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1Author    HartmutB. Stegmann, Klaus Stolze, Klaus SchelflerRequires cookie*
 Title    ESR-Untersuchungen des Adrenalon-Semichinons und analoger Verbindungen ESR-Investigations of Adrenalone-Semiquinones and Related Compounds  
 Abstract    The autoxidation of adrenalone and other 4-acyl-catecholamines in the presence of diorganothalliumhydroxide are investigated by ESR-spectroscopy. On the basis of the counterion splitting and the proton coupling constants as well as the g-values a semi-quinone structure was established. By comparing several monosubstituted o-benzosemi-quinones an increment system for the assignment of the different proton coupling constants was developed. The agreement between experimental and calculated values is good for all compounds investigated. Prolonged autoxidation of adrenalone yields a stable para-magnetic secondary product. 
  Reference    Z. Naturforsch. 38b, 243—247 (1983); eingegangen am 1. September 1982 
  Published    1983 
  Keywords    Adrenalone, Semiquinones, ESR Spectra 
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 TEI-XML for    default:Reihe_B/38/ZNB-1983-38b-0243.pdf 
 Identifier    ZNB-1983-38b-0243 
 Volume    38 
2Author    Wolfgang KaimRequires cookie*
 Title    Zur Reaktion aromatischer Phosphanderivate mit Elektronen, I. On the Reaction of Aromatic Phosphane Derivatives with Electrons, I  
 Abstract    The compounds ;p-Me2P(X)-CeH4-P(X)Me2, X = O, S, Se, NPh undergo one-electron reduction at a mercury cathode or on reaction with solvated electrons in a K/18-crown-6/THF mixture. The radical anions formed are persistent and have been characterized by ESR. They may be described as complexes of the spin-bearing moiety £>-Me2P-C6H4-PMe2 r with the coordinated groups X. 
  Reference    Z. Naturforsch. 36b, 150—156 (1981); eingegangen am 15. August 1980 
  Published    1981 
  Keywords    Organophosphorus Compounds, Reduction to Radical Anions, ESR Spectra 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0150.pdf 
 Identifier    ZNB-1981-36b-0150 
 Volume    36 
3Author    Herman Teeninga, WimC. Nieuwpoort, JanB F N EngbertsRequires cookie*
 Title    Sulfonamidyls, 4. Ab Initio MO Calculations on Sulfonyl and Carbonyl Substituted Aminyl Radicals  
 Abstract    The relative magnitude of the nitrogen hyper-fine splitting constants of sulfonamidyls and carboxamidyls is rationalized in terms of the results of ab initio MO calculations using the "double zeta" basis set of Roos and Siegbahn. 
  Reference    Z. Naturforsch. 36b, 279—281 (1981); received October 6 1980 
  Published    1981 
  Keywords    Sulfonamidyls, Carboxamidyls, ESR Spectra, Quantum Mechanical Calculations 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0279_n.pdf 
 Identifier    ZNB-1981-36b-0279_n 
 Volume    36 
4Author    M. Seul, H. Neubacher, W. LohmannRequires cookie*
 Title    Temperature Dependent ESR Studies on Platinum Pyrimidine "Blues": Evidence for a Structural Instability ?  
 Abstract    Frozen samples of aqueous solutions of oxidized Pt 6-methyl-uracil "blue" were studied bv ESR spectroscopy at temperatures T ranging between —196 °C and —10 °C. When T was raised a distinct change in the line pattern was observed at about —35 °C. The resulting type of spectrum is very similar to the ESR spectrum of MAGNUS' Green Salt. The observed effect is suggested to be due to a change of the nature of the system's electronic states possibly indicating a structural rearrangement. 
