Coordination reactions of 3,3′-bis(dipyrrolylmethene) with Co(II), Cu(II), and Zn(II) acetylacetonates, valinates, and dipyrrolylmethenates

Using spectrophotometry we found that ligand exchange in the systems of H2L-[MX2]-DMF, where M denotes Co2+, Cu2+, and Zn2+; X means Acac−, Val−, dpm−; Hdpm− is hexamethyldipyrrolylmethene, H2L is bis(2,4,7,8,9-pentamethyldipyrrolylmethene-3-yl)methane, proceeds through successive stages of formation of hetero- and homoleptic binuclear complexes. Conventional sensitivity of the spectrophotometric determination of Co2+, Cu2+, and Zn2+ reaches 10−9 M.