Syntheses of the Mo–Ag–Se complexes with a cubane-like core {MoAg3Se3X} (X=Cl and Br). Crystal structures of {MoAg3 Se3Cl}(PPh3)3Se and {MoAg3Se3Br}(PPh3)3Se·0.5Ph3PSe·

Transition Metal Chemistry -     

Reactions of tertiary phosphines with (3-chlorobuta-1,3-dienyl)(trimethyl)ammonium chloride

Tributylphosphine reacts with (3-chlorobuta-1,3-dienyl)(trimethyl)ammonium chloride to give 1,2,4-tris(tributylphosphonio)but-3-en-1-ide dichloride; triethylphosphine reacts in a similar way. Triphenylphosphine is inert to the above ammonium salt; whereas an analogous tris(triphenylphosphonium) derivative can be obtained from (3,4-dichlorobut-2-enyl)-(trimethyl)ammonium chloride.     

The reaction of tertiary phosphines with (Ph2Se2I2)2--the influence of steric and electronic effects

The reaction of (Ph(2)Se(2)I(2))(2) with a wide variety of tertiary phosphines possessing different steric and electronic properties has been studied, leading in most cases to R(3)PSe(Ph)I adducts; [R(3)P = (p-CH(3)C(6)H(4))(3)P (1), (m-CH(3)C(6)H(4))(3)P (2), (o-OCH(3)C(6)H(4))(3)P (4), Ph(2)MeP (6), Me(2)PhP (7), Me(3)P (8), Cy(3)P (9)]. All of the products formed were characterised by elemental analysis, Raman and multinuclear NMR spectroscopy. Both steric and electronic factors are important in determining the structural motif (CT vs. ionic) observed in the solid-state. In general, highly basic phosphines result in a lengthening of the Se-I interaction, and a preference for an ionic structure. The reaction with (o-CH(3)C(6)H(4))(3)P does not yield a stable R(3)PSe(Ph)I adduct, and instead (o-CH(3)C(6)H(4))(3)PI(2) (3) is formed. The unusually long P-I bond, [2.5523(12) A], and short I-I bond, [3.0724(4) A], exhibited by is a result of the high steric requirements of this phosphine. The similarly bulky (o-SCH(3)C(6)H(4))(3)P yields a mixture of (o-SCH(3)C(6)H(4))(3)PSe(Ph)I (5a) and [(o-SCH(3)C(6)H(4))(3)PSePh]I(3) (5b). The crystal structures of (m-CH(3)C(6)H(4))(3)PSe(Ph)I, 2, (o-CH(3)C(6)H(4))(3)PI(2), 3, [(o-OCH(3)C(6)H(4))(3)PSePh]I.CH(2)Cl(2), 4, [(o-SCH(3)C(6)H(4))(3)PSePh]I(3), 5b, two pseudo-polymorphs of Ph(2)MePSe(Ph)I, 6a/6b, and [Me(3)PSe(Ph)I](2).CH(2)Cl(2), 8, are reported. The R(3)PSe(Ph)I adducts formed exhibit one of four types of behaviour. Type I products, (such as 2) are CT in the solid-state and display fluxionality in solution. Type II products (such as 6a/6b) lie close to the CT/ionic structural borderline, displaying long Se-I bonds, and are more appropriately classified as [R(3)PSePh] (acceptor)/I(-) (donor) CT complexes. Type II complexes ionise in solution to [R(3)PSePh]I. Type III products, such as 8, are ionic in solution, but frequently show cation-anion, or cation-solvent interactions in the solid-state, although these interactions are weak and the linear P-Se-I motif is lost. Type IV products (such as 4) are ionic and feature bulky phosphines. They display no short cation-anion interactions in the solid-state.     

