Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XLIX. Reaktionen von Cerium(IV)-acetylacetonat mit Lithium- und Magnesiumorganylen

Contributions to the Chemistry of Organo Transition Metal Compounds. XLIX. Reactions of Cerium(IV) Acetylacetonate with Organolithium and Organomagnesium Compounds Reacting Ce(acac)₄ with lithium organyls RLi (R = CH₃ 1-Nor¹), ((CH₃)₂NCH₂CH₂CH₂) in the molar ratio 1:1 the cerium compound is reduced with formation of Li[Ce(acac)₄]. Using a molar ratio of Ce:Li = 1:4 organocerium complexes of the composition R₃Ce · 3 Li(acac) or Li₃[R₃Ce(acac)₃] are formed. From reactions with excess CH₃Li (Ce: Li = 1:7) Li₃[Ce(CH₃)₆] · 3 Li(acac) could be isolated. All cerium complexes are characterized by elementary analysis, hydrolysis products, i.r. spectra, and molecular weight determination.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XXXV. Zum Reaktionsverhalten von Tetrabenzyltitan gegenüber Lithiumalkylen

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXXV. Reactions in Tetrabenzyl Titanium/Alkyllithium Systems Organotitanium(IV) complexes of the type Li[(C₆H₅CH₂)₄TiR] (R = CH₃, C₂H₅, n-C₄H₉) were isolated from tetrabenzyl titanium and lithium alkyls at deep temperature. The reddish brown, crystalline compounds decompose between ?30 and 0°C with formation of benzyltitanates(II) which composition differs between Li₂[Ti(CH₂C₆H₅)₄] and Li[Ti(CH₂C₆H₅)₃]. From these complexes pure dibenzyl titanium can be isolated. The reaction mechanism is discussed. Experiments for isolation of a benzyl titanium(III) compound from (C₆H₅CH₂)₄Ti/RLi systems failed in all cases. Recent informations about stable tribenzyl titanium obtained from tetrabenzyl titanium and ethyl lithium could not be confirmed.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XLIV. Zur Bildung von Tetraorganylzirconaten(II)

Contributions to the Chemistry of Transition Metall Alkyl Compounds. XLIV. Formation of Tetraorganylzirconates(II) Zirconiumtetraorganyls are reduced by n-butyl lithium with formation of dilithium tetraorganyl zirconates(II). Li₂[Zr(CH₂C₆H₅)₄] and Li₂[Zr(CH₃)₄] were isolated in a definite form as extremely air sensitive compounds, from which a polymer structure can be assumed. The compounds were characterized by elementary analysis, hydrolyses products, reactions with iodine, magnetic moments, and the ESR spectra.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XL. Über Lithium-alkenylmanganate(II)

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XL. About Lithium Alkenylmanganates(II) MnCl₂ reacts with vinyl, 2,2-dimethylvinyl, allyl, and methallyl lithium giving rise to alkenyl manganates(II). In a pure state the compounds Li₂[Mn(CH?CH₂)₄] · 1.5 diox, Li₂[Mn(CH?C(CH₃)₂)₄] · 1.5 diox, Li₂[Mn(CH₂? CH?CH₂)₄] · 2.5 diox and Li₃[Mn(CH₂? C(CH₃)?CH₂)₅] · 2 diox were isolated. The compounds were characterized by elementary analysis, EPR and IR spectra, magnetic moments, and reactions with iodine.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XXXIX. Über 3(N,N-Dimethylamino)propyllanthanoid-Verbindungen

Contributions to the Chemistry of Transition Metal alkyl Compounds. XXXIX. About 3(N,N-Dimethylamino) propyl Lanthanide Compounds LaCl₃, PrCl₃, and ErCl₃ react with dimethylaminopropyl lithium (RLi) in tetrahydro-furan as a solvent with formation of complexes of the type Li₃[LnR₃Cl₃]. In a similar way the Li₃[CeR₆] derivative is formed from CeCl₃. The organolanthanide complexes were characterized by elementary analysis, hydrolysis and thermolysis products, the effective magnetic moments and the i.r. spectra.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XXXVII. Zur Existenz von 1-Norbornylverbindungen des Wolframs und Molybdäns

