77430-30-9Relevant academic research and scientific papers
Bis(aromat)chrom-Komplexe. Darstellung durch Cokondensation; IR-spektroskopische, cyclovoltammetrische und kinetische Untersuchungen
Brunner, Henri,Koch, Heinrich
, p. 65 - 83 (2007/10/02)
By cocondensation of Cr vapor, benzene and a substituted arene, in addition to bis(benzene)chromium(0), the compounds (arene)(benzene)chromium(0) (8a - 14a, 22a - 24a, 28a) and bis(arene)chromium(0) (15a - 21a, 25a - 27a, 29a) were synthesized.The complexes were oxidized to the corresponding bis(arene)chromium(I) iodides by titration with iodine solution.From the trend of the ν(C=O) frequencies in ester and keto substituents it follows that the (C6H6)Cr0 substituent is extremely electron donating, the (C6H6)CrI substituent, however, strongly electron withdrawing.In contrast, type and number of the substituents affect the redox potential Cr0/CrI irrespective of their arrangement at the bis(arene)chromium skeleton.The electron withdrawing character of the (C6H6)CrI-substituent is documented in a comparison of the base-catalyzed transesterification of free ang complexed methyl benzoate by rate differences of several powers of ten.The expected retardation of the transesterification of the corresponding chromium(0) complexes is outplayed by a chromium(I) catalysis.
