Platinum Indolylphosphine Fluorido and Polyfluorido Complexes: An Interplay between Cyclometallation,Fluoride Migration,and Hydrogen Bonding

The reaction of [PtCl₂(COD)] (COD=1,5-cyclooctadiene) with diisopropyl-2-(3-methyl)indolylphosphine (iPr₂P(C₉H₈N)) led to the formation of the platinum(ii ) chlorido complexes, cis-[PtCl₂{iPr₂P(C₉H₈N)}₂] ( 1 ) and trans-[PtCl₂{iPr₂P(C₉H₈N)}₂] ( 2 ). The cis-complex 1 reacted with NEt₃ yielding the complex cis-[PtCl{κ²-(P,N)-iPr₂P(C₉H₇N)}{iPr₂P(C₉H₈N)}] ( 3 ) bearing a cyclometalated κ²-(P,N)-phosphine ligand, while the isomer 2 with a trans-configuration did not show any reactivity towards NEt₃. Treatment of 1 or 3 with (CH₃)₄NF (TMAF) resulted in the formation of the twofold cyclometalated complex cis-[Pt{κ²-(P,N)-iPr₂P(C₉H₇N)}₂] ( 4 ). The molecular structures of the complexes 1–4 were determined by single-crystal X-ray diffraction. The fluorido complex cis-[PtF{κ²-(P,N)-iPr₂P(C₉H₇N)}{iPr₂P(C₉H₈N)}] ⋅ (HF)₄ ( 5 ⋅ (HF)₄) was formed when complex 4 was treated with different hydrogen fluoride sources. The Pt(ii ) fluorido complex 5 ⋅ (HF)₄ exhibits intramolecular hydrogen bonding in its outer coordination sphere between the fluorido ligand and the NH group of the 3-methylindolyl moiety. In contrast to its chlorido analogue 3 , complex 5 ⋅ (HF)₄ reacted with CO or the ynamide 1-(2-phenylethynyl)-2-pyrrolidinone to yield the complexes trans-[Pt(CO){κ²-(P,C)-iPr₂P(C₉H₇NCO)}{iPr₂P(C₉H₈N)}][F(HF)₄] ( 7 ) and a complex, which we suggest to be cis-[Pt{C=C(Ph)OCN(C₃H₆)}{κ²-(P,N)-iPr₂P(C₉H₇N)}{iPr₂P(C₉H₈N)}][F(HF)₄] ( 9 ), respectively. The structure of 9 was assigned on the basis of DFT calculations as well as NMR and IR data. Hydrogen bonding of HF and NH to fluoride was proven to be crucial for the existence of 7 and 9 .     

Beiträge zur Chemie des Phosphors. 152. Funktionalisierte Cyclotriphosphane des Typs (t-BuP)2PX (X = K,SiMe3, SnMe3, Cl,Br, PCl2, P(t-Bu)Cl,P(t-Bu)I)

Contributions to the Chemistry of Phosphorus. 152. Functionalized Cyclotriphosphanes of the Type (t-BuP)₂PX (X = K, SiMe₃, SnMe₃, Cl, Br, PCl₂, P(t-Bu)Cl, P(t-Bu)I) Functionalized cyclotriphosphanes of the type (t-BuP)₂PX with electropositive or electronegative substituents X have been prepared on various synthetic routes: KP(t-BuP)₂ ( 1 ) can be obtained in 50–55 per cent purity by reacting (t-BuP)₄ or (t-BuP)₃ with potassium. Reaction of 1 with Me₃SiCl or Me₃SnCl leads to the cyclotriphosphanes (t-BuP)₂PSiMe₃ ( 2 ) and (t-BuP)₂PSnMe₃ ( 3 ), respectively; the cyclocondensation of Cl(t-Bu)P? P(t-Bu)Cl with P(SnMe₃)₃, however, is more convenient for the preparation of 3 . In a similar way the halogenated compounds (t-BuP)₂PCl ( 4 ) and (t-BuP)₂PBr ( 5 ) can be obtained from Me₃Sn(t-Bu)P? P(t-Bu)SnMe₃ ( 6 ) and PX₃ (X = Cl, Br). The phosphino-substituted cyclotriphosphanes (t-BuP)₂P? PCl₂ ( 7 ), (t-BuP)₂P? P(t-Bu)Cl ( 8 ), and (t-BuP)₂P? P(t-Bu)I ( 9 ) are accessible by the reaction of 3 with PCl₃ and t-BuPX₂ (X = Cl, I), respectively. 2–9 could be obtained free from phosphorus-containing by-products and were ³¹P-NMR spectroscopically characterized as compounds with a cyclic P₃ skeleton.     