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXXVII. About the Existence of 1-Norbornyl Compounds of Tungsten and Molybdenum Reactions of WCl₆, WCl₄, WO₂Cl₂, WOCl₄, MoCl₅, and MoO₂(acac)₂ with 1-Norbornyl lithium (1-NorLi¹)) are described. From WCl₆ and WCl₄ [(1-Nor)₂W]_n is formed, whereas in dependence of the solvent WO₂Cl₂ and WOCl₄ are transformed into the complexes Li₂[1-NorWOCl₄] · THF, Li[WOCl₄], Li[WO₂Cl₂], and Li₂[WO₂Cl₂]. MoCl₅ and MoO₂(acac)₂ are reduced with formation of Li[MoCl₅], Li[MoO₂(acac)₂] and Li₂[MoO₂(acac)₂]. — Stable (1-Nor)₄M-derivatives of molybdenum and tungsten, comparable those of 3d-metals (M = Ti? Co) seem not to exist.     

Four‐ and Five‐Coordinate Gallium Complexes Stabilized by Bidentate 2‐(Dimethylaminomethyl)Pyrrole Ligand: Molecular Structures of Ga[NC4H3(CH2NMe2)‐2]3 and GaMe2[NC4H3(CH2NMe2)‐2]

Treatment of GaCl₃ with one equiv of Li[NC₄H₃(CH₂NMe₂)‐2] (n = 1, 2, 3) in diethyl ether at ?78 °C yields GaCl_3‐n[NC₄H₃(CH₂NMe₂)‐2]_n (n = 1, 1 ; n = 2, 2 ; n = 3, 3 ). Compound 1 reacts with two equiv of RLi to afford GaR₂[NC₄H₃(CH₂NMe₂)‐2] ( 4a, R=Me; 4b, R=Bu ) via transmetallation. Reacting 2 with one equiv of RLi in diethyl ether, 3 and 4 are formed via ligand redistribution. Variable temperature ¹H NMR spectroscopic experiments reveal that the five‐coordinate gallium compound 3 is fluxional and results in a coalescence temperature at 5 °C, at which ΔG^≠ is calculated at ca. 10.4 Kcal/mole. All the new compounds have been characterized by ¹H and ¹³C NMR spectroscopy and the structures of compounds 3 and 4a have also been determined by X‐ray crystallography.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XXXVI. Zur Existenz von 3(N,N-Dimethylamino)propyl-Verbindungen der 3d-Elemente und des Zirconiums

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXXVI. About the Existence of 3(N, N-Dimethylamino)propyl Compounds of 3d-Metals and Zirconium 3(N, N-dimethylamino)propyl lithium reacts with 3d-metal halides in a different manner. In crystalline state the compounds RTiCl₃, R₃Cr, R₄Zr, and the complexes LiVR₃Cl · 0.7 O(C₂H₅)₂ and Li₂CoR₄ (R = (CH₃)₂NCH₂CH₂CH₂) were isolated. The formation of the unstable R₄Ti and R₂Ni derivatives could be proved. Iron and nickel halides are reduced to the metals by dimethylaminopropyl lithium, even at a temperature of ?60°C.     

Mass spectra of organometallic compounds—VII; Organonitrogen derivatives of metal carbonyls

