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  • 1
    ISSN: 0044-2313
    Keywords: Nickel(0) ; binuclear compounds ; functionalized alkynes ; supramolecular structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Binuclear Nickel(0) Alkyne Coordination Compounds - Correlation between Ligand Periphery and Supramolecular StructureReaction of Ni(cdt: 1,5,9-cyclododecatriene) with functionalized alkynes and subsequent reaction with ethylenediamines gives binuclear compounds of the type (diamine)Ni(μ-alkyne)Ni(alkyne). Compounds with alkyne-diols (N⁁N)Ni2(HOR1R2C—C≡C—CR1R2OH)2 show supramolecular structures in which two identical intramolecular and one intermolecular hydrogen bonds are realized. 1 and 2 (chelate ligand in each case N,N,N′,N′-tetramethylethylenediamine, TMEDA, in 1 R1 = R2 = Me, in 2 R1 = R2 = Et) polymer-like chains are built up by connecting the binuclear units. Via two intermolecular hydrogen bonds per organometallic unit in 1 and via one intermoleculare hydrogen bond in 2 the chains are connected to give double chains. By substitution of one methyl group of TMEDA by hydrogen (3: R1 = R2 = Me) a polymerlike network is produced by connecting the polymer-like chains.In compound 4 in which one of the methyl groups of TMEDA is substituted by CH2CH2NMe2 the polymer-like chains remain unconnected. In 5 (diamine = TMEDA, alkyne = (CH3)3C—C≡C—CMe2OH) one intermolecular hydrogen bond per organometallic unit is observed forming again polymer-like chains that are independent of each other.
    Notes: Durch Reaktion von Ni(cdt) (cdt: Cyclododeca-1,5,9-trien) mit funktionalisierten Alkinen und anschließender Umsetzung mit Ethylendiaminen erhält man binucleare Alkin-Nickel(0)-Verbindungen des Typs (diamin)Ni(μ-alkin)Ni(alkin). In Verbindungen mit Alkindiolen (N ⁁ N)Ni2(HOR1R2C—C≡C—CR1R2OH)2 werden supramolekulare Strukturen aufgebaut, die jeweils zwei gleichartige intramolekulare und eine intermolekulare Wasserstoffbrückenbindung aufweisen. In 1 und 2 (Chelatligand jeweils N,N,N′,N′-Tetramethylethylendiamin, TMEDA, in 1 R1 = R2 = Me, in 2 R1 = R2 = Et) bilden sich durch Verknüpfung der binuklearen Einheiten polymere Stränge, die in 1 durch zwei und in 2 durch eine Wasserstoffbrückenbindung pro Organometalleinheit zu Doppelsträngen verknüpft werden. Ersatz einer Methylgruppe in TMEDA durch Wasserstoff (3: R1 = R2 = Me) bewirkt, daß die polymeren Stränge zu einem polymeren Netzwerk verknüpft werden. In Verbindung 4 (R1 = R2 = Me), in der im TMEDA eine Methylgruppe durch CH2CH2NMe2 ersetzt ist, bleiben die zu 1-3 analogen polymeren Stränge untereinander unverknüpft.In 5 (Diamin = TMEDA, Alkin = (CH3)3C—C≡C—CMe2OH) wird pro Organometalleinheit eine intermolekulare Wasserstoffbrückenbindung gebildet, was ebenfalls zu voneinander unabhängigen polymeren Strängen führt.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0009-2940
    Keywords: Nickel(0) ; Alkyne complexes ; Hydrogen bonds ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of (cdt)Ni (cdt: cyclododeca-1,5,9-triene) with 2 equivalents of 2-methyl-4-trimethylsilyl-3-butyn-2-ol leads to the selective formation of the homoleptic complex (alkyne)4Ni3 (compound 3), which can be isolated in excellent yields. The solid-state structure of 3 exhibits three Ni centers, forming a bent Ni3 chain connected by two bridging alkynes. The other two alkynes are terminally coordinated. Additionally, the trimeric units are stabilized by three intramolecular hydrogen bonds. Two intermolecular hydrogen bonds connect the trimeric units to form a polymer rope. According to the 13C- and 1H-NMR spectra in THF the structure of the complex 3 in solution is very similar to that in the solid state. The reaction of 3 with some alkynediols and with 2,5,5-trimethylhex-3-yn-2-ol affords compounds of the type (alkyne)2Ni. Cot (cot: 1,3,5,7-cyclooctatetraene) converts 3 into [(cot)Ni]2, which in turn reacts with 2,5-dimethylhex-3-yne-2,5-diol to form the dimeric complex (alkyne)2Ni2(cot) 6. X-ray analysis of 6 reveals a very symmetrical structure in which cot connects both Ni(0) centers at opposite sides of the ring system.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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