  Reference    Z. Naturforsch. 36b, 651—653 (1981); received February 12 1981 
  Published    1981 
  Keywords    Platinum Blue, ESR Spectra, Structural Instability, Localized States 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0651_n.pdf 
 Identifier    ZNB-1981-36b-0651_n 
 Volume    36 
5Author    Wolfgang Kaim, Peter Hänel, Hans BockRequires cookie*
 Title    Die Reduktion von Triphenylphosphan-Derivaten zu ihren Radikalanionen und zum Dibenzophosphol-Radikaldianion [1] The Reduction of Triphenylphosphane Derivatives to their Radical Anions and to the Radical Dianion of Dibenzophosphole [1]  
  Reference    Z. Naturforsch. 37b, 1382—1387 (1982); eingegangen am 20. August 1982 
  Published    1982 
  Keywords    Triphenylphosphane, Dibenzophosphole, Reduction, Radicals, ESR Spectra 
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 TEI-XML for    default:Reihe_B/37/ZNB-1982-37b-1382.pdf 
 Identifier    ZNB-1982-37b-1382 
 Volume    37 
6Author    Wolfgang KaimRequires cookie*
 Title    Zur Reaktion aromatischer Phosphanderivate mit Elektronen, III [1, 2] Phosphan-Borane, -Alane und -Gallane On the Reaction of Aromatic Phosphane Derivatives with Electrons, III [1, 2] Phosphane-Boranes, -Alanes, and -Gallanes  
 Abstract    The 1:2 molecular complexes formed from l,4-phenylenebis(dimethylphosphane) and boranes, trialkyl-aluminum and -gallium have been reduced by potassium in THF in the presence of a K + -complexing crown ether. The bis(borane) complex anion radicals proved to be quite persistent, whereas corresponding aluminum radical complexes could only be observed below 240 K. The bis(trimethylgallium) complex gave gallium metal on reduction with potassium. An ESR spectro-scopic comparison with the anion radicals of the free ligand, of corresponding chalcogenides, imines and phosphonium salts demonstrates negligible effects of P-complexation on the JI spin distribution but high sensitivity of the 31 P coupling constant towards coordination of electrophiles at the basic P(III) centers. 
  Reference    (Z. Naturforsch. 40b, 61—66 [1985]; eingegangen am 1. Oktober 1984) 
  Published    1985 
  Keywords    Molecular Complexes, Reduction, Anion Radicals, ESR Spectra 
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 TEI-XML for    default:Reihe_B/40/ZNB-1985-40b-0061.pdf 
 Identifier    ZNB-1985-40b-0061 
 Volume    40 
7Author    Alexander Halpern, Josef KnieperRequires cookie*
 Title    Spin Trapping of Radicals in Gas-Phase Cigarette Smoke  
 Abstract    Spin trapping with N-r-butyl-a-phenyl nitrone (PBN) and 5,5-dimethyl-l-pyrroline-oxide (DMPO) has been utilized to identify the radicals in the gas phase of cigarette smoke. ESR spectra reveal pre-dominantly alkoxy radicals which are continuously formed in smoke, but not directly in the flame. 
  Reference    Z. Naturforsch. 40b, 850—852 (1985); received January 25 1985 
  Published    1985 
  Keywords    Spin Trapping, ESR Spectra, Cigarette Smoke 
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 TEI-XML for    default:Reihe_B/40/ZNB-1985-40b-0850_n.pdf 
 Identifier    ZNB-1985-40b-0850_n 
 Volume    40 
8Author    G. Eorge, Sosnovsky, Jan LukszoRequires cookie*
 Title    Novel Spin Labeled Azacrown Ethers  
 Abstract    Four novel spin labeled azacrown ethers contain­ ing either endo-or exo-cyclic nitroxyl moieties were synthesized by short and convenient routes. These com pounds should be of interest in biological studies of m em branes using E SR spectroscopy. 
