The Reaction of Bunsen's Cacodyl Disulfide,Me2As(S)‐S‐AsMe2, with Iodine: Preparation and Properties of Dimethylarsinosulfenyl Iodide,Me2As‐S‐I

Bunsen's cacodyl disulfide, Me₂As(S)‐S‐AsMe₂ ( 1 ), reacted with iodine giving the novel dimethylarsinosulfenyl iodide, Me₂As‐S‐I ( 3 ) although theoretical calculations indicated that the As^V compound Me₂As(S)‐I ( 4 ) was more stable in the gas phase. The oily product was stable neat and as a solution in CDCl₃ at +4 °C and –20 °C for at least 15 d. Light, H₂O, H₂O₂, and Zn dust, but not NaI or Ag, decomposed it. Compound 3 did not interact with Ph₃N, with Ph₂NH and PhNH₂ it interacted but not reacted. 3 was decomposed by piperidine, with pyridine and 4‐dimethylaminopyridine it interacted and produced Me₂As‐SS‐AsMe₂ ( 2 ) and I₂ that formed charge transfer complexes Base · I₂, whereas Et₃N decomposed 3 , and 3Et₃N · 2I₂ was isolated. 3 was desulfurized by Ph₃P and (Me₂N)₃P completely, and by (PhO)₃P and (PhS)₃P partially. The reactions of 3 with (Me₂N)₃P, (PhS)₃P, and (EtO)₃P were complicated. From the As^III nucleophiles, only Ph₃As was bound, while (PhS)₃As reacted slowly in a complicated manner with 3 . No interaction of 3 with MeOH or PhOH was observed but NaOH, Ag₂O, and PhONa decomposed it. Thiophenol produced traces of Me₂As‐SPh ( 10 ) and sodium thiophenolate attacked mainly at As^III of 3 . Thus, externally stabilized sulfenium ions of the type Me₂As‐S‐Nu⁺I^– were not obtained.     

The Other Face of Bunsen's Cacodyl Disulfide,Me2As(S)‐S‐AsMe2: The Lewis‐Base Behaviour Towards Heavy Metal Cations

The reaction of Bunsen's cacodyl disulfide, Me₂As(S)‐S‐AsMe₂, with heavy metal cations in methanol produces insoluble salts (complexes) of dimethyldithioarsinic acid, Me₂AsS₂H, and dimethyl arsenium ion, Me₂As:⁺. This arsenium ion prefers to react with Me₂As(S)‐S‐AsMe₂, when in excess, compared to AcO^? or MeOH/H₂O and it is also reactive towards sulfur (S_x, x = 1‐8) producing the stabilized dimethylarsino sulfenium cation, . The complexes (Me₂AsS₂)_xM (x = 1 or 2) are unstable in the presence of their own heavy metal cations decomposing to colored solids. In an attempt to prepare salts of Me₂AsSH, the reactions of (Me₂AsS₂)_xM with triphenylphosphine and trimethyl phosphite gave the metal sulfide and Me₂As‐S‐AsMe₂ instead.     

Syntheses and Crystal Structures of New Palladium(II) and Platinum(IV) Trialkylsulfonium Compounds

The reactions of platinum(II) iodide with triethyl‐ or trimethylsulfonium iodide in acetonitrile solution lead to the formation of crystalline products (Et₃S)₂[PtI₆] ( 1 ) and [Me₃S]₂[PtI₆]·CH₃CN ( 2 ), respectively. The formation of Pt(IV) complexes may be explained either by disproportionation of PtI₂ or oxidation by oxygen. Palladium(II) iodide reacts with triethylsulfonium iodide to give the palladium(II) complex (Et₃S)₂[PdI₄] ( 3 ). The crystal structures of 1 – 3 were determined by single‐crystal X‐ray diffraction. In the crystal structures, the compounds 2 and 3 exhibit an extensive hydrogen‐bonding network.     

