Diphosphenyl Complexes Research Articles

Tetranuclear phosphide- and phosphinidene-bridged derivatives of the diphosphenyl complex [Mo2Cp2(μ-PCy2)(μ-κ(2):κ(2)-P2Me)(CO)2

Reaction of the title complex with excess [Fe2(CO)9] at room temperature gave the tetranuclear derivative [Fe2Mo2Cp2(μ4-P)(μ-PCy2)(μ3-PMe)(CO)9], following from formal insertion of an Fe(CO)3 fragment in the P-P bond of the diphosphenyl ligand with formation of a new heterometallic bond (Mo-Fe = 2.935 (1) Å), and coordination of an Fe(CO)4 fragment through the lone electron pair of the resulting phosphide ligand (P-Fe = 2.359(2) Å). Reactions of the title complex with excess of the tetrahydrofuran (THF) adducts [MLn(THF)] (MLn = MnCp'(CO)2, W(CO)5) led instead to tetranuclear diphosphenyl-bridged complexes [M2Mo2Cp2(μ-PCy2)(μ-κ(2):κ(1):κ(1):κ(1)-P2Me)(CO)2L2n] displaying a Mo-Mo double bond (Mo-Mo = 2.760(2) Å when M = W), along with the phosphide- and phosphinidene-bridged complex [Mo2W2Cp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)10], with the latter displaying a Mo-Mo triple bond (Mo-Mo = 2.5542(4) Å) and a trigonal planar phosphide ligand. Reaction of the title complex with excess [Mo(CO)4(THF)2] also resulted in facile P-P bond cleavage of the diphosphenyl ligand to give [Mo4Cp2(μ4-P)(μ-PCy2)(μ3-PMe)(CO)9], a cluster built on a Mo3 triangular core bridged by phosphinidene and phosphide ligands, with the latter further coordinated to an exocyclic Mo(CO)5 fragment. The related Mo2W2 complex [Mo2W2Cp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)9] could be rationally synthesized upon reaction of the trinuclear cluster [Mo2WCp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)6] with the adduct [W(CO)5(THF)]. The title complex reacted photochemically with [M2(CO)10] (M = Mn, Re) to give the 66-electron tetranuclear derivatives [M2Mo2Cp2(μ4-P)(μ-PCy2)(μ3-PMe)(CO)9], after formation of a new Mo-M bond (Mo-Mn = 2.9988(7) Å, Mo-Re = 3.1003(4) Å) and cleavage of the diphosphenyl P-P bond. In contrast, its room-temperature reaction with [Co2(CO)8] gave the 64-electron square-planar cluster [Co2Mo2Cp2(μ4-P)(μ-PCy2)(μ4-PMe)(μ-CO)(CO)6] resulting from formation of two new Mo-Co bonds (Mo-Co = 2.8812(7) and 2.9067(7) Å) and facile P-P bond cleavage in the diphosphenyl ligand.

Mild P–P Bond Cleavage in the Methyldiphosphenyl Complex [Mo2Cp2(μ-PCy2)(μ-κ2:κ2-P2Me)(CO)2] To Give Novel Phosphide-Bridged Trinuclear Derivatives

Reactions of the title diphosphenyl complex with [Fe2(CO)9] and [W(CO)4(THF)2] gave the trinuclear species [Mo2FeCp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)5] and [Mo2WCp2(μ3-P)(μ-PCy2)(μ3-PMe)(CO)6] following from formal insertion of the 14-electron fragments Fe(CO)3 and W(CO)4, respectively, in the P-P bond of the diphosphenyl ligand and formation of a new heterometallic bond [Mo-Fe = 2.9294(6) Å and Mo-W = 3.146(1) Å]. Reactions of the diphosphenyl complex with the tetrahydrofuran adducts [MLn(THF)] (MLn = MnCp'(CO)2, W(CO)5) led instead to trinuclear diphosphenyl complexes [Mo2MCp2(μ-PCy2)(μ3-κ(2):κ(2):κ(1)-P2Me)(CO)2Ln] following from coordination in each case of the corresponding 16-electron fragment MLn to the lone-pair-bearing P atom of the P2Me ligand. However, these diphosphenyl complexes were unstable and decomposed at room temperature or under mild heating by the release of methylphosphinidene (PMe), to give the corresponding derivatives [Mo2MCp2(μ3-P)(μ-PCy2)(CO)2Ln] displaying trigonal-planar phosphide ligands, giving rise to strongly deshielded (31)P NMR resonances (δP ca. 1100 ppm), while being involved in strong π bonding with the unsaturated Mo2 center of these molecules [Mo-Mo = 2.749(1) Å and Mo-P = ca. 2.30 Å when M = W]. An isolobal analogy could be established between the P→MLn fragments in these products and a carbyne ligand (CR), supported by density functional theory calculations on the tungsten compound, which also enabled an easy interpretation and prediction of their chemical behavior. Thus, the manganese complex could be reversibly carbonylated (pCO = ca. 3 atm, 293 K) to give the corresponding electron-precise pentacarbonyl [MnMo2Cp2Cp'(μ3-P)(μ-PCy2)(CO)5] [Mo-Mo = 3.1318(7) Å], a process also involving a trans-to-cis rearrangement of the Mo2Cp2 subunit. On the other hand, decarbonylation of the tungsten complex was accomplished in a refluxing toluene solution to give the hexacarbonyl [Mo2WCp2(μ3-P)(μ-PCy2)(μ-CO)(CO)5], a derivative containing an unsaturated 30-electron dimolybdenum center with an intermetallic triple bond.