Reaktionen von (tBu)2P?PP(Br)tBu2 mit LiP(SiMe3)2, LiPMe2 und LiMe,LitBu, LinBu

Reactions of (tBu)₂P? P?P(Br)tBu₂ with LiP(SiMe₃)₂, LiPMe₂ and LiMe, LitBu and LinBu The reactions of (tBu)₂P? P?P(Br)tBu₂ 1 with LiP(SiMe₃)₂ 2 yield (Me₃Si)₂P? P(SiMe₃)₂ 4 and P[P(tBu)₂]₂P(SiMe₃)₂ 5 , whereas 1 with LiPMe₂ 2 yields P₂Me₄ 6 and P[(tBu)₂]₂PMe₂ 7 . 1 with LiMe yields the ylid tBu₂P? P?P(Me)tBu₂ (main product) and [tBu₂P]₂PMe 15 . In the reaction of 1 with tBuLi [tBu₂P]₂PH 11 is the main product and also tBuP? P?P(R)tBu₂ 21 is formed. The reaction of 1 with nBuLi leads to [tBu₂P]₂PnBu 17 (main product) and tBu₂P? P?P(nBu)tBu₂ 22 (secondary product).     

ORGANOSTANNOXANE MOTIFS IN CAGES AND SUPRAMOLECULAR ARCHITECTURES

The reactions of n-butyl stannonic acid with(PhO) ₂ P(O)H leads to the formation of a hexameric tin cage [{(n-BuSn) ₃ (PhO) ₃ O} ₂ {HPO ₃ } ₄ ].This reaction involves an in situ P─O bond cleavage and the generation of a [HPO ₃ ] ^2? ion. A direct reaction of six equivalents of n-BuSnO(OH) acid with six equivalents of C ₆ H ₅ OH and four equivalents of H ₃ PO ₃ also leads to the formation of same cage structure. A tetranuclear organooxotin cage[(PhCH ₂ ) ₂ Sn ₂ O(O ₂ P(OH)-t-Bu) ₄ ] ₂ has been assembled by debenzylation involving the reaction of (PhCH ₂ ) ₂ SnCl ₂ ,(PhCH ₂ ) ₂ SnO·H ₂ O or (PhCH ₂ ) ₃ SnCl with two equivalents of t-BuP(O)OH ₂ . A half-cage intermediate [(PhCH ₂ ) ₂ Sn ₂ O(O ₂ P(OH)-t-Bu) ₄ ] has been detected. New organotin cations of the type [n-Bu ₂ Sn(H ₂ O) ₄ ] ²⁺[2,5-Me ₂ -C ₆ H ₃ SO ₃ ]^? ₂ and {[n-Bu ₂ Sn(H ₂ O) ₃ LSn(H ₂ O) ₃ (n-Bu) ₂ ] ²⁺[1,5-(SO ₃ ) ₂ -C ₁₀ H ₆ ] ^2?} have been obtained in the reactions of n-Bu ₂ SnO or (n-Bu ₃ Sn) ₃ O with 2,5-dimethyl sulfonic acid and 1,5-naphthalene disulfonic acid respectively. These organotin cations form interesting supramolecular structures in the solid state as a result of O─H─···O hydrogen bonding.     

Coordination modes of diphosphines in silver(I)–diphosphine complexes mediated by 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz)

Silver (I) complexes [Ag₂(tptz)(dppm)₂(DMF)](BF₄)₂·2DMF (1), [Ag(tptz)(dppe)]_n(BF₄)_n·2nH₂O·nMeOH (2), [Ag₂(tptz)₂(dppp)₂](BF₄)₂ (3) and [Ag₂(tptz)₂(dppb)](BF₄)₂ (4) were obtained from the reactions of AgBF₄ and diphosphine Ph₂P(CH₂) _nPPh₂ (L_pp, n=1–4) in the presence of 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) in MeOH–DMF. Single crystal analyses showed that the closed metallocyclic unit [Ag₂(L_pp)₂]²⁺ with double L_pp bridges was obtained in (1) and (3) with an odd number of n, while an open metallochain (Ag₂L_pp)²⁺ with a single bridge formed in (2) and (4) with n being even. Coordination modes for the diphosphines are directly related to the rigid tptz ligand with a large -system.     