Über den Einfluß der Substituenten im (R3Si)2(P–Si)R2Cl auf Bildung und Eigenschaften der Hexasila-tetraphosphadantane und deren 31P-NMR-Spektren

The Effect of the Substituents in (R₃Si)₂P–SiR₂Cl on the Formation and the Properties of the Hexasilatetraphospha-adamantanes and their ³¹P-NMR Spectra The thermolysis of (Me₃Si)₂P–SiEt₂Cl 4 at 300°C leads to the silylphosphanes with adamantane structure (Et₂Si)_x(Me₂Si)_6–x (x = 0–6), aside of (Me₃Si)₃P, (Et₂MeSi) (Me₃Si)₂P, (Et₂MeSi)₂(Me₃Si)P and Me₃SiCl, Et₂SiCl, Et₂MeSiCl. Due to the different positions of the Et₂Si-bridges in the adamantane cage the compounds featuring x = 2–4, form isomers. The thermolysis of (Me₃Si)₂P–SiEtMeCl 14 occurs analogously and leads to the adamantanes (EtMeSi)_x (Me₂Si)_6–xP₄ (x = 0–6). The introduction of the SiEtMe group causes the existence of chiralic isomers of the compounds featuring x = 2–6. From (Et₃Si)₂P–SiEt₂Cl 24 (Et₂Si)₆P₄ is obtained. The thermolyses of (Me₃Si)₂P–SiPh₂Cl 25 and [(Me₃Si)P–SiPh₂]₂ do not enable the formation of adamantanes with SiPh₂-bridges. They rather lead to Me- and Ph-substituted trisilylphosphanes. The syntheses of the starting compounds 4, 14, 24 , and 25 are reported. The ³¹P-NMR spectra of silylphosphanes with adamantane structure show, that the linear increase of the ³¹P-chemical shift values as dependent on the rising number of Et groups, which is observed in partially Et-substituted methyltrisilylphosphanes, allows the prediction of the δ³¹P values of the specific P atoms in an adamantane cage, heeding both the position and the direction of the SiEt groups in the particular molecule.     

Synthesen und Kristallstrukturanalysen von Tetraalkylphosphonium-, -arsonium- und -stiboniumtriiodiden

Syntheses and Crystal Structure Analyses of Tetraalkyl Phosphonium, Arsonium, and Stibonium Triiodides The reaction of Me₄EI (E?P, As), Me₃EtSbI, Me₂Et₂SbI, MeEt₃SbI, or Et₄SbI with I₂ in absence of solvent gives Me₄PI₃ (E?P, As), Me₃EtSbI₃, Me₂Et₂SbI₃, MeEt₃SbI₃, or Et₄SbI₃. Me₄SbI₃ is formed in a reversible reaction by addition of I₂ to (Me₄Sb)₃I₈ or by reaction of a solution of Me₄SbI in ethanol with I₂ in benzene. The crystal structures of Me₄EI₃ (E?P, Sb), and Me₃EtSbI₃ and the syntheses of the novel compounds are reported.     

Reaktion von N-Alkyl-bis(difluorophosphoryl)amiden,RN(POF2)2, mit silylierten Nukleophilen und Et2NSF3

Reaction of N-Alkyl-bis(difluorophosphoryl)amides, RN(POF₂)₂, with Silylated Nucleophiles and Et₂NSF₃ N-Alkyl-bis(difluorophosphoryl)amides, RN(POF₂)₂ (R = Me, Et), react in any case with silylated nucleophiles such as Me₃SiOMe and Me₃SiNEt₂ under cleavage of the PNP bridge forming derivatives of di- and monofluorophosphoric acid. In their reaction with Et₂NSF₃ (RNPF₃)₂ and OPF₃ or PF₅, resp., are obtained. The compounds F₂P(O)? NR? PF₄ and RN(PF₄)₂ postulated as intermediates are not stable.     