Facile and reproducible syntheses of bis(dialkylselenophosphenyl)-selenides and -diselenides: X-ray structures of ((i)Pr2PSe)2Se, ((i)Pr2PSe)2Se2 and (Ph2PSe)2Se

Facile and reproducible methods for the syntheses of bis(di-iso-propylselenophosphinyl)selenide ((i)Pr2PSe)2Se (1), bis(di-iso-propylselenophosphinyl)diselenide ((i)Pr2PSe)2Se2 (2) and bis(di-phenylselenophosphinyl)selenide (Ph2PSe)2Se (3) is reported.     

Reactivity of [Mo(NHNRPh)(NNRPh)(acac)X2] (R=Ph,Me; X=Br,I) toward tertiary phosphines

The reactivity of mixed [organohydrazido(1-)][organohydrazido(2-)]molybdenum(VI) complexes [Mo(NHNRPh)(NNRPh)(acac)X₂] {R?=?Ph, X?=?Br (1); R?=?Ph, X?=?I (2) and R?=?Me; X?=?I (3)} with tertiary phosphines as PPh₃, PMePh₂ and PMe₂Ph are examined. The syntheses of [Mo(NNPh₂)₂Br₂(PPh₃)] (4), [Mo(NNPh₂)₂Br₂(PMePh₂)₂] (5), [Mo(NNPh₂)₂Br₂(PMe₂Ph)₂] (6), [Mo(NNPh₂)₂(acac)I(PPh₃)] (7), [Mo(NNPh₂)₂(acac)(PMePh₂)₂]⁺I^? (8) and [Mo(NNMePh)₂(acac)(PMePh₂)₂]⁺I^? (9) are reported. All complexes were characterized by elemental analysis, UV-visible, IR, ¹H and ³¹P{H} NMR spectroscopy.     

Reactions of (CF3)3BCO with amines and phosphines

Reactions of tris(trifluoromethyl)borane carbonyl, (CF(3))(3)BCO, with ammonia yielded either a mixture of [NH(4)][(CF(3))(3)BC(O)NH(2)], [NH(4)][(CF(3))(3)BCN], and [NH(4)](2)[{(CF(3))(3)BC(O)}(2)NH] or neat [NH(4)](2)[{(CF(3))(3)BC(O)}(2)NH] depending on the reaction conditions. The salt K[(CF(3))(3)BC(O)NH(2)] was obtained as the sole product from the reaction of NH(3) with K[(CF(3))(3)BC(O)F]. A simple synthesis for cyanotris(trifluoromethyl)borates, M[(CF(3))(3)BCN], was developed by dehydration of M[(CF(3))(3)BC(O)NH(2)] (M = [NH(4)], K) using phosgene. In addition, syntheses of the tris(trifluoromethyl)boron species [(CF(3))(3)BC(O)NH(n)()Pr](-), [(CF(3))(3)BC(O)NMe(2)](-), and (CF(3))(3)BC(O)NMe(3), as well as of (CF(3))(3)BC(O)PMe(3), were performed. All species were characterized by multinuclear NMR spectroscopy. As far as neat substances resulted, IR and Raman spectra were recorded and their thermal behaviors were studied by differential scanning calorimetry. The interpretation of reaction pathways, structures, and vibrational spectra are supported by DFT calculations. The solid-state structure of K(2)[{(CF(3))(3)BC(O)}(2)NH].2MeCN was determined by single-crystal X-ray diffraction.     

Solvothermal synthesis and structure of a new selenium-rich selenophosphate K(3)PSe(4).2Se(6)

The compound K(3)PSe(4).2Se(6) was synthesized at 110 degrees C via solventothermal techniques from binary starting materials and Se in acetonitrile. The compound crystallizes in the space group Fd macro 3 of the cubic system with eight formula units in a cell with a dimension of a = 16.415(2) A at T = 193 K. The structure contains an unusual intermixing of ionic and uncharged species. The selenophosphate tetrahedral trianions PSe(4)(3-) are surrounded by potassium cations; other potassium cations in the structure are coordinated to 12 selenium atoms from four Se(6) rings in a tetrahedral arrangement. There are no short contacts between adjacent selenium rings. Heating the same reaction mixture to 160 degrees C results in the formation of only needles of trigonal selenium.     

