

The reactivity of the cyclo-P₄ ligand complex [Cp′′′Co(η⁴-P₄)] (1) (Cp′′′ = 1,2,4-tri-tert-butyl-cyclopentadienyl) towards reduction and main group nucleophiles was investigated.

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).

Oxidation and chalcogenylative disproportionation of anionic phosphide ligands in yttrium complexes with elemental sulfur and selenium

The oxidation and disproportionation of anionic phosphide ligands in yttrium complexes with elemental sulfur and selenium are reported. The mixed TpMe2/Cp supported yttrium phosphide complex TpMe2CpYPPh2(THF) (1) reacted with one equiv. of elemental S or Se in THF at room temperature to deliver two structurally characterized yttrium dithio- or monoseleno-phosphinates TpMe2CpYS2PPh2(THF) (2) and TpMe2CpYSePPh2(THF) (4Se), respectively. Further investigations showed that the yttrium thiophosphinate TpMe2CpYSPPh2(THF) (4S) can be isolated from the reactions of 2 and 1 or 1 and elemental S in a short reaction time. Moreover, after keeping 4S or 4Se in THF solution for some days, 2 or [(TpMe2)2Y]+[Se2PPh2]- (5) was obtained by a disproportionation process. The mechanism for the construction of the Ph2PE- and Ph2PE2- (E = S, Se) ligands has been discussed based on the in situ NMR experiments and some designed reactions.

Alkaline-earth metallacyclic complexes bearing a diborane-bridged tetraamide ligand: synthesis, structure and fluorescence property

A series of alkaline-earth (Mg, Ca, and Sr) metallacyclic complexes bearing a diborane-bridged tetraamide ligand were achieved for the first time through a clean one-step approach. All of these metallacycles were characterized by single-crystal X-ray diffraction analyses. UV-Vis absorption/emission spectroscopy showed deep blue fluorescence of these complexes.

Black Phosphorus: An Effective Feedstock for the Synthesis of Phosphorus-Based Chemicals

We propose and demonstrate the novel concept of synthesizing organophosphorus compounds directly from black phosphorus (BP) nanoparticles as the feedstock. Compounds such as alkyl phosphines, alkyl phosphine oxides, phosphine sulfide, and hexafluorophosphate anion are prepared with good isolation yields under mild conditions. Selective synthesis of primary, secondary, and tertiary organophosphorus compounds is also demonstrated utilizing this one-pot approach. Reaction mechanisms are proposed and discussed. Compared with traditional white phosphorus (P4)-based methods, the new synthetic concept and process utilizing elemental phosphorus are more efficient and environmentally friendly.

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.

Recent developments in actinide metallacycles

All-carbon metallacycles of the d-transition metals have received widespread attention over the past three decades because of their exceptional intrinsic reactivity. However, in recent years, significant progress has also been made in the synthesis and characterization of actinide metallacyclopropenes, metallacyclopentadienes, and metallacyclocumulenes (metallacyclopentatrienes). Such actinide metallacycles are of interest because of their unique structural properties, their potential application in novel group transfer reactions and catalysis, as well as their ability to engage the 5f orbitals in metal-ligand bonding. This short review summarizes the latest developments in this area focusing on all-carbon actinide metallacycles, i.e., metallacyclopropenes, metallacyclopentadienes, and metallacyclocumulenes (metallacyclopentatrienes).

Synthesis and molecular structure of pentadienyl complexes of the rare-earth metals

In combination with small and difficult to reduce rare-earth metals pdl′ undergoes CH-bond activations instead of sterically induced reductions to form dimeric complexes with a unique bridging six-membered metallacycle as the central structural motif.