Neue nitridoverbrückte Dreikernkomplexe des Rheniums

New Trinuclear Rhenium Complexes with Bridging Nitrido Ligands Trinuclear complexes with bridging nitrido ligands between the rhenium atoms are formed when [ReN(Et₂dtc)₂ · (Me₂PhP)] (Et₂dtc^– = N,N‐diethyldithiocarbamate) reacts with TlCl or Pr(O₃SCF₃)₃. [Cl(Me₂PhP)₂(Et₂dtc)Re≡N–Re(N) · Cl₂(Me₂PhP)–N≡Re(Et₂dtc)(Me₂PhP)₂Cl] and [(Et₂dtc)₂ · (Me₂PhP)Re≡N–Re(N)(Et₂dtc)(Me₂PhP)–N≡Re(Me₂PhP) · (Et₂dtc)₂]⁺ contain two almost linear, asymmetric nitrido bridges. Additional, terminal nitrido ligands are located at the middle rhenium atoms.     

Reactions of silylium ions with nucleophiles

Transformation of the diethylsilylium cation Et₂Si⁺H into ethyl-and dimethylsilylium ions EtSi⁺H₂ and Me₂Si⁺H in reactions with nucleophiles is induced by electron-donor compounds. Their activity increases in the order Bu₂O < BuOH < (Me₃Si)₂O < C₆H₆ and is determined by the structure of the intermediate adduct and electron density distribution in it. Qualitative estimation shows that the affinity of the tritiated diethylsilylium cation Et₂Si⁺T for a nucleophile increases in the order C₆H₆ < BuOH < Bu₂O < (Me₃Si)₂O. The higher affinity of the Et₂Si⁺H cation for hexamethyldisiloxane compared to dibutyl ether, at similar basicity of the nucleophiles, is attributable to the higher charge of the oxygen atom in (Me₂Si)₂O.     

Acyl iodides in organic synthesis. Reaction of acetyl iodide with thiols

The direction of reactions of acetyl iodide with aliphatic, aromatic, and heterocyclic thiols is determined by the thiol acidity and steric factors. Acetyl iodide reacted with aliphatic thiols, including trialkylsilylsubstituted derivatives R(CH₂) _n SH (R = Me, n = 3; R = Me₃Si, n = 3; R = Et₃Si, n = 2), to give the corresponding ethanethioates R(CH₂) _n SCOMe. Benzenethiol was oxidized with acetyl iodide to diphenyl disulfide. The reaction of acetyl iodide with 2-sulfanylethanol afforded 2-(2-iodoethyldisulfanyl)ethyl acetate as a result of three consecutive-parallel processes: acylation, iodination, and oxidation of the initial compound. 1,3-Benzothiazole-2-thiol reacted with acetyl iodide only at the nitrogen atom to give quaternary salt, whereas the SH group remained intact.     

Gemischtligandkomplexe des Rheniums. IX. Reaktionen am Nitridoliganden von [ReN(Me2PhP)(Et2dtc)2]. Synthese,Charakterisierung und Kristallstrukturen von [Re(NBCl3)(Me2PhP)(Et2dtc)2], [Re(NGaCl3)(Me2PhP)(Et2dtc)2] und [Re(NS)Cl(Me2PhP)2(Et2dtc)]

