Diphenylphosphine Groups Research Articles

Synthesis of a novel pyridine-diamino bridged diphosphine ligand and its macrocyclic metal complexes

A novel long chain diphosphine ligand with a pyridine-diamino bridge, 2,6-bis( N-benzyl- N-diphenylphosphinomethylamino)pyridine (PNP1), was prepared conveniently using the Mannich reaction of HPPh 2 with paraformaldehyde and 2,6-bis( N-benzylamino)pyridine in high yield. Reactions of the ligand with metal complexes, M(COD)Cl 2 (M = Pd, Pt), M(CH 3CN) 4ClO 4 (M = Cu, Ag) and M(CO) 6 (M = Mo, W) afforded the corresponding 10-numbered monometallic macrocyclic complexes with an uncoordinated pyridyl bridge. The monometallic chelate PdCl 2(PNP1) continued to react with Ag + or Cu + giving the μ-Cl bridged bicyclic metallic complex (μ-Cl) 2[PdCl(PNP1)] 2. The diphenylphosphine group coordinated with metal ion in cis-form in all the 10-numbered macrocyclic metal complexes. Ligand PNP1 and another known analogous 2,6-bis( N-diphenylphosphinoamino)pyridine (PNP2) reacted with Au(SMe 2)Cl giving the corresponding bimetallic Au 2Cl 2(PNP1) and Au 2Cl 2(PNP2), respectively. The latter bimetallic complexes continued to react with Ag + and diphosphine ligand to give the corresponding bimetallic macrocyclic complexes Au 2(ligand) 2(ClO 4) 2. All the complexes were characterized and the structures of some complexes were confirmed by X-ray single crystallography determination.

Synthesis and structural characterization of binuclear titanium(IV) and tantalum(V) cyclopentadienyl complexes containing bridging phosphinate ligands

The reaction of Ph2P(O)(OSiMe3) with [(η5-C5H5)TiCl3] or [(η5-C5Me5)TaCl4] in dichloromethane yields the complexes [{(η5-C5H5)TiCl2(µ-Ph2PO2)}2] (1) or [{(η5-C5Me5)TaCl3(µ-Ph2PO2)}2] (2), respectively. Structural analysis of 1 and 2 by single-crystal X-ray diffraction revealed the presence of eight-membered metallacycles consisting of bridging–bidentate diphenylphosphinate groups between two metal centers.Key words: inorganic rings, phosphinate complexes, tantalum, titanium.

Bis[hydrogen 1,1′-bis(diphenylphosphinato)ferrocenium] octachlorodiantimony(III)

In the title compound, [Fe(C(34)H(29)O(2)P(2))](2)[Sb(2)Cl(8)], the discrete centrosymmetric [Sb(2)Cl(8)]2- anions are formed from two edge-shared square pyramids of Cl atoms about each Sb atom. Within the cation, the two diphenylphosphinate groups share one H atom and the ferrocene cyclopentadienyl rings are in a staggered conformation, with the average value of the twist angle being 46 degrees. In the crystal, each [Sb(2)Cl(8)]2- anion is involved in eight C-H* * *Cl interactions with four surrounding cations and these interactions interconnect the ions to form molecular columns along the a direction.

Synthesis of New Chiral Bidentate (Phosphinophenyl)benzoxazine P,N-Ligands

Two new chiral bidentate (phosphinophenyl)benzoxazine P,N-ligands 2a and 2b were synthesized from highly enantiomer-enriched 2-(1-aminoalkyl)phenols 4. Ligand rac-2a was obtained on refluxing the t-Bu-substituted (aminomethyl)phenol 4a with 2-(diphenylphosphino)benzonitrile in chlorobenzene in the presence of anhydrous ZnCl2 followed by decomplexation (Scheme 2). This reaction, when carried out with (+)-(S)-4a, was accompanied by racemization at the stereogenic center of the alkyl side chain. The enantiomerically pure ligands (+)-(R)-2a and (-)-(S)-2a were obtained using a stepwise procedure via the amides (-)-(R)- and (+)-(S)-5b, respectively, followed by cyclization to benzoxazines (+)-(R)- and (-)-(S)-7b, respectively, with triflic anhydride and by F-atom substitution by diphenylphosphide (Schemes 3 and 5). In the case of the i-Pr analogue 2b, this last step resulted in racemization (Scheme 6). This was overcome by preparing the bromo derivative and introducing the diphenylphosphine group via Br/Li exchange and reaction with chlorodiphenylphosphine (Scheme 7). The first application of (+)-(R)-2a in an asymmetric Heck reaction showed high enantioselectivity (91%) (Scheme 8).

