Syntheses, spectral characterization of the nickel (II) complexes of macrocyclic dioxotetraamine and the effect of the functional pendant arms on their properties

A series of new macrocyclic dioxo[13]aneN(4) bearing various functional pen dants, 2-methylfuran (LF), 2-methylthiophene (LT), 2-methylpyridine (LP), h ave been synthesized and characterized , where dioxo[13]aneN(4) is 1, 4, 7, 10-tetraazacyclotridecane-11, 13-dione. The solution behaviours of the nic kel (I) complexes have been studied by Uv-vis, cyclic voltammetric techniqu es. The red-shifts were observed for the absorption band maxima of the elec tronic spectra from NiLR1 to NiLR2 (R = 2-methylfuran , 2-methylthiophene, 2-methylpyridine). The value of E-1/2 of the NiLR2 is less than NiLR2 and b oth of them are lower than that of the nickel (I) complex of the unsubstitu ted ligand, and these reasons are discussed.