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'Mixed Valence State' in keywords
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2000 (1)
1995 (1)
1980 (1)
1Author    D. Chales De Beaulieu, Hk Müller-BuschbaumRequires cookie*
 Title    Gemischtvalente Oxovanadate, I Ein neuer Strukturtyp für die Verbindung BaV10O15 Oxovanadates with Mixed Valence, I A New Crystal Structure of BaVioOis  
 Abstract    BaVioOis was prepared by high temperature reaction of BaO and V2O3 in H2-atmosphere (T > 1800°). X-ray investigations of single crystals show a new structure type with octa-hedral coordination of V 3+ /V 2+ (statistical distribution) and cuboctahedral surrounding of Ba 2+ . Orthorhombic symmetry, space group D^|-Ccmb, a = 995,8; b = 1161,8; c = 941,0; Z = 4. 
  Reference    Z. Naturforsch. 35b, 669—671 (1980); eingegangen am 5. Februar 1980 
  Published    1980 
  Keywords    Barium, Vanadium, Oxide, Mixed Valence State, Crystal Structure 
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 TEI-XML for    default:Reihe_B/35/ZNB-1980-35b-0669.pdf 
 Identifier    ZNB-1980-35b-0669 
 Volume    35 
2Author    Hidenari Inoue3, Shuichi Narino3, Naoki Yoshioka3, Ekkehard FluckbRequires cookie*
 Title    Thermal Decomposition of Prussian Blue Analogues of the Type Fe[Fe(CN)5NO]  
 Abstract    The structure and properties o f the thermal decomposition products of Fe[Fe(CN)sNO] • x H2O (x = 5 ~ 6) have been studied by M össbauer and FT-IR spectroscopy, X-ray diffraction, and conductivity measurements. The valence state and coordination environment of the iron ions change dramatically when the nitrosyl ligand is eliminated by heat-treatment under vacuum at 200 °C. The dark blue product obtained by heat-treatment under vacuum at 250 °C is characteristic of the mixed-valence state in Prussian blue analogues. The electrical conductivity of the dark blue product is higher by a factor o f 103 than that o f the starting material because of the mixed-valence state between Fe(III)[Fe(II)(CN)5] and Fe(II)[Fe(III)(CN)5]. Heat-treatment under vacuum at 350°C yields a new product Fe(II)[Fe(II)(CN)4] the crystal structure of which is different from that of the starting material. The electrical conductivity of the decomposition product obtained at 350 °C is about 105 times higher than that of the starting material. 
  Reference    Z. Naturforsch. 55b, 685—690 (2000); received April 5 2000 
  Published    2000 
  Keywords    Prussian Blue Analogues, Mixed-Valence State, Thermal Decomposition 
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 TEI-XML for    default:Reihe_B/55/ZNB-2000-55b-0685.pdf 
 Identifier    ZNB-2000-55b-0685 
 Volume    55 
3Author    Kenta Takahashi, Keisuke Umakoshi, Akihiro Kikuchi, Yoichi Sasaki, Masato Tominaga, Isao TaniguchiRequires cookie*
 Abstract    New trinuclear rhodium(III) complexes, [Rh3(//3-0)(/i-CH3C00)6(L)3]+ (L = imidazole (Him), 1-methylimidazole (Meim), and 4-methylpyridine (Mepy)) have been prepared. The Him, Meim, and Mepy complexes show reversible one-electron oxidation waves at E1/2 = +1.12, +1.12, and +1.28 V vs Ag/AgCl, respectively, in acetonitrile. Electronic absorption spectra of the one electron oxidized species of these complexes and [Rh3(M3-0)(M-CH3C 0 0)6(py)3]+ (py = pyridine) (E 1 /2 = +1.32 V) were obtained by spectroelectrochemical techniques. While the Rh3(III,III,III) states show no strong visible absorption, the Rh3(III,III,IV) species give a band at ca. 700 nm (e = 3390-5540 mol dm" 3 cm" 1). [Ir3(«3-0)(//-CH3C00)6(py)3]+ with no strong absorption in the visible region, shows two reversible one-electron oxidation waves at +0.68 and +1.86 V in acetonitrile. The electronic absorption spectrum of the one-electron oxidized species (Ir3(III,III,IV)) also shows some absorption bands (688 nm (e, 5119), 1093 (2325) and 1400 (ca. 1800)). It is suggested that the oxidation removes an electron from the fully occupied anti-bonding orbital based on metal-d7r-/^3-0-pjr interactions, the absorption bands of the (III,III,IV) species being assigned to transitions to the a«r/-bonding orbital. esting because of their characteristic strong visible absorption and reversible multi-step redox behav­ iour [2-14]. It has been suggested that such char­ acteristic properties are associated with strong in-termetallic interactions through the central oxide bridge. The Ru(d^r)-^3 -0 (p jr) interaction is sig­ nificantly stronger than that of analogous tri­ nuclear complexes o f first row transition elements. The djr-pjr molecular orbitals shown in Fig. 1 have been proposed for the trinuclear ruthenium complexes [3,15,16], In the study of mixed ruthe-nium-rhodium complexes, it was suggested that a similar molecular orbital scheme should be appli­ cable to trirhodium and mixed ruthenium-rho-dium complexes [7]. Electronic states o f the oxo-centered triiridium (III) complexes [17,18] should also be considered in terms of the djr-pjr molec­ ular orbital scheme. Thus the oxo-centered tri­ metal complexes of heavy transition elements could be significantly different from those of first row transition elements with respect to the extent of metal-oxygen-metal interactions. The trinuclear 
  Reference    Z. Naturforsch. 50b, 551—557 (1995); received October 5 1994 
  Published    1995 
  Keywords    Trinuclear Complexes, Rhodium Complexes, Iridium Complexes, dn-ipji Interaction, Spectroelectrochemistry, Mixed Valence State 
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 TEI-XML for    default:Reihe_B/50/ZNB-1995-50b-0551.pdf 
 Identifier    ZNB-1995-50b-0551 
 Volume    50