Reactivity of the Anionic Diphosphorus Complex [Mo2Cp2(μ-PCy2)(CO)2(μ-κ2:κ2-P2)]− Toward ER3X Electrophiles (E = C to Pb): Insights into the Multisite Donor Ability and Dynamics of the P2 Ligand

The Li(+) salt of the unsaturated anion [Mo(2)Cp(2)(μ-PCy(2))(μ-CO)(2)](-) reacted with P(4) in tetrahydrofuran at room temperature to give the title complex. This fluxional anion reacted with MeI and ClCH(2)Ph to give the diphosphenyl complexes [Mo(2)Cp(2)(μ-κ(2):κ(2)-P(2)CH(2)R)(μ-PCy(2))(CO)(2)] (R = H, Ph), with the incoming electrophile being attached at the basal P atom of the Mo(2)P(2) tetrahedron via the lone electron pair (P-P-CH(3) = 122.8(1)(o)). In contrast, reactions with ClER(3) (ER(3) = GePh(3), SnPh(3), PbMe(3), PbPh(3)) gave neutral complexes [Mo(2)Cp(2)(μ-κ(2):κ(2)-P(2)ER(3))(μ-PCy(2))(CO)(2)] having the incoming electrophile attached at the basal P atom but defining an acute P-P-E angle close to 90° with elongated P-P lengths of ca. 2.20 Å. These complexes undergo an easy fluxional process involving an exchange of the ER(3) group between the P atoms that could be properly modeled through DFT calculations, and some of them displayed minor isomers in solution. Their structure could be rationalized as derived from the interaction of the electrophile with high-energy orbitals of the anion having both σ(Mo-P) and π(P-P) bonding character. Reaction with BrSiMe(3) gave instead the agostic phosphenyl complex [Mo(2)Cp(2)(μ-κ(2):κ(1),η(2)-HP(2))(μ-PCy(2))(CO)(2)], formally derived from the attachment of a proton to a basal Mo-P edge of the anion (computed length 2.810 Å) and displaying an unusually low P-H coupling of 4 Hz. A similar structure, with the agostic H atom replaced with SnH(3), was found to be a satisfactory model for the minor isomer of the tin compound and represents a third and unprecedented coordination mode of the diphosphorus ligand. The agostic complex undergoes a fluxional process involving the intermediacy of the nonagostic isomer [Mo(2)Cp(2)(μ-κ(2):κ(2)-P(2)H)(μ-PCy(2))(CO)(2)], which was computed to display a geometry comparable to the major isomers of the ER(3) compounds (P-P = 2.183 Å; P-P-H = 81.7°).