The positive-ion mass spectra of the following organonitrogen derivatives of metal carbonyls are discussed: (i) The compounds NC₅H₄CH₂Fe(CO)₂C₅H₅, NC₅H₄CH₂COMo(CO)₂C₅H₅, NC₅H₄CH₂W(CO)₃C₅H₅, NC₅H₄CH₂COMn(CO)₄, C₅H₁₀NCH₂CH₂Fe(CO)₂C₅H₅, (CH₃)₂NCH₂CH₂COFeCOC₅H₅ and (CH₃)₂NCH₂CH₂COMn(CO)₄ obtained from metal carbonyl anions and haloalkylamines, (ii) The isocyanate derivative C₅H₅Mo(CO)₃CH₂NCO; (iii) The arylazomolybdenum derivatives RN₂Mo(CO)₂C₅H₅ (R ? phenyl, p-tolyl, or p-anisyl); (iv) The compound (C₆H₅N)₂COFe₂(CO)₆ obtained from Fe₃(CO)₁₂ and phenyl isocyanate; (v) The N,N,N′,N′-tetramethylethylenediamine complex (CH₃)₂NCH₂CH₂N(CH₃)₂W(CO)₄. Further examples of eliminations of hydrogen, CO, and C₂H₂ fragments were noted. In addition evidence for the following more unusual processes was obtained: (i) Elimination of HCN fragments from the ions [NC₅H₄CH₂MC₅H₅]⁺ to give the ions [(C₅H₅)₂M]⁺ (M ? Fe, Mo and W); (ii) Conversion of C₅H₅Mo(CO)₃CH₂NCO to C₅H₅Mo(CO)₂CH₂NCO within the mass spectrometer; (iii) Elimination of N₂ from [RN₂MoC₅H₅]⁺ to give [RMoC₅H₅]⁺; (iv) Novel eliminations of HNCO, FeNCO, and C₆H₅NC fragments in the mass spectrum of (C₆H₅N)₂COFe₂(CO)₆; (v) Facile dehydrogenation of the N,N,N′,-N′-tetramethylethylenediamine ligand in the complex (CH₃)₂NCH₂CH₂N(CH₃)₂W(CO)₄.     

Ruthenium NNN complexes with a 2‐hydroxypyridylmethylene fragment for transfer hydrogenation of ketones

Four NNN tridentate ligands L₁–L₄ containing 2‐methoxypyridylmethene or 2‐hydroxypyridylmethene fragment were synthesized and introduced to ruthenium centers. When (HOC₅H₃NCH₂C₅H₃NC₅H₇N₂) (L₂) and (HOC₅H₃NCH₂C₅H₃NC₆H₆N₃) (L₄) reacted with RuCl₂(PPh₃)₃, two ruthenium chloride products Ru(L₂)(PPh₃)Cl₂ ( 1 ) and Ru(L₄)(PPh₃)Cl₂ ( 2 ) were isolated, respectively. Reactions of (MeOC₅H₃NCH₂C₅H₃NC₅H₇N₂) (L₁) and (MeOC₅H₃NCH₂C₅H₃NC₆H₆N₃) (L₃) with RuCl₂(PPh₃)₃ in the presence of NH₄PF₆ generated two dicationic complexes [Ru(L₁)₂][PF₆]₂ ( 3 ) and [Ru(L₃)₂][PF₆]₂ ( 4 ), respectively. Complex 1 reacted with CO to afford product [Ru(L₂)(PPh₃)(CO)Cl][Cl]. The catalytic activity for transfer hydrogenation of ketones was investigated. Complex 1 showed the highest activity, with a turnover frequency value of 1.44 × 10³ h^?1 for acetophenone, while complexes 3 and 4 were not active.     

Aminostannanes and aminostannylenes containing a C,N-chelated ligand

Aminotin(II and IV) compounds {[(2,6-i-Pr-C₆H₃)(H)N]-μ-(Sn)-Cl}₂, {2-[(CH₃)₂NCH₂]C₆H₄}₂Sn[N(H)(2,6-i-Pr-C₆H₃)]₂ and {2-[(CH₃)₂NCH₂]C₆H₄}Sn[N(2,6-i-Pr-C₆H₃)(SiMe₃)] were prepared by lithium halide elimination from tin halides and corresponding lithium complexes. [(2,6-i-Pr-C₆H₃)(H)N]Li (1) reacts with one half of molar equivalent of SnCl₂ to give {[(2,6-i-Pr-C₆H₃)(H)N]-μ-(Sn)-Cl}₂. The same lithium amide (1) gave with R₃SnCl corresponding aminostannanes. Further reactions of these compounds with n-butyllithium gave the starting 1 and tetraorganostannanes. {2-[(CH₃)₂NCH₂]C₆H₄}₂SnBr₂ reacts with two equivalents of 1 to {2-[(CH₃)₂NCH₂]C₆H₄}₂Sn[N(H)(2,6-i-Pr-C₆H₃)]₂. The dimeric heteroleptic stannylene {[(2,6-i-Pr-C₆H₃)(SiMe₃)N](μ₂-Cl)Sn}₂ reacts with 2-[(CH₃)₂NCH₂]C₆H₄Li to the monomeric {2-[(CH₃)₂NCH₂]C₆H₄}Sn[N(2,6-i-Pr-C₆H₃)(SiMe₃)]. The structure in the solid state and in solution and reactivity of products is also discussed. The unique decatin cluster has been isolated by hydrolysis of {[(2,6-i-Pr-C₆H₃)(H)N]-μ-(Sn)-Cl}₂. The structure of some compounds was also evaluated by theoretical DFT methods.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XXXIV. Darstellung und Eigenschaften von 3-(N,N-Dialkylamino)-propylmangan-Verbindungen