Association,emulsifying, and solubilization properties of amphiphilic hyperbranched poly(acrylic acid) with short polystyrene stickers

Amphiphilic hyperbranched copolymer chains made of large hyperbranched poly(acrylic acid) cores grafted with short polystyrene stickers (HB‐PAA_n‐g‐PS_{n + 1}) with different n values (n = 1, 10, 47) were well prepared and confirmed by size exclusion chromatography, Fourier transform infrared spectroscopy and ¹H nuclear magnetic resonance. The study on the interchain association behavior of these amphiphilic chains indicates that larger HB‐(PAA)_n‐g‐(PS)_{n + 1} copolymer chains have a less tendency to undergo interchain association. Moreover, the simple vial‐inversion and rheological experiments show that the apparent critical gel concentration (C_g) decreases with n, but no sol–gel transition was observed for triblock PS‐PAA‐PS even when the concentration is up to 200 g L^?1. Further transmission electron microscopy study of the latex particles prepared with HB‐(PAA)_n‐g‐(PS)_{n + 1} as surfactant reveals that the latex particles are spherical and narrowly dispersed; while the measured latex particle number (N_p) indicates the surfactant efficiency of HB‐(PAA)₄₇‐g‐(PS)₄₈ is poorer than that of triblock PS‐PAA‐PS (n = 1). Finally, pyrene solubilization measurement shows the solubilization efficiency of HB‐(PAA)_n‐g‐(PS)_{n + 1} copolymers decreases with n, consistent with the previous observed interchain association result. The present study demonstrates that both the chain topology and the styrene weight fraction dominates the final solution properties of amphiphilic HB‐(PAA)_n‐g‐(PS)_{n + 1} chains in aqueous solution. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 128–138     

Synthesis,characterization, and some electrocatalytic properties of heteromultinuclear FeI/RuII Clusters

A series of new heteromultinuclear Fe^I/Ru^II clusters are described. The complexes (η⁶-arene)RuFe₂S₂(CO)₆ (arene = p-cymene 1 , C₆Me₆ 2 ) and Fe₂[μ-S (Cp*Ru)(CO)₂]₂(CO)₆ (Cp* = η⁵-C₅Me₅) ( 3 ) were prepared by the reduction reactions of (μ-S)₂Fe₂(CO)₆ with 2 equiv of LiHBEt₃, followed by treatment (μ-SLi)₂Fe₂(CO)₆ with ruthenium-arene complexes Ru₂(μ-Cl)₂Cl₂(η⁶-arene)₂ or Cp*Ru (CO)₂Cl in 22–33% yields. Further reactions of 1 and 2 with 1 equiv of triphenylphosphine in the presence of the decarbonylating agent Me₃NO·2H₂O, afforded the corresponding monophosphine-substituted Fe^I/Ru^II complexes (η⁶-arene)RuFe₂S₂(CO)₅(Ph₃P) (arene = p-cymene 4 , C₆Me₆ 5 ) in 75% and 78% yields. While treatment of parent complex 1 or 2 with 1 equiv of diphosphine Ph₂PCH₂PPh₂ (dppm) in xylene at reflux temperature resulted in the formation of the diphosphine-bridged RuFe₂S₂(CO)₉ derivate RuFe₂S₂(CO)₇(dppm) ( 6 ). The possible pathway for the formation was proposed. Two isomers of novel macrocyclic complexes involve the (η⁶-arene) Ru-bridged quadruple-butterfly Fe/S clusters [{μ-S (CH₂)₃S-μ}{(μ-CS₂)Fe₂(CO)₆}₂]₂[(η⁶-arene)Ru]₂ (arene = p-cymene 7a and 7b , C₆Me₆ 8a and 8b ) were isolated by reactions of two μ-CS₂-containing dianion [{μ-S (CH₂)₃S-μ}{(μ-S=CS)Fe₂(CO)₆}₂]²⁻ with [Ru₂(μ-Cl)₂Cl₂(η⁶-arene)₂], in which the propylene groups are attached to two S atoms by ee and ea types of bonds respectively. All the new complexes 1 – 8 have been characterized by elemental analysis, spectroscopy, and particularly for 1 – 6 , 7b and 8a by X-ray crystallography. In addition, the electrochemical properties of representative complexes 1 – 4 and 6 have been investigated.     

