Bridging Diphosphine Research Articles

μ-[1,2-Bis(diethylphosphino)ethane]-P:P'-bis[bis(diethyldithiocarbamato-S,S')zinc(II)] ditoluene solvate

The title complex, [Zn 2 (C 5 H 10 NS 2 ) 4 (C 10 H 24 P 2 )], is positioned symmetrically about an inversion center at the cell origin, which is situated at the center of the bridging diphosphine ligand. Toluene is disordered in this structure such that the rotation F between the two positions of the methyl C atom is 36 o . The geometry about Zn can be described as a distorted trigonal bipyramid. The Zn-P distance is 2.388 (2) A and the Zn-S distances range from 2.320 (2) to 2.653 (2) A

Gold complexes with selenium ligands. Part 7. Synthesis and crystal structures of oligonuclear gold(I)-selenolate complexes

Cationic and neutral Oligonuclear organophosphinegold(I) complexes with organic selenolate ligands SeR [R = Ph, CH2Ph, C6H4NH2– 4, C6H4Cl – 4 or C10H7, (naphthyl)] have been prepared and characterized by spectroscopic methods. Additionally, X-ray crystal structure analyses have been performed for [(AuPPh3)2(SeCH2Ph)]SbF6, the mixed cationic-neutral complex [(AuPPh3)2(SeC10H7)]SbF6·[Au(PPh3)(SeC10H7)] and for [(AuSePh)2(dppe)][dppe = 1,2-bis(diphenylphosphino)ethane]. The Au–Se bond lengths lie in the range 2.41 2 A(neutral complexes) to 2.465 A(cationic complexes). All crystal structures show distortions of the co-ordination geometry at selenium and reveal short Au ⋯ Au contacts. The molecular structure of [(AuPPh3)2(SeCH2Ph)]SbF6 represents the first example of a cationic alkylselenolate-gold complex. The complex [(AuPPh3)2(SeC10H7)]SbF6·[Au(PPh3)(SeC10H7)] exhibits an unexpected structure: the cationic and the corresponding neutral selenolate complex are linked by intermolecular Au ⋯ Au interactions, thus forming a trinuclear selenolate complex. The complex [(AuSePh)2(dppe)] is the first structurally characterized gold-organoselenolate complex with a bridging diphosphine ligand.

Cobalt carbonyl complexes with bridging diphosphine ligands

Cobalt carbonyl complexes with bridging diphosphine ligands

Reactions of coordinated ligands VII. Preparation of (CO) 5 MR(H)PP(Cl)RM(CO) 5 (M  Cr, Mo, W; R  Ph, NEt 2) by dehydrohalogenation of (CO) 5MPRHCl, and some of their reactions leading to complexes with bridging diphosphine ligands

Removal of HCl from (CO) 5MPRHCl (M  Cr, Mo, W; R  Ph, NEt 2) by treatment with NEt 3 has given the complexes (CO) 5,MPh(H)PP(Cl)PhM(CO) 5 (M Cr, Mo, W) ( 1) and (CO) 5CrNEt 2(H)PP(Cl)NEt 2Cr(CO) 5 ( 2) containing bridging diphosphine ligands. Surprisingly, (CO) 5CrCl 2PPCl 2Cr(CO) 5 ( 3) was formed from treatment of (CO) 5CrPHCl 2 with NEt 3. Reaction of 1 with tetrabutylammoniumfluoride, of 2 with gaseous HCl, and of 3 with MeOH gave (CO) 5,CrPh(H)PP(F)PhCr(CO) 5, ( 4), (CO) 5CrCl(H)PPCl 2Cr(CO) 5 ( 5) and (CO) 5Cr(MeO) 2PP(OMe) 2Cr(CO) 5 ( 6) respectively. Except for Cl 2PPCl 2, the diphosphine ligands in 1–6 are unknown in the free state. Attempts to abstract HCl from 1 to give the diphosphene complex (CO) 5CrPhPPPhCr(CO) 5 failed.

