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  • crystal structure  (8)
  • Carbene complexes  (7)
  • Wiley-Blackwell  (15)
  • American Geophysical Union (AGU)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 479-488 
    ISSN: 0009-2940
    Keywords: Heterobimetallic complexes ; Carbene complexes ; Alkynes ; Coupling reaction ; Bridging ligands ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sequential reaction of the dimethylamino(trimethylsilylethylnyl)carbene complexes [(CO)5M'=C(NMe2)C≡CSiMe3] [M' = W (1a)] with KF/THFMeOH, nBuLi and transition metal halides, [XMLn], affords heterobimetallic propynyliden complexes of the type [(CO)5M'=C(N-Me2)C≡CMLn] [MLn = Ni(PPh3) Cp (4a, b). Ni(PMe2Ph)2- {Mes) (Mes=2,4,6-C6H2Me3) (5a), Rh(CO)(PPh3)2 (6a), Fe(CO)2Cp (7a,b)]. In contrast, reaction of 1a with MeLi · LiBr and [IFe(CO)2Cp] yields the novel N-metallated complex [(CO)5W=C{N(ME)Fe(CO)2Cp}C≡CSiMe3] (8a). The complexes [(CO)5M'=C(NMe2)C≡CMLn=Fe(CO)2Cp (7a, b), Ru(CO)2Cp (10a,b), Ru(CO)(PPh3)Cp (11a), Mn(CO)5 (12a), Re(CO)5 (13a)] are accessible by Pd-catalyzed coupling of the C-stannylated carbene complexes [(CO)5M'=C-(NMe2)C≡CSnBu3] (9a, b) with [XMLn]. The related monomethylaminocarbene complexes [(CO)5M'=C(NHMe)C≡ CSnBu3] (16a, b), obtained by stannylation of [(C))5M'=C(NHMe)C=CH] (15a, B) with Bu3SnNEt2, react with [IFe(CO)2Cp] to give the bimetallic complexes [(CO)5M'=C(NHMe)C≡CFe(CO)2Cp] (17a, b). The complexes 4a, 5a, 7a and 10a were characterized by X-ray structural analysis. The spectroscopic and structural data suggest that the two metal centers in 4-7, 10-13, and 17 interact only weakly.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2373-2378 
    ISSN: 0009-2940
    Keywords: Imidazolium manganese complexes ; Carbene complexes ; Cyclization ; Carbyne manganese complexes, cationic ; Cyanamides ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Coupling of Cyanamides with a Carbyne Ligand - Formation of η2-(C,N)-Imidazolium Complexes and Ansa-Carbene ComplexesHerrn Prof. Dr. Ernst Otto Fischer zum 75. Geburtstag gewidmet.Dicarbonyl(cyclopentadienyl)(phenylcarbyne)manganese complexes [Cp(CO)2Mn≡CPh]+X- (1-X) (X = BF4, BCl4) react with dimethyl- (2a), diethyl- (2b), and diisopropylcyanamide (2c) in five-fold excess by a head-to-tail cyclization of two cyanamides with the carbyne ligand to give η2-(C,N)-imidazolium complexes (3a-c-X). As byproducts ansa-amino(alkylide-neamino)carbene complexes (4a-c) are formed in which a N=C(Ph) group bridges the carbene carbon and the Cp ring. With increasing excess of the cyanamide the product ratio 3-X: 4 increases. Among the products of the reaction of 1-X with the cyanamides N≡CNR2 [NR2 = N(iBu)2, N(Bzl)2, N(Me)Ph] no imidazolium complexes 3-X are detected, only ansa-carbene complexes 4 are isolated. PMe3/H2O or pyridine/H2O displaces the heterocyclic ligand from 3a-BF4. The structure of 3a-BF4 is established by an X-ray analysis.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 373-378 
    ISSN: 0009-2940
    Keywords: Carbene complexes ; Carbyne complexes ; Carbohydrates ; Diastereoselective addition ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cationic carbyne complexes [Cp(CO)2M≡CR]+ [BX4]- [M = Mn, X = F: R = Ph (1), Tol (2); M = Re, X = 3,5-C6H2(CF3)2: R = Ph (3)] add the anion of monodeprotonated protected mannofuranose (4a), glucofuranose (4b), and fructopyranose (4c) to the carbyne carbon atom to form the carbohydratocarbene complexes 5a-c, 6a, b, and 7a. With 5b, 5c, and 6b the addition proceeds with retention of configuration at the anomeric center. Due to inversion of configuration in the deprotonation step the complexes 5a, 6a, and 7a are obtained as β-glycosides. The carbene ligand is oxidatively cleaved from the