Synthesis and structures of triphenylbismuth diaroxides Ph3Bi(OAr)2, Ar = C6H3(Br2-2,4), C6H2(Br2-2,6)(NO2-4), and C6H2[(NO2)3-2,4,6]

Triphenylbismuth diaroxides Ph₃Bi(OAr)₂ (Ar = C₆H₃(Br₂-2,4) (I), C₆H₂(Br₂-2,6)(NO₂-4) (II), and C₆H₂[(NO₂)₃-2,4,6] (III) are synthesized in yields up to 74% by the reaction of triphenylbismuth with phenols in the presence of hydrogen peroxide (taken at a molar ratio 1: 2: 1, respectively) in ether. According to X-ray diffraction data, the bismuth atoms in compounds I-III have distorted trigonal-bipyramidal coordination with the aroxyl substituents in the axial positions; the Bi-C, Bi-O bond lengths and the OBiO, CBiC angles vary in the intervals 2.162–2.204, 2.150–2.299 ? and 172.4°–176.1°, 109.6°–139.9°, respectively. Compound II exhibits intramolecular contacts between the central atom and ortho-Br atoms (3.924, 4.101 ?), and compound III has similar contacts of the Bi atom with the O atoms of the ortho-nitro groups (3.114, 3.313 ?). Original Russian Text ? V.V. Sharutin, I.V. Egorova, O.K. Sharutina, A.P. Pakusina, M.A. Pushilin, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 1, pp. 14–21.     

New Synthesis of Triphenylbismuth Diaroxides

The reaction of triphenylbismuth, hydrogen peroxide, and phenol (molar ratio 1 : 1 : 2) in ether was used to synthesize triphenylbismuth diaroxides Ph₃Bi(OAr)₂ [Ar = C₆H₃(NO₂)₂-2,4, C₆H₂(NO₂)₃-2,4,6, C₆H₃Cl₂-2,6, C₆H₂Cl₃-2,4,6, C₆H₃Br₂-2,4, C₆H₂Br₃-2,4,6, C₆H₂Br₂-2,4,Me-6, C₆H₂Br₂-2,6, NO₂-4]. At an equimolar reagent ratio, bridged bismuth compounds (Ph₃BiOAr)₂O are formed. The crystal structure of bis-(2,4-dinitrophenoxy)triphenylbismuth Ph₃Bi[OC₆H₃(NO₂)₂-2,4]₂ was studied by X-ray diffraction to show that the bismuth atom has a distorted trigonal bipyramidal coordination and the 2,4-dinitrophenoxyl ligands are axial. The CBiC and OBiO angles are 109.6(5)°, 122.3(5)°, 128.1(5)°, and 175.6(3)°. The Bi-O^1,6 and Bi-C bond lengths are 2.256(10), 2.242(9) and 2.18(1), 2.18(1), 2.19(1) Å, respectively.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 927–929.Original Russian Text Copyright © 2005 by Sharutin, Egorova, Tsiplukhina, Molokov, Fukin.     

Palladium-catalyzed coupling of tetraphenylbismuth(V) derivatives with methyl acrylate

Tetraphenylbismuth(V) derivatives of the general formula Ph₄BiX [X = OSO₂C₆H₄Me-4, OC₆H₂(NO₂)₃-2,4,6, OC₆H₂(NO₂-4)(Br₂-2,6), OSO₂C₆H₃(OH)(COOH)] react with methyl acrylate in the presence of palladium dichloride (1:3:0.04 molar ratio) in acetonitrile at 20°C to form the cross-coupling products, methyl cinnamate (0.17–0.54 mol mol^?1 starting bismuth compound) and methylhydrocinnamate (0.10–0.73 mol mol^?1), diphenyl (0.06–0.80 mol mol^?1), and benzene (0.02–0.36 mol mol^?1). The highest C-phenylating activity is shown by Ph₄BiOSO₂C₆H₄Me-4. The mechanisms with the palladium-catalyzed cross-coupling reactions are suggested.     