Bridging rather than chelation in the substitution chemistry of the osmium(I) complex [Os 2(MeCO 2) 2(CO) 6] with potentially chelating phosphines and arsines

Substitution of the osmium(I) dimer [Os 2(MeCO 2) 2(CO) 6] with monophosphines has been previously shown to give mono- and disubstituted products with the introduced ligands exclusively trans to the OsOs bond. This has allowed the preparation of the complexes, [Os 2(MeCO 2) 2(CO) 4(PPh 3)(η 1-L)] and [Os 2(MeCO 2) 2(CO) 4(η 1-L) 2], in which the ligands L are Ph 2PCH 2PPh 2 (dppm), Ph 2PCH 2CH 2PPh 2 (dppe) or 1,2-C 6H 4(AsMe 2) 2 (diars). These ligands are normally found to be chelating or bridging but here are coordinated through a single heteroatom, but these complexes show no tendency to lose CO ligands cis to the metal-metal bonds to allow the ligands L either to chelate or bridge. There is, however, a strong tendency to form oligomers with bridging diphosphine ligands linking separate OS 2 groups, but the designed synthesis of chains Of Os 2 units has failed because of slow redistribution reactions involving cleavage of the OsLOs bridges.

ChemInform Abstract: Electronic Emission from Bis(bridging diphosphine) Derivatives of Re2(CO)10. Characterization of the Emissive State as 3(do → do*).

AbstractThe complexes (I) are highly emissive at low temperature.

Electronic emission from bis(bridging diphosphine) derivatives of Re2(CO)10.cntdot. Characterization of the emissive state as 3(d.sigma. .fwdarw. d.sigma.*)

Electronic emission from bis(bridging diphosphine) derivatives of Re2(CO)10.cntdot. Characterization of the emissive state as 3(d.sigma. .fwdarw. d.sigma.*)

Crystal structure determination of an organometallic compound from synchrotron radiation Laue diffraction photographs

Laue diffraction patterns for a small single crystal of the organometallic compound [FeRhCl(CO)sdppee] [dppee is PhEPCH(=CHE)PPh2] were recorded with the SRS wiggler beam at SERC Daresbury Laboratory. The intensities were measured from these photographs and the structure determined by Patterson and Fourier methods. The crystal had previously given weak Cu Ka Weissenberg photographs from which the unit-cell dimensions and space group were determined. The diffraction data did not extend to plane spacings much less than 1.2,~ and the crystals were found to be disordered; refinement with stereochemical restraints gave R = 0.14. This is a pilot study; the technique could have uses for very small crystals or for 'kinetic crystallography'. The crystals of [FeRhCI(CE6HE2P2)(CO)s], Mr= 730.7, are monoclinic, a=8.26, b= 19.81, c = 9.77 A, fl = 111.3 (2) ° (e.s.d. of ratio of cell edges ca O. 1% from Laue diffraction pattern fitting, e.s.d, of absolute values ca 1% from weak, lowresolution Weissenberg photograph), U= 1489.5 t13, F(000) = 732, space group P2~ or P21/m from systematic absences (in Weissenberg photograph, not accessible from Laue), Z= 2, D,, (flotation)= 1.62, D x-- 1.63 g cm -3. The molecule has an Fe-Rh bond, 2.7 A, and a bridging diphosphine group.

Protonation and hydrogenation of triosmium clusters containing the bridging diphosphine ligands Ph 2P(CH 2nPPh 2 ( n  1 to 4)

Members of the series of bridging diphosphine clusters [Os 3(CO) 10(diphos)] where diphos  Ph 2P(CH 2 n PPh 2 [dppm ( n = 1), dppe ( n = 2), dppp ( n = 3), or dppb ( n = 4)] show interesting differences in their reactivity towards H + and H 2. Protonation leads to [Os 3(μ-H)(CO) 10(diphos)] + with the hydrides bridging the same osmium atoms as the diphos ligand when diphos is dppe, dppp, or dppb, whereas the hydride and dppm bridge different edges in [Os 39μ-H)(CO) 10(dppm)] +. Hydrogenation of the 1,2-diphos compounds leads to [Os 3(μ-H) 2(CO) 8(diphos)] (diphos = dppm, dppe, dppp) in good to excellent yield but the dppb analogue could not be made. Geometric and electronic factors affecting the ability to incorporate hydride ligands in these clusters are discussed.