metal by trimethylamine N-oxide or air. Cleavage of the C(carbene)—O bond with reformation of the cation of the carbyne complex 2 is achieved by reaction of 6a with BCl3. Photolysis of [Cp(CO)2Mn=C(Ph)OEt] in the presence of L affords the carbene complexes [Cp(CO)(L)Mn=C(Ph)OEt] [L = P(OMe)3 (11), P(Tol)3 (12)]. Ethoxide abstraction from 11 and 12 by BF3 gives the chiral cationic carbyne complexes [Cp(CO)(L)Mn=CPh]+[EF4]- (13, 14) which add 4a to form the corresponding mannofura-nosylcarbene complexes (15, 16). When 0.5 equivalents of 4a are employed in the reaction with 13, 14 the ratio of diastereomers is 3:2, both for 15 and 16. Complex 11 was characterized by an X-ray structural analysis.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 1063-1067 
    ISSN: 0009-2940
    Keywords: Heterobimetallic complex ; Carbene complexes ; Bridging ligands ; Coupling reaction ; Alkynes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sequential reaction of the dimethylamino(ethynyl)carbene complex [(CO)5 W=C(NMe2)C≡CH] (1) with nBuLi, CuI and BrC≡CSiMe3 affords the dimethylamino(trimethylsilylbutadiynyl)carbene [(CO)5W=C(NMe2)C≡C—C≡C—SiMe3] (2). Desilylation of 2 with KF/THF/MeOH gives [(CO)5W=C(NMe2)C≡C—C≡CH] (3). The C-stannylated carbene complex [(CO)5W=C(NMe2)C≡C—C≡CSnBu3] (4) is obtained by deprotonation of 3 with nBuLi and subsequent reaction with Bu3SnCl. Pd-catalyzed coupling of complex 4 with [ClRu(CO),Cp] affords the heterobimetallic pentadiynylidene complex [(CO)5W=C(NMe,)C≡C—C≡CRu-(CO)2Cp] (5) The analogous Fe derivative [(CO),W=C(NMe,)C≡C—C≡CFe(CO)2Cp] (6) is obtained by sequential reaction of 3 with nBuLi and [IFe(CO)2Cp] Similarly, treatment of 3 first with nBuLi and then with half an equivalent of HgCl2 affords the novel C4HgC4-bridged biscarbene complex [(CO)3W=C(NMe2)C≡C—C≡CHgC≡C—C≡CC(NMe2)=W(CO)5]( 7 ) All new compounds are stable at room temperature. Spectroscopic data suggest weak interaction of the metal centers in 5 - 7.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 385-390 
    ISSN: 0009-2940
    Keywords: Carbene complexes ; Carbyne complexes ; Carbohydrates ; Diastereoselective substitution ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The substitution of PR3 (R = C6H4CH3-p, C6H4Cl-p, C6H11,OCH3) for a CO ligand in chiral carbohydratocarbene complexes [(η5-C5H5)(CO)2Mn=C(OR*)Ph] [OR* = α- (1α) and β-mannofuranosyl (1β), (-)-menthyloxy (9)] proceeds diastereoselectively. The diastereoselectivity depends on PR3 and on the OR* substituent and ranges from 12% de (R = OCH3) to 80% (R = C6H4CH3-p). In contrast, the reaction of 1β with P(OPh)3 is non-selective. The diastereoselectivity generally increases with increasing nucleophilicity of PR3 and decreases in the series 1β 〉 1α 〉 9. The highest diastereoselectivity was observed in the reaction of 1β with P(C6H4CH3-p)3. Predominantly, the isomer with the (S) configuration at the metal [(S Mn)-2β] was formed which could be separated from the diastereomeric mixture by chromatography and be obtained in a pure form. Subsequent reaction of (SMn)-2β with BF3 afforded the carbyne-manganese complex (SMn)-[(η5-C5H5){P(C6H4CH3-p)3}(CO)Mn≡CPh]BF4.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 191-202 
    ISSN: 1434-1948