Synthesis and structure of 2,4,6-tribromophenoxytetraphenylbismuth

Four new complexes of pentavalent bismuth are synthesized: Ph₃Bi[OC₆H₂(Br₃-2,4,6)]₂, Ph₃Bi[OC₆H₂(Cl₃-2,4,6)]₂, Ph₄BiOC₆H₂(Br₃-2,4,6), and Ph₄BiOC₆H₂(Cl₃-2,4,6). Tetraphenylbismuth aroxides are produced by the disproportionation reaction of ligands from pentaphenylbismuth and triphenylbismuth diaroxides in toluene or from pentaphenylbismuth and phenol. Triphenylbismuth diaroxides are synthesized from phenol, triphenylbismuth, and hydrogen peroxide taken at a molar ratio of 2 : 1 : 1, respectively, in diethyl ether. According to the X-ray diffraction data, the bismuth atom surrounding in 2,4,6-tribromophenoxytetraphenylbismuth has the configuration of a trigonal bipyramid with the aroxyl ligand in the axial position. The Bi-C and Bi-O bond lengths are 2,184, 2.190, 2.234, and 2.514 Å, respectively, and the equatorial CSbC angles are equal to 111.4°, 121.3°, and 121.3°.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 935–938.Original Russian Text Copyright © 2004 by Sharutin, Egorova, Tsiplukhina, Gerasimenko, Pushilin.     

N‐Heterocyclic Carbene Analogues of Thiele and Chichibabin Hydrocarbons

Stable N‐heterocyclic carbene analogues of Thiele and Chichibabin hydrocarbons, [(IPr)(C₆H₄)(IPr)] and [(IPr)(C₆H₄)₂(IPr)] ( 4 and 5 , respectively; IPr=C{N(2,6‐iPr₂C₆H₃)}₂CHCH), are reported. In a nickel‐catalyzed double carbenylation of 1,4‐Br₂C₆H₄ and 4,4′‐Br₂(C₆H₄)₂ with IPr ( 1 ), [(IPr)(C₆H₄)(IPr)](Br)₂ ( 2 ) and [(IPr)(C₆H₄)₂(IPr)](Br)₂ ( 3 ) were generated, which respectively afforded 4 and 5 as crystalline solids upon reduction with KC₈. Experimental and computational studies support the semiquinoidal nature of 5 with a small singlet?triplet energy gap ΔE_S?T of 10.7 kcal mol^?1, whereas 4 features more quinoidal character with a rather large ΔE_S?T of 25.6 kcal mol^?1. In view of the low ΔE_S?T, 4 and 5 may be described as biradicaloids. Moreover, 5 has considerable (41 %) diradical character.     

Palladium-catalyzed reaction of some triphenylbismuth(V) sulfonates and phenolates with methyl acrylate

Triphenylbismuth(V) derivatives Ph₃BiX₂ [X = OC₆H₂(NO₂)₃-2,4,6, OC₆H₂(NO₂-4)Br₂-2,6, OTs, OSO₂C₆H₄OH-4] react with methyl acrylate and PdCl₂ (1:3:0.04 molar ratio) in acetonitrile at 20°C to form the cross-coupling products, methyl cinnamate (0.26–0.51 mol mol^?1 starting bismuth compound) and methyl hydrocinnamate (0–0.17 mol mol^?1); diphenyl, the homocoupling product (0–0.13 mol mol^?1); and benzene (0.02–0.15 mol mol^?1). The reaction of Ph₃Bi(OSO₂C₆H₄OH-4)₂ is characterized by the selective formation of methyl cinnamate, but the reagent activity is low. Ph₃Bi(OTs)₂ exhibits the highest activity among the derivatives studied, but the reaction selectivity is low. The mechanisms of the palladium-catalyzed formation of homo-and cross-coupling products are proposed.     