Redox reactions between phosphines (R3P; R = nBu, Ph) or carbene (iPr2IM) and chalcogen tetrahalides ChX4 (iPr2IM = 2,5-diisopropylimidazole-2-ylidene; Ch = Se, Te; X = Cl, Br)

The reactions between chalcogen tetrahalides (ChX(4); Ch = Se, Te; X = Cl, Br) and the neutral donors (n)Bu(3)P, Ph(3)P, or the N-heterocyclic carbene, 2,5-diisopropylimidazole-2-ylidene ((i)Pr(2)IM), have been investigated. In cases involving a phosphine, the chemistry can be understood in terms of a succession of two-electron redox reactions, resulting in reduction of the chalcogen center (e.g., Se(IV) --> Se(II)) and the oxidation of phosphorus to the [R(3)P-X] cation (P(III) --> P(V)). The stepwise reduction of Se(IV) --> Se(II) --> Se(0) --> Se(-II) occurs upon the successive addition of stoichiometric equivalents of Ph(3)P to SeCl(4), which can readily be monitored by 31P{(1)H} NMR spectroscopy. In the case of reacting SeX(4) with (i)Pr(2)IM, a similar two-electron reduction of the chalcogen is observed and there is the concomitant production of a haloimidazolium hexahaloselenate salt. The products have been comprehensively characterized, and the solid-state structures of [R(3)PX][SeX(3)] (9), [Ph(3)PCl](2)[TeCl(6)] (10), (i)Pr(2)IM-SeX(2) (11), and [(i)Pr(2)IM-Cl](2)[SeCl(6)] (12) have been determined by X-ray diffraction analysis. These data all support two electron redox reactions and can be considered in terms of the formal reductive elimination of X2, which is sequestered by the Lewis base.     

Selenophosphate phase diagrams developed in conjunction with the synthesis of the new compounds K(2)La(P(2)Se(6))(1/2)(PSe(4)), K(3)La(PSe(4))(2), K(4)La(0.67)(PSe(4))(2), K(9-x)La(1+x/3)(PSe(4))(4) (x = 0.5), and KEuPSe(4)

Five new rare-earth metal polyselenophosphates have been synthesized by the reactive flux method and characterized by single-crystal X-ray diffraction: K(2)La(P(2)Se(6))(1/2)(PSe(4)) (I), K(3)La(PSe(4))(2) (II), K(4)La(0.67)(PSe(4))(2) (III), K(9-x)()La(1+)(x/3)(PSe(4))(4) (x = 0.5) (IV), and KEuPSe(4) (V). Compound I crystallizes in the monoclinic space group P2(1)/n with a = 9.4269(1) A, b = 7.2054(1) A, c = 21.0276(5) A, beta = 97.484(1) degrees, and Z = 4. Compound II crystallizes in the monoclinic space group P2(1)/c with a = 9.5782(2) A, b = 17.6623(4) A, c = 9.9869(3) A, beta = 90.120(1) degrees, and Z = 4. Compound III crystallizes in the orthorhombic space group Ibam with a = 19.0962(2) A, b = 9.1408(1) A, c = 10.2588(2) A, and Z = 4. Compound IV crystallizes in the orthorhombic space group Ccca with a = 18.2133(1) A, b = 38.0914(4) A, c = 10.2665(1) A, and Z = 8. Compound V crystallizes in the orthorhombic space group Pnma with a = 17.5156(11) A, b = 7.0126(5) A, c = 6.9015(4) A, and Z = 4. Optical band gap measurements show that compound V has an optical band gap of 1.88 eV. Solid-state Raman spectroscopy of compounds II-V shows the four normal vibrations expected for the (PSe(4))(3-) unit. The observation of compounds I-V in several reactions has allowed the creation of a quasi-quaternary phase diagram for potassium rare-earth-metal polyselenophosphates. This phase diagram can qualitatively be separated into three regions on the basis of the oxidation state of phosphorus in the crystalline products observed and takes the next step in designing solid-state compounds.     