  Reference    Z. Naturforsch. 40b, 1586—1588 (1985); received May 15 1985 
  Published    1985 
  Keywords    Azacrown E thers, ESR Spectra, Synthesis, Nitroxyl Radical 
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 TEI-XML for    default:Reihe_B/40/ZNB-1985-40b-1586_n.pdf 
 Identifier    ZNB-1985-40b-1586_n 
 Volume    40 
9Author    Conny Vogler, Wolfgang Kaim, H.-D HausenRequires cookie*
 Title    Zweikernige Bisphosphankupfer(I)-Komplexe mit dem 2,2 -Bipyrimidin-Brückenliganden: Strukturelle Analogie zu "Blauen" Kupferzentren und Reduktion zu paramagnetischen Spezies Dinuclear Bis(phosphane)copper(I) Complexes with 2,2'-Bipyrimidine as Bridging Ligand: Structural Analogy to " Blue" Copper Centers and Reduction to Paramagnetic Species  
 Abstract    Dinuclear complexes [(PR3)2C u(//:/74-bpym)Cu(PR3)2](BF4)2 with the bis-chelating bridging ligand 2,2'-bipyrimidine (bpym) and various m onodentate and bidentate phosphanes were synthesized via a four com ponent "self assembly" reaction. The reversible electrochemical reduction to m onocationic radical complexes was studied by cyclic voltammetry and electron spin resonance (ESR). Highly resolved ESR spectra revealed the presence o f the bpym anion radical ligand via resolved hyperfine coupling with 'H, 14N , 31P, 63Cu and 65Cu nuclei. The variation o f phosphane ligands was accompanied by significant changes o f electrochemical potentials which were rationalized considering electronic and structural effects. The configura­ tional flexibility o f Cu(I) in this environment is evident from the X-ray crystal structure ana­ lysis o f [(PPh3)2C u(//:^4-bpym)Cu(PPh3)2](BF4)2 H2O C H 3OH for which the coordination at the metal can be described as 3 + 1 (N N'P + P'), qualitatively similar to the (NN'S + S') arrange­ ment around the type 1 Cu centers o f "blue" copper proteins. Intramolecular cooperative n donor/;: acceptor/^ donor "Sandwich" interactions provide parts o f the driving force for this highly distorted coordination geometry which illustrates the proclivity o f Cu(I) towards such an "entatic state" arrangement. 
  Reference    Z. Naturforsch. 48b, 1470—1480 (1993); eingegangen am 5. Mai 1993 
  Published    1993 
  Keywords    Copper Complexes, Structure, Electrochemistry, ESR Spectra, Phosphane Ligands 
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 TEI-XML for    default:Reihe_B/48/ZNB-1993-48b-1470.pdf 
 Identifier    ZNB-1993-48b-1470 
 Volume    48 
10Author    S. V. Volkov, V. A. Bandur, N. I. BuryakRequires cookie*
 Title    The Structure and Catalytic Properties of Coordination Polyhedra of 3d-Metals in Metaphosphate Melts  
 Abstract    By EAS and ESR spectroscopy, oxygenated complexes of d-metals have been established in high-temperature melts N a P 0 3-C r 20 3-0 2 and N a P 0 3-C 0 0 -0 2 and others of the type M (P 0 3)J(.0 2, where M is Cr, Co, V, and their structure has been established. The ' "O/'^O exchange reaction in the N a P 0 3-V 20 5-0 2 melt has been studied by mass spectrometry both in the presence of the oxidized substrate and in its absence. A general approach has been proposed explaining the interaction between polyphosphate complexes of 3d-metal ions and molecular oxygen and the oxidation ability of the oxygenated complexes in terms of the MO theory. It has been established three types of interaction between 3d-metal ions and molecular oxygen: donor, acceptor and donor-acceptor ones. Oxygenated complexes of the ions of the midle of the 3d-elem ent series (d4-d 7) were found to possess the revealed "par­ tial" oxidation ability towards alkanes. 
  Reference    Z. Naturforsch. 49b, 1539—1543 (1994); received March 10 1994 
  Published    1994 
  Keywords    EAS Spectra, ESR Spectra, M etaphosphate Melts 
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 TEI-XML for    default:Reihe_B/49/ZNB-1994-49b-1539.pdf 
 Identifier    ZNB-1994-49b-1539 
 Volume    49 
11Author    Requires cookie*
 Title    ESR-spektrometrischer Nachweis des Polysulfidradikalions S3~  
  Reference    (Z. Naturforsch. 30b, 88—90 [1975]; eingegangen am 27. September 1974) 
  Published    1975 
  Keywords    Sulfur Chemistry, Nonaqueous Solvents, ESR Spectra 
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 TEI-XML for    default:Reihe_B/30/ZNB-1975-30b-0088.pdf 
 Identifier    ZNB-1975-30b-0088 
 Volume    30 
12Author    Mit Alkylderivaten Von Bor, GalliumUnd Aluminium, Indium, Wolfgang KaimRequires cookie*
 Title    Koordinationsverbindungen des reduzierten Pyrazins  
 Abstract    The alkyls MR3 (M = B, AI, Ga, In) react with pyrazine (Pz) and sodium in THF to yield persistent radical complexes Pz(MR2)2 ,+ MR4~ (1). Use of TIR3 leads to rapid deposi-tion of thallium metal. The formation of these ionic complexes 1 is the result of MR3 dissociation into +MR2 and -MR4 ions. All radicals have been identified and characterized by ESR; the data reveal the influence of N3B back bonding in the boron derivative. 