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXXIV. Synthesis and Properties of 3-(N,N-dialkylamino)propyl Manganese Compounds MnCl₂ reacts with lithium organyls of the type R₂N(CH₂)₃Li with formation of definite organomanganese complexes. The pure [(CH₃)₂N(CH₂)₃]₂Mn, [(C₂H₅)₂N(CH₂)₃]₂Mn, [(CH₂)₅N(CH₂)₃]₂Mn and the complexes [(CH₃)₂N(CH₂)₃]₂Mn · LiCl and Li{Mn[(CH₂)₃N(CH₃)₂]₃} · 1,5 THF were isolated. [(CH₃)₂N(CH₂)₃]₂Mn · 2 Li(acac) was obtained as a result of reactions of Mn(acac)₂ and Mn(acac)₃ with the corresponding lithium organyl. The σ-organomanganese(II) derivatives were characterized in detail by elementary analysis, molecular weight determination, ESR- and IR-spectra, conductivity measurements and the magnetic moments.     

Koordinationschemische Untersuchungen an Zinkdialkylen. XIV. Über Lithium- und Zink-3-(N,N-dialkylamino)-propyl-Verbindungen

Investigations on the Coordination Chemistry of Zinc Dialkyls. XIV. On Lithium and Zinc 3(N, N-Dialkylamino)propyl Compounds It is reported on synthesis and properties of organo lithium compounds of the type [R₂NCH₂CH₂CH₂Li]_n. The structure is proposed by reason of molecular weight determination and ¹³C-NMR spectra. In dependence of the molar ratio the lithium dialkylamino propyls and the corresponding Grignard reagents react with zinc chloride forming dimer alkyl zinc chlorides [R₂NCH₂CH₂CH₂ZnCl]₂ or monomer spiranoide chelate complexes of the formula [R₂NCH₂CH₂CH₂]₂Zn (R = CH₃, C₂H₅).     

Umsetzung von Alkalimetallphosphiden mit Salzen aromatischer Sulfonsäuren 2. Mitt.: Die Reaktion substituierter aromatischer Sulfonate mit Kaliumdiphenylphosphid