Mixed-ligand Complexes of Rhenium. IX. Reactions on the Nitrido Ligand of [ReN(Me₂PhP)(Et₂dtc)₂]. Synthesis, Characterization, and Structures of [Re(NBCl₃)(Me₂PhP)(Et₂dtc)₂], [Re(NGaCl₃)(Me₂PhP)(Et₂dtc)₂], and [Re(NS)Cl(Me₂PhP)₂(Et₂dtc)] BCl₃, GaCl₃ and S₂Cl₂ react with the well-known [ReN(Me₂PhP)(Et₂dtc)₂] by attack of the nucleophilic nitrido ligand. Final products of these reactions are [Re(NBCl₃)-(Me₂PhP)(Et₂dtc)₂], [Re(NGaCl₃)(Me₂PhP)(Et₂dtc)₂], and [Re(NS)Cl(Me₂PhP)₂Et₂dtc)] which have been studied by mass spectrometry, IR spectroscopy and X-ray diffraction. [Re(NBCl₃)(Me₂PhP)(Et₂dtc)₂] crystallizes in the triclinic space group P1 , Z = 2, a = 8.151(6), b = 9.935(8), c = 18.67(1) Å; α = 94.42(4), β = 97.09(1), γ = 101.35(4)°. The coordination geometry is a distorted octahedron. The equatorial coordination sphere is occupied by one phosphorus and three sulphur atoms. The fourth sulphur atom is in trans position to the Re?N? B moiety. The almost linear Re?N? B unit has an Re?N? B angle of 170.5(3)° with a Re? N bond length of 1.704(3) Å. The analogous [Re(NGaCl₃)(Me₂PhP)(Et₂dtc)₂] crystallizes in P2₁/c with a = 8.138(3), b = 18.279(2), c = 19.880(6) Å; β = 99.81(2)°; Z = 4. Rhenium has a distorted octahedral environment. The Re? N? Ga bond is slightly bent with an angle of 154.5(4)° and a Re? N bond length of 1.695(6) Å. [Re(NS)Cl(Me₂PhP)₂(Et₂dtc)] crystallizes in the triclinic space group P1 , Z = 4, a = 9.514(2); b = 16.266(5); c = 18.388(3) Å; α = 88.75(2), β = 76.59(2), γ = 85.50(2)° with two crystallographically independent molecules in the asymmetric unit. Rhenium has a distorted octahedral environment with the chloro ligand in trans position to the almost linear thionitrosyl group. The Re?N bond lengths are 1.795(6) and 1.72(1) Å, respectively, and the N?S distances are 1.55(1) and 1.59(1) Å, respectively.     

Solvent-dependent tautomerism of the inverted isomer of <Emphasis Type="Italic">meso</Emphasis>-tetraphenylporphine: Effect of the polarity of the medium

It is found that aza-imino tautomerism (a ? b) of the inverted porphyrinoids and its mechanism are, along with the stability of tautomeric forms in the Solv–B system, determined by the nature of a base B and the polarity of a solvent Solv. It is shown that the transition from the C₆H₆–B system to MeCN–B is characterized by an approximate doubling of stability constants K_T of the imine form (b), and by a change of the number of molecules B involved in the process (from two to one). According to quantum-chemical data (DFT, B3LYP, CC-pVDZ) and the results from spectral measurements (electronic absorption spectra, EAS), the stability of tautomer b (imino form) falls in the series of solvents DMF > Py ~ Et₂NH > MeCN > Me₂CO, and tautomer a is to a lesser extent stabilized in the given media by electron donors through the formation of hydrogen bonds (except for Me₂CO: DMF > Py ? Me₂CO ? MeCN, Et₂NH).     

Zur reaktion von metallkoordiniertem kohlenmonoxid mit yliden: XIV. Eisenacyl-phosphor-ylide mit elektronenreicher organometallgruppierung

Treatment of [C₅Me₅(CO)₃Fe]BF₄ (I) with the phosphines Me₃P and Et₃P under thermal or photochemical conditions yields the novel iron salts [C₅Me₅-(CO)₂(R₃P)Fe]BF₄ (R = Me (IIa), R = Et (IIb)) and [C₅Me₅(CO)(Me₃P)₂Fe]BF₄ (IIc). The reaction of I and IIa with two mol of the ylide Me₃PCH₂ leads to the formation of the ironacyl-ylides C₅Me₅(CO)(L)FeC(O)CHPMe₃ (L = CO (IVa), Me₃P (IVb)). IVa selectively reacts at the “ylidic” carbon with the electrophilic reagents MeI, MeOSO₂F, Me₃SiOSO₂CF₃ to give the ironacyl-phosphonium salts [C₅Me₅(CO)₂FeC(O)CH(R)PMe₃] X (VaVc), while IVb is partially converted to [C₅Me₅(CO)₂FeC(O)CH₂PMe₃]BF₄ (IIIa) is obtained together with [C₅Me₅-(CO)₂Fe]₂ from I and IVa.     