Übergangsmetall-substituierte Diphosphene, XXVI Zum Einfluß des Ringliganden auf Bildungstendenz und Stabilität von Diphosphenyleisenkomplexen des Typs (η5-C5R5)(CO)2Fe-P= P-Mes (Mes = 2,4,6-tBu3C6H2). Röntgenstrukturanalyse von (η5-C5Me4Et)(CO)2Fe-P(SiMe3)2 / Transition Metal Substituted Diphosphenes, XXVI Investigations on the Influence of the Ring Ligand upon Formation and Stability of Diphosphenyl Complexes (η5-C5R5)(CO)2Fe-P=P-Mes (Mes = 2,4,6-tBu3C6H2). X-Ray Analysis of (η5-C5Me4Et)(CO)2Fe-P(SiMe3)2

The disilylphosphido iron complexes (η5-C5R5)(CO)2Fe-P(SiMe3)2 (1b–d) result from the reaction of the corresponding bromo compounds (η5-C5R5)(CO)2FeBr with LiP(SiMe3)2 · 2 THF. The complexes 2b–d are cleanly converted into the diphosphenyl complexes (η5-C5R5)(CO)2Fe-P=P-Mes* (2b–d) by treatment with equimolar amounts of Mes*PCl2. The products 1b–d and 2b–d have been characterized by elemental analysis as well as spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structure of η5-C5Me4Et)(CO)2Fe-P(SiMe3)2 (1b) has been established by single-crystal X-ray analysis.

Platinum-complex-catalyzed 1,4-disilylation of 1,3-dienes using organodisilanes: remarkable effect of a phenyl functionality on silicon atom

The diphosphenyl complex (eta-5-C5Me5)-(CO)2Fe-P=P-Mes* (Mes* = 2,4,6-tBu3C6H2) undergoes a [3 + 2] dipolar cycloaddition with hexafluoroacetone to give the metalla heterocycle (eta-5-C5Me5)(CO)-Fe-P(=PMes*)OC(CF3)2C(O) with a remarkably short Fe-P bond (2.084 (4) angstrom) and an exocyclic P=P bond. When stored in solution at -40-degrees-C, this complex partly rearranges to the metalated 1-oxa-2,3-diphosphetane (eta-5-C5Me5)(CO)2Fe-P-P(Mes*)OC(CF3)2. The molecular structures of both isomers were elucidated by single-crystal X-ray analyses.

Übergangsmetall-substituierte Diphosphene, XXIV [1] Cheletrope [1+4]-Cycloaddition von Azodicarbonsäureestern und -amiden an das metallsubstituierte Diphosphen ( η5-C5Me5)(CO)2Fe - P = P - Mes* (Mes* = 2,4,6-tBu3C6H2). Struktur von Transition Metal Substituted Diphosphenes, XXIV [1] Cheletropic [1+4] Cycloaddition of Azodicarboxylic Esters and Amides to the Metal Substituted Diphosphene

The diphosphenyl complex (η5 -C5Me5)(CO)2Fe -P = P -Mes* (1) (Mes* = 2,4,6tBu3C6H2) reacts with equimolar amounts of the azo compounds R(O)C -N = N - C(O)R (2a: R = OEt; 2b: R = O-tBu; 2c: R = OCH2C6H5; 2d: R = NC5H10) in a cheletropic [1 +4] cycloaddition to afford stereoselectively the metal substituted oxadiazaphospholenes The products have been characterized by elemental analysis as well as by spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structure of 3a has been elucidated by single crystal X-ray analysis.

ChemInform Abstract: Transition Metal‐Substituted Diphosphenes. Part 19. Reactivity of Disilylphosphido Iron Complexes Towards 2,4,6‐(CF3)3C6H2PCl2 and 2,6‐(CF3)2C6H3PCl2. Diphosphenyl Complexes with Fluoroaryl Substituents.

AbstractEquimolar reaction of the Fe complex (I) with the title phosphanes (II) results in the formation of the thermolabile, NMR spectroscopically identified diphosphenyl complexes (III).

Übergangsmetall‐substituierte Diphosphene, XIX. Zur Reaktivität von Disilylphosphido‐Eisenkomplexen gegenüber 2,4,6‐(CF3)3C6H2PCl2und 2,6‐(CF3)2C6H3PCl2— Diphosphenylkomplexe mit Fluorarylsubstituenten

Transition‐Metal‐Substituted Diphosphenes. XIX. ‐ On the Reactivity of Disilylphosphido Iron Complexes towards 2,4.6‐(CF3)3C6H2PCl2and 2.6‐(CF3)2C6H3PCl2. Diphosphenyl Complexes with Fluoroaryl Substituents(η5‐C5Me5)(CO)2FeP(SiMe3)2(2a) and (η5‐C5H5)(CO)(PPh3)‐FeP(SiMe3)2(2c) react with ArylPCl2[3a: Aryl  2,4,6‐(CF)3‐C6H2;b: Aryl  2,6‐(CF)2C6H3] to yield the thermolabile diphosphenyl complexes (η5‐C5Me5)(CO)2FePP‐Aryl (4a,b) and (η5‐C5H5)(CO)(PPh3)FePP‐Aryl (4c,d), respectively. The isolation of the pure compounds4a‐dfailed. They are, however, intercepted as their (CO)5Cr adducts5a–dby treatment with [(Z)‐cyclooctene]Cr(CO)5‐ Complex (η5C5Me5)(CO)2FeP[Cr(CO)5] P‐C6H2(CF3)3‐(2,4,6) (5a) is characterized by single‐crystal X‐ray diffraction analysis.