Zusammenfassung Die Umsetzung von Alkalidiphenylphosphid mit Methylaryl-sulfonaten zu tert. Phosphinen gelingt umso leichter, je weniger Methylgruppen der Arylrest enthält. Folgende Phosphine (C₆H₅)₂PR wurden dargestellt: R=2-CH₃C₆H₄–, 4-CH₃C₆H₄–, 2,4-(CH₃)₂C₆H₃– und 4-Methyl--naphthyl. Ebenso wurden die Phosphine mit R=3-(CH₃)₂NC₆H₄– und 2-(CH₃)₂NC₆H₄– aus den Dimethylanilinsulfonaten erhalten. Die Umsetzung von (C₆H₅)₂PK mit Na-1,4-Chlorbenzolsulfonat im Molverhältnis 2:1 gibt fast quantitativ 1,4-Phenylen-bis-diphenylphosphin, im Molverhältnis 1:1 aber entsteht (bei tieferen Temperaturen) Diphenylphosphin-p-benzolsulfonat. Diphenyl-(2,4,6-trimethyl-phenyl)phosphin wird am besten aus Diphenylchlorphosphin und Mesitylmagnesiumbromid hergestellt.Zusammenfassung Alkali diphenylphosphides react with methylarylsulfonates giving tert. phosphines. The yield increases with decreasing number of methyl groups in the arylsulfonate. The following phosphines (C₆H₅)₂PR were prepared: R=2-CH₃C₆H₄, 4-CH₃C₆H₄, 2,4-(CH₃)₂C₆H₃, and 4-methyl--naphthyl. Similarly the phosphines with R=3-(CH₃)₂NC₆H₄ and 2-(CH₃)₂NC₆H₄ were prepared from dimethylaniline sulfonates. The reaction of (C₆H₅)₂PK with sodium 1,4 chlorophenyl sulfonate at a molar ratio of 2:1 yields nearly quantitatively 1,4-phenylene-bis(diphenylphosphine); however at a mole ratio of 1:1 and at lower temperatures sodium diphenylphosphine-p-phenyl sulfonate is obtained. The best way to prepare diphenyl(2,4,6-trimethyl-phenyl)phosphine was to use diphenyl-chloro phosphine and mesitylmagnesium bromide.     

Untersuchungen zur Kristallstruktur von Lithium‐dodecahydro‐closo‐dodecaborat aus wäßriger Lösung: Li2(H2O)7[B12H12]

Investigations on the Crystal Structure of Lithium Dodecahydro‐closo‐dodecaborate from Aqueous Solution: Li₂(H₂O)₇[B₁₂H₁₂] By neutralization of an aqueous solution of the acid (H₃O)₂[B₁₂H₁₂] with lithium hydroxide (LiOH) and subsequent isothermic evaporation of the resulting solution to dryness, it was possible to obtain the heptahydrate of lithium dodecahydro‐closo‐dodecaborate Li₂[B₁₂H₁₂] · 7 H₂O (≡ Li₂(H₂O)₇[B₁₂H₁₂]). Its structure has been determined from X‐ray single crystal data at room temperature. The compound crystallizes as colourless, lath‐shaped, deliquescent crystals in the orthorhombic space group Cmcm with the lattice constants a = 1215.18(7), b = 934.31(5), c = 1444.03(9) pm and four formula units in the unit cell. The crystal structure of Li₂(H₂O)₇[B₁₂H₁₂] can not be described as a simple AB₂‐structure type. Instead it forms a layer‐like structure analogous to the well‐known barium compound Ba(H₂O)₆[B₁₂H₁₂]. Characteristic feature is the formation of isolated cation pairs [Li₂(H₂O)₇]²⁺ in which the water molecules form two [Li(H₂O)₄]⁺ tetrahedra with eclipsed conformation, linked to a dimer via a common corner. The bridging oxygen atom (∢(Li‐ O ‐Li) = 112°) thereby formally substitutes Ba²⁺ in Ba(H₂O)₆[B₁₂H₁₂] according to (H₂ O )Li₂(H₂O)₆[B₁₂H₁₂]. A direct coordinative influence of the [B₁₂H₁₂]^2— cluster anions to the Li⁺ cations is not noticeable, however. The positions of the hydrogen atoms of both the water molecules and the [B₁₂H₁₂]^2— units have all been localized. In addition, the formation of B‐H^δ—···^δ+H‐O‐hydrogen bonds between the water molecules and the hydrogen atoms from the anionic [B₁₂H₁₂]^2— clusters is considered and their range and strength is discussed. The dehydratation of the heptahydrate has been investigated by DTA‐TG measurements and shown to take place in two steps at 56 and 151 °C, respectively. Thermal treatment leads to the anhydrous lithium dodecahydro‐closo‐dodecaborate Li₂[B₁₂H₁₂], eventually.     

