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  • Inorganic Chemistry  (10)
  • 1-(Haloalkyl)pyridinium halides  (1)
  • 1
    ISSN: 0044-2313
    Keywords: Zirconium ; Lithium ; Hydroxoligands ; Oxoligand ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: An Unusual Trimeric Bimetallic Li—Zr Complex with the Backbone [Zr3(μ2-OH)3(μ3-O)Li5] by Reaction of Zirconiumorgano and Hydrido Complexes with WaterThe reaction of compounds of the type [(LZr)(LiH)(L′)]n and [(LZr)(LiH)(L′)(alkyne)]n (L: 2,2′-Biphenolato-dianion, L′: thf, Bu3P, alkyne: Ph—C≡C—SiMe3, CH≡CH) with water at 0°C in a thf solution results in the formation of th trimeric bimetallic complex 8 [(L2Zr)3(μ2-OH)3(μ3-O)Li5(thf)8(H2O)5] in 50% yield. The X-ray analysis of 8 shows that a planar six-membered ring Zr3(μ2-OH)3 is formed. In the middle of this ring is a dianionic oxygen atom placed, coordinating to the three L2Zr centres in a planar μ3-coordination (bond angles 120,05μ). Five lithium ions stabilize the anionic backbone by bridging the biphenolato chelate ligands, which form seven-membered chelate rings with the atoms.1H-, 13C-, and 7Li-NMR spectra exhibit that the solid state structure remains unchanged in solution (thf).
    Notes: Die Reaktion von Verbindungen des Typs [(LZr)(LiH)(L′)]n und [(LZr)(LiH)(L′)(alkin)]n (L: 2,2′-Biphenolato-dianion, L′: thf, Bu3P, alkin: Ph—C≡C—SiMe3, CH≡CH) mit Wasser führt bei 0°C in thf in 50% Ausbeute zum trimeren Bimetallkomplex 8 [(L2Zr)3(μ2-OH)3(μ3-O) Li5(thf)8(H2O)5]. Die Kristallstrukturanalyse von 8 zeigt, daß ein planarer Zr3(μ2-OH)3-Sechsring gebildet wird. In seiner Mitte ist ein dianionisches Sauerstoffatom fixiert, das an den drei L2Zr-Zentren mit planarer μ3-Koordination gebunden ist (Bindungswinkel Zr—O—Zr 120,05°). Fünf Lithiumionen stabilisieren das anionische Gerüst durch Verbrückung der Biphenolatchelatliganden, die mit den Zr-Atomen Chelatsiebenringe ausbilden. 1H-, 13C- und 7Li-NMR-Spektren zeigen, daß in Lösung (thf) die Festkörperstruktur unverändert erhalten bleibt.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 623 (1997), S. 1135-1143 
    ISSN: 0044-2313
    Keywords: Copper(I) ; 1-azadienes ; oxidation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Copper(I) Complexes with 1-Azadiene Chelate Ligands and Their Reaction with OxygenThe reaction of the bidendate 1-azadiene ligands Me2N—(CH2)n—N=CH—CH=CH—Ph with CuX results in the formation of the dimeric compounds [ACuX]2 and [BCuX]2 (A: n = 2, B: n = 3, X: I, Cl). The structure of complex 1 [ACuI]2 was determined by X-ray crystal structure analysis. 1 consists of two tetrahedrally coordinated Cu atoms connected by two iodo bridges. (Cu—Cu bond length: 261 pm).The ligand Me—N(CH2CH2N=CH—CH=CH—Ph)2 (C) reacts with CuX to form the monomeric complexes [CCuX] (5: X=I, 6: X=Cl). The crystal structure of 5 shows that the ligand acts as a tridendate ligand. The bond lengths of the CuN(sp2) bonds are significantly shorter than the Cu—N(sp3) distance.Reacting the podand-type ligands N(CH2CH2—N=CH—R)3 (D: R=Ph, E: R=-CH=CH—Ph) with CuX yields the ionic complexes 7 [DCu][CuCl2] and 8 [ECu][CuCl2]. 7 was characterized by X-ray analysis which confirmed that D acts as a four-dendate podand ligand.The compounds 1-8 are unreactive towards CO2 but take up O2 even at deep temperatures. At -78°C the orange-red complex 4 [BCuCl]2 reacts with O2 in CH2Cl2 to form a deep violet solution, but the primary product of the oxidation could not be isolated. It reacts at room temperature to form the green complex 9 [μ-Cl, μ-OH][BCuCl]2. The X-ray structure analysis of 9 confirms that a dimeric CuII complex is formed in which both a chloro- and a hydroxo group are bridging the monomeric units. The CuII centers exhibit a distorted tetragonal-pyramidal coordination.The pathway of the reaction with O2 will be discussed.