Reactions of polyfluoroaromatic compounds with electrophilic agents in the presence of tris(dialkylamino)phosphines

When reacted with P(NEt₂)₃ and a proton donor, pentafluoropyridine, 3-chlorotetrafluoropyridine, pentafluorobenzonitrile, and octafluorotoluene yield products of replacement of the fluorine atom by hydrogen at position 4. This process is accompanied by the side reaction of aminodefluorination. In the case of 3-H-heptafluorotoluene and octafluoronaphthalene, aminodefluorination is the main reaction. Reactions of perfluoro-4-isopropyltoluene, 4-H-heptafluorotoluene, and 4-methylheptafluorotoluene do not occur under the above-mentioned conditions. For Part 7, see Ref. I. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1498–1500, August, 1997.     

Reactions of [Ru(H(2)O)(6)](2+) with water-soluble tertiary phosphines

In aqueous solutions under mild conditions, [Ru(H(2)O)(6)](2+) was reacted with various water-soluble tertiary phosphines. As determined by multinuclear NMR spectroscopy, reactions with the sulfonated arylphosphines L =mtppms, ptppms and mtppts yielded only the mono- and bisphosphine complexes, [Ru(H(2)O)(5)L](2+), cis-[Ru(H(2)O)(4)L(2)](2+), and trans-[Ru(H(2)O)(4)L(2)](2+) even in a high ligand excess. With the small aliphatic phosphine L = 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1(3,7)]decane (pta) at [L]:[Ru]= 12:1, the tris- and tetrakisphosphino species, [Ru(H(2)O)(3)(pta)(3)](2+), [Ru(H(2)O)(2)(pta)(4)](2+), [Ru(H(2)O)(OH)(pta)(4)](+), and [Ru(OH)(2)(pta)(4)] were also detected, albeit in minor quantities. These results have significance for the in situ preparation of Ru(II)-tertiary phosphine catalysts. The structures of the complexes trans-[Ru(H(2)O)(4)(ptaMe)(2)](tos)(4)x2H(2)O, trans-[Ru(H(2)O)(4)(ptaH)(2)](tos)(4)[middle dot]2H(2)O, and trans-mer-[RuI(2)(H(2)O)(ptaMe)(3)]I(3)x2H(2)O, containing protonated or methylated pta ligands (ptaH and ptaMe, respectively) were determined by single crystal X-ray diffraction.     

Reactions of dichloro-bis-[N(1)-benzyl-2-(arylazo)imidazole] ruthenium(II) with tertiary phosphines

The title reaction proceeds smoothly in MeOH-H2O togive the salts [RuCl(P)L2](ClO4), H2O (1, 2) or [Ru(PP)L2](ClO4)2, H2O (3, 4) where L=N(1)-benzyl-2-(arylazo)imidazole, P=PPh3, or PPh2Me, and PP=Ph2P(CH2)2PPh2 (dppe) or Ph2P(CH2)3PPh2(dppp). The complexes have been characterised by physico-chemical and spectroscopic methods.     

Darstellung und Kristallstrukturen von (Ph3PNPPh3)2[Re2Br10] und (Ph4P)[Re2Br9]