The synthesis, X-ray crystal structure, and solution characterization of a bis(diphosphine)-bridged dirhodium(I) complex containing a Rh2P4 six-membered ring

The preparation of [{Rh(cod)}2(µ-L1)2][BF4]2(1) from ([graphics omitted])2(L1) and [Rh(cod)2]-BF4(cod = cyclo-octa-1,5-diene) is described. The compound crystallizes in the monoclinic space group P21/c(C52h), with a= 9.650(1), b= 11.609(1), c= 21.884(3)A, β= 117.07(1)°, and Z= 2. The structure was refined to R= 0.033 for 3 434 reflections. The solid-state structure shows two diphosphine ligands L1 bridging two rhodium(I) atoms to form a six-membered Rh2P4 ring in a chair conformation. Solution studies (1H and 13C-{1H} variable-temperature n.m.r. spectra) exhibit characteristics of a ring inversion equilibrium with ΔG271= 14.0(0.2) kcal mol–1. Computer simulation of the 31P-{1H} n.m.r. spectrum is used to analyse the internuclear couplings of the AA′A″A‴XX′ pattern (A =31P, X =103Rh). The bridging diphosphine ligands exhibit a deshielding effect on the trans olefinic carbon atoms of cod in (1) which is in the range normally found for phosphine ligands.

Complexes du titane et du zirconium contenant les ligands cyclopentadienyldiphenylphosphine et cyclopentadienylethyldiphenylphosphine: acces a des structures heterobimetalliques

Reactions of Ph 2P(CH 2) n (C 5H 4)Li, ( n = 0, 2), with MCl 4 or CpTiCl 3 (M = Ti, Zr; Cp = η 5-C 5H 5) form Cl 2M[(η 5-C 5H 4)(CH 2) n PPh 2] 2 or Cl 2CpTi[(η 5-C 5H 4)-(CH 2) 2PPh 2] in good yields. Chemical reduction with Al, or electrochemical reduction of these complexes, under CO, are described. The titanium(IV) and zirconium(IV) derivatives react with metal carbonyls (Mo(CO) 6, Cr(CO) 6, Fe(CO) 5, Mo(CO) 4(C 8H 12)) under formation of new heterobimetallic complexes. Reduction with Al of Cl 2CpTi[(η 5-C 5H 4)(CH 2) 2PPh 2]Mo(CO) 5 under CO results in a new heterobimetallic species containing low valent titanium. Both complexes Cl 2M[(η 5-C 5H 4)(CH 2) 2PPh 2] 2 (M = Ti, Zr) react with [Rh(μ-Cl)(CO)(C 2H 4)] 2 to yield {RhCl(CO)(Cl 2M[(η 5-C 5H 4)(CH 2) 2PPh 2] 2)} x, which is assumed to be a dimer, in which the titanium or the zirconium compounds act as bridging diphosphine ligands between the rhodium atoms.

A NOVEL TYPE OF BRIDGING OF THE β-DIKETONATE DIANIONS BETWEEN TWO PALLADIUM(II) ATOMS: η3-COORDINATION AND O,O′-CHELATION

Abstract Complexes of a novel type, [(PP)Pd(O,O′-β-dik(2–)-C1–C3)Pd(PP)](ClO4)2 containing dianions of acetylacetone and ethyl acetoacetate as a bridging ligand and diphosphines (PP) were prepared and characterized mainly by IR and 1H, 13C, and 31P NMR spectroscopy.

ChemInform Abstract: NOVEL REACTIONS OF METAL‐METAL BONDS. ADDITION OF SULFUR DIOXIDE AND SULFUR TO DICHLOROBIS(BIS(DIPHENYLPHOSPHINO)METHANE)DIPALLADIUM AND THE OXIDATION O COORDINATED SULFIDE

AbstractSO2 schiebt sich in die M‐M‐Bindung der Di.phosphin‐ oder Diarsin‐verbrückten Komplexe (I) unter Bildung der SOg‐verbrückten Komplexe (II) ein.

