Synthesis and unprecedented coordination behaviour of a novel 1,2,3-triphosphaferrocene complex

Access to 1,2,3-triphospholide ligands by reduction of di-tert-butyldiphosphatetrahedrane

Di-tert-butyldiphosphatetrahedrane (tBuCP)2 (A) is a reactive tetrahedral molecule which may serve as a source of new phosphaorganic molecules and ligands. However, the redox chemistry of this compound has not yet been investigated. Here, we show that the reduction of A with alkali metals (AM = Li, Na, K, Rb and Cs) affords 1,2,3-triphospholides [AM(crown ether)][1,2,3-P3C2tBu2] (1-5, [AM(crown ether)] = [Li([12]crown-4)2]+, [Na([15]crown-5)2]+, [K([18]crown-6)]+, [Rb([18]crown-6)]+, and Cs+) with 1,3-diphospholides [AM(crown ether)][1,3-P2C3tBu3] (6-10) formed as by-products. The potassium salt 3 was isolated on a preparative scale, allowing for reactivity studies. Transmetalation with iron(II) and ruthenium(II) chlorides yielded the sandwich complexes [Cp*M(η5-1,2,3-P3C2tBu2)] (11, M = Fe; 12, M = Ru, Cp* = C5Me5) featuring η5-coordinated triphospholide ligands. Treatment of 3 with [Cp2Fe][BAr4F] or [H(Et2O)2BAr4F] (BAr4F = B{C6H3(CF3)2}4) afforded the polyphosphorus compound tBu4C4P6 (13), which presumably results from the dimerisation of a 1,2,3-triphospholyl radical intermediate (1,2,3-P3C2tBu2)˙ (3˙). Tetracyclic 13 is closely structurally related to an isomer of the hydrocarbon hypostrophene (C10H10).

Synthesis, structure and electrochemical properties of 3,4,5-triaryl-1,2-diphosphaferrocenes

New 3,4,5-triaryl-1,2-diphosphaferrocenes [FeCp(η5-P2C3R3)] have been extensively studied experimentally (NMR, UV-Vis, electrochemical studies, X-ray) and quantum chemically.

Transition-Metal-Mediated Functionalization of White Phosphorus

Recently there has been great interest in the reactivity of transition-metal (TM) centers towards white phosphorus (P4 ). This has ultimately been motivated by a desire to find TM-mediated alternatives to the current industrial routes used to transform P4 into myriad useful P-containing products, which are typically indirect, wasteful, and highly hazardous. Such a TM-mediated process can be divided into two steps: activation of P4 to generate a polyphosphorus complex TM-Pn , and subsequent functionalization of this complex to release the desired phosphorus-containing product. The former step has by now become well established, allowing the isolation of many different TM-Pn products. In contrast, productive functionalization of these complexes has proven extremely challenging and has been achieved only in a relative handful of cases. In this review we provide a comprehensive summary of successful TM-Pn functionalization reactions, where TM-Pn must be accessible by reaction of a TM precursor with P4 . We hope that this will provide a useful resource for continuing efforts that are working towards this highly challenging goal of modern synthetic chemistry.

Synthesis, structure, and electrochemical properties of 4,5-diaryl-1,2,3-triphosphaferrocenes and the first example of multi(phosphaferrocene)

Novel 1,2,3-triphosphaferrocenes have been extensively studied experimentally (NMR, UV-Vis, and X-ray) and quantum chemically.

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.

Insertion of phenyl isothiocyanate into a P-P bond of a nickel-substituted bicyclo[1.1.0]tetraphosphabutane

A new reaction mode for bicyclo[1.1.0]tetraphosphabutanes is reported. The C[double bond, length as m-dash]S and C[double bond, length as m-dash]N bonds of phenyl isothiocyanate reversibly insert into a P-P bond of [{CpNi(IMes)}2(μ-η(1):η(1)-P4)] (, IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene), forming isomers and . X-ray crystallography and (31)P{(1)H} NMR spectroscopy revealed similar bicyclo[3.1.0]heterohexane structures for these compounds.

Progress in Polyarsolyl Chemistry

The synthesis of heteroatom analogues of the cyclopentadienyl anion Cp^- is a fascinating and challenging field of research. The replacement of methine moieties by phosphorus is well investigated for the synthesis of mono-, tri- and pentaphospholyl ligands. On the other hand, arsenic derivatives are rare and 1,2,4-triarsolyl and tetraarsolyl salts are unknown. Herein, we report on the synthesis of Cs[E₃ C₂ (trip)₂ ] (1 a: E=P; 1 b: E=As; trip=2,4,6-triisopropylphenyl) and Cs[E₄ C(trip)] (2 a: E=P; 2 b: E=As). Compound 1 b represents the first 1,2,4-triarsolyl and 2 b the first tetraarsolyl anion. All salts are obtained in one-pot syntheses using E(SiMe₃ )₃ , 2,4,6-triisopropylbenzoyl chloride and CsF. The products 1 a⋅2 C₄ H₈ O₂ , 2 a⋅Et₂ O and 2 b⋅3 C₄ H₈ O₂ were characterized by X-ray structural analysis, which revealed planar heterocycles. Nucleus-independent chemical shifts (NICS) confirmed the aromaticity of these anions. Notably, compound 2 a⋅Et₂ O is only the second tetraphospholyl ligand which is structurally characterized.

1,2,4-Triphospholyl anions - versatile building blocks for the formation of 1D, 2D and 3D assemblies

The potential of K[P₃C₂R₂] (R = ^tBu, Mes) as building blocks in metallo-supramolecular chemistry was investigated and self-assembly processes with Cu(i) halides resulted in the formation of a large variety of unprecedented one-, two- and even three-dimensional aggregates.

The potential of K[P₃C₂R₂] (R = ^tBu, Mes) as building blocks in metallo-supramolecular chemistry was investigated and self-assembly processes with Cu(i) halides resulted in the formation of a large variety of unprecedented one-, two- and even three-dimensional aggregates. The 3D networks showed an interesting topological similarity to allotropes of carbon: diamond and the theoretically proposed polybenzene. Furthermore, the negative charge of the phospholyl ligand favoured the generation of cationic Cu_aX_b (a > b, X = Cl, Br, I) assemblies, a challenging area within the well-studied coordination chemistry of CuX units. In addition, the 1D strands were also characterized in solution, revealing the presence of oligomeric units.

Synthesis and magnetic properties of manganese carbonyl complexes with different coordination modes of 3,4,5-triaryl-1,2-diphospholide ligands

The set of binuclear manganese complexes (2a–c) undergo an irreversible rearrangement to mononuclear 3,4,5-triaryl-1,2-diphosphacymantrenes(3a–c).