    Notes: Die Reaktion der zweizähligen 1-Azadienliganden Me2N—(CH2)n—N=CH—CH=CH—Ph mit CuX führt zu den dimeren Komplexen [ACuX]2 and [BCuX]2 (A: n = 2, B: n = 3, X: I, Cl). Die Struktur des Komplexes 1 [ACuI]2 wurde durch Kristallstrukturanalyse bestimmt. 1 enthält zwei tetraedrisch koordinierte Cu-Atome, die über zwei Iodobrücken miteinander verknüpft sind Cu—Cu-Bindungslänge: (261 pm).Der Ligand Me—N(CH2CH2N=CH—CH=CH—Ph)2 (C) reagiert mit CuX unter Bildung der monomeren Komplexe [CCuX] (5: X = I, 6: X=Cl). Die Kristallstruktur von 5 zeigt, daß der Ligand dreizählig koordiniert. Die Bindungslängen der Cu—N(sp2)-Bindungen sind signifikant kleiner als der Cu—N-(sp3)-Abstand.Die Reaktion der Podand-Liganden N(CH2CH2—N=CH—R)3 (D: R=Ph, E: R=-CH=CH—Ph) mit CuX führt zu den ionischen Komplexen 7 [DCu][CuCl2] bzw. 8 [ECu][CuCl2]. 7 wurde durch Röntgenstrukturanalyse charakterisiert, die ausweist, daß D als vierzähliger Ligand fungiert.Die Komplexe 1-8 sind gegenüber CO2 nicht reaktiv, nehmen aber O2 schon bei tiefen Temperaturen auf. Bei -78°C reagiert der orangerote Komplex 4 [BCuCl]2 mit O2 in CH2Cl2 zu einer tiefvioletten Lösung, das Primärprodukt der Oxidation konnte jedoch nicht isoliert werden. Es reagiert bei Raumtemperatur zu dem grünen Komplex 9 [μ-Cl, μ-OH][BCuCl]2. Die Kristallstrukturanalyse belegt, daß ein dimerer CuII-Komplex gebildet wird, in dem eine Chloro- und eine Hydroxobrücke die Monomereinheiten verbrücken. Die CuII-Zentren weisen eine verzerrt tetragonal-pyramidale Koordination auf.Der Reaktionsweg der Umsetzung mit O2 wird diskutiert.
