Thermal reactions of some cis- and trans-[Coen2(OCOC6H4X)2]NO3 complexes mixed with ammonium or sodium chloride, nitrate and sulphate are reported. Reflectance spectra have shown a cis to trans thermal isomerization and, in the presence of NH4Cl, the formation of trans-[Coen2Cl2]Y as final product. For the cis-isomers, the most interesting result is the chromatographic evidence of a stepwise reaction, resulting in the replacement of one carboxylato ligand by chloride and the formation of an intermediate species, characterized as trans-[Coen2(OCOC6H4X)Cl]Y. These intermediate species, are hardly detectable in the corresponding reactions of the trans-isomers. These results may mean that in the trans-carboxylato compounds the reaction rate of the second step is higher than that of the first, while the reverse can be supposed in the corresponding reaction of the cis-isomers.
ASJC Scopus subject areas
- Chemistry (miscellaneous)
- Physical and Theoretical Chemistry