Olefin Oligomerization and Isomerization Catalysts. The Preparation, Properties and Catalytic Action of Dithio Nickel(II) Complexes With Chelating Phosphines

1986 ◽  
Vol 39 (7) ◽  
pp. 1129 ◽  
Author(s):  
KJ Cavell ◽  
AF Masters
Keyword(s):  
Double Bond ◽  
General Formula ◽  
Nickel Complexes ◽  
High Specificity ◽  
Catalytic Action ◽  
Chelating Phosphines ◽  
Olefin Oligomerization ◽  
Double Bond Shift

The syntheses and properties of cationic nickel complexes containing dithio-β-diketonate and chelating bisphosphine ligands of general formula [Ni{R1C(S)CR2C(S)R3}{(PL1L2)R(PL3L4)}]X(Rj,Lj = alkyl or aryl, R = (CH2)n, n = 1-4, X = halide, BPh4, PF6, etc.) are described. The compounds are shown to be effective catalysts for the oligomerization and double bond shift isomerization of olefins with a high specificity for dimeric products rich in desirable linear and near linear isomers.

ChemInform Abstract: A REGIOSPECIFIC DOUBLE BOND SHIFT INDUCED BY TITANOCENE CATALYSTS

1980 ◽  
Vol 11 (22) ◽  
Author(s):  
F. TURECEK ◽  
H. ANTROPIUSOVA ◽  
K. MACH ◽  
V. HANUS ◽  
P. SEDMERA
Keyword(s):  
Double Bond ◽  
Double Bond Shift

Infrared Study of Some Structural Changes in Natural Rubber during Vulcanization

1958 ◽  
Vol 31 (4) ◽  
pp. 719-736 ◽  
Author(s):  
Frederic J. Linnig ◽  
James E. Stewart
Keyword(s):  
Double Bond ◽  
Gamma Rays ◽  
Structural Changes ◽  
Elemental Sulfur ◽  
Carboxyl Groups ◽  
Double Bonds ◽  
Infrared Study ◽  
Tetramethylthiuram Disulfide ◽  
Vulcanized Rubber ◽  
Double Bond Shift

Abstract A knowledge of the structure of vulcanized rubber is essential to the interpretation of vulcanization and oxidation studies and the physical properties of the material. In the present work an infrared study has been made of structures resulting from a number of different methods of vulcanization. Sulfur vulcanizates show the presence of a shifted double bond, originally observed by Sheppard and Sutherland. The presence of conjugated double bonds is also indicated. Accelerators such as tetramethylthiuram disulfide and zinc dibutyl dithiocarbamate increase the rate of the double-bond shift and reduce the amount of conjugated double bonds. Neither the double-bond shift nor conjugation is observed as a result of vulcanization with tetramethylthiuram disulfide alone, hydrogen sulfide and sulfur dioxide (Peachey process), a peroxide, or gamma rays. These result in a possible decrease in carbonyl structures, and in the case of the last three, possible increased absorption due to OH and ionized carboxyl groups. Apparently, the double-bond shift and conjugation are primarily phenomena related to the use of elemental sulfur. The other vulcanization systems studied evidently involve different mechanisms. An implication of the present work is that there may be a relationship between the reported ease of oxidation of sulfur vulcanizates, accelerated vulcanizates, and sulfurless vulcanizates (tetramethylthiuram disulfide alone), which decreases in the order named, and the probable amount of conjugation in the compound, which decreases in the same order.

ChemInform Abstract: Synthesis and Properties of Copper and Nickel Complexes of the General Formula (B11H11)2Mn-. Crystal Structure of ((n-Bu)4N)3(Cu(B11H11)2).

ChemInform ◽  
2010 ◽  
Vol 26 (15) ◽  
pp. no-no
Author(s):  
J. G. KESTER ◽  
D. KELLER ◽  
J. C. HUFFMAN ◽  
M. A. BENEFIEL ◽  
W. E. JUN. GEIGER ◽  
...  
Keyword(s):  
Crystal Structure ◽  
General Formula ◽  
Nickel Complexes
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