Homo- and hetero-bimetallic glycolates and triethanolaminates of niobium

[Nb(OⁱPr)₅] reacts with 2,5-dimethylhexane-2,5-diol (LH₂), 2,3-dimethylbutane-2,3-diol (L¹H₂) and triethanolamine (teaH₃) in different stoichiometric ratios to yield complexes of the types: [Nb(OⁱPr)₃(L)] (1), [Nb(OⁱPr)(L)₂] (2), [Nb(L)₂(LH)] (3), [Nb(L¹)₂(L¹H)] (4) and [Nb(tea)(teaH)] (5). Equimolar reactions of (3), (4) and (5) with Al(OⁱPr)₃, Ti(OⁱPr)₄ and [Ta(OⁱPr)₅] yield novel heterobimetallic isopropoxide-glycolate (6)–(9) and -triethanolaminate (10)–(12) derivatives. Reactions in appropriate molar ratios of (1), (2) and (10) with alkoxyethanols [ROC₂H₄OH; R = Me, Et] and acetylacetone [acacH] give derivatives [(MeOC₂H₄O)₃Nb(L)] (13), [(acac)Nb(L)₂] (14), [Nb(tea)₂{Al(OC₂H₄OMe)₂}] (15), [Nb(tea)₂{Al(OC₂H₄OEt)₂}] (16) and [Nb(tea)₂{Al(acac)₂}] (17). The complexes (6), (8) and (10) on reaction with an excess of t-BuOH give the tert-butoxo analogues (18), (19) and (20), respectively. These new derivatives have been characterized by elemental analyses, spectroscopic studies and molecular weight measurements.     

First Observation of an Inverse Ruddlesden‐Popper Series: (A3n+1ONn−1)Bin+1 with A = Sr,Ba and n = 1, 3

Single crystals ((Ba_0.78(1)Sr_0.22)₄O)Bi₂ and ((Ba_0.62(1)Sr_0.38)₁₀N₂O)Bi₄ were successfully prepared from melt beads of Ba, Sr, and Bi in nitrogen atmosphere with oxygen impurities. The phases can be prepared in single phase from the appropriate mixtures of alkaline‐earth metal, bismuth, and bismuth oxide upon heating in pure nitrogen atmosphere. ((Ba_0.78(1)Sr_0.22)₄O)Bi₂ crystallizes in the K₂NiF₄ structure type (space group I4/mmm, No. 139, a = 522.34(5) pm, c = 1844.0(2) pm, Z = 2, R_gt(F) = 0.039) with layers of vertex‐sharing octahedra ((Ba,Sr)_4/2Ba₂O). ((Ba_0.62(1)Sr_0.38)₁₀N₂O)Bi₄ crystallizes as an isotype of Sr₄Ti₃O₁₀ (space group I4/mmm, No. 139, a = 531.3(1) pm, c = 3983.2(4) pm, Z = 2, R_gt(F) = 0.050) containing slabs of three layers of vertex‐sharing octahedra further connected via corners. These compounds are interpreted in terms of members of an inverse Ruddlesden‐Popper series with the general formula n (A₃ON_n?1)Bi · ABi or (A_3n+1ON_n?1)Bi_n+1, respectively, with n = 1, 3. Partial order of the alkaline‐earth metal ions is analyzed.     

Schrittweise Darstellung von verzweigten tripodalen Chlor‐Methyl‐Siloxanen der allgemeinen Formel tBuSi[{OSiMe2}yOSiMe3–xClx]3 [x = 0–3; y = 0–2] sowie Synthese der Silanole tBuSi[(OSiMe2)xOH]3 [x = 1, 2] und des bicyclischen Siloxans tBuSi(OSiMe2O)3SitBu