Experimental and Computational Studies on the Formation of Thorium–Copper Heterobimetallics

The formation of actinide–transition metal heterobimetallics mediated by a terminal actinide imido complex was comprehensively studied. The reaction of the thorium imido complex [(η⁵‐C₅Me₅)₂Th=N(mesityl)(DMAP)] ( 3 ), prepared from [(η⁵‐C₅Me₅)₂ThMe₂] ( 1 ) and mesitylNH₂ or [(η⁵‐C₅Me₅)₂Th(NHmesityl)₂] ( 2 ) in the presence of 4‐(dimethylamino)pyridine (DMAP), with copper(I) halides gave the first thorium–copper heterobimetallic compounds [(η⁵‐C₅Me₅)₂Th(X){N(mesityl)Cu(DMAP)}] (X=Cl ( 4 ), Br ( 5 ), I ( 6 )). Complexes 4 – 6 feature an unusual geometry with a short Th?Cu distance, which DFT studies attribute to a weak donor–acceptor bond from the Cu⁺ atom to the electropositive Th⁴⁺ atom. They are reactive species, as was shown by their reaction with the dimethyl complex [(η⁵‐C₅Me₅)₂ThMe₂] ( 1 ). Furthermore, a comparison between Th and early transition metals confirmed that Th⁴⁺ exhibits distinctively different reactivity from d‐transition metals.     

Untersuchungen an Polyhalogeniden. XXII [1]. Dimethyldiphenylammoniumpolyiodide (Me2Ph2N)In mit n = 3, 13/3, 6, 8: Darstellung und strukturelle Charakterisierung eines Triiodids (Me2Ph2N)I3, Tridecaiodids (Me2Ph2N)3I13, Dodecaiodids (Me2Ph2N)2I12 und Hexadecaiodids (Me2Ph2N)2I16

Studies of Polyhalides. 22. On Dimethyldiphenylammoniumpolyiodides (Me₂Ph₂N)I_n with n = 3, 13/3, 6, and 8: Preparation and Crystal Structures of a Triiodide (Me₂Ph₂N)I₃, Tridecaiodide (Me₂Ph₂N)₃I₁₃, Dodecaiodide (Me₂Ph₂N)₂I₁₂, and Hexadecaiodide (Me₂Ph₂N)₂I₁₆ The new compounds [(CH₃)₂(C₆H₅)₂N]I₃, [(CH₃)₂(C₆H₅)₂N]₃I₁₃, [(CH₃)₂(C₆H₅)₂N]₂I₁₂ and [(CH₃)₂(C₆H₅)₂N]₂I₁₆ have been prepared by the reaction of dimethyldiphenylammonium iodide [(CH₃)₂(C₆H₅)₂N]I with iodine I₂ in ethanol. Their crystal structures have been determined by single crystal X-ray diffraction methods. The structure of the triiodide may be described as a layerlike packing of pairs of nearly linear symmetric anions and tetraedral cations. The tridecaiodide forms zig-zag chains of iodide ions and iodine molecules with the iodide ion also weakly coordinated by two pentaiodide groups. The dodecaiodide is built from two pentaiodide-groups, which are bridged by an iodine molecule and connected with secondary bonds forming double chains. The hexadecaiodide ion forms layers built up from two heptaiodide groups and one iodine molecule. Thus the dimethyldiphenylammonium cation stabilizes a unique series of polyiodides of extraordinary composition and structure.     