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  • 3
    ISSN: 1434-193X
    Keywords: Thia-aza heterocycles ; Bis(azolyl)alkanes ; 1-(Haloalkyl)pyridinium halides ; Synthetic methods ; Cyclization reactions ; Ab initio calculations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel 5/6/5 heterocycles, 1,3,4-thiadiazolo[3,2-a]-1,3,4-thiadiazolo[3,2-d]-1,3,5-triazinium halides 7, have been synthesized by the reaction of 2-amino-1,3,4-thiadiazoles 6 with either 1-(haloalkyl)pyridinium halides 4 or N,N′-methylenebis(pyridinium) dibromides 5. The tricyclic compounds 7 are generated in the course of several successive reaction steps in which specific proton migrations, bond-breaking and bond-forming processes occur. The structures 7 have been verified by spectral data (1H and 13C NMR, MS), X-ray analysis and ab initio calculations. The latter show that both sp2-C atoms C(10) and C(12) of 7 are significantly positively charged and, therefore, exhibit electrophilic properties towards the primary amino group of the amino-thiadiazoles 6. In the course of a multi-step reaction cascade of the 6/7 mixture, novel multi-aza/thia heterocycles 8 are formed. The structures of the latter compounds have been confirmed by X-ray analysis as well as by detailed experimental and theoretical NMR-spectroscopic studies.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 405-412 
    ISSN: 0009-2940
    Keywords: Sodium oxalamidinates ; 2-Imidazolidinone ; Ionic molybdenum carbonyl complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ion Pairing and Cyclization on Coordinatively Bound OxalamidinesThe tetraphenyloxalamidine ligand of complex 8a reacts easily in the presence of bases with elementorganic dichlorides (R2MCl2) to form coordinated metalacycles. The cyclization with phosgene gives the (CO)4Mo-coordinated 1,3-diphenyl-4,5-bis(phenylimino)-2-imidazolidinones 10. In contrast to the reaction forming the piperazine derivative 2, the reaction of 8a with oxalyl chloride also proceeds to 10 by decarbonylation. The product of this cyclization, (CO)4Mo(OCTPOA) (10), and two possible intermediates, the dinuclear sodium salts Na2(THF)8[(CO)4Mo(HTPOA)]2 (11a) and Na(THF)4[(CO)4Mo(EtO2COCTTOA)]2 (15) have been characterized by X-ray analyses. 11a contains the coordinated oxalaminate anion. The structure of the ionic complex 15 shows the simultaneous attack at both sp3-hybridized nitrogen atoms and the selective formation of the five-membered 2-imidazolidinone heterocycle by coordination of the oxalamidine. Both sodium complexes 11a and 15 are dimeric and centrosymmetric ion pairs. Complex 11a contains two C≡O—Na—O≡C bridges while compound 15 has a central [Na2O2] four-membered ring consisting of sodium alcoholate bridges.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1643-1646 
    ISSN: 0009-2940
    Keywords: Nickel Schiff base complexes ; Base adducts ; Chirality ; Steric hindrance ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of the ligand meso-H2L, derived from cis-diaminocyclohexane and ethyl cyano(ethoxymethylene)acetate, with nickel(II) acetate gives meso-NiL. Spectrophotometric titration of RR-NiL and meso-NiL with various nitrogen bases reveals a strong influence of the steric hindrance of the diaminocyclohexanediyl bridge in meso-NiL on the base adduct stability. The structures of RR-NiL and meso-NIL have been established by X-ray diffraction.
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  • 6
    ISSN: 0009-2940
    Keywords: Carbon dioxide fixation ; 1-Azadiene ligands ; Nickel(0) complexes ; Carboxylation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organometallic CO2 Reservoires from Nickel(0)-1-Azadiene-Type Ligands and Their Reactivity in the Carboxylation of Acetophenone1-Azadiene-type ligands yield with nickel(0) binuclear organometallic compounds of the type [Ni(1-azadiene)n,]2 (n = 1, 2). The structures of the complexes 1 (n = 2, ligand A) and 3 (n = 1, ligand C) have been characterized by X-ray crystallography. 1 is unreactive towards CO2, 3 and similar compounds are able to react with CO2 to give metallacyclic carbamato complexes of Ni(II). In these compounds CO2 is activated and can carboxylate acetophenone to yield benzoylic acid upon protolysis. These reactions mimic biologic conversion reactions of CO2 into organic material by organometallics. - The addition of two moles of the (bpy)Ni(0)-fragment [from (bpy)Ni(COD)] to 3 gives the tetranuclear complex 6. The X-ray analysis of the monomeric model compound (bi-py)Ni(A) (11) shows that only the olefin part is coordinated. 6 and 11 can also react with CO2. Cu(I) complexes with 1-azadiene-type ligands are not reactive towards CO2.
