Josef Novosad

Displacement of triphenylphosphine from Cu(PPh3)2NO3 and Co(PPh3)2Cl2 by a diselenoimidodiphosphinato ligand. X-ray crystal structure of (PPh3)Cu[Ph2P(Se)NP(Se)Ph2] and Co[Ph2P(Se)NP(Se)Ph2]2 containing the novel CuSe2P2N and CoSe2P2N inorganic metallocycles

The reaction of Cu(PPh3)2NO3 with K[Ph2P(Se)-N-P(Se)Ph2] produced a tricoordinate copper(I) complex, Cu(PPh3)[Ph2P(Se)-N-P(Se)Ph2], containing the novel inorganic (carbon-free) CuSe2P2N metallocycle. The same diselenium reagent gave with Co(PPh3)2Cl2 a spirobicyclic compound Co[Ph2P(Se)-N-P(Se)Ph2]2, containing the novel inorganic CoSe2P2N metallocycle. The crystal structure of the two compounds was investigated by X-Ray diffraction. In both compounds the inorganic metallocycles are nonplanar and display strongly distorted twisted boat conformations.

THE PREPARATION AND X-RAY STRUCTURE OF M(SEPPH2)2N)2, M = NI, PD, PT

Abstract Reaction of [Ni(CH3CO)2]4H2O, H2PdCl4 or H2PtCl6 with HN[P(Se)Ph2]2 in water/acetone gave the title compounds in good yield. The compounds were characterised by IR/Raman, NMR and X-ray crystallography. The square planar metal centres form parts of spiro pseudo-boat rings. The X-ray structures allow comparison of the radii of Pt and Pd atoms.

A true square-planar tin(II) spiro complex: molecular structure of bis(imidotetraphenyldiselenodiphosphino-Se,Se′)tin(II) and its distorted tetragonal-pyramidal isomer

The yellow complex [Sn{N(SePPh2)2-Se,Se′}2] is the first example of a true square-planar spiro tin(II) compound; the structure of the distorted tetragonal-pyramidal isomer is also described.

Reaction of large-bite ligands with various tellurium compounds: Synthesis and structural characterization of [Te2(μ-Cl)2{(SPPh2)2N}2], [(4-MeOC6H4TeCl3)2{μ-Ph2P(S)CH2CH2P(S)Ph2}] and [Te2(μ-Ph2PS2)2] representing novel types of tellurium complexes

Abstract The three title compounds have been synthesized and their structures determined by X-ray crystallography. [Te2(μ-Cl)2{(SPPh2)2N}2], 1, is a dinuclear square planar Te(II) complex where each Te atom is coordinated to the two sulfur atoms of the bidentate dithiolate ligand and to the two bridging chloride ligands. The Te–S bond lengths are 2.4980(8) and 2.5054(8) A, while the Te–Cl bond lengths are 2.9065(9) and 2.9230(9) A. In [(4-MeOC6H4TeCl3)2{μ-Ph2P(S)CH2CH2P(S)Ph2}], 2, the dithio ligand is neutral and adds a molecule of [4-MeOC6H4TeCl3] at each sulfur atom, thus bridging the two Te(IV) atoms. The coordination of both tellurium atoms is ψ-octahedral with the anisyl group and a lone pair of electrons in axial positions. The Te–S bonds, 2.7747(6) and 2.8198(5) A, are surprisingly weak while the Te–Cl bonds lie in the range 2.4247(5) to 2.5343(6) A, those trans to Te–S being shortest. [Te2(μ-Ph2PS2)2], 3, is a binuclear Te(I) complex, mainly held together by a Te–Te bond of 2.7298(5) A. Both anisobidentate diphenyldithiophosphinate ligands bridge the two tellurium atoms. The resulting coordination around each tellurium is best described as T-shaped with the Te–Te bond along the stem. In the asymmetric near linear S–Te–S system, the short Te–S bonds are 2.487(2) and 2.495(2) A while the long bonds are 2.947(2) and 3.033(2) A, respectively. The strongly different trans influences of the dithio ligands of 1 and 2 are discussed and it is suggested that they are dependent upon the basicity of the sulfur atoms.

Synthesis and Structural Characterization of [Te{(SePPh2)2N}2]and 4-MeOPhTe{(SPPh2)2N}2.

Reaction of K[(SePPh2)2N] with [Te(tu)4]Cl2 (tu = thiourea) in methanol gave [Te{(SePPh2)2N}2], (1), while reaction of K[(SPPh2)2N] with 4-MeOPhTeCl3 in methanol gave [4-MeOPhTe-{(SPPh2)2N}]2, (2). The crystals of 1 are triclinic and contain centrosymmetric molecules. The ligands are bidentate and form a true square planar Te(II) complex with TeSe4 coordination. For 2, the crystals are also triclinic, and the dimeric molecules are centrosymmetric. Each dithiolate ligand bridges the two Te(II) atoms; the result is a T-shaped coordination around each tellurium atom. A tendency to weak TeTe bonding across the ring-formed dimer roughly in the direction of the missing fourth ligand in a potential square planar tellurium coordination sphere is also found [TeTe = 3.761 (1) A]. In 1, the Te–Se bonds have an average length of 2.797 A. The Te–S bonds in 2 are quite asymmetric with Te(1)–S(1) = 2.551 (3) A and Te(1)–S(2a) = 2.873 (3) A, while Te(1)–C(1) = 2.10 (1) A.

