Activation Of White Phosphorus Research Articles

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

AbstractDespite 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‐P4C(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 (Me3SiCN) and isocyanides provide insight into a plausible mechanism of this [3+1] fragmentation reaction, as these reagents partially displace the P4C(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))2PCN (10).

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).

A bis(silylene)-stabilized diphosphorus compound and its reactivity as a monophosphorus anion transfer reagent

In contrast to the well-established transition-metal-mediated activation of white phosphorus (P4), the metal-free direct functionalization of P4 has remained rare. The conversion of P4 into a reactive zero-valent diphosphorus compound (P2) has proven challenging to carry out without relying on metal reactivity. Herein, we describe the facile degradation of P4 mediated by two divalent silicon atoms in a bis(silylene) scaffold, resulting in a silylene-stabilized zero-valent P2 complex. The presence of two lone pairs of electrons on each P atom in the silylene-stabilized P2 complex enables a rich reactivity towards small molecules; reaction of the P2 species with CO2, water or a borane leads to the formation of P-C, P-H or P-B bonds, respectively. Notably, the P2 complex also serves as a single phosphorus anion (P-) transfer reagent towards metal carbonyls and a chlorogermylene compound, leading to the synthetically valuable phosphaketenide (PCO-) ligand and a phosphinidene germylene complex, respectively.

3+2] Fragmentation of a Pentaphosphido Ligand by Cyanide.

The activation of white phosphorus (P4) by transition‐metal complexes has been studied for several decades, but the functionalization and release of the resulting (organo)phosphorus ligands has rarely been achieved. Herein we describe the formation of rare diphosphan‐1‐ide anions from a P5 ligand by treatment with cyanide. Cobalt diorganopentaphosphido complexes have been synthesized by a stepwise reaction sequence involving a low‐valent diimine cobalt complex, white phosphorus, and diorganochlorophosphanes. The reactions of the complexes with tetraalkylammonium or potassium cyanide afford a cyclotriphosphido cobaltate anion 5 and 1‐cyanodiphosphan‐1‐ide anions [R2PPCN]− (6‐R). The molecular structure of a related product 7 suggests a novel reaction mechanism, where coordination of the cyanide anion to the cobalt center induces a ligand rearrangement. This is followed by nucleophilic attack of a second cyanide anion at a phosphorus atom and release of the P2 fragment.

Activation of white phosphorus by low-valent group 5 complexes: formation and reactivity of cyclo-P4 inverted sandwich compounds.

We report the synthesis and comprehensive study of the electronic structure of a unique series of dinuclear group 5 cyclo-tetraphosphide inverted sandwich complexes. White phosphorus (P4) reacts with niobium(III) and tantalum(III) β-diketiminate (BDI) tert-butylimido complexes to produce the bridging cyclo-P4 phosphide species {[(BDI)(NtBu)M]2(μ-η3:η3P4)} (1, M = Nb; 2, M = Ta) in fair yields. 1 is alternatively synthesized upon hydrogenolysis of (BDI)Nb(NtBu)Me2 in the presence of P4. The trinuclear side product {[(BDI)NbNtBu]3(μ-P12)} (3) is also identified. Protonation of 1 with [HOEt2][B(C6F5)4] does not occur at the phosphide ring but rather involves the BDI ligand to yield {[(BDI#)Nb(NtBu)]2(μ-η3:η3P4)}[B(C6F5)4]2 (4). The monocation and dication analogues {[(BDI)(NtBu)Nb]2(μ-η3:η3P4)}{B(ArF)4}n (5, n = 1; 6, n = 2) are both synthesized by oxidation of 1 with AgBArF. DFT calculations were used in combination with EPR and UV–visible spectroscopies to probe the nature of the metal–phosphorus bonding.

Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus

Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus

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

Simultaneous Fragmentation and Activation of White Phosphorus

Simultaneous Fragmentation and Activation of White Phosphorus

Inside Cover: Isolation of a Neutral P8Cluster by [2+2] Cycloaddition of a Diphosphene Facilitated by Carbene Activation of White Phosphorus (Angew. Chem. Int. Ed. 16/2013)

Inside Cover: Isolation of a Neutral P₈Cluster by [2+2] Cycloaddition of a Diphosphene Facilitated by Carbene Activation of White Phosphorus (Angew. Chem. Int. Ed. 16/2013)

Iodine Activation of Coordinated White Phosphorus: Formation and Transformation of 1,3‐Dihydride‐2‐iodidecyclotetraphosphane

Double stabilization: Previously unknown polyphosphorus compounds are obtained by activation of white phosphorus (P(4)) coordinated between two CpRu(PPh(3))(2) moieties with iodine, and subsequent hydrolysis. The polyphosphorus compounds (P(4) H(2) I, P(4) H(2), P(3) H(5); see scheme, Cp=cyclopentadienyl) are all stabilized by coordination to two ruthenium centers.