Zur Reaktion des Diphosphenyl‐Komplexes (η5‐C5Me5)(CO)2Fe – P=P – Aryl (Aryl = 2,4,6‐tBu3C6H2) mit elektronenarmen Alkenen. Röntgenstrukturanalyse des Diphosphetans

Transition‐Metal‐Substituted Diphosphenes, XVIII1). – On the Reactivity of the Diphosphenyl Complex (η5‐C5Me5)(CO)2Fe – P=P – Aryl (Aryl = 2,4,6‐tBu3C6H2) with Electron‐Deficient Alkenes. X‐ray Analysis of the Diphosphetane The transition‐metal‐substituted diphosphene (η5‐C5Me5)(CO)2Fe – P=P – Aryl (1) reacts with fumarodinitrile (2a) to give the 1,2 diphosphetane all‐trans‐ as the result of a [2 + 2] cycloaddition. Similarly, compound 1 is converted by either dimethyl fumarate (2b) or dimethyl maleate (2c) into the same cycloadduct all‐trans‐ (3b). Diphosphetane 3a was completely characterized by a single‐crystal X‐ray analysis.

Transition-metal-substituted diphosphenes. 16. [1 + 4] Cycloaddition of a diphosphene to .alpha.,.beta.-unsaturated carbonyl compounds: synthesis of dihydro-1,2-.lambda.5-oxaphospholes with exocyclic phosphorus-phosphorus double bonds and x-ray structure analysis of [cyclic] (.eta.5-C5Me5)(CO)2FeP[OCH:CHCH2](:PAr) (Ar = 2,4,6-tert-Bu3C6H2)

The reaction of [Fe]P:PR ([Fe] = (h5-C5Me5)(CO)2Fe, R = 2,4,6-tert-Bu3C6H2] with acrolein, methacrolein, and 3-buten-2-one in benzene at 20 Deg afforded the oxaphospholes I (R1 = R2 = H; R1 = H, R2 = Me; R1 = Me, R2 = H) with exocylic P:P double bonds. A similar Ru diphosphenyl complex was also prepd. The crystal structure of I (R1 = R2 = H) was detd.

ChemInform Abstract: Arsaphosphenyl and Diphosphenyl Complexes of Chromium and Molybdenum.

AbstractThe reaction of the pentamethylcyclopentadienyl‐substituted arsaphosphene (I) with the tris(acetonitrile)tricarbonyl complexes (II) affords the arsaphosphenyl complexes (IIIa) and (IIIb) via a transfer of the cyclopentadienyl ligand from As to the metal center.

Übergangsmetall-substituierte Diphosphene, XIV. Zur Reaktivität des Diphosphenylkomplexes (μ5-C5Me5)(CO)2Fe—P=P—Ar (Ar = 2,4,6-t-Bu3C6H2) gegenüber Schwefel, Selen und Tellur. Synthese und Struktur des ersten Thioxo-λ5-diphosphenyl-Komplexes (μ5-C5Me5)(CO)2Fe-P(=S)(=P-Ar) / Transition Metal Substituted Diphosphenes. On the Reactivity of the Diphosphenyl Complex (μ5-C5Me5)(CO)2Fe-P=P-Ar (Ar = 2,4,6-t-Bu3C6H2) towards Sulfur, Selenium, and Tellurium. Synthesis and X-Ray Structure Analysis of the First Thioxo-λ5-diphosphenyl Complex (μ5-C5Me5) (CO)2Fe - P(=S)(=P - Ar)

Abstract The diphosphenyl complex (μ5-C5Me5)(CO)2Fe-P=P-Ar (1a) (Ar = 2,4,6-tert-Bu3C6H2) reacts with an equimolar amount of sulfur to yield the first thioxo- λ5 -diphosphenyl complex (μ5-C5Me5)(CO)2Fe-P(=S)=P-Ar (2). Heating of 2 in boiling benzene affords the metal functionalized thiadiphosphirane 3. Similarily the selenoxo-λ5 -diphosphenyl complex (μ5-C5Me5)(CO)2Fe-P(=Se)=P-Ar (5) and selena-diphosphirane 6 are synthesized. The products have been characterized by elemental analysis as well as by spectroscopic data (IR, 1H, 13C, 31P NMR, MS). The molecular structure of 2 has been elucidated by single crystal X-ray analysis.