Organoselenium compounds containing pyrazole or phenylthiazole groups: Synthesis,structure, tin(IV) complexes and antiproliferative activity

The diorganodiselenides (pzCH₂CH₂)₂Se₂ ( 1 ) and (PhtzCH₂)₂Se₂ ( 2 ) were prepared by reacting Na₂Se₂ with 1‐(2‐bromoethyl)‐1H‐pyrazole and 4‐(chloromethyl)‐2‐phenylthiazole, respectively, while the reactions between 1‐(2‐bromoethyl)‐1H‐pyrazole or 4‐(chloromethyl)‐2‐phenylthiazole and the lithium organoselenolates [2‐(Et₂NCH₂)C₆H₄]SeLi and [2‐{O(CH₂CH₂)₂NCH₂}C₆H₄]SeLi in a 1:1 molar ratio resulted in the heteroleptic diorganoselenium(II) compounds [2‐(Et₂NCH₂)C₆H₄](R)Se (R = pzCH₂CH₂ ( 3 ) or PhtzCH₂ ( 5 )) and [2‐{O(CH₂CH₂)₂NCH₂}C₆H₄](R)Se (R = pzCH₂CH₂ ( 4 ) or PhtzCH₂ ( 6 )). The diorganotin(IV) bis(organoselenolato) derivatives of type R₂Sn(SeCH₂CH₂pz)₂ (R = 2‐(Me₂NCH₂)C₆H₄ ( 7 ) or Me ( 8 )) were obtained by reacting (pzCH₂CH₂)SeNa with the appropriate diorganotin(IV)dichloride in a 2:1 molar ratio. All compounds were investigated using NMR spectroscopy (¹H, ¹³C, ⁷⁷Se, ¹¹⁹Sn as appropriate) and ESI+ mass spectrometry. The molecular structures of 2 and 6 were determined using single‐crystal X‐ray diffraction. The formation of a 10–Se–3 hypercoordinated species was evidenced for 6 in the solid state, as a consequence of the C,N coordination behaviour of the 2‐{O(CH₂CH₂)₂NCH₂}C₆H₄ group. Compounds 1 , 7 and 8 were investigated for their antiproliferative activity towards the mouse colon carcinoma C26 cell line with the preliminary results showing a better activity than 5‐fluorouracil.     

Synthesis and characterization of novel chelated dimethylamino lithium alkoxides: molecular structures of [1‐LiOC(C6H11)2‐2‐NMe2C6H4]2 and [1‐LiOCPh2CH2‐2‐NMe2C6H4]2

From the reaction of 1‐HOCPh₂‐2‐NMe₂C₆H₄ ( 1 ), 1‐HOC(C₆H₁₁)₂‐2‐NMe₂C₆H₄ ( 2 ) and 1‐HOCPh₂CH₂‐2‐NMe₂C₆H₄ ( 3 ) with n‐BuLi in diethyl ether, the solvent‐free chelated dimethylamino lithium alkoxides [1‐LiOCPh₂‐2‐NMe₂C₆H₄]₂ ( 4 ), [1‐LiOC(C₆H₁₁)₂‐2‐NMe₂C₆H₄]₂ ( 5 ) and [1‐LiOCPh₂CH₂‐2‐NMe₂C₆H₄]₂ ( 6 ) were obtained. The lithium alkoxides 4 – 6 were characterized by ¹H, ⁷Li, and ¹³C NMR spectroscopy. Crystal structure determinations of 5 and 6 were carried out. Compounds 5 and 6 are examples of structurally characterized solvent‐free chelated dimethylamino lithium alkoxides and 6 is a rare example of this type containing a seven‐membered ring. Copyright © 2002 John Wiley & Sons, Ltd.     

Thiohalogeno-Verbindungen von Niob und Tantal: NbSCl3, TaSCl3, [NbSCl5]2−, [TaSCl5]2−, [NbSBr4]− Die Kristallstrukturen von (PPh4)2[NbSCl5] · 2 CH2Cl2 und NEt4[NbCl6]

