Receptors based on 2,2':6',2'-terpyridine fragments containing peripheral amino groups

摘要

The reaction of 2,2':6',2"-terpyridinyl-4'-carboxaldehyde with the diamine N-methyl-1,3-propanediamine yields the terpyridine derivative containing amino groups 1-(2,2':6'2"-terpyridin-4'-yl)-2,6-diaza-2-methylcyclohexane (L~1), whereas under similar experimental conditions the reaction of 2,2':6',2"-terpyridinyl-4'-carboxaldehyde with N,N-dimethylethylenediamine yields the expected 1-(2,2':6',2"-terpyridin-4'-yl)-2,5-diaza-5-methyl-hexa-1-ene (L~2) imine and the [4'-COO-tpy][H_3NCH_2CH_2N(CH_3)_2] salt (L~3). The crystal structure of L~3 was determined by X-ray single-crystal analysis. The structure consists of terpyridine carboxylate and protonated diamines linked together by ionic and hydrogen bonding interactions. The homoleptic complexes [Co(L~1)_2]~(2+) and [Fe(L~1)_2]~(2+) have been prepared. These contain peripheral amino groups and their interactions with protons and the anions ATP, chloride, sulphate and phosphate have been studied in acetonitrile and in THF:water (70:30 v/v) using electrochemical techniques.