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'Pyrazine' in keywords
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1999 (1)
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1Author    G. Brolo, DonaldE. IrishRequires cookie*
 Title    Alexandre  
 Abstract    Dedicated to Prof. Hitoshi Ohtaki on the occasion of his 60th birthday Raman spectra of aqueous pyrazine have been investigated in acidic media: HCl from pH = 4 up to 11 M; HC104 from 0.1 M to 12 M; H2S04 form 0.1 M to 18 M. From observation of the shifts of the bands from neutral solutions, it has been possible to identify bands uniquely characteristic of unprotonated pyrazine and its two protonated forms. The diprotonated form was only observed for high concentrations of HC104 and H2S04. From bandfitting of the spectral contours it has been possible to construct the species distribution diagram and estimate the pK values. Raman bands of the three species have been identified and assigned. The results are used to explain an unassigned band at 1235 cm-1, reported by several authors, in SERS from pyrazine on silver and gold elec­ trodes. R a m a n S p e c tr a l S tu d ie s o f A q u e o u s A c id ic P y r a z in e S o lu tio n s 
  Reference    Z. Naturforsch. 50a, 274—282 (1995); received October 31 1994 
  Published    1995 
  Keywords    Pyrazine, Pyrazinium, SERS, Raman spectroscopy 
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 TEI-XML for    default:Reihe_A/50/ZNA-1995-50a-0274.pdf 
 Identifier    ZNA-1995-50a-0274 
 Volume    50 
2Author    Karl Hensen, Jens GaedeRequires cookie*
 Title    Thermodynamische Interpretation der Schmelzdiagramme binärer Systeme aus Methylchlorsilanen und Pyridazin bzw. Pyrazin  
 Abstract    By analyzing the cooling curves and the resulting melting point diagrams of the chloro-methylsilane-pyridazine and pyrazine systems the existence of the incongruently melting addition compounds CH 3 SiCl 3 • Pyridazine, (CH 3) 2 SiCl 2 • (Pyridazine) 2 , (CH 3) 3 SiCl • (Pyridazine) 2 , CH 3 SiCl 3 • (Pyrazine) 2 , (CH 3) 2 SiCl 2 • (Pyrazine) 2 , (CH 3) 3 SiCl • (Pyrazine) 2 was proved. By electro-optical measurements of the turbidity point it was proved that the system (CH 3) 3 SiCl-Pyridazine exhibits a miscibility gap which intersects the liquidus curve of the amine. Based on certain approximations it was possible to fit thermodynamic functions to the experimental results to obtain the excess data of mixing of the corresponding systems. These data allow for a more profound understanding of the Lewis-acid base behaviour of the silanes and amines. A) Experimentelle Ergebnisse 
  Reference    Z. Naturforsch. 42a, 341—351 (1987); eingegangen am 23. Juli 1986 
  Published    1987 
  Keywords    Chloromethylsilanes, Pyridazine, Pyrazine, Phase Diagrams, Addition Compounds, Thermo-dynamic Excess Functions 
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 TEI-XML for    default:Reihe_A/42/ZNA-1987-42a-0341.pdf 
 Identifier    ZNA-1987-42a-0341 
 Volume    42 
3Author    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 
4Author    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 
5Author    B. Roßenbeck, W. S. SheldrickRequires cookie*
 Title    Three-dimensional Copper(I) Halide Based Coordination Networks with Asymmetrically Substituted Bridging N-Donor Ligands  
 Abstract    The discrete complex [(Cul)2 (pyzCN)4] (1) and the coordination polymers ^ [CuI(pyzCN)] (2) and 3 [(CuX)3 (pyzCN)2] (3, 4; X = Br, Cl) may be prepared from the respective copper(I) halide CuX and 2-cyanopyrazine (pyzCN) by self-assembly in acetonitrile solution at 100-120°C. Whereas 2 exhibits 1 [Cul] staircase double chains as its characteristic substructure, the three-dimensional netwo'rks of 3 and 4 contain single zigzag CuX strings. The influence of the copper(I) halide on both the connectivity pattern and the dimensionality of a resulting coordination network is particularly apparent for the 1:1 complexes ^ [CuI(pymMe)] (5), 3 [(CuBr)3(pymMe)_3] (6) and ^ [CuCl(pymMe)] (7), which were generated by reaction of öaX with 4-methylpyrimidine (pymMe) under reaction conditions similar to those above. 
  Reference    Z. Naturforsch. 54b, 1510—1516 (1999); received August 27 1999 
  Published    1999 
  Keywords    Copper (I) Halides, Coordination Polymers, Crystal Engineering, Pyrazine, Pyrimidine 
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 TEI-XML for    default:Reihe_B/54/ZNB-1999-54b-1510.pdf 
 Identifier    ZNB-1999-54b-1510 
 Volume    54