Dinucleating Schiff base ligand in Zn/4f coordination chemistry: synthetic challenges and catalytic activity evaluation

Four Zn/4f polynuclear coordination clusters (PCCs) formulated as [ZnII2DyIII2L2(CO3)2(NO3)2] (1), [ZnIIYIIIL(NO3)2(o-van) (MeOH)] (MeOH) [2 (MeOH)] and [ZnIILnIIIL(NO3)2Cl(EtOH)] where Ln is Dy (3) and Y (4) and where H2L is the dinucleating Schiff base ligand N,N′ bis(3-methoxysalicylidene)cyclohexane-1,2-diamine and o-van is ortho-vanillin, were prepared and fully characterised for the first time. These air-stable heterometallic PCCs, obtained in high yields from commercially available materials, were shown to remain stable in solution in their dinuclear [ZnIILnIIIL] form. Their catalytic activity was evaluated in various catalytic transformations including the Friedel-Crafts alkylation of 2 acyl imidazoles with indole