The reactivities of aminoarsines toward diarsines

The reactions of Me₂AsNR₂ with Et₂AsAsEt₂, and of Et₂AsNR₂ with Me₂AsAsMe₂ (R = Me or Et), were investigated over the temperature range 24–75°C by using ¹H and ¹³C NMR spectroscopy. The NMR data indicate the initial formation of the unsymmetrical diarsine, Me₂AsAsEt₂, and the respective dialkylamino-dialkylarsine, Et₂AsNR₂ or Me₂AsNR₂. The Me₂AsAsEt₂ then undergoes symmetrization to yield Me₂AsAsMe₂ and Et₂AsAsEt₂. Additional competitive reactions involving AsAs-AsNandAsN-AsN systems also occur in the reaction mixture. In each case, the percentage distribution of products and reactants in the studied systems at equilibrium is independent of temperature within experimental measurement. The reaction rates are dependent upon the nature of R and the alkyl group in the diarsine. In addition, equilibrium constants for several competitive reactions have been determined.     

Use of Neodymium Diiodide in the Synthesis of Organosilicon, ‐Germanium and ‐Tin Compounds

The reactivity of neodymium diiodide, NdI₂ ( 1 ), towards organosilicon, ‐germanium and ‐tin halides has been investigated. Compound 1 readily reacts with Me₃SiCl in DME to give trimethylsilane (6 %), hexamethyldisilane (4 %) and (Me₃Si)₂O (19 %). The reaction with Et₃SiBr in THF results in formation of Et₃SiSiEt₃ (17 %) and Et₃SiOBuⁿ (34 %). Alkylation of Me₃SiCl with PrⁿCl in the presence of 1 in THF affords Me₃SiPrⁿ (10 %), Me₃SiOBuⁿ (52 %) and Me₃SiSiMe₃ (1 %). The main product identified in the reaction mixture formed upon interaction of 1 with dichlorodimethylsilane Me₂SiCl₂ in THF is di‐n‐butoxydimethylsilane Me₂Si(OBuⁿ)₂ (54 %) together with minor amounts of Me₂Si(OBuⁿ)Cl. The reaction of 1 with Me₃GeBr under the same conditions produces Me₃GeGeMe₃ (44 %), Me₃GeH (3 %), and Me₃GeI (7 %). An analogous set of products was obtained in the reaction with Et₃GeBr. Treatment of trimethyltin chloride with 1 causes reduction of the former to tin metal (74 %). Me₃SnH (7 %) and hexamethyldistannane (11 %) were identified in the volatile products. The reaction of 1 with Me₃SiI provides straightforward access to hepta‐coordinated NdI₃(THF)₄ ( 2 ), the structure of which was determined by X‐ray diffraction.     

Gemischtligandkomplexe des Technetiums. XV. Zur Reaktion von [TcNCl2(Me2PhP)3] mit Dialkyldithiocarbamaten und N,N-Dialkylthiocarbamoylbenzamidinen

Mixed-ligand Complexes of Technetium. XV. The Reaction of [TcNCl₂(Me₂PhP)₃] with Dialkyldithiocarbamates and N,N-Dialkylthio-carbamoylbenzamidines [TcN(Cl)(Me₂PhP)₂(Et₂dtc)], [TcN(Me₂PhP)(Et₂dtc)₂], and [TcN(Et₂dtc)₂] can be prepared by stepwise ligand exchange reactions starting from dichlorotris(dimethylphenylphosphine)nitridotechnetium(V), [TcNCl₂(Me₂PhP)₃], and diethyldithiocarbamate. In contrast to this, only one intermediate, [TcN(Cl)(Me₂PhP)₂(HEt₂tcb)], could be isolated during the reaction with N,N-Diethlthiocarbamoylbenzamidine, which yields the bis chelate [TcN(HEt₂tcb)₂]. [TcN(Me₂PhP)(Et₂dtc)₂] crystallizes in the monoclinic space group P2₁/c; a = 17.369(5) Å, b = 15.024(1) Å, c = 9.906(3) Å, β = 76.47(1)º, Z = 4. The phosphine is coordinated equatorially. The multiply bonded nitrogen ligand (Tc? N(1) 1.624(3) Å) strongly labilizes the trans positioned donor atom (distance Tc? S(4) 2.826(1) Å). [TcN(HEt₂tcb)₂] crystallizes in the triclinic space group P1 with a = 9.749(4) Å, b = 11.264(4) Å, c = 12.359(4) Å, α = 75.34(2)º, β = 79.69(2)º, γ = 87.55(2)º, Z = 2. The metal is five-coordinate with the nitrido donor atom occupying the apex of a square pyramid. It's basal plane is formed by the cis-coordinated chelate ligands. The technetium is situated over the basal plane by about 0.6 Å. The Tc?N distane was found to be 1.610(5) Å.     