  Reference    Z. Naturforsch. 36b, 677—682 (1981); eingegangen am 6. März 1981 
  Published    1981 
  Keywords    Pyrazine, Alkali Metal Reduction, Group III Alkyls, Radical Complexes, ESR Spectra 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-0677.pdf 
 Identifier    ZNB-1981-36b-0677 
 Volume    36 
13Author    Wolfgang KaimRequires cookie*
 Title    Koordinationschemie reduzierter N-Heterozyklen. Komplexe des Pyrazin-Radikalanions mit Phenylmetallkationen +MPh von Beryllium, Magnesium und Zink Coordination Chemistry of Reduced N-Heterocycles. Complexes of Pyrazine Anion Radical with Phenyl Metal Cations + MPh of Beryllium, Magnesium and Zinc  
 Abstract    The diphenyls MPh2 (M = Be, Mg, Zn, Cd, Hg) have been reacted with pyrazine (Pz) in tetrahydrofuran. Only the magnesium derivative undergoes electron transfer to yield the 1:1 radical complex [Pz(MgPh)] -. However, in the presence of sodium or potassium persistent 1:2 complexes [Pz(MPh)2]t are formed with M = Be, Mg, Zn. Use of the higher homologues CdPh2 and HgPh2 leads to reduction to the metals. The 1:2 complexes have been characterized by ESR spectroscopy; metal coupling constants of 9 Be, 25 Mg and 67 Zn could be determined in natural isotopic abundance. 
  Reference    Z. Naturforsch. 36b, 1110—1116 (1981); eingegangen am 4. Mai 1981 
  Published    1981 
  Keywords    Pyrazine, Electron Transfer, Group II Aryls, Radical Complexes, ESR Spectra 
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 TEI-XML for    default:Reihe_B/36/ZNB-1981-36b-1110.pdf 
 Identifier    ZNB-1981-36b-1110 
 Volume    36 
14Author    Jiří Kohout, Jerzy Mroziński, Mária HvastijováRequires cookie*
 Title    Cy anato -Kupfer (II) -Komplexe mit organischen Liganden, XX [1] ESR-und magnetische Untersuchung des Dicyanato-bis(pyridin)kupfer(II)-Komplexes Cyanato-Copper(II) Complexes with Organic Ligands, XX [1] ESR and Magnetic Study of Dicyanato-bis(pyridine)copper(II)  
 Abstract    The ESR spectra and the temperature dependence of the magnetic susceptibility of Cu(NCO)2(pyridine)2 were measured. The ESR spectrum at room temperature shows a single reversed line; at —130 °C it is isotropic. The susceptibility down to 4.2 K obeys the Curie-Weiss law with a small 6 value. These results are interpreted on the basis of the known crystal and molecular structure. 
  Reference    (Z. Naturforsch. 37b, 102—104 [1982]; eingegangen am 28. September 1981) 
  Published    1982 
  Keywords    ESR Spectra, Magnetic Susceptibility, Exchange Coupling, Magnetic Interaction, Orbital Mixing 
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 TEI-XML for    default:Reihe_B/37/ZNB-1982-37b-0102.pdf 
 Identifier    ZNB-1982-37b-0102 
 Volume    37 
15Author    Wolfgang KaimRequires cookie*
 Title    from the Single Electron Transfer Reaction of Diisobutylaluminum Hydride with N-Heterocycles  
 Abstract    Diisobutylaluminum hydride i Bu2AlH reacts with N-heterocycles L (L = pyrazine, 2,2'-bipyridine, 4,4'-bipyridine) via single electron transfer to vield 1:1 radical complexes [L(A1'BU2)-]. 
