Infrared spectra and x‐ray diffractions of 24 nylons were investigated. The positions of the NH stretching and the amide I bands indicate that the amide groups form hydrogen bonds almost completely, irrespective of the number of CH2 groups. The position of the amide V band has been correlated with the crystal structure. Nylons characterized by a predominant peak at 725 cm.−1 show only one reflection in the x‐ray photograph. Odd‐odd nylons belong to this type (γ form). Even‐odd and odd‐even nylons also take this γ form when prepared from the melt through quenching. When cast from solution, they seem to take a new form. Amino acid nylons with an odd number of CH2 groups have a tendency to take the γ form. Three bands closely related with the position of the amide V band are found.
Reduction of iron(III) acetylacetonate and cobalt(III) acetylacetonate with ethoxydiethylaluminum in the presence of ethylenebis(diphenylphosphine) (EDP) gives Fe(EDP)2-C2H4 and HCo(EDP)2, respectively. Ultraviolet irradiation of Fe(EDP)2 • C2H4 results in the formation of HFe(C6H4PPh • CH2CH2 • PPh2)(EDP), in which hydrogen transfer from a phenyl group of the ligand to the iron atom takes place. The hydrogen atom of the Fell bond of the iron hydride is labile and returns to the original ligand with ease. The iron hydride is converted into Fe(EDP)2 • C2H4 under ethylene pressure. Reaction of the iron hydride with deuterium chloride affords DFeCl-(EDP)2 and HFeCl(C6H4DPPh • CH2CH2 • PPh2)(EDP) in a ratio of 80:20. The iron complexes Fe(EDP)s • C2H4 and HFe(C6H4PPh CH2CH2 • PPh2)(EDP) react with hydrogen at atmospheric pressure to give H2Fe(EDP)2.
The allylic groups of ethers and esters exchange with a variety of active hydrogen compounds in the presence of palladium catalysts.IN the degradation of octa-Z,7-dienyl phenyl ether to phenol and octa-1,3,7-triene with a palladium catalyst,l Smutny observed the formation of a small amount of 2and 4-(octa-2,7-dienyl)phenol,2 which is obviously not formed via a normal or abnormal Claisen rearrangement of the ether.We find that the octadienyl group of octa-2,7-dienyl phenyl ether exchanges with a variety of active-hydrogen compounds in the presence of palladium catalysts, and further research has led to the finding that the allylic compounds (I) react with active-hydrogen compounds to give allylic derivatives of the active-hydrogen compounds R10-CH2CH = CHR2
Active methylene compounds, such as acetylacetone and ethyl acetoacetate, reacted with 1,3-butadiene in the presence of palladium-diphosphine complex catalysts to yield two 1 : 1 adducts, 1 and 2. Primary and secondary amines also afforded two 1 : 1 adducts, 10 and 11. Isoprene, 1,3-pentadiene, and 2,4-hexadiene also reacted with the active methylene compounds and the amines in a manner similar to that of 1,3-butadiene. The most effective and easily available catalyst is the combination of PdBr2(Ph2PCH2CH2PPh2)2 and sodium phenoxide.
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