Synthesis, crystal structures, and deprotonation of cis- and trans-octahedral nickel(II) complexes with a 14-membered tetraaza macrocycle bearing two N-phenacyl pendant arms

► Preparation of a new functionalized tetraaza macrocycle (H2L2) bearing two N-CH2COC6H5 pendant arms. ► Isolation of two geometric isomers, trans-[Ni(H2L2)]2+ and cis-[Ni(H2L2)]2+, and their crystal structures. ► Deprotonation behaviors of the two geometric isomers in basic conditions.