Thiohalo Compounds of Niobium and Tantalum: NbSCl₃, TaSCl₃, [NbSCl₅]^2?, [TaSCl₅]^2?, [NbSBr₄]^?. Crystal Structures of (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ and NEt₄[NbCl₆] NbSCl₃ can be obtained from NbCl₅ by reaction with H₂S or bistrimethylsilyl sulfide in a suspension of CCl₄ or CH₂Cl₂, respectively; in the latter case the product contains a rest of trimethylsilyl groups. This also applies for TaSCl₃, NbSBr₃ and TaSBr₃, which are formed from the metal pentahalides and S(SiMe₃)₂. NEt₄[NbSCl₄] is formed together with NEt₄[NbCl₆] in the reaction of NbCl₅ with NEt₄SH in CH₂Cl₂. PPh₄[NbCl₆] reacts with S(SiMe₃)₂ in dichloromethane yielding (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂, whereas PPh₄[NbSBr₄] is obtained from PPh₄[NbBr₆] and S(SiMe₃) under the same conditions. (PPh₄)₂[TaSCl₅] · 2 CH₂Cl₂ was obtained from TaSCl₃ and PPh₄Cl in CH₂Cl₂. According to an X-ray crystal structure determination (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ crystallizes in the β-(AsPh₄)₂[UCl₆] · 2 CH₂Cl₂ type with positionally disordered, octahedral anions. Crystal data: a = 1 021.7, b = 1120.4, c = 1 243.3 pm, α = 70.77, β = 80.24, γ = 80.54°, space group P1 , Z = 2; 2462 unique observed reflexions, R = 0.036. NEt₄[NbCl₆] crystallizes isotypic to NEt₄[WCl₆], a = 723.5, b = 1 018.0, c = 1 174.6 pm, β = 100.07°, space group P2₁/n, Z = 2; 1 875 reflexions, R = 0.075.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XLIII. Über die Reduktion von Organozirconium(IV)-Verbindungen mit Lithiumorganylen

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XLIII. Reduction of Organozirconium(IV) Compounds with Lithium Organyls. (C₅H₅)₂ZrR₂ derivatives react with lithium organyls by forming of organozirconium(III) or organozirconium(II) compounds. (C₅H₅)Zr(CH₂C₆H₅)₂ · O(C₂H₅)₂ and (C₅H₅)ZrC₆H₅ · 3 O(C₂H₅)₂ were isolated in a definite form. Informations on the formation of (C₅H₅)Zr(C₆H₅)₂ · 2 O(C₂H₅)₂ could be confirmed. The compounds obtained were characterized by elementary analysis, hydrolysis products, reactions with iodine, magnetic moments, and the IR and EPR spectra.     

Hypercoordinated diorganoantimony(III) compounds of types [2-(Me2NCH2)C6H4]2SbL and [PhCH2N(CH2C6H4)2]SbL (L = Cl,ONO2, OSO2CF3). Synthesis,structure and catalytic behaviour in the Henry reaction

The compounds [2-(Me₂NCH₂)C₆H₄]₂SbL (L = ONO₂ ( 2 ), OSO₂CF₃ ( 3 )) and [PhCH₂N(CH₂C₆H₄)₂]SbL (L = ONO₂ ( 5 ), OSO₂CF₃ ( 6 )) were prepared by reacting [2-(Me₂NCH₂)C₆H₄]₂SbCl ( 1 ) and [PhCH₂N(CH₂C₆H₄)₂]SbCl ( 4 ), respectively, with the appropriate silver(I) salt in a 1:1 molar ratio. The new species 2 – 6 were structurally characterized in solution using multinuclear NMR and in the solid state using infrared spectroscopy. The solid-state structures for compounds 2 , 4 and 6, as well as for the hydrolysis ionic product [{2-(Me₂N⁺HCH₂)C₆H₄}{2-(Me₂NCH₂)C₆H₄}SbOH][CF₃SO₃]⁻ ( 3h ) were determined using single-crystal X-ray diffraction. Medium to strong intramolecular N→ Sb interactions were observed in all these four compounds, thus resulting in hypercoordinated organoantimony(III) species 14-Sb-6 in 2 and 10-Sb-4 in the cation of 3h and in 4 and 6 . Compounds 1 – 6 and the starting amines PhCH₂NMe₂ and PhCH₂N(CH₂C₆H₄Br-2)₂ were investigated as catalysts in the Henry (nitroaldol) addition of nitromethane to benzaldehyde. The activity of compounds 1 – 6 resulted as an effect of the cooperation of the positively charged antimony with the negatively charged nitrogen.