Structural diversity of transition-metal coordination polymers and dinuclear metallocycles constructed by bispyridyl-substituted diphthalic diimide ligands

Four coordination polymers (CPs), namely, {[Ni(L1)2Cl2]·(CHCl3)}n(1), {[Co(L1)1.5(NO3)2]·(CHCl3)}n (2), {[Ag2(L2)2(NO3)2]·(CHCl3)}n (3), [Cd(L2)2(Cl)2]n (4), and two dinuclear metallocycles, namely, {[Zn2(L3)2(Cl)4]·2CHCl3}n (5) and [Cu2(L3)2(Cl)4] (6), (L1 = 2,2′-bis(pyridin-3-ylmethyl)-[5,5′-biisoindoline]-1,1′,3,3′-tetraone), L2 = 5,5′-oxybis(2-(pyridin-3-ylmethyl)isoindoline-1,3-dione), L3 = 5,5′-carbonylbis(2-(pyridin-3-ylmethyl)isoindoline-1,3-dione)), have been adeptly constructed using solvothermal conditions and successfully delineated by non-destructive single-crystal (X-ray) diffraction. Structural analyses provide insights into a two-dimensional (2D) 44 grid layer of complex 1 and a three-dimensional (3D) 63 network of 2. Additionally, the connection between these two complexes is established via hydrogen bonding (CH···O) to further accomplish a three-dimensional (3D) supramolecular framework system. Similarly, Complex 3 and 4 possess a one-dimensional (1D) wave-like chain and loop-like chains composed of olive-like metallacycle building units, respectively. These chains are bridged by CH···O hydrogen bond and π∙∙∙π stacking interactions to generate 3D supramolecular structure. Finally, complexes 5 and 6 occupies zero-dimensional (0D) square-like array also called as olive-like dimeric M2L2 metallacycles. The distinct structural configurations of the six complexes are in close alliance with different conformations of the N-donor pyridyl ligands and coordination arrangement of the transition metal centers.