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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Inorganic chemistry 18 (1979), S. 2629-2631 
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Transition metal chemistry 4 (1979), S. 191-198 
    ISSN: 1572-901X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The trinuclear complexes {CpCo[P(O)(OMe)2]3}2Co and {CpCo[P(O)(OEt)2]3}2M, where M=Mg, Ca, Sr, Ba, Pb, Mn, Co, Ni, Cu, Zn, Cd or Hg, have been studied by x-ray diffraction methods and the crystal structures of {CpCo[P(O)(OR)2]3}2M [R=Me with M=Co (1) and R = Et with M = Cu (2)] have been solved by the heavy atom technique. Complex (2) crystallizes in the triclinic space group P 1 with two crystallographically independent molecules per unit cell. The cell dimensions area = 12.195(3) Å,b = 20.429(6) Å, c = 12.518(3) Å,α = 102.39(2)°, β=120.15(2)°, γ=92.28(2)°. The molecule contains two cobalt atoms and one copper atom in a linear arrangement with copper situated on a center of symmetry. Each of the cobalt atoms is bonded to a cyclopentadienyl ring and is connected to the central copper atom by three phosphonate groups acting as bridging ligands. Disorder phenomena within these phosphonate groups are best described as an enhanced thermal motion corresponding mainly to a rotation around the Co-Cu-Co axis. The CuO6 coordination octahedra exhibit a small (4+2) distortion. The electronic spectrum of this copper complex has been measured in solution and in the solid state and is in accord with the Jahn-Teller distorted octahedral coordination of the copper ion found in the x-ray structure. Complex (1) is monoclinic, space group P21/c with two formula units per cell. Its molecular structure shows the same general features as the copper complex. The coordination of the central cobalt atom is regularly octahedral within the limits of error. Parts of the phosphonate P(O)(OMe)2 groups are disordered over two distinct sites in the crystal with occupancy factors ofca. 0.75 and 0.25. D.s.c. measurements of the trinuclear compounds containing disordered P(O)(OEt)2 groups show phase transitions occurring in the 160–230 K temperature range that are best discussed in terms of order-disorder transitions. From d.s.c. measurements of the corresponding complexes with P(O)(OMe)2 ligands, there are no phase transitions visible in the 100–300 K range.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 59 (1976), S. 844-854 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The fluxional behaviour of triphenylmethyl substituted cyclopentadienyl metal compounds1H-NMR. spectroscopy has been used to study the influence of the triphenylmethyl substituent on the metallotropic rearrangement in C5H4(CPh3)Si(CH3)3 and C5H4 (CPh3)Sn(CH3)3. The most likely mechanism corresponds to a degenerate metal exchange between two neighbouring ring positions. The AA'XX' spectrum of the cyclopentadienyl ring protons in C5H4(CPh3)Sn(CH3)3 has been analysed under rapid exchange conditions. The free energy of activation for the sigmatropic [1,5]-Sn shift has been measured by comparison with computer simulated spectra for slow exchange.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Basic Metals. II. Protonation and Alkylation Reactions of π-Cyclopentadienyl-metal-bis(tert.-phosphite) ComplexesFür «Basische Metalle. I» siehe [1].The complexes C5H5Co[P(OR)3]2 (R = CH3, C2H5) and C5H5Rh[P(OR)3]2 (R = CH3, C2H5, C6H5, C6H4-o-CH3) react with electrophilic agents E+, e.g. H+ and CH3+, to give [C5H5ME(P(OR)3)2]+. Salts of these cation have been isolated with BF4- and PF6- as the anions. The formation of compounds with direct M-H and M-CH3 bonds points to the pronounced Lewis-base properties of the metal atom in the starting complexes. The NMR. data of the cations [C5H5MH(P(OR)3)2]+ and [C5H5MCH3(P(OR)3)2]+ will be discussed.