Pyridinium tetrakis(nitrato-κ2O,O′)(2,2′:6′,2′′-terpyridine-κ3N)cerate(III) pyridine solvate and bis(methanol-κO)tris(nitrato-κ2O,O′)(2,2′:6′,2′′-terpyridine-κ3N)cerium(III)

The title complexes, (C₅H₆N)[Ce(NO₃)₄(C₁₅H₁₁N₃)]·C₅H₅N or (Hpy)­[Ce(NO₃)₄(terpy)]·py, (I) (py is pyridine, C₅H₅N, and terpy is ter­pyridine, C₁₅H₁₁N₃), and [Ce(NO₃)₃­(C₁₅H₁₁N₃)(CH₄O)₂] or [Ce(NO₃)₃(terpy)(OHCH₃)₂], (II), are 11-coordinate. The coordination polyhedron of the Ce atom in (I) is irregular, while that in (II) can be described as an icosahedron with two vertices replaced by one.     

Three new binuclear copper(II) complexes with isonicotinic acid N-oxide: syntheses,crystal structures and properties

Three new copper(II) complexes with isonicotinic acid N-oxide (HL) and 1,10-phenanthroline (phen) as ligands, [Cu(L)(phen)(H₂O)]₂(NO₃)₂···2H₂O (1), [Cu(L)(phen)(H₂O)]₂(ClO₄)₂···2H₂O (2), and [Cu(L)(phen)Br]₂- [Cu(L)(phen)(H₂O)]₂Br₂···6H₂O (3) have been synthesized and structurally characterized. The structures of all three complexes feature a Cu₂ dimer formed by two Cu(II) ions interconnected by two bridging ligands. Each copper(II) ion has a distorted square pyramidal coordination geometry with elongated axial coordination by an aqua ligand or halogen anion. The isonicotinic acid N-oxide anion is bidentate, being coordinated to two Cu(II) ions through its N-O oxygen and one of its carboxylate oxygen atoms. Magnetic susceptibility measurements show a Curie–Weiss paramagnetic behavior characteristic of one unpaired electron for a copper(II) ion for all three complexes.     

A monomeric three-coordinate magnesium bis(amide)

The metallation reaction between di­butyl­magnesium and 2,6-diiso­propyl-N-(tri­methyl­silyl)­aniline gives the unusual monomeric three-coordinate complex (diethyl ether-κO)­bis­[2,6-diiso­propyl-N-(tri­methyl­silyl)­anilido-κN]­magnesium(II), [Mg(C₁₅H₂₆NSi)₂(C₄H₁₀O)] or [Mg{(Me₃Si)(2,6-ⁱPr₂C₆H₃)N}₂(Et₂O)]. This low-coordinate species has a distorted trigonal-planar coordination environment, with an additional short Mg—C_ipso contact of 2.799 (2) Å.     

Paddlewheel dirhodium complexes bridged by para‐substituted benzoates

The dirhodium complex bis­(benzonitrile)tetra­kis[μ‐4‐(diethyl­amino)benzoato‐κ²O:O′]dirhodium(II)(Rh—Rh) benzonitrile disolvate, [Rh₂(C₁₁H₁₄NO₂)₄(C₇H₅N)₂]·2C₇H₅N, lies about an inversion centre. The dirhodium complex (methanol)tetra­kis(μ‐4‐nitro­benzoato‐κ²O:O′)(pyridine)dirhodium(II)(Rh—Rh) dichloro­methane solvate, [Rh₂(C₇H₄NO₄)₄(C₅H₅N)(CH₄O)]·CH₂Cl₂, lies in a general position in the unit cell, but the complexes dimerize around an inversion centre via O—H⋯O hydrogen bonding of the axial MeOH to a carboxyl­ate O atom. In the latter crystal structure, π–π stacking inter­actions between the bridging 4‐nitro­benzoate ligands and the axial pyridine ligand are observed between adjacent mol­ecules.     

