147513-93-7Relevant articles and documents
Syntheses and Spectral Characterizations of Tricarbonylchromium Complexes of Calixarenes
Iki, Hideshi,Kikuchi, Taketoshi,Shinkai, Seiji
, p. 205 - 210 (2007/10/02)
The 1:1 arene-tricarbonylchromium complexes were synthesized for the first time from four conformational isomers of 25,26,27,28-tetrapropoxycalixarene (14Pr) and Cr(CO)6.The 1:2, 1:3 and 1:4 complexes of cone-14Pr were also synthesized by increasing the ratio of Cr(CO)6 against cone-14Pr.The 1:2 complex was a mixture of two compounds, which were identified as distal and proximal isomers of cone-14Pr*2Cr(CO)3.The relative stability of the 1:1 complex was estimated via its oxidation by CuCl2.The pseudo-first-order rate constants appeared to be in the order of 1,3-alternate-14Pr > 1,2-alternate-14Pr > cone-14Pr > 2,6-dimethylanisole.The results indicate that the 14r*Cr(CO)3 complexes are less stable than the corresponding monomeric complex.The 1:1 complexes with partial-cone-14Pr and 1,2-alternate-14Pr were demonstrated to be a pair of racemates by 1H NMR spectroscopy using a chiral shift reagent (Pirkle's reagent).