    Additional Material: 1 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1296-1303 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and NMR. Spectra of Novel Lanthanide-Cobalt Sandwich CompoundsThe reaction of [(C5H5)Co{P(O)(OR)2}2{P(OH)(OR)2}] (3, R = CH3, C2H5) with lanthanide(III) compounds yields the cationic trinuclear complexes [{(C5H5)Co[P(O)(OR)2]3}2Ln]⊕X⊖ (2, R = CH3, C2H5; Ln = La, Eu, Pr; X = BF4, BPh4). According to thermogravimetric and NMR. studies these compounds do not contain additional coordinated water molecules. It is therefore supposed that the central lanthanide ion has a regular sixfold coordination of phosphoryl ligands. The 31P- and 1H-NMR. spectra of 2 (R = CH3; Ln = La, Eu, Pr) and 3 are discussed. It can be shown that the Fermi contact shift as well as the coordination shift make significant contributions to the observed lanthanide induced shift of the cyclopentadienyl signal.The dominating influence of the Fermi contact interaction on the 31P chemical shift is in accord with theoretical considerations and comparable experimental values. The temperature dependence of the proton chemical shifts of 2 (R = CH3; Ln = Eu) is also discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [π-C5H5Co{P(OR)2O}3BF]BF4: Synthesis, Structure, and Reactivity of (Cyclopentadienyl)cobalt Complexes Containing New Cage-forming Phosphite Chelating LigandsThe trinuclear complexes (π-C5H5)2Co3[P(O)(OR)2]6 (1a, b) react with HBF4 to produce the salt-like compounds [π-C5H5Co{P(OR)2O}3BF]BF4 (3a, b) in nearly quantitative yields. The X-ray structure analysis of 3 b shows that in the cationic complex a tris(diethylphosphito)fluoroborate anion is coordinated to the metal as a tridentate cage-forming chelating ligand.
    Notes: Bei den Reaktionen der Dreikernkomplexe (π-C5H5)2Co3[P(O)(OR)2]6 (1 a, b) mit HBF4 entstehen in nahezu quantitativer Ausbeute die salzartigen Verbindungen [π-C5H5Co{P(OR)2O}3BF]BF4 (3a, b). Die Röntgenstrukturanalyse von 3b zeigt, daß in dem Komplexkation ein Tris(diethylphosphito)fluoroborat-Anion als dreizähniger käfigbildender Chelatligand an das Metall koordiniert ist.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 451-468 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trinuclear Sandwich Compounds Containing Dialkylphosphonate as Bridging Ligands: Synthesis, NMR-, IR-, and Raman StudiesThe solvolysis of [C5H5Co{P(OR)2O}3BF]BF4 (3) leads to the half-sandwich complex [C5H5Co{P(O)(OR)2}2{P(OH)(OR)2}] (4). 4 is a novel O3-tripod ligand which reacts with the bivalent metalions M = Mg, Ca, Sr, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg to give the trinuclear compounds [{(C5H5)Co[P(O)(OR)2]2}2M] (5a-m). In these sandwich like complexes the dialkylphosphonate ligands are forming bridges of the type Co—(P—O)3—M—(O—P)3—Co between the three metal centers. The 1H NMR spectra are discussed. Due to a non-regular octahedral coordination of the central ion M = Cu and Hg the vP = O and δP = O bands in the IR spectra of 5j and 5m are split. It is shown by means of the IR spectra that the Jahn-Teller distorted octahedral coordination of CuII in 5j is changed to a regular one under the influence of high pressure (35 kbar).