Metallorganische Verbindungen der Lanthanoide. 88. Monomere Lanthanoid(III)-amide: Synthese und Röntgenstrukturanalyse von [Nd{N(C6H5)(SiMe3)}3(THF)], [Li(THF)2(μ-Cl)2Nd{N(C6H3Me2-2,6)(SiMe3)}2(THF)] und [ClNd{N(C6H3-iso-Pr2-2,6)(SiMe3)}2(THF)]

Organometallic Compounds of the Lanthanides. 88. Monomeric Lanthanide(III) Amides: Synthesis and X-Ray Crystal Structure of [Nd{N(C₆H₅)(SiMe₃)}₃(THF)], [Li(THF)₂(μ-Cl)₂Nd{N(C₆H₃Me₂-2,6)(SiMe₃)}₂(THF)], and [ClNd{N(C₆H₃-iso-Pr₂-2,6)(SiMe₃)} ₂(THF)] A series of lanthanide(III) amides [Ln{N(C₆H₅) · (SiMe₃)}₃(THF)_x] [Ln = Y ( 1 ), La ( 2 ), Nd ( 3 ), Sm ( 4 ), Eu ( 5 ), Tb ( 6 ), Er ( 8 ), Yb ( 9 ), Lu ( 10 )] could be prepared by the reaction of lanthanide trichlorides, LnCl₃, with LiN(C₆H₅)(SiMe₃). Treatment of NdCl₃(THF)₂ and LuCl₃(THF)₃ with the lithium salts of the bulky amides [N(C₆H₃R₂-2,6)(SiMe₃)]^? (R = Me, iso-Pr) results in the formation of the lanthanide diamides [Li(THF)₂(μ-Cl)₂Nd{N(C₆H₃Me₂-2, 6)(SiMe₃)}₂(THF)] ( 11 ) and [ClLn{N(C₆H₃-iso-Pr₂-2,6)(SiMe₃)} ₂(THF)] [Ln = Nd ( 12 ), Lu ( 13 )], respectively. The ¹H- and ¹³C-NMR and mass spectra of the new compounds as well as the X-ray crystal structures of the neodymium derivatives 3 , 11 and 12 are discussed.     

Terminal Ligand and Packing Effects on Slow Relaxation in an Isostructural Set of [Dy(H2dapp)X2]+ Single Molecule Magnets**

We report three structurally related single ion Dy compounds using the pentadentate ligand 2,6-bis((E)-1-(2-(pyridin-2-yl)-hydrazineylidene)ethyl)pyridine (H₂dapp) [Dy(H₂dapp)(NO₃)₂]NO₃ ( 1 ), [Dy(H₂dapp)(OAc)₂]Cl ( 2 ) and [Dy(H₂dapp)(NO₃)₂]Cl_0.92(NO₃)_0.08 ( 3 ). The (H₂dapp) occupies a helical twisted pentagonal equatorial arrangement with two anionic ligands in the axial positions. Further influence on the electronic and magnetic structure is provided by a closely associated counterion interacting with the central N−H group of the (H₂dapp). The slow relaxation of the magnetisation shows that the anionic acetates give the greatest slowing down of the magnetisation reversal. Further influence on the relaxation properties of compounds 1 and 2 is the presence of short nitrate-nitrate intermolecular ligand contact opening further lattice relaxation pathways.     

