Spectroscopic Characterization of Croconate Bridging Complex: Conversion of Rhodizonate (C6O6 2-) to Croconate Bridging Ligand in a Pyridine Modified Large Macrocyclic Metal Arrangements

摘要

Rhodizonic acid (H2RHOD) was reacted with Co(PF6)2.6H2O in the presence of pyridine modified large macrocyclic ligand (H2Lopy) and triethylamine in N,N-dimethylformamide under argon atmosphere. Instead of [Co4(RHOD)2(Lopy)](PF6)2 (1), the main product of this reaction was a crystalline compound [Co4(CROC)2(Lopy)](PF6)2, which was isolated in low yield (< 25%). Based on the elemental analysis, ESI-mass spectroscopy, and infrared spectrum, the isolated compound was confirmed to be [Co4(CROC)2(Lopy)](PF6)2 (2), where CROC2- is croconate anion C5O52-.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 2, 101-108, 2016