Direct synthesis of cyclic and polymeric phosphazenes bearing diphenylphosphine groups and their complexes with [W(CO) 5] fragments

The reactions of the cyclotriphosphazenes [N 3P 3Cl 6] or [N 3P 3(O 2C 12H 8) 2Cl 2] with the phenolic phosphine PPh 2(C 6H 4-OH) in the presence of Cs 2CO 3 give, respectively, the cyclic phosphazene phosphines [N 3P 3(OC 6H 4PPh 2) 6] ( 1) and [N 3P 3(O 2C 12H 8) 2(OC 6H 4PPh 2) 2] ( 2), very pure and in high yield. The similar reaction with the linear polyphosphazene {[NP(O 2C 12H 8)] 0.65[NPCl 2] 0.35} n in THF gives the diphenylphosphine polymer {[NP(O 2C 12H 8)] 0.65[NP(OC 6H 4PPh 2) 2] 0.35} n ( 3). The phenolic tungsten pentacarbonyl complex {W(CO) 5[PPh 2(C 6H 4-OH)]} reacts in the same way with those cyclic and polymeric phosphazenes to give the corresponding complexes {N 3P 3[OC 6H 4PPh 2-W(CO) 5] 6} ( 4), [N 3P 3(O 2C 12H 8) 2(OC 6H 4PPh 2-W(CO) 5) 2] ( 5), and {[NP(O 2C 12H 8)] 0.65[NP(OC 6H 4PPh 2-W(CO) 5) 2] 0.35} n ( 6).

H···H Interaction in Four-Membered P−H···H−M (M = Osmium, Ruthenium) Rings

The dihydrido-1-butene complex OsH2(η2-CH2CHEt)(CO)(PiPr3)2 (1) reacts with PHPh2 to give OsH2(CO)(PHPh2)(PiPr3)2 (2), which can also be prepared from the reaction of OsH(η2-H2BH2)(CO)(PiPr3)2 (3) with PHPh2. Similarly, treatment of RuH(η2-H2BH2)(CO)(PiPr3)2 (4) with PHPh2 affords RuH2(CO)(PHPh2)(PiPr3)2 (5). Complex 2 reacts with HBF4 in dichloromethane-d2 as the solvent to give the cis-hydrido−dihydrogen derivative [OsH(η2-H2)(CO)(PHPh2)(PiPr3)2]BF4 (6), which in solution exchanges the relative positions of the hydrido and dihydrogen ligands. The protonation of 2 with HBF4 in acetone affords the solvate complex [OsH{η1-OC(CH3)2}(CO)(PHPh2)(PiPr3)2]BF4 (7). The reaction of 7 with carbon monoxide leads to a mixture of the cis-dicarbonyl-[OsH(CO)2(PHPh2)(PiPr3)2]BF4 (8) and trans-dicarbonyl-[OsH(CO)2(PHPh2)(PiPr3)2]BF4 (9). The reactions of 7 with CH3CN, LiC⋮CPh, and KBr give [OsH(CH3CN)(CO)(PHPh2)(PiPr3)2]BF4 (10), OsH(C2Ph)(CO) (PHPh2)(PiPr3)2 (11), and OsHBr(CO)(PHPh2)(PiPr3)2 (12), respectively. The structures of 5 and 8 have been determined by X-ray diffraction analysis. In both cases, the coordination geometry around the metal center is octahedral, with the two triisopropylphosphine ligands in a trans position. Also in both cases, the H−P hydrogen atom of the diphenylphosphine ligand points toward one hydrido ligand, suggesting that there is a H···H interaction between the hydrido and the HP hydrogen atom. For 5 the H−H separation is about 2.6 Å, while for 8 the H−H separation is about 2.9 Å. Spectroscopic studies also suggest that one of the hydrido ligands of 2 and the HP hydrogen atom of the diphenylphosphine interact. In this case, the estimated H−H separation is 2.5 Å. In 2 and 5, the H···H interaction blocks the free rotation of the diphenylphosphine group around the Os−P axis, while in 8 it only permits a light oscillation.

