Diorganoindium-Kationen. Die Kristallstruktur von [Mes2In][BF4]

Diorganoindium Cations. The Crystal Structure of [Mes₂In][BF₄] (PhCH₃)₂In and Mes₃In react with BF₃ · OEt₂ in a ratio of 3:4 at 80°C in toluene to the corresponding salts [R₂In][BF₄] [R = PhCH₂ ( 1 ), Mes ( 2 )]. The same results could be obtained, when the diorganoindium fluorides (PhCH₂)₂InF and Mes₂InF were treated with BF₃ · OEt₂ at 80°C in toluene. 1 und 2 were characterized by NMR-, IR- und MS-techniques. The arrangement of the ions in 2 could be established by an X-ray structure determination. The cations and anions of 2 are forming infinite chains. The metal centers are coordinated by two BF₄^?-ions, so that every In atom possesses a distorted octahedral coordination sphere.     

Stabilization and Transfer of the Transient [Mes*P4]− Butterfly Anion Using BPh3

The transient bicyclo[1.1.0]tetraphosphabutane anion, generated from white phosphorus (P₄) and Mes*Li (Mes*=2,4,6‐tBu₃C₆H₂), can be trapped by BPh₃ in THF. This Lewis acid stabilized anion can be used as an [RP₄]^? transfer agent, reacting cleanly with neutral Lewis acids (B(C₆F₅)₃, BH₃, and W(CO)₅) to afford unique singly and doubly coordinated butterfly anions, and with the trityl cation to form a neutral, nonsymmetrical, all‐carbon‐substituted P₄ derivative. This reaction path enables a simple, stepwise functionalization of white phosphorus.     

Preparation of 1‐X‐2, 2‐Difluoroethenylxenon(II) Tetrafluoroborates [CF2=CXXe][BF4]

The new type of alkenylxenon(II) salts [CF₂=CXXe] [BF₄] (X = H, Cl, CF₃) was prepared by reacting the corresponding alkenyldifluoroboranes CF₂=CXBF₂ with XeF₂ in 1, 1, 1, 3, 3‐pentafluoropropane (PFP) at —60 °C. The alkenylxenon(II) salts were characterised by multinuclear NMR spectroscopy. The influence of the substituent X at C‐1 on the stability of alkenylxenon(II) salts is discussed. Additionally the preparation of the potassium alkenyltrifluoroborate salts K [CF₂=CXBF₃] and their transformation into the boranes CF₂=CXBF₂ by fluoride abstraction in PFP is reported.     

Synthese,Kristallstruktur und spektroskopische Charakterisierung von [Au12(PPh)2(P2Ph2)2(dppm)4Cl2]Cl2

Synthesis, Crystal Structure and Spectroscopic Characterization of [Au₁₂(PPh)₂(P₂Ph₂)₂(dppm)₄Cl₂]Cl₂ The reaction of [(AuCl)₂dppm] (dppm = Ph₂PCH₂PPh₂) with P(Ph)(SiMe₃)₂ in CHCl₃ results in the formation of [Au₁₂(PPh)₂(P₂Ph₂)₂(dppm)₄Cl₂]Cl₂ ( 1 ), the crystal structure of which was determined by single crystal X‐ray analysis (space group P2₁/c, a = 1425.3(3) pm, b = 2803.7(6) pm, c = 2255.0(5) pm, β = 95.00(3)°, V = 8977(3)·10⁶ pm³, Z = 2). The dication in 1 consists of two Au₆P₃ units built by highly distorted Au₃P and Au₂P₂ heterotetrahedra, connected via four bidentate phosphine ligands. Additionally, the compound was characterized by IR‐, UV‐ and NMR spectroscopy. The ³¹P{¹H} NMR spectrum is discussed in detail.     

Synthesis of a novel pentacycle: 8-Methyl-10-phenylpyrazolo[4′,3′: 5,6]-pyrano[3,2-c]-[1,10]phenanthrolin-7(10H)-one

The title compound — a derivative of a hitherto unknown pentacyclic ring system — results from the reaction of 3-methyl-1-phenyl-2-pyrazolin-5-one and 4-chloro-1,10-phenanthroline-3-carbonyl chloride in the presence of Ca(OH)₂ in boiling 1,4-dioxane. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 884–890, June, 2008.     

[(C6F5)2IF2][BF4], the First Salt with the Electrophilic Cation [(C6F5)2IF2]+: Synthesis,Reactivity, and Structure

The substitution of hypervalently bonded fluorine atoms in C₆F₅IF₄ was performed with C₆F₅BF₂ and resulted in the new salt [(C₆F₅)₂IF₂][BF₄]. The iodonium(V) salt was characterized by multi‐NMR and Raman spectroscopy and X‐ray crystal structure analysis. The fluorinating ability of the new electrophilic cation [(C₆F₅)₂IF₂]⁺ was exemplified in reactions with monovalent iodine compounds (C₆F₅I, p‐FC₆H₄I, and I₂) and with electron‐poor tri(organyl)pnictanes ER₃ (E = P, As, Sb, Bi; R = C₆F₅). In a heterogeneous reaction with CsF in MeCN the [(C₆F₅)₂IF₂]⁺ cation forms the dinuclear [{(C₆F₅)₂IF₂}₂F]⁺ cation.     