The branched tripodal chloro‐methyl‐siloxanes of the general formula tBuSi[{OSiMe₂}_yOSiMe_3–xCl_x]₃ [x = 0–3; y = 0–2] were synthesized, starting with tert‐Butyl‐trisilanol ( 1 ). The treatment of 1 with the chloro‐methyl‐silanes (Me_3–xSiCl_x+1) (x = 0–3) in the presence of triethylamine leads to the compounds tBuSi(OSiMe₂Cl)₃ ( 2 ), tBuSi(OSiMeCl₂)₃ ( 3 ) and tBuSi(OSiCl₃)₃ ( 4 ). The siloxanes 2 – 4 are colourless oily liquids, which can be purified by distillation. Their yields decrease with the number of chloro substituents. In the reaction of compound 2 with three equivalents of water the silantriol tBuSi(OSiMe₂OH)₃ ( 5 ) is generated which is used to create the branched tripodal chloro‐methyl‐siloxanes tBuSi(OSiMe₂OSiMe₃)₃ ( 6 ), tBuSi(OSiMe₂OSiMe₂Cl)₃ ( 7 ), tBuSi(OSiMe₂OSiMeCl₂)₃ ( 9 ) and tBuSi(OSiMe₂OSiCl₃)₃ ( 10 ). Compound ( 7 ) is only a side product with a yield of 25 %., The cyclic tBuSi[{(OSiMe₂)₂Cl}(OSiMe₂)₃O] ( 8 ) can be isolated and characterised. The transformation of the compound tBuSi(OSiMe₂OSiMe₂Cl)₃ ( 7 ) into the trisilanol tBuSi(OSiMe₂OSiMe₂OH)₃ ( 11 ) allows to prepare the tripodale siloxane tBuSi(OSiMe₂OSiMe₂OSiMe₃)₃ ( 12 ) in good yields., The reaction of tBuSi(OSiMe₂Cl)₃ ( 2 ) with tert‐butyl trisilanol 1 leads to the formation of bicyclic tBuSi(OSiMe₂O)₃SitBu ( 13 ). An X‐ray structure determination on 13 reveals a [3.3.3]‐bicycle with a C₃ axis, which crystallizes in the cubic crystal system in the space group Pa . The reported compounds 2 – 13 were characterised by NMR‐ and IR spectroscopy ( 5 , 11 ) and show correct elemental analyses. The ²⁹Si‐NMR‐data of the compounds show interesting trends with respect to the Si–O chain length and the chloro substistuents.     

The Syntheses and crystal structures of trans-dichlorobis (10-thiabenzo-15-crown-5)-palladium(Ⅱ)and trans-dichlorobis-(10-selenabenzo-15-crown-5)palladium(Ⅱ)

The preparation and X-ray crystal structures of the adducts of 10-thiabenzo-15-crown-5 and 10-selenabenzo-15-crown-5 with PdCl2 are reported. [PdCl2(C14H20O4S)2] (1): or-thorhombic, space group Pbca with cell dimensions of a=17.285(5), 6=8.354(3), c=21.689(4) A, K=3131.9 A3, Z=4;R=0.0330 for 2301 reflections with I > 3o(I), [PdCl2(C14H2oO4Se)2] (2): monoclinic, space group P21/n with cell dimensions of a=18.928(4), b=8.912(3), c=9.813(2) A, β=96.90(2)0, V=1643.4 A3, Z=2; R=0.0289 for 2617 reflections with I> 3σ(I), Both complexes are monomeric, square-planar palladiurn(Ⅱ) compounds with the Pd(Ⅱ) ion situating on a crystal-lographic inversion centre, and the crown ligands all adopt the axial coordination with the Pd-S bond of 2.3233(7) A and the Pd-Se bond of 2.4357(3) A. Their complexing characteristics are discussed in brief.     

Bridging Nonaselenium Ring in [Se9(IrBr3)2], and Three Modifications of the Mononuclear Complex [IrBr3(SeBr2)3]

The reaction of iridium powder with an excess of selenium and SeBr₄ yielded lustrous, vermillion crystals of the mononuclear iridium complex [IrBr₃(SeBr₂)₃]. The transition metal is coordinated octahedrally by three SeBr₂ and three bromide ligands with facial or meridional configuration. Three different modifications were obtained under similar conditions: a‐fac‐IrBr₃(SeBr₂)₃, space group P$\bar{1}$ , with a = 789.4(1) pm, b = 830.4(1) pm, c = 1334.4(1) pm, α = 81.634(5)°, β = 84.948(5)°, γ = 67.616(4)°; m‐fac‐IrBr₃(SeBr₂)₃, space group P2₁/n, with a = 1205.3(1) pm, b = 962.4(1) pm, c = 1383.9(1) pm, β = 91.114(3)°; mer‐IrBr₃(SeBr₂)₃, space group P2₁/n with a = 859.7(1) pm, b = 1284.3(1) pm, c = 1437.5(1) pm, β = 94.427(3)°. A lower bromine content in the starting composition resulted in shiny, deep‐red crystals of [Se₉(IrBr₃)₂]. X‐ray diffraction on a single‐crystal revealed a tetragonal lattice (space group I4₁/a) with a = 1245.4(1) pm and c = 2486.8(1) pm at 296(1) K. In the [Se₉(IrBr₃)₂] complex, a crown‐shaped uncharged Se₉ ring coordinates two iridium(III) cations as a bridging bis‐tridentate ligand. Three terminal bromide ions complete the distorted octahedral coordination of each transition metal atom.     