Chemically bonded chelates as selective complexing sorbents for gas chromatography: VI . Modification of silica with NiCl2 and CoCl2 via β-diketonate groups

Results are presented of studies of new types of packings for gas chromatography which contain nickel(II) and cobalt(II) chlorides and nickel(II) acetylacetonate chemically bonded via β-diketonate groups to a silica surface. Taking into account the ability of the metals in the chlorides and acetylacetonate to interact with compounds showing electron-donor properties, the study was performed using such adsorbates as aliphatic linear and branched hydrocarbons. The study allowed the determination of the influence of structure and configuration of adsorbate molecules on their retention and the definition of the usefulness of thus prepared packings in chromatographic analysis. The obtained results point to selectivity of the packings to the compounds which contain π electrons. Moreover, to determine the influence of the type of functional group bonded with hydrocarbon chain of a given silane on charge-transfer interactions, the obtained results were compared with those for the packings in which nickel(II), cobalt(II) chlorides and nickel(II) acetylacetonate were bonded with silica via diphenylphosphine groups.

A new cyclam with a triphenylphosphine-pendant and its metal complexes

A new triphenylphosphine-pendant cyclam (triphenylphosphine = TPP; cyclam = 1,4,8,11-tetraazacyclotetradecane) was synthesized by reaction of an ethyl cinnamate derivative bearing a diphenylphosphine group at the ortho position of the phenyl group with 2,3,2-tetraamine (= 1,9-diamino-3,7-diazanonane) in refluxing McOH, followed by BH 3 reduction. Triphenylphosphine oxide-pendant cyclam (triphenylphosphine oxide = TPPO) was derived by treatment of TPP-pendant cyclam with benzyl alcohol in CCl 4. The TPP-pendant cyclam formed stable 1:1 metal inclusion complexes with Ni II and Mn III. The TPPO-pendant cyclam yielded a 1:1 Ni II complex which was the best catalyst among the cyclam-Ni II and -Mn III complexes for epoxidation of trans-stilbene with NaClO in CH 2Cl 2. Gold(I) reacted with TPP-pendant cyclam to yield a stable 1:1 complex, in which Au I binds only to the pendant phosphine. On the other hand, gold(III) reacted with TPP-pendant cyclam to give an Au III-inclusion complex with the pendant TPP coordination. The Au I complex reacted with [Au III(dien)Cl] 2+ in CH 3CN to yield an Au I(out)-Au III(in-cyclam) mixed complex. The Ni II complex with TPP-pendant cyclam reacted with Au I(PEt 3)Cl in CH 2Cl 2, yielding a novel Aul(out)-Ni II(in-cyclam) binuclear complex.

Synthesis and X-ray molecular structure of cis, cis-1,3,5-Tris(diphenylphosphino)- 1,3,5-tris(methoxycarbonyl) cyclohexane

The novel tripodal phosphine ligand cis, cis-1,3,5-tris(diphenylphosphino)-1,3,5-tris(methoxycarbonyl)cyclohexane (tdppcyme) ( 2) has been synthesized. 1H, 13C and 31P NMR spectroscopy shows that in solution the sterically demanding diphenylphosphine groups occupy equatorial positions on the cyclohexane ring. An X-ray crystal investigation confirms this result for the solid state. Treatment of tdppcyme with Mo( η 6-C 7H 8)(CO) 3 gives Mo(tdppcyme)(CO) 3 ( 3), with octahedral molybdenum coordination.

Synthese und Kristallstrukturen von Dimethylgalliumdiphenylphosphinat und Diethylindiumdiphenylphosphinat / Synthesis and Crystal Structures of Dimethylgalliumdiphenylphosphinate and Diethylindiumdiphenylphosphinate

The synthesis of diethylindiumdiphenylphosphinate and the crystal structures of dimethylgalliumdiphenylphosphinate and diethylindiumdiphenylphosphinate are reported. The two structures confirm the proposed dimeric nature of the title compounds with bridging diphenylphosphinate groups. [Ph2P(O)2Ga(CH3)]2 crystallizes triclinically, PĪ, with a = 9.483(6), b = 10.216(4), c = 8.780(9)Å, α = 101.66(5)°, β = 113.74(5)°, γ = 69.93(5)° and Ζ = 1 (dimer). [Ph2P(O)2In(C2H5)2]2 crystallizes monoclinically, C2/c, with a = 19.971(5), b = 8.590(2), c = 19.457(5)Å, β = 102.91(2)° and Ζ = 4 (dimers). Both structures contain tetrahedrally coordinated phosphorous and metal atoms.