Arsaphosphenyl‐ und Diphosphenyl‐Komplexe von Chrom und Molybdän

Arsaphosphenyl and Diphosphenyl Complexes of Chromium and Molybdenum The reaction of the (pentamethylcyclopentadienyl)(Cp*)-substituted arsaphosphene Cp* AsPAr (2, Ar = 2,4,6-tri-tert-butylphenyl) with M(CO)3(CH3CN)3 (M = Cr, Mo) in toluene affords the novel arsaphosphenyl complexes (η5-C5Me5)(CO)3MAs = PAr (M = Cr: 4; M = Mo: 5) via a transfer of the Cp* ligand from arsene to the metal centre. The corresponding diphosphenyl complex (η5-C5Me5)(CO)3CrPPAr 3 is obtained analogously from Cp*PPAr 1 and Cr(CO)3(CH3CN)3. The compounds were characterized by spectroscopic methods.

ChemInform Abstract: Transition Metal‐Sustituted Diphosphenes. Part 9. Synthesis and Structure of Metalated 1,3‐Diphospha‐2‐propanones. ‐ Carbonylation of Diphosphenyl Complexes.

AbstractThe diphosphenyl complexes (Ia,b) react with Fe2(CO)9 (II) to yield the adducts (IIIa,b) which on further treatment with (II) give the 1,3‐diphospha‐2‐propanone complexes (IVa,b) by catalytic carbonylation of the activated P=P double bond.

1 + 4] Cycloaddition of a Diphosphene to Acrolein: Synthesis and Structure of a Dihydro‐1,2λ5‐oxaphosphole with an Exocyclic PP Bond

A cheletropic [1 + 4] cycloaddition with retention of the PP bond occurs upon reaction of the diphosphenyl complex 1 with acrolein. The product 2 is characterized by a relatively long exocyclic PP bond (206.4(2) pm). Cp* = C5Me5, R = 2,4,6-tBu3C6H2.

ChemInform Abstract: Transition Metal Substituted Diphosphenes. Part 6. Reactivity of Diphosphenyl Complexes of Iron and Ruthenium Towards Tetracarbonyl Nickel.

AbstractThe diphosphenyl complexes (I) react with an excess of Ni(CO)4 (II) to yield the adducts (III).

Übergangsmetall-substituierte Diphosphene, VI [1]Zur Reaktivität von Diphosphenylkomplexen des Eisens und Rutheniums gegenüber Tetracarbonylnickel / Transition Metal Substituted Diphosphenes, VI [1] On the Reactivity of Diphosphenyl Complexes of Iron and Ruthenium towards Tetracarbonyl Nickel

Abstract The diphosphenyl complexes (?/ 5 -CsMe0(CO 2)M-P = P-Ar (8) (M = Fe, Ru; Ar = 2,4,6-rm-BU,C 6 H 2) react with excess Ni(CO) 4 to yield the adducts (77 5 -C 5 Me 5)(CO) 2 M[Ni(CO) 3 ]P=PAr (9). The products have been characterized by elemental analysis as well as by spectroscopic data (IR. 'H, 13 C, 31 P NMR).

On the Reactivity of Disilylphosphido Complexes of Transition Metals Towards Acid Chlorides

Abstract The first phosphaalkenyl complex Cp(CO)2Fe-P=C (OSiMe3)(t-Bu) was generated from Cp(CO)2FeP(SiMe3)2 and t-Bu(CO)Cl. In order to test the validity of this synthetic approach, we varied the ring ligand (Cp, C5Me5), the metal (Fe, Ru, Os), the main group element (P, As), and the carbonyl chlorides. The diphosphenyl complexes (C5Me5)(CO)2M-P=P-[2,4,6-t-Bu3C6H2] were obtained from (C5Me5)(CO)2M-P(SiMe3)2 and the corresponding phosphonous chloride. These metallated diphosphenes are easily converted to diphospho-ureas by treatment with Fe2(CO)9.