P−P Bond Activation of P4 Tetrahedron by Group 13 Carbenoid and its Bis Molybdenum Pentacarbonyl Adduct

Activation of white phosphorus with Ga(DDP) (DDP = 2-diiso-propylphenylamino-4-diiso-propylphenylimino-2-pentene) afforded [(DDP)Ga(P(4))] (1) by insertion of the Ga(I) center at one of the six P-P bonded edges of the P(4) tetrahedron. Further reaction of 1 with three equivalents of Mo(CO)(6) results in the formation of [(DDP)Ga(eta(2:1:1)-P(4)){Mo(CO)(5)}(2)] x 2 toluene (2). Compounds 1 and 2 are characterized by (1)H, (13)C, and (31)P NMR spectroscopy, elemental analysis, and single crystal X-ray structural analysis. The solid-state structure of molecule 1 reveals the first example of a structurally characterized GaP(4) core stabilized by a beta-diketiminate ligand. Compound 2 represents a rare type of coordination mode of a gallium supported P(4) butterfly structure.

ChemInform Abstract: P4 Activation by Main Group Elements and Compounds

AbstractReview: 324 refs.

P4Activation by Main Group Elements and Compounds

An overview about the activation of white phosphorus, P4 with main group elements and compounds is given.

Activation of White Phosphorus by Reduction in the Presence of a Zirconium Diamidodiphosphine Macrocycle: Formation of a Bridging Square-Planarcyclo-P4Unit

Activation of White Phosphorus by Reduction in the Presence of a Zirconium Diamidodiphosphine Macrocycle: Formation of a Bridging Square-Planar<i>cyclo</i>-P₄Unit

Activation of White Phosphorus by Reduction in the Presence of a Zirconium Diamidodiphosphine Macrocycle: Formation of a Bridging Square-Planarcyclo-P4Unit

Activation of White Phosphorus by Reduction in the Presence of a Zirconium Diamidodiphosphine Macrocycle: Formation of a Bridging Square-Planar<i>cyclo</i>-P₄Unit

A Snapshot of P4 Tetrahedron Opening: Rh‐ and Ir‐Mediated Activation of White Phosphorus

P und P gesellt sich gern: Weißer Phosphor reagiert mit [M(dppm)2]OTf (M=Rh, Ir; dppm=PPh2CH2PPh2) zu [M(dppm)(Ph2PCH2PPh2PPPP)]OTf. Dabei entsteht durch Bildung einer P-P-Bindung zwischen einer PPh2-Gruppe von dppm und einem aktivierten P4-Molekül ein trihaptischer „P5“-Ligand (P grün, M rot, C weiß; Phenylgruppen nicht gezeigt). In-situ-31P-NMR-Studien sprechen für einen Reaktionsweg, der über eine Dimetallzwischenstufe verläuft.

A Snapshot of P4 Tetrahedron Opening: Rh‐ and Ir‐Mediated Activation of White Phosphorus

P's in a pod: White phosphorus reacts with [M(dppm)2]OTf (M=Rh, Ir; dppm=PPh2CH2PPh2) to give [M(dppm)(Ph2PCH2PPh2PPPP)]OTf whereby a trihapto “P5” ligand is assembled through PP bond formation between one dppm PPh2 group and an activated P4 molecule (see scheme; P green, M red, C white, phenyl groups omitted). A bimetallic reaction pathway leading to the final product is proposed, as based on in situ 31P NMR studies.

Activation of white phosphorus in the coordination sphere of nickel complexes with σ-donor ligands

Routes of white phosphorus activation in the coordination sphere of the nickel complexes with different ligands are shown. The first route is based on the coordination of a P4 molecule with the metal, resulting in the deformation of the P4 tetrahedron without destruction. This case is characteristic of the NiX2L complexes, which are reduced at higher cathodic potentials (|Ered| > 0.9 V) (X = BF4, Br, and Cl; L is bpy in DMF, MeCN, and acetone; 2,9-dimethyl-1,10-phenanthroline (phen) and PPh3 in DMF and acetone). To cleave the P—P bonds in the P4 molecule, this complex should be reduced on the electrode. The second route is the oxidation of white phosphorus in the coordination sphere of the NiII complex. It occurs when the complex has a sufficiently high oxidizing ability and is reduced rather easily (|Ered| < 0.9 V) (X = BF4, L is 1,1,1-tris(diphenylphosphinomethyl)ethane (triphos) in acetone; 1,1′,5,5′-bis[methylenedi(p-phenylene)]di(3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane) (n2p2) in DMF; phen and PPh3 in MeCN). The P4 molecule opening is observed to form a new NiI complex containing the (P3) fragment, for example, [(triphos)Ni(P3)Ni(triphos)](BF4)2.