Novel reactions of metal-metal bonds. Addition of sulfur dioxide and sulfur to dichlorobis(bis(diphenylphosphino)methane)dipalladium and the oxidation of coordinated sulfide

Sulfur dioxide inserts into the metal-metal bond of Pd/sub 2/(dpm)/sub 2/X/sub 2/ (dpm = bis(diphenylphosphino)methane, X = Cl or Br), Pd/sub 2/(dam)/sub 2/Cl/sub 2/ (dam = bis(diphenylarsino)methane), and Pt/sub 2/(dpm)/sub 2/Cl/sub 2/. The adducts have been crystallized and characterized by infrared, electronic, and /sup 1/H NMR spectroscopy. The structure of Pd/sub 2/(dpm)/sub 2/(..mu..-SO/sub 2/)Cl/sub 2/ has been determined by x-ray crystallography. The compound crystallizes in the orthorhombic space group P2/sub 1/2/sub 1/2/sub 1/ with four molecules per unit cell of dimensions a = 15.582 (3), b = 16.457 (3), and c = 19.184 (5) A. Full-matrix least-squares refinement yields R = 0.069. The binuclear molecules contain two approximately planar palladium ions, each coordinated to a terminal chloride, a bridging sulfur dioxide, and two trans phosphorus donors from the bridging diphosphines. The ability of crystal packing forces to alter the Pd...Pd separation (3.383 (4) and 3.220 (4) A for the two crystallographically independent molecules) reflects the lack of a direct metal-metal bond. Pd/sub 2/(dpm)/sub 2/Cl/sub 2/ reacts with cyclo-octasulfur or propylene sulfide to give Pd/sub 2/(dpm)/sub 2/(..mu..-S)Cl/sub 2/, which has been crystallized and characterized by infrared, electronic, and /sup 1/H NMR spectra. Crystals of Pd/sub 2/(dpm)..mu..-S)Cl/sub 2/ are tetragonal, space groupmore » P4/sub 1/, with Z = 4 and cell dimensions a = 21.015 (4) and c = 14.281 (2) A. Refinement of this complex yields an R of 0.076. Oxidation of Pd/sub 2/(dpm)/sub 2/(..mu..-S)Cl/sub 2/ with m-chloroperbenzoic acid has been monitored by electronic spectroscopy at -60/sup 0/C; Pd/sub 2/(dpm)/sub 2/(..mu..-SO/sub 2/)Cl/sub 2/ is formed. The utility of the /sup 1/H NMR spectra of the methylene region of these dpm-bridged complexes in diagnosing the structure of the complexes is discussed. 5 figures, 8 tables.« less

Five-coordinate cobalt(II), four- and five-coordinate nickel(II), and six-coordinate cobalt(III) complexes of the flexible diphosphine ligand 1,3-bis(dimethylphosphino)propane

The flexible, aliphatic, diphosphine ligand (CH 3) 2PCH 2CH 2CH 2P(CH 3) 2, dmp, forms the five-coordinate complexes [M(dmp) 2X] + (M = Ni, X = Cl, Br, I, NCS; M = Co, X = Cl, Br, I), as well as the four-coordinate, planar Ni(dmp)X 2 and six-coordinate trans-[Co(dmp) 2X 2] + complexes. In the case of nickel cyanide, the only isolatable five-coordinate compound corresponded to the dinuclear Ni 2(dmp) 3(CN) 4, which contains a bridging diphosphine ligand. All of the complexes were characterized by elemental analyses and by conductance, magnetism, infrared, and electronic spectral measurements. In the five-coordinate nickel series [Ni(dmp) 2X] +, the bromide and iodide complexes appear to possess trigonal-bipyramidal structures, whereas the analogous chloride and thiocyanate complexes have distorted structures of approximately C s microsymmetry.