  Reference    Z. Naturforsch. 37b, 783—785 (1982); eingegangen am 27. November 1981 
  Published    1982 
  Keywords    Electron Transfer, N-Heterocycles, Diisobutylaluminum Hydride, Radical Complexes, ESR Spectra 
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 TEI-XML for    default:Reihe_B/37/ZNB-1982-37b-0783_n.pdf 
 Identifier    ZNB-1982-37b-0783_n 
 Volume    37 
16Author    H. Ans Bocka, W. Olfgang Kaima, Mitsuo Kira3, LouisR. Eneb, H. Einz-G, V. Ünther, IehebRequires cookie*
 Title    Radikalionen, 61 [ 1 , 2 ] Dialkylamino-substituierte Acetylene und Allene: Ionisation, Oxidation und AlCI3-katalysierte Wasserstoffübertragung Radical Ions, 61 [1, 2] D ialkylam ino-substituted Acetylenes and Allenes: Ionisation, O xidation and AlCl3-Catalyzed Hydrogen Transfer  
 Abstract    The photoelectron (P E) spectra of bis(dialkylam ino) acetylenes R 2N — C = C —N R 2 and o f tet-rakis(dialkylam ino) allenes (R 2N)2C = C = C (N R 2)i with R = C H 3, C2H 5 exhibit characteristic ionization patterns which are assigned to re radical cation states of the two m olecular halves twisted against each other. The low first ionization potentials betw een 7.0 eV and 7.7 eV stim u­ lated attempts to oxidize using A1C13 in H 2CC12 or D 2CC12. The hyperfine structured E SR spectra observed can be unequivocally assigned to the ethylene radical cations R 2N — HC = CH — N R 2 © which are formed from the obviously non-persistent species R2N —C ^ C — N R 2 ® via a hydrogen transfer. During the oxidation o f the dialkylam ino-substituted allenes no paramagnetic interm edi­ ates could be d etected , presumably due to a rapid dimerisation o f the allene radical cation (R 2N)2C = C = C (N R 2)2'®. 
  Reference    Z. Naturforsch. 39b, 763—770 (1984); eingegangen am 28. N ovem ber 1983 
  Published    1984 
  Keywords    D ialkylam ino Substituted n Systems Radical Cations, ESR Spectra, PE Spectra 
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 TEI-XML for    default:Reihe_B/39/ZNB-1984-39b-0763.pdf 
 Identifier    ZNB-1984-39b-0763 
 Volume    39 
17Author    E. N. Esr, HartmutB. Stegmann, Klaus Stolze, Klaus SchefflerRequires cookie*
 Title    ESR-und ENDOR-Untersuchungen der Autoxidationsprodukte des Adrenalons und analoger Verbindungen Investigations of the A utoxidation Products of Adrenalone and Related Compounds  
 Abstract    The signs of the proton coupling constants of adrenalone sem iquinone and related compounds were determ ined by E N D O R and T R IP L E resonance studies, thereby verifying the increment system described in our previous paper [2], Com parison of the spin-distribution of several substi­ tuted acylcatechols showed the conform ational influence on the coupling constants due to mesomeric interaction of the carbonyl group with the arom atic 7r-system. A drenalone and other N -m onosubstituted catecholam ines showed rather stable secondary radi­ cals after the decay of the prim ary sem iquinone radical. They were identified as substituted dihydropyrazinium cation radicals after selective deuteration and comparison of their ESR-, EN D O R -and TRIPLE -resonance spectra with those of the non-deuterated species. They are formed by cyclic condensation of two molecules with subsequent oxidation. E in fü h ru n g 
  Reference    Z. Naturforsch. 41b, 776 (1986); eingegangen am 24. Januar 1986 
  Published    1986 
  Keywords    A drenalone, Semiquinones, ESR Spectra, E N D O R Spectra 
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 TEI-XML for    default:Reihe_B/41/ZNB-1986-41b-0776.pdf 
 Identifier    ZNB-1986-41b-0776 
 Volume    41 
18Author    Sylvia Ernst, Volker Kasack, Christian Bessenbacher, Wolfgang KaimRequires cookie*
 Title    Ein-und zweikernige Bis(2,2'-bipyridyI)ruthenium-Komplexe mit N,0-Mode!liganden für Dehydrogenase-Cofaktoren Mono-and Binuclear Bis(2,2'-bipyridine)ruthenium Complexes with N,0-Ligands Modelling Dehydrogenase Cofactors  
 Abstract    Coordination of substitutionally inert [Ru(bpy) 2 ] 2+ fragments (bpy: 2,2'-bipyridine) to the a-iminoketone chelate ligands pyrazine-2-dimethylcarboxamide (4) and 4,7-phenanthroline-5,6-dione (5) yields the complexes [(N,0-4)Ru(bpy) 2 ] 2 ®, [(0,0'-5 e)Ru(bpy) 2 ]® and {(N,0; N',0'-5)[Ru(bpy) 2 ] 2 } 4 ® which exhibit a rich electrochemistry. The distinctly different electronic structures of the complexes are evident from the ESR behaviour of paramagnetic intermediates: N.O-coordinated complexes have the unpaired electron residing in the ligand n system upon reduction, albeit with g<2 for the complex of 4 but with g>2 for the binuclear complex of 5. The paramagnetic 0,0'-coordinated mononuclear complex with 5 has its redox potentials shifted positively relative to that of the binuclear system. These results are particularly noteworthy because 4 and 5 can be regarded as model compounds for the flavin and methoxatin dehydrogenase cofactors. 