Synthesis of the First Neutral Spiro Selenium(II) Complex Containing a True Square Planar Se(Se4) Core – Preparation and Crystal Structure of Bis[N‐(diphenylphosphanylselenoyl)‐P,P‐diphenylphosphanylselenoic amidato‐Se, Se′]selenium(II)

The Bis[N-(diphenylphosphanylselenoyl)-P,P-diphenylphosphanylselenoic amidato-Se,Se′]selenium(II) (1) was prepared by treating [K{N(SePPh2)2}] with [Se{S2P(O-iPr)2}2] in THF. The title compound was characterized by means of IR and 31P-NMR spectroscopy and positive-ion FAB mass spectrometry and elemental analysis. The molecular structure was determined using single-crystal X-ray diffraction. The Se(Se4) core exhibited a quasi perfect square planar geometry. Two selenide ligands are coordinated symmetrically to the central atom forming a spiro complex.

The synthesis and characterisation of bis(diisopropylphosphoryl)ferrocene Fe[(η5-C5H4)P(O)iPr2]2, bis(diisopropylthiophosphoryl)ferrocene Fe[(η5-C5H4)P(S)iPr2]2, and bis(diisopropylselenophosphoryl)ferrocene Fe[(η5-C5H4)P(Se)iPr2]2, the oxidised derivatives of bis(diisopropylphosphino)ferrocene

Abstract The synthesis and spectroscopic characterisation of three chalcogenophosphoryl ligands derived from ferrocene is reported. The synthesis was based on the oxidation of Fe[(η5-C5H4)PiPr2]2 by elementary sulfur and selenium, and hydrogen peroxide, respectively. All new compounds were characterised by X-ray crystallography and comparison with their aryl analogues was made. Contrary to Fe[(η5-C5H4)P(E)Ph2]2 (E=O, S, Se), the prepared compounds are not centrosymmetric, with the iso-propyl groups showing more flexibility than the phenyl substituents.

The synthesis and characterization of N-(diphenylthiophosphinyl)-P-phenyl-thiophosphonamidic acid phenyl ester and related compounds chiral at phosphorus

The synthesis and spectroscopic characterization of three novel phosphorus(V) compounds, chiral at phosphorus, are reported. All three compounds were characterized by X-ray crystallography, and for one compound a 1H-31P HETCOR experiment was performed.

Novel usage of palladium complexes with P-N-P ligands as catalysts for diphenyl carbonate synthesis

Two palladium complexes with P-N-P ligands [Pd{(sPPh(2))(2)N}(2)]{Pd(S,S)} and [Pd{(SePPh)(2)N}(2)] {PPd(Se,Se)} were prepared and investigated as novel polladium catalysts for oxidative carbonylation of phenol using carbon monoxide and oxygen along with a redox catalyst (for in situ regeneration of palladium) and ammonium halide, The efficiency of these new catalysts was compared with that of a PdCl2-based catalyst system. In order to obtain the maximum efficiency, the effects of various parameters such as concentration of redox catalyst and ammonium halide, the effect of solvent, the influence of a quinone-type redox catalyst in addition to inorganic redox catalyst, and the effect of temperature were studied, Under the reaction conditions employed, the Pd(S,S) catalyst was found to perform better than PdCl2-based catalyst system, whereas the Pd(Se,Se) catalyst had extremely low efficiency.

New Cu(I) and Ag(I) binuclear complexes containing the dppa ligand

New Cu(I) and Ag(I) binuclear complexes were prepared by reaction of [M(NCCH3)4][PF6] (M = Ag, Cu) with the bidentate phosphine ligands Ph2PNHPPh2 (dppa) and Ph2PCH2PPh2 (dppm). In the reaction of Cu(I) with dppa the phosphine is easily oxidized to give the octahedral species of [Cu(dppaO2)3][PF6], 1. In an inert atmosphere, the binuclear complexes [Cu2(dppa)2(NCCH3)3][PF6]2, 2, [Cu2(dppa)2(NCCH3)4][PF6]2, 3, [Ag2(dppa)2(NCCH3)2][PF6]2, 4, and [Ag2(dppm)2][PF6]2, 5, were formed and structurally characterized by X-ray diffraction (except for 5). The electrochemical studies showed that the most relevant property of the binuclear species was the ease of forming the metal upon reduction. EH and DFT calculations were performed in order to try and understand the structural features of the [M2(dppa)2(NCCH3)x]n+ complexes, including the 0.47 A increase in M⋯M distance upon going from 2 to 3.