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  • 7
    ISSN: 0009-2940
    Keywords: Benzamidinate ; Zirconium complexes ; Allyl ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complexes of the type (siam)2Zr(allyl)2 (1a) and (siam)Zr(allyl)nClm are described (2a: n = 1, m = 2; 2b: n = 2, m = 1; 2c: n = 3, m = 0; siam: N,N′ -bis(trimethylsilyl)benzamidinato group). The molecular structure of 1a shows that both allyl groups are differently bonded. One allyl ligand is η3-, the other η1-coordinated. The X-ray crystal structure of the tris-(allyl) complex 2c shows a chiral molecule with two η3-allyl ligands. The third allyl ligand is coordinated in a mode intermediate between η3 and η1, thus serving as a model for an intermediate in the η3-η1 intramolecular rearrangement of the allyl ligands observed in solution. Temperature-dependent 1H- and 13C-NMR spectra of 1a, 2b and 2c indicate a rapid η1-η3 rearrangement of the allyl groups at 60°C. At -50°C two different coordination modes of the allyl groups can be observed in the case of 2b and 2c.
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  • 8
    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.
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  • 9
    ISSN: 0009-2940
    Keywords: Steroids ; Chiral amino alcohols ; Copper(II) salicylideneimine complexes ; X-ray analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The steroidal 16β-salicylideneimino-17β-hydroxy compound 1, synthesized from the corresponding 16β, 17β-amino alcohol, served as a new tridentate chiral ligand for Cu2+-complexation. The X-ray data for 1 and for two dimeric copper complexes 2 and 3 are presented and discussed. Using copper(II) acetate for complexation, dideprotonation of 1 is observed. The neutral complex 2 obtained is characterized by a central planar four-membered copper - oxygen ring. The cycloaliphatic 17β-oxygen anions are bridging atoms; the copper ions are tetracoordinated. Reaction of 1 with copper(II) perchlorate gave only monodeprotonation of the phenolic groups. These oxygen anions are now the bridging atoms; furthermore the two copper ions are bridged by a perchlorate anion. Thus the central four-membered ring is folded (22°), and the copper ions are hexacoordinated (binding of a molecule of water). The crystal lattices of 2 and 3 are also quite different.
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  • 10
    ISSN: 0044-2313
    Keywords: Alkyne Complexes ; Zirconocene ; structure ; NMR-dynamics ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure, Properties, and NMR Spectroscopical Characterization of Cp2Zr(pyridine)(Me3SiC≡CSiMe3)Displacement of the THF ligand in Cp2Zr(THF)(Me3SiC≡CSiMe3) (1) with pyridine yields Cp2Zr(η1-NC5H5)(Me3SiC≡CSiMe3) (3). Unlike 1, the complex 3 is stable in hydrocarbon solvents. According to the temperature dependent 1H and 13C NMR spectra, the structure of complex 3 in solution is dynamic due to a rotation of the alkyne ligand. In addition, when 3 is dissolved in pyridine an easy exchange between coordinated and free molecules of pyridine takes place. In the solid state complex 3 displays a tetrahedral coordination sphere at the zirconium center composed of Cp ligands, alkyne and pyridine as shown by an X-ray structure analysis. The complex 3 reacts readily with water and carbon dioxide giving the same products as in the case of 1.
    Notes: Die Substitution des THF-Liganden in Cp2Zr(THF)(Me3SiC≡CSiMe3) (1) durch Pyridin ergibt den Komplex Cp2Zr(η1-NC5H5)(Me3SiC≡CSiMe3) (3). Im Gegensatz zu 1 ist Komplex 3 stabil in Kohlenwasserstoffen.In temperaturabhängigen 1H- und 13C-NMR-Spektren zeigt 3 in Lösung dynamisches Verhalten durch eine Rotation des Alkin-Liganden. Zusätzlich tritt beim Lösen von 3 in Pyridin ein Austausch zwischen koordinierten und freien Pyridin-Molekülen auf. Die Kristallstrukturanalyse von 3 belegt eine tetraedrische Koordinationsgeometrie am Zirkonium-Zentrum bestehend aus den Cp-, Alkin- und Pyridin-Liganden. Der Komplex 3 reagiert wie Verbindung 1 mit Wasser und Kohlendioxid zu gleichen Produkten.
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