Synthesis and crystal structure of KBi(C6H4O7) · 3.5H2O

A novel compound, KBi(C₆H₄O₇) · 3.5H₂O (I), has been synthesized in the Bi(NO₃)₂-K₃(HCit) system (HCit^3? is an anion of citric acid C₆H₈O₇) at a component ratio (n) of 8 in a water-glycerol mixture, and its crystal structure has been determined. The crystals are unstable in air. The crystals are triclinic: a = 7.462 Å, b = 10.064 Å, c = 17.582 Å, α = 100.27°, β = 99.31°, γ = 105.48°, V = 1221.2 ų, Z = 2, space group $P\bar 1$ . In the structure of I, asymmetric binuclear fragments [Bi₂(Cit^4?)₂(H₂O)₂]^2? are linked through inversion centers into polymeric chain anions. Ions K⁺ and crystal water molecules are arranged in channels between the chains. The Bi(1)...Bi(2) distances in the binuclear fragment are 4.62 Å, and the Bi(1)...Bi(1) and Bi(2)...Bi(2) distances between bismuth atoms in the chain are 5.83 and 5.95 Å, respectively. The chains are linked through bridging oxygen atoms of the ligands Cit to form layers. In the centrosymmetric four-membered chelate ring Bi₂O₂ formed through Bi-O(Cit) bonds, the distances Bi(1)-Bi(1) are equal to 4.55 Å, and Bi(1)-O are 2.66 and 2.84 Å. The Bi-O bond lengths in I are in the range 2.12–3.16 Å. The Cit ligands act as hexadentate chelating/bridging ligands.     

Bimetallic Rare Earth Alkyl Complexes Bearing Bridged Amidinate Ligands: Synthesis and Activity for L-Lactide Polymerization

Four novel bridged‐amidines H₂L {1,4‐R¹[C(=NR²)(NHR²)]₂ [R¹=C₆H₄, R²=2,6‐ⁱPr₂C₆H₃ (H₂L¹); R¹=C₆H₄, R²=2,6‐Me₂C₆H₃ (H₂L²); R¹=C₆H₁₀, R²=2,6‐ⁱPr₂C₆H₃ (H₂L³); R¹=C₆H₁₀, R²=2,6‐Me₂C₆H₃ (H₂L⁴)]} were synthesized in 65%–78% isolated yields by the condensation reaction of dicarboxylic acid with four equimolar amounts of amines in the presence of PPSE at 180°C. Alkane elimination reaction of Ln(CH₂SiMe₃)₃(THF)₂ (Ln=Y, Lu) with 0.5 equiv. of amidine in THF at room temperature afforded the corresponding bimetallic rare earth alkyl complexes (THF)(Me₃SiCH₂)₂LnL¹Ln(CH₂SiMe₃)₂(THF) [Ln=Y ( 1 ), Lu ( 2 )], (THF)(Me₃SiCH₂)₂LnL²Ln‐ (CH₂SiMe₃)₂(THF) [Ln=Y ( 3 ), Lu ( 4 )], (THF)(Me₃SiCH₂)₂YL³Y(CH₂SiMe₃)₂(THF) ( 5 ), (THF)(Me₃SiCH₂)₂YL⁴‐ Y(CH₂SiMe₃)₂(THF) ( 6 ) in 72% –80% isolated yields. These neutral complexes showed activity towards L‐lactide polymerization in toluene at 70°C to give high molecular weight (M>10⁴) and narrow molecular weight distribution (M_w/M_n≦1.40) polymers     

Bis(μ‐6‐hydroxy­picolinato)‐μ‐oxo‐bis­[di­pyridine­manganese(III)] monohydrate

The title compound, [Mn₂(μ‐O)(C₆H₃NO₃)₂(C₅H₅N)₄]·H₂O, was isolated from the reaction of 2,6‐pyridine­di­carboxylic acid with [Mn₁₂O₁₂(CH₃COO)₁₆(H₂O)₄] in pyridine. The dimanganese complex has twofold symmetry; the Mn^III atoms are bridged by one oxo and two amidate ligands and show compressed octahedral Jahn–Teller distortion. The molecular packing comprises a three‐dimensional structure constructed by means of extensive intermolecular interactions, including three kinds of hydrogen bonds and π–π interactions.     