Die Kristallstrukturen einer Serie von Verbindungen mit Kationen des Typs [R3PNH2]+, [R3PN(H)SiMe3]+ und [R3PN(SiMe3)2]+

Crystal Structures of a Series of Compounds with Cations of the Type [R₃PNH₂]⁺, [R₃PN(H)SiMe₃]⁺, and [R₃PN(SiMe₃)₂]⁺ The crystal structures of a series of compounds with cations of the type [R₃PNH₂]⁺, [R₃PN(H)SiMe₃]⁺, and [R₃PN(SiMe₃)₂]⁺, in which R represents various organic residues, are determined by means of X‐ray structure analyses at single crystals. The disilylated compounds [Me₃PN(SiMe₃)₂]⁺I^–, [Et₃PN(SiMe₃)₂]⁺I^–, and [Ph₃PN(SiMe₃)₂]⁺I₃^– are prepared from the corresponding silylated phosphaneimines R₃PNSiMe₃ with Me₃SiI. [Me₃PNH₂]Cl (1): Space group P2₁/n, Z = 4, lattice dimensions at –71 °C: a = 686.6(1), b = 938.8(1), c = 1124.3(1) pm; β = 103.31(1)°; R = 0.0239. [Et₃PNH₂]Cl (2): Space group Pbca, Z = 8, lattice dimensions at –50 °C: a = 1272.0(2), b = 1147.2(2), c = 1302.0(3) pm; R = 0.0419. [Et₃PNH₂]I (3): Space group P2₁2₁2₁, Z = 4, lattice dimensions at –50 °C: a = 712.1(1), b = 1233.3(2), c = 1257.1(2) pm; R = 0.0576. [Et₃PNH₂]₂[B₁₀H₁₀] (4): Space group P2₁/n, Z = 4, lattice dimensions at –50 °C: a = 809.3(1), b = 1703.6(1), c = 1800.1(1) pm; β = 96.34(1)°; R = 0.0533. [Ph₃PNH₂]ICl₂ (5): Space group P1, Z = 2, lattice dimensions at –60 °C: a = 825.3(3), b = 1086.4(3), c = 1241.2(4) pm; α = 114.12(2)°, β = 104.50(2)°, γ = 93.21(2)°; R = 0.0644. In the compounds 1–5 the cations are connected with their anions via hydrogen bonds of the NH₂ groups with 1–3 forming zigzag chains. [Me₃PN(H)SiMe₃][O₃S–CF₃] (6): Space group P2₁/c, Z = 8, lattice dimensions at –83 °C: a = 1777.1(1), b = 1173.6(1), c = 1611.4(1) pm; β = 115.389(6)°; R = 0.0332. [Et₃PN(H)SiMe₃]I (7): Space group P2₁/n, Z = 4, lattice dimensions at –70 °C: a = 1360.2(1), b = 874.2(1), c = 1462.1(1) pm; β = 115.19(1)°; R = 0.066. In 6 and 7 the cations form ion pairs with their anions via NH … X hydrogen bonds. [Me₃PN(SiMe₃)₂]I (8): Space group P2₁/c, Z = 8, lattice dimensions at –60 °C: a = 1925.4(9), b = 1269.1(1), c = 1507.3(4); β = 111.79(3)°; R = 0.0581. [Et₃PN(SiMe₃)₂]I (9): Space group Pbcn, Z = 8, lattice dimensions at –50 °C: a = 2554.0(2), b = 1322.3(1), c = 1165.3(2) pm; R = 0.037. [Ph₃PN(SiMe₃)₂]I₃ (10): Space group P2₁, Z = 2, lattice dimensions at –50 °C: a = 947.7(1), b = 1047.6(1), c = 1601.6(4) pm; β = 105.96(1)°; R = 0.0334. 8 to 10 are built up from separated ions.     

