76374-90-8Relevant academic research and scientific papers
Comparative measure of the electronic influence of highly substituted aryl isocyanides
Carpenter, Alex E.,Mokhtarzadeh, Charles C.,Ripatti, Donald S.,Havrylyuk, Irena,Kamezawa, Ryo,Moore, Curtis E.,Rheingold, Arnold. L.,Figueroa, Joshua S.
, p. 2936 - 2944 (2015)
To assess the relative electronic influence of highly substituted aryl isocyanides on transition metal centers, a series of C4v-symmetric Cr(CNR)(CO)5 complexes featuring various alkyl, aryl, and m-terphenyl substituents have been prepared. A correlation between carbonyl-ligand 13C{1H} NMR chemical shift (δCO) and calculated Cotton-Kraihanzel (C-K) force constant (kCO) is presented for these complexes to determine the relative changes in isocyanide σ-donor/π-acid ratio as a function of substituent identity and pattern. For nonfluorinated aryl isocyanides possessing alkyl or aryl substitution, minimal variation in effective σ-donor/π-acid ratio is observed over the series. In addition, aryl isocyanides featuring strongly electron-releasing substituents display an electronic influence that nearly matches that of nonfluorinated alkyl isocyanides. Lower σ-donor/π-acid ratios are displayed by polyfluorinated aryl isocyanide ligands. However, the degree of this attenuation relative to nonfluorinated aryl isocyanides is not substantial and significantly higher σ-donor/π-acid ratios than CO are observed in all cases. Substituent patterns for polyfluorinated aryl isocyanides are identified that give rise to low relative σ-donor/π-acid ratios but offer synthetic convenience for coordination chemistry applications. In order to expand the range of available substitution patterns for comparison, the syntheses of the new m-terphenyl isocyanides CNArTripp2, CNp-MeArMes2, CNp-MeArDArF2, and CNp-FArDArF2 are also reported (ArTripp2 = 2,6-(2,4,6-(i-Pr)3C6H2)2C6H3); p-MeArMes2 = 2,6-(2,4,6-Me3C6H2)2-4-Me-C6H2); p-MeArDArF2 = 2,6-(3,5-(CF3)2C6H3)2-4-Me-C6H2); p-FArDArF2 = 2,6-(3,5-(CF3)2C6H3)2-4-F-C6H2).
COBALT CHLORIDE: AN INEXPENSIVE CATALYST FOR THE SUBSTITUTION OF CO BY ISONITRILES ON M(CO)6 (M = Cr, Mo, W)
Albers, Michel O.,Coville, Neil J.,Ashworth, Terence V.,Singleton, Eric,Swanepoel, Hester E.
, p. 55 - 62 (2007/10/02)
CoCl2 * 2 H2O has been found to catalyse the substitution of CO on Group VI metal carbonyls by isonitriles to yield M(CO)6-n(RNC)n M=Cr, Mo, W, n=1-3, RNC=t-BuNC; M=Cr, Mo, W, n=1, RNC=MeNC, XNC (2,6-di-methylphenylisocyanide); M=Mo, n=2, R=MeNC, XNC; fa