    Keywords: Polynuclear complexes ; Carbene complexes ; Bridging ligands ; Alkynyl complexes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The sequential reaction of two equivalents of the dimethylamino(ethynyl)carbene complexes [(CO)5M=C(NMe2)C≡CH] [M = W (1a), Cr (1b)] with two equivalents of nBuLi and one equivalent of a transition metal dichloride, [Cl2M′(Ln)], affords trinuclear biscarbene complexes of the type [(CO)5M=C(NMe2)C≡C-M′(Ln)-C≡CC(NMe)2=M(CO)5] [M′(Ln) = Ni(PEt3)2 (2a, b), Pd(PEt3)2 (3a, b), Pt(PEt3)2 (4a, b), Fe(dmpe)2 (6a), Hg (8a), Ti(η5-C5H5)2 (9a, b)] [dmpe = 1,2-bis(dimethylphosphino)ethane]. Treatment of 1a with equimolar amounts of first nBuLi and then [Cl2M′(Ln)] results in the formation of the monosubstitution products [(CO)5W=C(NMe2)C≡CM′(Ln)] [M′(Ln) = trans-Pd(PEt3)2Cl (5a), trans-Fe(dmpe)2Cl (7a)]. Additionally, the synthesis of the heterobimetallicethynylcarbene complex [(CO)5W=C(NMe2)C≡CPd(PEt3)2C≡CH] (10a), starting from 1a and [ClPd(PEt3)2C≡CH], is described. When three equivalents of 1a are treated, first with three equivalents of nBuLi and then with one equivalent of the trihalides PCl3 or BBr3, the novel tris(ethynylcarbene) complexes [{(CO)5W=C(NMe2)C≡C}3E] [E = B (11a), P (12a)] are obtained. The reaction of four equivalents of 1a,b with four equivalents of nBuLi, followed by addition of one equivalent of a group 14 tetrachloride [M′Cl4], yields the novel tetrakis(ethynylcarbene) complexes [{(CO)5M=C(NMe2)C≡C}4M′] [M′ = Si (13a, b), Ge (14a), Sn (15a, b)]. The complexes 8a, 9a, 12a, and 15a were characterized by X-ray structural analyses. All spectroscopic and structural data suggest that the carbene fragments and the central transition metal or heteroatom in these new bis-, tris-, and tetrakis(ethynylcarbene) complexes interact only weakly.
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  • 7
    ISSN: 1434-1948
    Keywords: Carbene complexes ; Carbyne complexes ; Asymmetric synthesis ; Carbohydrates ; Chiral auxiliaries ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chiral carbene complexes [Cp(CO)2Mn=C(OR*)Ph] (4a-e) were prepared by reaction of [Cp(CO)2Mn=C(OAc)Ph] (2) with HOR* [HOR* = 1,2:3,4-di-O-isopropylidene-D-galactopyranose (3a), 2,3,4,6-tetra-O-acetyl-D-galactopyranose (3b), 2,3,4,6-tetra-O-acetyl-D-glucopyranose (3c), (S)- (3d) and (R)-1,2-O-isopropylideneglycerol (3e)]. The replacement of a CO ligand with PTol3 in 4a-e proceeded diastereoselectively to give [Cp(CO)(PTol3)Mn=C(OR*)Ph] (5a-e). The diastereoselectivity increased in the order a, b, c, d: de = 8% (5a), 33% (5b), 70% (5c), 〉 96% (5d). For (R)-5d the isomer with the (S) configuration at manganese (SMn) was formed predominantly. For (S)-5d, only (RMn,S)-5d was detected (de 〉 96%). Photolysis of (R)-4d in the presence of phosphites or phosphanes afforded (SMn)-[Cp(CO)(PR3)Mn=C(OR*)Ph] [PR3 = P(OPh)3 (8), P(OMe)3 (9), P(OMe)2Ph (10), P(OMe)Ph2 (11), PPh3 (12), P(C6H4Cl-p)3 (13)] with a de 〉 96%. Photolysis of (S)-4d in the presence of P(OMe)3 gave (RMn,S)-9. Complex (R)-14 [related to (R)-4d] was obtained from [Cp(CO)2Mn=C(OAc)Tol-p] and 3d. Replacement of CO by PR3 in (R)-14 gave (SMn,R)-[Cp(CO)(PR3)Mn=C(OR*)Tol-p] [R = Tol-p (15), OMe (16), C6H4Cl-p (17)] with a de 〉 96%. In solution, the PTol3-substituted complex 5d is configurationally stable whereas the P(OMe)3 complex 9 epimerizes slowly at room temperature in CH2Cl2, Et2O, and THF within about one week.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 621 (1995), S. 177-180 
    ISSN: 0044-2313
    Keywords: Oxomanganate(VI), Rb2[MnO4] ; preparation ; crystal structure ; MAPLE calculation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A ‘Reductive Exchange Reaction’: Single Crystals of Rb2[MnO4] from Li[MnO4]By heating of well ground mixtures of the oxides RbO0.9 and Li[MnO4] (Rb:Mn = 1.5:1; Ag-tubes; 660°C, 56 d) dark-green, orthorhombic single-crystals of Rb2[MnO4] were obtained. The structural determination revealed the isotype to K2[MnO4]; a β-K2SO4-typ. Thus, for the first time by a pure solid-state-chemical way, via a reductive, complete alkali-metal exchange, single crystals of an oxomanganate(VI) of the alkali metals were prepared.The Madelung Part of the Lattice Energy, MAPLE, and the charge distribution were calculated.
