Synthesis and acid-base properties of phosphorylated diazocycloalkanes and their cyclic analogs

Article abstract of DOI:10.1007/BF00696324

Novel cyclopendant organophosphorus complexing agents, viz. 1,5-bis(2-diphenylphosphorylmethyl(or ethyl))-1,5-diazacyclooctane (1, 2) and 1-methyl-4-(2-diphenylphosphorylethyl)piperazine (3), were synthesized on the basis of 1,5-diazacyclooctane and piperazine.The protonation constants of the compounds synthesized and some of their analogs were determined by potentiometric titration in 70percent aqueous ethanol and in nitromethane. the nitrogen atoms of the ring are the protonation sites in all of the systems studied.The regularities of the variation of protonation constants have been explained by the formation of intramolecular hydrogen bonds.The conformational possibilities of the formation of H-bonds in the cations of the ligands have been examined by molecular mechanics. - Key words: cyclopendant ligands, phosphorylated diazacycloalkanes, protonation constants, potentiometric titration, intramolecular hydrogen bonds, conformational analysis.