Two saccharinate complexes: [Mn(phen)2(sac)(H2O)]+·sac– and [Co(bipy)2(sac)(H2O)]+·sac–

The title saccharinate complexes, aqua[1,2‐benzisothiazol‐3(2H)‐onato 1,1‐dioxide‐N]bis(1,10‐phenanthroline‐N,N′)man­ganese(II) 1,2‐benz­isothia­zol‐3(2H)‐onate 1,1‐dioxide,[Mn(C₇H₄NO₃S)(C₁₂H₈N₂)₂(H₂O)](C₇H₄NO₃S), and aqua[1,2‐benz­iso­thiazol‐3(2H)‐onato 1,1‐dioxide‐N]­bis­(2,2′‐bi­pyri­dine‐N,N′)­cobalt(II) 1,2‐benz­iso­thia­zol‐3(2H)‐onate 1,1‐di­oxide, [Co­(C₇H₄NO₃S)­(C₁₀H₈N₂)₂­(H₂O)]­(C₇H₄NO₃S), have been prepared and their crystal structures determined at 150 K. The structure of the manganese complex consists of repeated alternating [Mn(phen)₂(sac)(H₂O)]⁺ cations and non‐coordinated saccharinate anions. The water molecule, bound to manganese as part of a slightly distorted octahedral arrangement, is hydrogen bonded to an O atom of the SO₂ group in the saccharinate counter‐ion. In contrast, the cobalt complex has one pseudo‐octahedral [Co(bipy)₂(sac)(H₂O)]⁺ cation, with the cobalt‐bound water molecule hydrogen bonded to the N atom of the accompanying free saccharinate anion.     

Complexes of Co(II), Ni(II), and Cu(II) with 4-(3,4-dichlorophenyl)-1,2,4-triazole

Novel oligonuclear complexes of Co(II), Ni(II), and Cu(II) with 4-(3,4-dichlorophenyl)-1,2,4-triazole (L) of the composition [M₃L₁₀(H₂O)₂](NO₃)₆ (M = Co(II), Ni(II)), [Ni₃L₆(H₂O)₆]Hal₆ (Hal = Cl^?, Br^?), and [Cu₅L₁₆(H₂O)₂](NO₃)₁₀ · 2H₂O were synthesized and studied by magnetic susceptibility, electronic and IR spectroscopy, and powder X-ray diffraction methods. All the above complexes are X-ray amorphous. Antifer-romagnetic exchange interactions between the M²⁺ ions were discovered in the [Co₃L₁₀(H₂O)₂](NO₃)₆ and [Ni₃L₁₀(H₂O)₂](NO₃)₆ complexes, whereas ferromagnetic exchange interactions were observed in the complexes [Ni₃L₆(H₂O)₆]Cl₆, [Ni₃L₆(H₂O)₆]Br₆, and [Cu₅L₁₆(H₂O)₂](NO₃)₁₀ · 2H₂O.     

Synthesis and characterization of two isostructural 3d–4f coordination compounds based on pyridine‐2,6‐dicarboxylic acid and 4,4′‐bipyridine

The design and synthesis of 3d–4f heterometallic coordination polymers have attracted much interest due to the intriguing diversity of their architectures and topologies. Pyridine‐2,6‐dicarboxylic acid (H₂pydc) has a versatile coordination mode and has been used to construct multinuclear and heterometallic compounds. Two isostructural centrosymmetric 3d–4f coordination compounds constructed from pyridine‐2,6‐dicarboxylic acid and 4,4′‐bipyridine (bpy), namely 4,4′‐bipyridine‐1,1′‐diium diaquabis(μ₂‐pyridine‐2,6‐dicarboxylato)tetrakis(pyridine‐2,6‐dicarboxylato)bis[4‐(pyridin‐4‐yl)pyridinium]cobalt(II)dieuropium(III) octahydrate, (C₁₀H₁₀N₂)[CoEu₂(C₁₀H₉N₂)₂(C₇H₃NO₄)₆(H₂O)₂]·8H₂O, (I), and 4,4′‐bipyridine‐1,1′‐diium diaquabis(μ₂‐pyridine‐2,6‐dicarboxylato)tetrakis(pyridine‐2,6‐dicarboxylato)bis[4‐(pyridin‐4‐yl)pyridinium]cobalt(II)diterbium(III) octahydrate, (C₁₀H₁₀N₂)[CoTb₂(C₁₀H₉N₂)₂(C₇H₃NO₄)₆(H₂O)₂]·8H₂O, (II), were synthesized under hydrothermal conditions and characterized by IR and fluorescence spectroscopy, thermogravimetric analysis and powder X‐ray diffraction. Both compounds crystallize in the triclinic space group P. The Eu^III and Tb^III cations adopt nine‐coordinated distorted tricapped trigonal–prismatic geometries bridged by three pydc^2? ligands. The Co^II cation has a six‐coordination environment formed by two pydc^2? ligands, two bpy ligands and two coordinated water molecules. Adjacent molecules are connected by π–π stacking interactions to form a one‐dimensional chain, which is further extended into a three‐dimensional supramolecular network by multipoint hydrogen bonds.     