  Reference    Z. Naturforsch. 42b, 425—430 (1987); eingegangen am 6. August 1986 
  Published    1987 
  Keywords    Dehydrogenase Cofactors, Ruthenium Complexes, Oxidation States, ESR Spectra, a-Iminoketones 
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 TEI-XML for    default:Reihe_B/42/ZNB-1987-42b-0425.pdf 
 Identifier    ZNB-1987-42b-0425 
 Volume    42 
19Author    Yuzo Nishida, Naoko Oshino, Tadashi TokiiRequires cookie*
 Title    Crystal Structure and Magnetic Property of the Binuclear Manganese(III) Complex with /u-Acetate and Di-ji-Alkoxo Bridges  
 Abstract    Binuclear manganese(III) complex, [Mn : L(u-OCH 3)0<-CH 3 COO)(OHCH : ,)]ClO 4 was pre-pared and characterized in terms of crystal structure determination, magnetic measurement, and ESR spectroscopy, where H 3 L represents the Schiff base derived from salicylaldehvde and 1,5-diamino-3-pentanol. 
  Reference    Z. Naturforsch. 43b, 472—474 (1988); received November 9/December 17 1987 
  Published    1988 
  Keywords    Binuclear Manganese(III) Complex, Crystal Structure, ESR Spectra, Magnetic Property 
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 TEI-XML for    default:Reihe_B/43/ZNB-1988-43b-0472.pdf 
 Identifier    ZNB-1988-43b-0472 
 Volume    43 
20Author    Conny Vogler, Wolfgang KaimRequires cookie*
 Title    Einkernige Bis(triphenylphospin)kupfer(I)-Komplexe der Bidiazine M ononuclear Bis(triphenylphosphine)copper(I) Complexes of the Bidiazines  
 Abstract    The cationic d 10 metal complexes [(bdz)Cu(PPh3).J+ o f the n accepting bidiazine (bdz) che­ late ligands 3,3'-bipyridazine, 2,2'-bipyrazine, 2,2'-and 4,4'-bipyrimidine were synthesized and compared with the analogous com plex o f 2,2'-bipyridine. The long wavelength metal-to-ligand charge transfer (M LCT) absorption maxima and the reduction potentials indicate relatively little 7i* orbital stabilization by +Cu(PPh3)2. The particular d orbital splitting in a tetrahedral ligand field results in an additional contribution from J , to the energy difference between the first and second MLCT band. Only the most easily reduced com plexes o f 4,4'-bipyrimidine and 2,2'-bipyrazine yield neutral radical complexes ("Cu(0)") which were characterized by ESR spectroscopy. 
  Reference    Z. Naturforsch. 47b, 1057—1062 (1992); eingegangen am 11. März 1992 
  Published    1992 
  Keywords    Copper Complexes, Heterocyclic Ligands, Electrochemistry, Absorption Spectroscopy, ESR Spectra 
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 TEI-XML for    default:Reihe_B/47/ZNB-1992-47b-1057.pdf 
 Identifier    ZNB-1992-47b-1057 
 Volume    47 
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