Silylium dual catalysis in living polymerization of methacrylates via In situ hydrosilylation of monomer

Silylium ions (“R₃Si⁺”) are found to catalyze both 1,4‐hydrosilylation of methyl methacrylate (MMA) with R₃SiH to generate the silyl ketene acetal initiator in situ and subsequent living polymerization of MMA. The living characteristics of the MMA polymerization initiated by R₃SiH (Et₃SiH or Me₂PhSiH) and catalyzed by [Et₃Si(L)]⁺[B(C₆F₅)₄]^– (L = toluene), which have been revealed by four sets of experiments, enabled the synthesis of the polymers with well‐controlled M_n values (identical or nearly identical to the calculated ones), narrow molecular weight distributions (? = 1.05–1.09), and well defined chain structures {H? [MMA]_n? H}. The polymerization is highly efficient too, with quantitative or near quantitative initiation efficiencies (I* = 96–100%). Monitoring of the reaction of MMA + Me₂PhSiH + [Et₃Si(L)]⁺[B(C₆F₅)₄]^– (0.5 mol%) by ¹H NMR provided clear evidence for in situ generation of the corresponding SKA, Me₂C?C(OMe)OSiMe₂Ph, via the proposed “Et₃Si^+”‐catalyzed 1,4‐hydrosilylation of monomer through “frustrated Lewis pair” type activation of the hydrosilane in the form of the isolable silylium‐silane complex, [Et₃Si? H? SiR₃]⁺[B(C₆F₅)₄]^–. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1895–1903     

Die ersten Röntgenstrukturen kationischer Diorganylzinn(IV)‐Dichelate [R2Sn(L–L)2]2⊕ mit zweizähnigen Phosphanoxid‐Liganden: Di(methansulfonyl)amid als nichtkoordinierendes Gegenion

Polysulfonylamines. CXI. The First X‐Ray Structures of Cationic Diorganyltin(IV) Dichelates [R₂Sn(L–L)₂]^2⊕ Involving Bidentate Phosphine Oxide Ligands: Di(methanesulfonyl)amide as a Non‐Coordinating Counter‐Ion The reaction of Me₂Sn(A)₂, where A^⊖ = (MeSO₂)₂N^⊖, with DPPOE = ethane‐1,2‐diylbis(diphenylphosphine oxide) or CDPPOET = cis‐ethene‐1,2‐diylbis(diphenylphosphine oxide) yields the ionic dichelates [Me₂Sn(dppoe)₂]^2⊕ · 2 A^⊖ ( 1 ; monoclinic, space group P2₁/c) and [Me₂Sn(cdppoet)₂]^2⊕ · 2 A^⊖ ( 2 ; monoclinic, P2₁/n). A solvated variety of 2 , [Me₂Sn(cdppoet)₂]^2⊕ · 2 A^⊖ · Et₂O · 0.15 MeCN ( 4 ; triclinic, P 1), was serendipitously obtained by thermal degradation of the new compound [Me₂Sn(A)(μ‐OH)]₂ · 2 CDPPOET in an MeCN/Et₂O medium. The crystals of 1 , 2 and 4 consist of discrete formula units (one independent unit for 1 and 2 , two independent units for 4 ); in the structure of 4 , the solvent molecules are located in lattice cavities. All the tin atoms lie on crystallographic inversion centres and display moderately distorted octahedral C₂O₄ coordinations with short Sn–O bonds in the range 218–223 pm. Within the formula units, the anions are connected to the P–CH donor groups of the chelating ligands by C–H…O/N interactions, some of which are remarkably short (e.g. in 1 : H…O 220 pm, C–H…O 170°; H…N 242 pm, C–H…N 153°).