Synthesis and Crystal Structures of (Ph₃PNPPh₃)₂[Re₂Br₁₀] and (Ph₄P)[Re₂Br₉] Depending on the molar ratio by reaction of [n-Bu₄N]₂[ReBr₆] with the Lewis acid BBr₃ in dichloromethane the bioctahedral complexes [n-Bu₄N]₂[Re₂Br₁₀] and [n-Bu₄N][Re₂Br₉] are formed. The X-ray structure determination on (Ph₃PNPPh₃)₂[Re₂Br₁₀] (monoclinic, space group C 2/c, a = 20.007(4), b = 15.456(5), c = 24.695(4) Å, β = 107.53(2)°, Z = 4) reveals a centrosymmetric edge-sharing complex anion with approximate D_2h symmetry and mean terminal and bridging Re–Br bond lengths of 2.453 (equatorial), 2.482 (axial) and 2.591 Å, respectively, and a Re–Re distance of 3.880 Å. (Ph₄P)[Re₂Br₉] (triclinic, space group P 1, a = 11.062(2), b = 12.430(3), c = 13.163(5) Å, α = 72.94(2), β = 68.47(2), γ = 82.09(2)°, Z = 2) contains a confacial bioctahedral anion with nearly D_3h symmetry and mean terminal and bridging Re–Br distances of 2.460 and 2.536 Å, respectively, and a Re–Re distance of 2.780 Å.     

Reactions of bis(α-hydroxyalkyl)phosphines with iminoboranes

Conclusions Bis(-hydroxyalkyl)phosphines react with iminoboranes as either proton donors or cryptoaldehydes depending on the substituents at the carbon atom.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2409–2411, October, 1988.     

Cyclic sulfur nitrogen compounds and phosphorus reagents: Part XII. Reactions of S4N4 with (2-pyridylamino) phosphines [1]

Tetrasulfurtetranitride, S₄N₄ reacts with (2-pyridylamino)-diphenylphosphine in MeCN at room temperature to form the cyclotrithiazene (NC₅H₄NH)-Ph₂PN S₃N₃ ( 1 ) in good yield. By contrast, the cyclophosphathiazenes Ph₂PS₂N₃ ( 2 ) and 1,5(Ph₂P)₂S₂N₄ ( 3 ) are isolated from the same reaction mixture under reflux conditions. In solution, compound 1 is found to be transformed into 2 . The reaction of S₄N₄ with (2-pyridylamino)phenyl(dicyclohexylamino)phosphine in MeCN at room temperature affords Ph(DCA)PS₂N₃ ( 4 ) (DCA = dicylohexylamino) as the only reaction product. This on treatment with norbornadiene produces the addition product Ph(DCA)PS₂N₃·C₇H₈ ( 5 ). The structure of 4 has been established by X-ray diffraction. Its PSN ring adopts a skew boat conformation with S N bond lengths varying from 1.574(4) to 1.606(4) Å. The mean value of the endocyclic P N bonds amounts to 1.618(3) Å.     

Organometallic synthesis in the furazan series. 4. Reactions of azofurazans with organolithium compounds

The reactions of azofurazans, including macrocyclic azofurazans, with BuⁿLi and Li derivatives of methylfurazans were studied. Several competitive processes were found to occur: the addition of a Li reagent at the N=N bond, the redox reaction giving rise to hydrazofurazans, and the reaction of the side chain of azofurazan.     

Reactions of titanium alcoholates Ti(OR)4 (R = n-Bu, t-Bu) with tertiary organic and organometallic hydroperoxides

tert-Butyl and cumyl hydroperoxides in the reactions with Ti(OR)₄ are reduced to alcohols with the evolution of oxygen via formation of titanium-containing peroxides and trioxides. The pathways of the reactions of Ti(OR)₄ with triphenylelement hydroperoxides R₃EOOH (E = C, Si, Ge) depend on element E and on the structure of R; the reactions involve the rearrangement of the peroxides, and with (n-BuO)₄Ti the alkoxy group is oxidized either with preservation or with breakdown of the hydrocarbon skeleton.     

Metal complexes of selenophosphinates from reactions with (R2PSe)2Se: [M(R2PSe2)n] (M = Zn(II), Cd(II), Pb(II), In(III), Ga(III), Cu(I), Bi(III), Ni(II); R = (i)Pr, Ph) and [Mo(V)2O2Se2(Se2P(i)Pr2)2

The reactions of bis(dialkylselenophosphinyl)selenide with a series of metals have been investigated: synthesis of several metal selenophosphinate complexes and their structures are reported.