Reactions of β-keto sulfones with t-butyl aluminum compounds: Reinvestigation of tri-t-butyl aluminum synthesis

t-Butyl derivatives play a significant role in the organometallic chemistry of group 13 metals. It was shown on the basis of reactions of t-Bu₃Al·OEt₂ with [p-RC₆H₄S(O)₂C(H)₂C(Ph) = O] (where R = CH₃, Cl) β-keto sulfones that the structure of the reaction products depends on the purity of the aluminum compound used. In the reactions, in addition to the expected complexes [p-RC₆H₄S(O₂)C(H) = C (Ph)-OAl(t-Bu)₂] [where R = CH₃ ( 2 ); R = Cl ( 4 )] possessing β-keto sulfone ligands, complexes with β-hydroxy sulfone ligands [p-RC₆H₄S(O₂)C(H)₂-C (Ph)-OAl(t-Bu)₂] [where R = CH₃ ( 1 ); R = Cl ( 3 )] were formed. Compounds 1 and 3 were the result of the hydroalumination reaction of the β-keto sulfone ligands with t-Bu₂AlH, which is an impurity of t-Bu₃Al. These compounds are obtained, for the first time, as intermediate products in the hydrogenation reaction of β-keto sulfones. In this work, during t-Bu₃Al·OEt₂ production t-Bu₂AlH·OEt₂ formed as a by-product. Re-examination of reaction conditions of AlCl₃ with t-BuMgCl resulted in a control of the t-Bu₂AlH·OEt₂ by-product content in t-Bu₃Al·OEt₂.     

Chromium(V) Oxide Trichloride,and some Pentachlorido‐­oxido‐chromate(V) Salts: Structures and Spectroscopic ­Characterization

Crystalline CrOCl₃ contains [Cl₂OCr(μ‐Cl)₂CrOCl₂] molecules with two square pyramidal CrOCl₄ units sharing a common edge and with the Cr–O arranged anti, a new structure type for transition metal MOX₃ compounds. Crystals are monoclinic with space group P2₁/c, Z = 4, with a = 5.735(5), b = 13.738(7), c = 11.318(4) Å, α = 90°, β = 98.346(6)°, γ = 90°. Its IR and UV/Vis spectra are reported and compared with those of the C_3v monomer found in the gas phase. Structures are also reported for M₂[CrOCl₅] (M = Cs or Rb) and show a pseudo‐octahedral anion. Cs₂[CrOCl₅] adopts a K₂PtCl₆‐type structure with [CrOCl₅]^2– ions randomly orientated, but Rb₂[CrOCl₅] is orthorhombic with space group Pnma with a = 13.6471(7), b = 9.9175(5), and c = 6.9562(4) Å. Rietveld refinement of the data on the rubidium salt gave Cr–O = 1.628(1), Cr–Cl_transO = 2.652(7), Cr–Cl_transCl = 2.239(8)–2.342(3) Å. Corresponding Cr^V oxide bromide species do not form.     

Metal-Rich Metallaboranes: Synthesis,Structure, and Bonding of Heteronuclear Trimetallic Clusters containing (μ3-BH) Ligand

Building upon our earlier results on the chemistry of nido-1,2-[(Cp*RuH)₂B₃H₇] (Cp*=ɳ⁵-C₅Me₅) (nido- 1 ) with different transition metal carbonyls, we continued to investigate the reactivity with group 7 metal carbonyls under photolytic condition. Photolysis of nido- 1 with [Mn₂(CO)₁₀] led to the isolation of a trimetallic [(Cp*Ru)₂{Mn(CO)₃}(μ-H)(μ-CO)₃(μ₃-BH)] ( 2 ) cluster with a triply bridging borylene moiety. Cluster 2 is a rare example of a tetrahedral cluster having hydrido(hydroborylene) moiety. In an attempt to synthesize the Re analogue of 2 , a similar reaction was carried out with [Re₂(CO)₁₀] that yielded the trimetallic [(Cp*Ru)₂{Re(CO)₃}(μ-H)(μ-CO)₃(μ₃-BH)] ( 3 ) cluster having a triply bridging borylene unit. Along with 3 , a trimetallic square pyramid cluster [(Cp*Ru)₂{Re(CO)₃}(μ-H)₂(μ-CO)(μ₃,ɳ²-B₂H₅)] ( 4 ), and heterotrimetallic hydride clusters [{Cp*Ru(CO)₂}-{Re(CO)₄}₂(μ-H)] ( 5 ) and [{Cp*Ru(CO)}{Re(CO)₄}₂(μ-H)₃] ( 6 ) were isolated. Cluster 4 is a unique example of a M₂M′B₂ cluster having diboron capped Ru₂Re-triangle. The hydride clusters 5 and 6 have triangular RuRe₂ frameworks with one and three μ-Hs respectively. All the clusters have been characterized by using mass spectrometry, ¹H, ¹¹B{¹H}, ¹³C{¹H} NMR and IR spectroscopies analyses and the structures of clusters 2 – 6 have been unambiguously established by XRD analyses. Furthermore, to understand the electronic, structural, and bonding features of the synthesized metal-rich clusters, DFT calculations have been performed.     