Bifunctional ligands for the preparation of heterobinuclear complexes. Synthesis and characterization of Tl( 5H 4)P(CH 3) 2, [(η 5-C 5H 4)P(CH 3) 2] 2ZrCl 2 and the heterobinuclear complex {μ-(η 5-C 5H 4)P(CH 3) 2]ZrCl 2}Mo(CO) 4

The synthesis and spectroscopic characterization of the bifunctional ligand Tl(C 5H 4)P(CH 3) 2, the ring functional^metalloligand, [(η 5-C 5H 4)P(CH 3) 2] 2ZrCl 2, prepared from it and the heterobinocular complex, {μ-(η 5-C 5H 4)P(CH 3) 2] 2ZrCl 2}Mo(CO) 4, are reported. This heterobifunctional ligand will complement work with metallocene complexes of C 5H 4)PPh 2 because of the smaller steric demands and anticipated higher basicity of the dimethylphosphine unit compared to the diphenylphosphine group.

Chemie Polyfunktioneller Moleküle: CII. Metallpentacarbonyl- und Cobaltnitrosylcarbonyl-Komplexe eines Diphenylphosphin-substituierten Cyclophosphamids. Röntgenstrukturanalyse des Bis(dicarbonylnitrosylcobalt)-Derivats

Treatment of rac-(Ph 2PCH 2CH 2) 2N P(O)NH(CH 2) 3O ( 2) with M(CO) 5THF (M = Cr, Mo, W) gives the bimetallic complexes rac-[(OC) 5MPPh 2CH 2CH 2] 2N P(O)NH(CH 2) 3O ( 3a–c). The reaction of 2 with Co(CO) 3NO yields the analogous cobalt complex rac-[(OC) 2Co(NO)PPh 2CH 2CH 2] 2N P(O)NH(CH 2) 3O ( 4). In boiling toluene 4 reacts, under elimination of CO, to give the bicyclic compound rac-(OC)(ON)Co(PPh 2CH 2CH 2) 2N P(O)NH(CH 2) 3O ( 5). The complexes have been characterized by 1H, 31P and 13C NMR, IR, Raman and mass spectroscopy as far as possible. The crystal structure of 4 has been determined by X-ray diffraction studies. The crystals are monoclinic, space group P2 1/ c with a 1296.6(4), b 1745.2(5), c 1974.2(8) pm, β 105.73(3)° and Z = 4. The molecule consists of an organophosphorus six-membered ring. Each dicarbonylnitrosylcobalt group is coordinated by the diphenylphosphine group of both of the sidechains. In the cystal each R-enantiomer is connected with its S-enantiomer by hydrogen bonds.

Investigation of specific interaction between olefins and cyano-silica modified with copper(II) complexes

Silica gel packings containing copper salt bonded to cyano functional groups on the surface of silica particles were synthesized. It was found that such packings are capable of specific interactions with olefins. The interactions were diversified enough to allow the separation of geometrical isomers. Moreover, it was found that, because of the character of the cyano group, the differences between the packing with free −CN groups and the packing containing −CN groups bonded into a complex with Cu(II) were less marked than in the case of diphenylphosphine and thiol groups investigated earlier.

(1R,3R,4S,5R,6R)-6-cyano-5-diphenylphosphino-3,4-O-isopropylidene-2-oxabicyclo(3.2.0)heptane-3,4-diol: X-ray crystal structure and proton nuclear magnetic resonance spectrum.

The title compound, C22H22NO3P, crystallizes in space group P21, with a=13.219 (8), b=10.536 (7), c=7.143 (4) A, β=94.87 (6), and Z=2. The structure was solved by the direct method and refined to an R value of 0.0353. A unique structure having a cyclobutane ring fused with a furanoside moiety, and a diphenylphosphine group at the ring juncture, was confirmed by the analysis. A 270 MHz proton nuclear magnetic resonance (1H-NMR) analysis of the compound showed interesting coupling features of the cyclobutane ring protons and phosphorus.

Metal-complex catalysts coordinately fixed on inoeganic supports with the aid of organosilicon Compounds. 1. Some laws of synthesis of modified inorganic supports

A method has been devised for obtaining inorganic supports (silica gels) with nearly equal values of the density of surface-bound organosilicon modifiers containing electron-donor (diphenylphosphine) groups. These silica gels can be used to obtain a series of comparable“heterogenized” metal-complex catalysts.

Organometallic polymers. VI. Anchoring of arenechromium carbonyl complexes to macroreticular polymers

AbstractThe phenanthrenechromium dicarbonyl moiety was anchored by a photosubstitution reaction onto commercial resins substituted by diphenylphosphine groups. From scanning electron microscope photographs it was found that, whereas the chloromethylation reaction proceeded homogeneously throughout the polymer beads, the phosphination and photochemical reactions behaved differently, depending on the macrostructure and the morphology of the polymer beads. Large pore size dimensions (1300 Å) allowed the reagents (phosphine and chromium complex) to react throughout the polymer beads, whereas small pore sizes (< 50 Å) permitted penetration of the reagent only to a limited extent.

