Polymers with a conjugated bond system and heteroatoms in the conjugation chain—XXVI. Polyazophenyleneferrocenes

1963 ◽  
Vol 4 (4) ◽  
pp. 935-936
Keyword(s):  
Conjugation Chain ◽  
Bond System

Natural and Synthetic Rubber. IV. 4-Methyl-4-Octene by Isoprene Ethylation

1930 ◽  
Vol 3 (3) ◽  
pp. 483-484
Author(s):  
Thomas Midgley ◽  
Albert L. Henne
Keyword(s):  
Double Bond ◽  
Synthetic Rubber ◽  
Double Bond System ◽  
Bond System ◽  
Usual Behavior ◽  
Natural And Synthetic ◽  
Long Chains

Abstract Isoprene has been ethylated; 4-methyl-4-octene was formed exclusively. The structure of this nonene is in agreement with the usual behavior of a conjugated double bond system. This type of addition is further evidence in favor of the hypothesis which regards the polymerization of isoprene to synthetic rubber as the formation of long chains of isoprene units linked together- by ordinary valences in the 1,4-position.

Pyridine 1:1 adducts of urea (Z′ = 1) and thiourea (Z′ = 8)

2018 ◽  
Vol 74 (4) ◽  
pp. 406-410 ◽  
Author(s):  
Mark Strey ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Layer Structure ◽  
Urea Adduct ◽  
Standard Type ◽  
Space Group ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Bifurcated Hydrogen Bond ◽  
Urea Adducts

During our studies of urea and thiourea adducts, we noticed that no adducts with unsubstituted pyridine had been structurally investigated. The 1:1 adduct of pyridine and urea, C5H5N·CH4N2O, crystallizes in the P21/c space group with Z = 4. The structure is of a standard type for urea adducts, whereby the urea molecules form a ribbon, parallel to the a axis, consisting of linked R 2 2(8) rings, and the pyridine molecules are attached to the periphery of the ribbon by bifurcated (N—H...)2N hydrogen bonds. The 1:1 adduct of pyridine and thiourea, C5H5N·CH4N2S, crystallizes in the P21/n space group, with Z = 32 (Z′ = 8). The structure displays similar ribbons to those of the urea adduct. There are two independent ribbons parallel to the b axis at z ≃ 0 and 1 \over 2, and three at z ≃ 1 \over 4 and 3 \over 4; the latter are crosslinked to form a layer structure by additional long N—H...S interactions, which each formally replace one branch of a bifurcated hydrogen-bond system.

Spin–Spin Correlations in Site Disordered ±J 2D Ising Spin Glasses

1998 ◽  
Vol 09 (05) ◽  
pp. 685-691
Author(s):  
B. Kawecka-Magiera ◽  
A. Z. Maksymowicz ◽  
M. Kowal ◽  
K. Kulakowski
Keyword(s):  
Correlation Functions ◽  
Spin Glasses ◽  
Interatomic Distance ◽  
Spin Correlation ◽  
Two Dimensional ◽  
Spin Correlations ◽  
Ising Spin ◽  
Bond System ◽  
Random Site

Spin–spin correlation functions <S(0)S(R)> as dependent on interatomic distance R are studied in the random-site two-dimensional Ising S=1/2 ±J system. Oscillations of the correlation functions are found, which is not a case in the random-bond system.

Zur Reaktivität von C=N-Doppelbindungssystemen, XII1 über Kupfer(II)- und Nickel(II)-Komplexe von Aminomethylen-1.3-dicarbonylverbindungen / The Reactivity of the C=N-Double Bond System, XII1 Copper(II) and Nickel(II) Complexes of Aminomethylen-1,3-dicarbonyl Compounds

1977 ◽  
Vol 32 (9) ◽  
pp. 1077-1083 ◽  
Author(s):  
Otto S. Wolfbeis ◽  
Erich Ziegler
Keyword(s):  
Tautomeric Form ◽  
Primary Amines ◽  
Direct Reaction ◽  
Metal Acetate ◽  
X Ray Crystallography ◽  
Organic Complexes ◽  
Double Bond System ◽  
Active Methylene Compounds ◽  
Bond System ◽  
Active Methylene

Reaction of active methylene compounds (2,4-pentanedione, dimedone, 4-hydroxycoumarin, 4-hydroxycarbostyriles) with triethyl orthoformate and primary amines (aniline, o-methylmercapto aniline, cyclohexylamine) yields substituted aminomethylen-1.3-dicarbonyles (1-5), which in their tautomeric form (B) give stable, deeply coloured Cu··- and Ni- --organic complexes (6-27). The same chelates may also be obtained by direct reaction of orthoformate, amine and active methylene in the presence of the metal acetate at 40-50 °C in 65-90% yield.Anilinomethylene-3-methyl-1-phenylpyrazolone in turn does not exhibit any tendency to chelate Cu·· or Ni··. The X-ray crystallography of its o-methylmercaptoderivative shows it to exist in the virtually planar enamin form.

Über Derivate des Hydrazins, VII Zur Reaktivität von Bis(trimethylsilyl)aminoisocyanid / On Derivatives of Hydrazine, VII Reactivity of Bis(trimethylsilyl)aminoisocyanide

1977 ◽  
Vol 32 (9) ◽  
pp. 1003-1009 ◽  
Author(s):  
Nils Wiberg ◽  
Gerhard Hübler
Keyword(s):  
Double Bond ◽  
Oxidation State ◽  
Ring Cleavage ◽  
Reaction Paths ◽  
Stable Compound ◽  
Oxidizing Agents ◽  
Formal Oxidation State ◽  
Double Bond System ◽  
Bond System ◽  
Derivatives Of

The chemistry of bis(trimethylsilyl)aminoisocyanide (1) is determined by three reactive centres of the system : the hydrolyzable Si–N-bond, the oxidizable carbon in the formal oxidation state two, the additionable double bond system. Reactions of the oxygen stable compound 1 with halogens X2 or sulfenyl halides RSX as oxidizing agents gives compounds of type (Me3Si)2NNCX2 or (Me3Si)2NNCX(SR). Heterocumulenes such as CO2, CS2, RNCS (R = (Me3Si)2N), SO2 add to 1, leading to heterocycles, which decompose at higher temperatures by ring cleavage. With other heterocumulenes such as PhNCO, Me3SiNSO, Me3SiNSNSiMe3 products are found, the formation of which could be explained by reaction paths including the building and cleavage of heterocycles.

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