Beiträge zur Chemie des Phosphors. 128. Synthese des Diphosphastanna-cyclopropans (t-BuP)2Sn(t-Bu)2

Contributions to the Chemistry of Phosphorus. 128. Synthesis of the Diphosphastanna-cyclopropane (t-BuP)₂Sn(t-Bu)₂ The first three-membered P₂Sn heterocycle, 1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastanna-cyclopropane (1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastannirane) ( 1 ), has been synthesized by [2+1] cyclocondensation of K(t-Bu)P—P(t-Bu)K with (t-Bu)₂SnCl₂. 1 is stable at room temperature. Besides, (t-BuP)₂[Sn(t-Bu)₂]₂ ( 2 ), (t-BuP)₄Sn(t-Bu)₂ ( 3 ), and (t-BuP)₄ are formed. In the reaction with Et₂SnCl₂, the six-membered ring compound [(t-BuP)₂SnEt₂]₂ ( 4 ) is the main-product; the four- and five-membered cyclostannaphosphanes (t-BuP)₃SnEt₂ ( 5 ) and (t-BuP)₃(SnEt₂)₂ ( 6 ) are also formed. 1 could be isolated in the pure state and has been unambiguously characterized as a three-membered heterocycle with a P₂Sn skeleton. The ³¹P-NMR parameters of the other new cyclostannaphosphanes 2–6 are reported.     

Beiträge zur Chemie des Phosphors. 159. Über die Reaktion des Diphosphaborirans (t-BuP)2BN(i-Pr)2 mit Kalium bzw. Kaliumnaphthalid

Contributions to the Chemistry of Phosphorus. 159. On the Reaction of the Diphosphaborirane (t-BuP)₂BN(i-Pr)₂ with Potassium or Potassium Naphthalenide The reaction of (t-BuP)₂BN(i-Pr)₂ with potassium or K-naphthalenide in tetrahydrofuran leads to K(t-Bu)P? ;BN(i-Pr)₂? P(t-Bu)K ( 1 ) via P? ;P bond cleavage of the three-membered ring skeleton. Above ? 78°C 1 changes into the asymmetric compound K(t-Bu)P? ;P(t-Bu)? BHN(i-Pr)₂ ( 2 ). In dimethoxyethane additionally the monometallated diphosphaborirane K(t-Bu)P₂BN(i-Pr)₂ ( 3 ) is formed. 1 and 3 , which could be isolated free from other phosphorus containing compounds, as well as the corresponding silylphosphanes Me₃Si(t-Bu)P? ;BN(i-Pr)₂? ;P(t-Bu)SiMe ₃ ( 4 ) and Me₃Si(t-Bu)P₂BN(i-Pr)₂ ( 5 ) were characterized by NMR spectroscopy. Protolysis of 3 or 5 leads to a decomposition of the three-membered ring skeleton with formation of H(t-Bu)P? ;PH₂.     