    Notes: Es wird über die Synthese des Halbsandwichkomplexes [C5H5Co{P(O)(OR)2}2{P(OH)(OR)2}] (4) aus [C5H5Co{P(OR)2O}3BF]BF4 (3) berichtet. 4 ist ein neuartiger O3-Tripodligand, der mit den zweiwertigen Metall-Ionen M = Mg, Ca, Sr, Ba, Pb, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg zu dreikernigen Verbindungen der Zusammensetzung [{(C5H5)Co[P(O)(OR)2]3}2M] (5a-m) reagiert. In den sandwich-artigen Komplexen 5 bilden die Dialkylphosphonatliganden Brücken der Art Co—(P—O)3—M—(O—P)3—Co zwischen den drei Metallzentren. Die 1H-NMR-Spektren werden diskutiert. Im IR-Spektrum beobachtet man als Folge der nicht regulären Oktaederkoordination beim CuII-Komplex 5j und bei der Quecksilberverbindung 5m eine Aufspaltung der VP = O und δP = O-Banden. An Hand der IR-Spektren wird gezeigt, daß die Jahn-Teller-Verzerrung des CuII-Komplexes 5j unter einem Druck von 35 kbar aufgehoben werden kann.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 10 (1977), S. 126-131 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimethylphosphonate HP(O)(OCH3)2 and the dimethylphosphonate complexes [(C5H5)MX{P(O) (OCH3)2}{P(OCH3)3}] (M=Co, Rh; X=I, CH3), [(C5H5)Co{P(O)(OCH3)2}2 {P(OH)(OCH3)2}] and [(C5H5)Ni{P(O)(OCH3)2}{P(OCH3)3}] have been studied by 1H n.m.r. spectroscopy. The chiral shift reagent Eu(tfc)3 has been used to resolve the spectra of the enantiomeric mixtures of [(C5H5)MX {P(O)(OCH3)2}{P(OCH3)3}]. The substituent X in [(C5H5)MX{P(O)(OCH3)2}{P(OCH3)3}] has a strong influence on the anischrony of the diastereotopic phosphonate methyls in the presence of Eu(tfc)3. The same shift reagent also resolves the enantiotopic protons in HP(O)(OCH3)2 but not in [(C5H5)Ni {P(O)(OCH3)2}{P(OCH3)3}]. The addition of Eu(tfc)3 to [(C5H5)Ni{P(O)(OCH3)2}{P(OCH3)3}] eliminates the 3J(POCH) coupling in the coordinated dimethylphosphonate. The cobalt complex [(C5H5)Co{P(O)(OCH3)2}2{P(OH)(OCH3)2}] reacts as a chelating ligand with Eu(tfc)3 to give one tfcH per Eu(tfc)3.
    Notes: Dimethylphosphonat HP(O)(OCH3)2 und die Dimethylphosphonat-Komplexe [(C5H5)MX{P(O)(OCH3)2}{P(OCH3)3}] (M = Co, Rh; X = I; CH3), [(C3H5) Co{P(O)(OCH3)2}2{P(OH)(OCH3)2}] und [(C5H5)Ni{P(O) (OCH3)2}{P(OCH3)3}] werden 1H-NMR spektroskopisch untersucht. Es wird gezeigt, dass sich die enantiomeren Formen von [(C5H5)MX{P(O)(OCH3)2}{P(OCH)3)}] in Gegenwart des chiralen Shiftreagens Eu(tfc)3 getrennt beobachten lassen. Man findet einen starken Einfluss des Substituenten X auf die Unterscheidbarkeit der diastereotopen Phosphonat-Methoxylgruppen in [(C5H5)MX{P(O)(OCH3)2}{P(OCH3)3}]. Die enantiotopen Phosphonat-Methoxylgruppen in HP(O)(OCH3)2 werden durch Wechselwirkung mit Eu (tfc)3 unterscheidbar. Die gleichen Gruppen in [(C5H5)Ni{P(O)(OCH3)2}{P(OCH3)3}] werden durch Zugabe von Eu(tfc)3 von 31P entkoppelt. Der entkoppelt. Der komplex [(C5H5)Co{P(O)(OCH3)2}2P(OH)(OCH3)2}] reagiert als Chelatligand mit Eu(tfc)3 unter Freisetzung von tfcH.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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