Analysis of the 1H and 13C NMR spectra of bicyclo[6.2.1]undecane ring systems

A detailed NMR analysis with full assignment of the ¹H and ¹³C spectral data for two polycyclic compounds is described. These compounds are derivatives of the product obtained from the pericyclic reaction between cyclopentadiene and tropone. Peculiar intriguing conformational features of these molecules are discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Isolation of Reduced Zirconium Chloride Clusters [(Zr6CCl12)Cl6]4− and [(Zr6BCl12)Cl6]5− from Acidic Aqueous Solution

Crystallizable from concentrated hydrochloric acid : Compounds containing [(Zr₆BCl₁₂)Cl₆]⁵⁻ and [(Zr₆CCl₁₂)Cl₆]⁴⁻ clusters survive dissolution in deoxygenated water, and this enabled the study of reduced zirconium compounds in aqueous solution for the first time. In the solid state, the clusters are surrounded by novel hydrogen-bonded water networks that interact with the terminal chloride ligands (see graphic; black circles: Zr, smaller circle: B, gray circles: Cl, open circles: O of H₂O).     

From Ion‐Like Ethylzinc Aluminates to [EtZn(arene)2]+[Al(ORF)4]− Salts

Attempts to prepare previously unknown simple and very Lewis acidic [RZn]⁺[Al(OR^F)₄]^? salts from ZnR₂, AlR₃, and HO?R^F delivered the ion‐like RZn(Al(OR^F)₄) (R=Me, Et; R^F=C(CF₃)₃) with a coordinated counterion, but never the ionic compound. Increasing the steric bulk in RZn⁺ to R=CH₂CMe₃, CH₂SiMe₃, or Cp*, thus attempting to induce ionization, failed and led only to reaction mixtures including anion decomposition. However, ionization of the ion‐like EtZn(Al(OR^F)₄) compound with arenes yielded the [EtZn(arene)₂]⁺[Al(OR^F)₄]^? salts with arene=toluene, mesitylene, or o‐difluorobenzene (o‐DFB)/toluene. In contrast to the ion‐like EtZn(η³‐C₆H₆)(CHB₁₁Cl₁₁), which co‐crystallizes with one benzene molecule, the less coordinating nature of the [Al(OR^F)₄]^? anion allowed the ionization and preparation of the purely organometallic [EtZn(arene)₂]⁺ cation. These stable materials have further applications as, for example, initiators of isobutene polymerization. DFT calculations to compare the Lewis acidities of the zinc cations to those of a large number of organometallic cations were performed on the basis of fluoride ion affinity. The complexation energetics of EtZn⁺ with arenes and THF was assessed and related to the experiments.     

Stereocontrolled Synthesis of Spiro[n.2]alkenes by Ring Contraction of Fused‐Cyclobutanols

An unusual ring‐contraction rearrangement to give spirocyclopropanes from fused cyclobutanols (see scheme) has been developed. It is found that the strain energy of the substrates derived from an additional fused ring and the stereoelectronic effect of the migrating σ bond are important factors. It is noteworthy that the rearrangement proceeds in a stereospecific manner. Moreover, the method provides a spiro(cyclopropane–indane) framework from tricyclo[6.3.0.02,5]undecane, which corresponds to illudane and the protoilludane skeleton.     

Phosphorus(III) Cations Supported by a PNP Pincer Ligand and Sub‐Stoichiometric Generation of P4 from Thermolysis of a Nickel Insertion Product

Neutral, mono‐, and dicationic phosphorus(III) compounds are accessible with a supporting PNP pincer ligand (PNP=[4‐Me‐2‐iPr₂P‐C₆H₃)₂N]). Reaction of (PNP)H with PCl₃ and nBu₃N furnished (PNP)PCl₂ ( 1 ), which displays a highly temperature‐dependent structure in solution. Synthesis and characterization by NMR spectroscopy and X‐ray crystallography of Cl/Br‐scrambled derivatives, a monocationic derivative [(PNP)PCl][HCB₁₁H₁₁] ( 4 ), and the dicationic derivatives [(PNP)P][OTf]₂ ( 5 ), [(PNP)P][B(C₆F₅)₄]₂ ( 6 ), [(PNP)P][B₁₂Cl₁₂] ( 7 ) established that 1 not only undergoes several fluxional processes in solution but also possesses a temperature‐dependent ground state structure. Reaction of 1 with a Ni⁰ source initially leads to a phosphine–phosphinidene complex, followed by thermal generation of P₄.