Bidentate coordination of a diketo phosphorus ylide: synthesis and structure of [(C6H5)3PC(COCH3)(COC6H5)-κO,O′]UO2(NO3)2

A 1?:?1 chelate complex [(C₆H₅)₃PC(COCH₃)(COC₆H₅)-κO,O′]UO₂(NO₃)₂ has been synthesized by reaction of (C₆H₅)₃PC(COCH₃)(COC₆H₅) with UO₂(NO₃)₂?·?6H₂O in methanol at room temperature and characterized by elemental analysis, spectroscopy as well as by single-crystal X-ray diffraction. The complex crystallizes in P2₁/n space group with a?=?10.007(2)?Å, b?=?15.285(7)?Å, c?=?19.20(1)?Å, β?=?91.22(3)°, V?=?2936(2)?ų, Z?=?4, D _c?=?1.847?g?cm^?3. In the solid state structure, the dihedral angle [88.1(4)°] between the planes defined by the two quartets of atoms O1 O8 O2 O4 and O6 O5 O3 O7 is close to 90°, as expected for a triangulated dodecahedral geometry around uranium.     

Reaktionen von Fluorphosphoranen mit dem N,O-Bis(trimethylsilyl)-Derivat des o-Aminophenols

Reactions of Fluorophosphoranes with the N,O-Bis(trimethylsilyl) Derivative of o-Aminophenol The reaction of the N,O-bis(trimethylsilyl) derivative of o-aminophenol, 5 , with the tetrafluorophosphoranes, RPF₄, 2a–2d , (R = F, Me, Ph, and 1-adamantyl) in a 1:1 molar ratio led to monocyclic-1,3,2λ⁵-4,5-benzoxazaphospholes, C₆H₄(O)(NH)PF₂R, 6a–6d . ¹⁹F n.m.r. spectroscopic studies suggest a trigonal-bipyramidal structure with the C₆H₄(O)(NH) grouping attached to one axial and one equatorial position at five-coordinate phosphorus for these compounds. The spirophosphoranes, [C₆H₄(O)(NH)]₂PR, 8a – 8d (R = F, Me, Ph, 1-adamantyl) were obtained from the reaction of the appropriate tetrafluorophosphorane, RPF₄, 2a – 2d with 5 in a 1:2 molar ratio. The compounds 8a – 8d also result from a spontaneous scrambling reaction of 6a – 6d , with the corresponding tetrafluorophosphoranes, RPF₄ ( 2a – 2d ) as the other product. Reaction of the difluorophosphorane, Bu₃ⁿPF₂ with 5 and with N,N′-dimethyl-N,N′-bis(trimethylsilyl)urea furnished the cyclic, fluorine-free phosphoranes, 9 and 10 , respectively. The phosphonium bromide, Bu₃ⁿPFBr, reacted with 5 in a 1:1 and a 2:1 molar ratio to produce the ionic compounds, [C₆H₄(OSiMe₃)(NHPBu₃ⁿ)]⁺Br^?, 11 , and [C₆H₄(OPBu₃ⁿ)HNPBu₃ⁿ]²⁺ 2 Br^?, 12 , respectively.