Preparation and properties of rhodium(I) complexes of phosphinated poly(methylsiloxanes)

A series of poly(methylsiloxanes) that contain carbon-functional diphenylphosphine groups were prepared and subsequently treated with RhCl(CO)(PPh 3) 2 to produce polymer-attached chlorocarbonylrhodium(I) complexes. The materials are soluble in a variety of organic solvents, and are easily precipitated from solution by the addition of excess methanol. The polymer complex A derived from a phosphinated silicone polymer containing one PPh2 group per 60 siloxy units has a molecular weight of 21000 daltons and contains 0.8% Rh. In accord with its formulation, the polymer shows a ν(CO) at 1970 cm -1 and an ultraviolet absorption at 3625 Å. Similar rhodium(I) complexes derived from phosphinated silicones containing one PPh 2 group per 20 (complex B) and 8 (complex C) siloxy units were also investigated. Complexes A and B catalyze the hydroformylation of hex-1-ene at 100°C, 1000 psi CO/H 2 pressure yielding the linear/branched heptaldehyde in a ratio of 0.9 with 95% selectivity and an overall conversion of 97% to products in 3 h. Although the hydroformylation conditions do not lead to depolymerization, both Rh and P are lost from the polymers and the actual catalyst appears to be a free rhodium carbonyl species. Complex C is a less active hydroformylation catalyst (14% aldehyde conversion, normal/branched ratio 1.7) and the polymer undergoes extensive degradation in the reaction.

Interaction between a polyphosphinic ligand and square planar Rh(I) complexes

Abstract Diphenylphosphine groups were introduced into spherical beads of chloromethylated 2% crosslinked polystyrene. The product obtained is the polymeric analog of the monomeric ligand triphenylphosphine. The kinetics of the interaction between the solid polymeric ligand and three Rh(I) square planar complexes— RhCl(CO)(P φ 3 ) 2 , Rh(P φ 3 ) 3 Cl and [RhCl(CO) 2 ] 2 —were investigated. Mechanisms for each comple are suggested, each consisting of the unique chemical interaction of the particular case and the mass transfer mode of the reactants into the polymer beads.

Use of polymer matrices to activate palladium(0) catalysts and reduce catalyst agglomeration

The dimerization–alkylation of butadiene to 1-methoxy-3,7-octadiene and 3-methoxy-1,7-octadiene has been studied in benzene at 100°C using both homogeneous and resin-attached palladium(0) catalysts. Pd(PPh 3) 4 was used as the homogeneous catalyst. Styrene-divinylbenzene (1% crosslinked) resins, functionalized with diphenylphosphine groups, were treated with Pd(PPh 3) 4 to give the resin-bound catalysts by ligand exchange. The rates of the homogeneously catalyzed reactions reach a limiting value as the catalyst concentration reaches 4 X 10 −3 to 6 X 10 −3 M due to equilibrium processes which limit the concentration of active species. The concentration of palladium in the resins is far higher (0.5 X 10 −1 to 7 X 10 −1 M), yet at similar P/Pd ratios the rates are greater per Pd using the resins. Furthermore, much larger catalyst charges may be employed, with the resin catalysts, without reaching limiting rates. Apparently, the resin retards the ability polymer-attached phosphines to highly coordinate (i.e., 3 or 4) palladium(0) relative to the corresponding situation in homogeneous solution. The resin matrix appears to retard the tendency, exhibited in the homogeneous reactions, for the catalyst to agglomerate and precipitate from solution as an inactive material.

Inorganic coordination polymers—XVII[1] the preparation and properties of tantalum(V) diphenylphosphinates

Tantalum diphenylphosphinate alkoxides and oxides were prepared with one, two and three diphenylphosphinate groups per tantalum. They were found to be low molecular weight polymers in solution. The i.r. spectra of the tantalum diphenylphosphinate oxides indicate that the phosphinate groups have predominately one mode of coordination (probably symmetrical bridging) in Ta[OP(C 6H 5) 2O]O 2·H 2O, whereas in Ta[ OP( C 6 H 5) 2 O] O 3 2 · XH 2 O and Ta[ OP( C 6 H 5) 2 O] 3· XH 2 O they have a variety of coordination modes. The thermal stabilities of tantalum diphenylphosphinate dioxide and tantalum bis(diphenylphosphinate) sesquioxide were considerably greater than tantalum tris(diphenylphosphinate) oxide.