    Notes: Durch Tempern inniger Gemenge der Oxide RbO0,9 und Li[MnO4] (Rb:Mn = 1,5:1; Ag-Zylinder; 660°C, 56 d) wurden dunkelgrüne, orthorhombische Einkristalle von Rb2[MnO4] erhalten. Die Einkristallstrukturbestimmung belegt die Isotypie zu K2[MnO4]; es liegt der β-K2SO4-Typ vor. Somit konnten erstmals auf rein festkörperchemischem Weg, über einen reduktiven, vollständigen Alkalimetall-Austausch, Einkristalle eines Oxomanganates(VI) der Alkalimetalle dargestellt werden.Der Madelung-Anteil der Gitterenergie, MAPLE, sowie die Ladungsverteilung wurden berechnet.
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  • 9
    ISSN: 0044-2313
    Keywords: Alkali uranium halides, A2UX5 (A = K, Rb; X = Cl, Br, I) ; preparation ; crystal structure ; magnetic susceptibility ; UV-Vis spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese, Kristallstruktur, Magnetismus und Absorptionsspektren von Halogeniden des Typs A2UX5 (A = K, Rb; X = Cl, Br, I)Die ternären Uran(III)-halogenide A2UX5 (A = K, Rb; X = Cl, Br, I) wurden aus den binären Komponenten AX und UX3 in verschweißten Tantalampullen gewonnen. Nach Guinier-Aufnahmen (Raumtemperatur) kristallisieren sie sämtlich im K2PrCl5/Y2HfS5-Typ. Einkristall-Strukturverfeinerungen wurden für K2UI5 und Rb2UCl5 unternommen. Magnetische Suszeptibilitätsmessungen erfolgten mit einem SQUID-Magnetometer von Raumtemperatur bis zur Temperatur des flüssigen Heliums: Eindimensionale (innerhalb einer Kette) und dreidimensionale antiferromagnetische Ordnung wird bei tiefen Temperaturen, abhängig vom Abstand U3+—U3+, beobachtet. Absorptionsspektren wurden zwischen 4000 und 28000 cm-1 aufgenommen. Sie zeigen die für U3+ charakteristischen Übergänge und, abhängig vom Halogenid, sehr starke f - d Übergänge oberhalb 14000 bzw. 15000 cm-1.
    Notes: The ternary uranium(III) halides A2UX5 (A = K, Rb; X = Cl, Br, I) have been prepared from the binary components AX and UX3 in sealed tantalum containers. According to their Guinier X-ray powder patterns, they all crystallize with the K2PrCl5/Y2HfS5 type of structure. Lattice constants for ambient temperature are reported. Single-crystal structure refinemens were undertaken for K2UI5 and Rb2UCl5. Magnetic susceptibility data were recorded with a SQUID magnetometer from liquid helium to room temperature. One-dimensional (intrachain) and three-dimensional antiferromagnetic ordering occur at low temperatures dependent upon the U3+—U3+ distance. Absorption spectra were recorded between 4 000 and 28 000 cm-1. They show f - f transitions typical for U3+ and, depending on the halide, very strong f - d transitions above 14 000 to 15 000 cm-1, respectively.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 622 (1996), S. 153-156 
    ISSN: 0044-2313
    Keywords: Tripotassium oxide chloride ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structures of α- and β-K3OClThe orange coloured compound K3OCl has been prepared. It exists in a low temperature modification (α-K3OCl) and a high temperature modification (β-K3OCl). The transition temperature is 364 ± 5 K. The crystal structures were determined by x-ray diffraction. α-K3OCl crystallizes at room temperature in the orthorhombic space group Pbnm (Z = 4) with the cell parameters a = b = 723.9(2) pm and c = 1 027.7(2) pm in the anti-GdFeO3-structure type. The high temperature modification β-K3OCl crystallizes (Z = 1) in the cubic space group Pm3m in the β-Ag3SI-structure type with a = 516.2(2) pm (T = 393 K).
    Notes: Die orangefarbene Verbindung K3OCl wurde dargestellt. Sie tritt in einer Tieftemperaturmodifikation (α-K3OCl) und in einer Hochtemperaturmodifikation (β-K3OCl) auf. Die Umwandlungstemperatur beträgt 364 ± 5 K. Die Kristallstrukturen wurden durch Röntgenstrukturanalyse aufgeklärt. α-K3OCl kristallisiert bei Raumtemperatur in der orthorhombischen Raumgruppe Pbnm (Z = 4) mit den Gitterkonstanten a = b = 723,9(2) pm und c = 1 027,7(2) pm im anti-GdFeO3-Strukturtyp. Die Hochtemperaturmodifikation, β-K3OCl, kristallisiert mit Z = 1 in der kubischen Raumgruppe Pm3m im β-Ag3SI-Strukturtyp mit a = 516,2(2) pm (T = 393 K).
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