NEW POLYHETEROATOMIC CYCLIC MOLECULES CONTAINING ELEMENTS of the 13.–16. GROUP

During studies of the reactions of ─N(H)SiMe ₃ and ─N(Me)SiMe ₃ derivatives of Cl ₃ PNSO ₂ Cl with acetonitrile and BCl ₃ we have obtained six-membered polyheteroatomic cycles ?P(Cl ₂ )NSO ₂ (Cl)N(H) C(Me)N? and ?P(Cl ₂ )NS(O)(Cl)OB(Cl ₂ )N(Me)?.^{1, 2} In the system Ph ₂ PCl ₃ , H ₂ NSO ₂ Cl and HN(SiMe ₃ ) ₂ we have identified and isolated several P─N─S cycles, e.g. the reaction of Ph ₂ PCl ₃ with H ₂ NSO ₂ Cl gives Ph ₂ ClPNSO ₂ Cl³ which with HN(SiMe ₃ ) ₂ reacts to ?S(O ₂ )N(H)P(Ph) ₂ N(H)SO ₂ N(H)P(Ph) ₂ N(H)?, ?S(O ₂ )N(H)S(O ₂ )N(H)P(Ph) ₂ N(H)P(Ph) ₂ N(H)? and ?[S(O ₂ )N(H) P(Ph) ₂ NP(Ph) ₂ N(H)]⁺? Cl^?; Ph ₂ PCl ₃ with HN(SiMe ₃ ) ₂ gives N[P(Ph) ₂ N(H)SiMe ₃ ] ₂ ⁺ Cl^?, and H ₂ NSO ₂ Cl with HN(SiMe ₃ ) ₂ leads to SO ₂ (NHSiMe ₃ ) ₂ . The reaction of Ph ₂ PCl ₃ with HN(SiMe ₃ ) ₂ gives N(P(Ph) ₂ NHSiMe ₃ ) ₂ Cl in a very good yield which was further used to syntheses of metal-containing heterocycles. By the reaction of N[P(Ph) ₂ N(H)SiMe ₃ ] ₂ ⁺Cl^? with some covalent halogenides we have obtained six-membered heterocycles containing B, As, In, and Sn. The same cyclic compounds can also obtained by the reaction of N[P(Ph ₂ )NH ₂ ] ₂ ⁺Cl^? or HN(P(R ₂ )N(H)SiMe ₃ ) ₂ with covalent halogenides.^4?6 However, the synthetic route via N[P(Ph) ₂ NHSiMe ₃ ] ₂ ⁺Cl^? is more convenient and gives the compounds in almost quantitative yields. The identity of all compounds was unambiguously establised by their X-ray structure determination.     

Diversity of Strontium Nitridogermanates(IV): Novel Sr4[GeN4], Sr8Ge2[GeN4], and Sr17Ge2[GeN3]2[GeN4]2

Single crystals of three new strontium nitridogermanates(IV) were grown in sealed niobium ampules from sodium flux. Dark red Sr₄[GeN₄] crystallizes in space group P2₁/c with a = 9.7923(2) Å, b = 6.3990(1) Å, c = 11.6924(3) Å and β = 115.966(1)°. Black Sr₈Ge₂[GeN₄] contains Ge^4– anions coexisting with [Ge^IVN₄]^8– tetrahedra and adopts space group Cc with a = 10.1117(4) Å, b = 17.1073(7) Å, c = 10.0473(4) Å and β = 115.966(1)°. Black Sr₁₇Ge₆N₁₄ features the same anions alongside trigonal planar [Ge^IVN₃]^5– units. It crystallizes in P1 with a = 7.5392(1) Å, b = 9.7502(2) Å, c = 11.6761(2) Å, α = 103.308(1)°, β = 94.651(1)° and γ = 110.248(1)°.     

Organometallic Molecular Wires with Thioacetylene Backbones,trans-{RS-(C≡C)n}2Ru(phosphine)4: High Conductance through Non-Aromatic Bridging Linkers

In this work, the design, synthesis, and single-molecule conductance of ethynyl- and butadiynyl-ruthenium molecular wires with thioether anchor groups [RS=n-C₆H₁₃S, p-tert-Bu−C₆H₄S), trans-{RS−(C≡C)_n}₂Ru(dppe)₂ (n=1 ( 1^R ), 2 ( 2^R ); dppe: 1,2-bis(diphenylphosphino)ethane) and trans-(n-C₆H₁₃S−C≡C)₂Ru{P(OMe)₃}₄ 3^hex ] are reported. Scanning tunneling microscope break-junction study has revealed conductance of the organometallic molecular wires with the thioacetylene backbones higher than that of the related organometallic wires having arylethynylruthenium linkages with the sulfur anchor groups, trans-{p-MeS−C₆H₄-(C≡C)_n}₂Ru(phosphine)₄ 4 ⁿ (n=1, 2) and trans-(Th−C≡C)₂Ru(phosphine)₄ 5 (Th=3-thienyl). It should be noted that the molecular junctions constructed from the butadiynyl wire 2^R , trans-{ Au −RS−(C≡C)₂}₂Ru(dppe)₂ ( Au : gold metal electrode), show conductance comparable to that of the covalently linked polyynyl wire with the similar molecular length, trans-{ Au −(C≡C)₃}₂Ru(dppe)₂ 6³ . The DFT non-equilibrium Green's function (NEGF) study supports the highly conducting nature of the thioacetylene molecular wires through HOMO orbitals.