Engineering the Structure and Magnetic Properties of Crystalline Solids via the Metal-Directed Self-Assembly of a Versatile Molecular Building Unit

We report the supramolecular chemistry of several metal complexes of N-(4-pyridyl)benzamide
(NPBA) with the general formula [Ma(NPBA)2AbSc], where M = Co2+, Ni2+, Zn2+, Mn2+, Cu2+, Ag+; A =
NO3-, OAc-; S = MeOH, H2O; a = 0, 1, 2; b = 0, 1, 2, 4; and c = 0, 2. NPBA contains structural features
that can engage in three modes of intermolecular interactions:  (1) metal−ligand coordination, (2) hydrogen
bonding, and (3) π−π stacking. NPBA forms one-dimensional (1-D) chains governed by hydrogen bonding,
but when reacted with metal ions, it generates a wide variety of supramolecular scaffolds that control the
arrangement of periodic nanostructures and form 1- (2−4), 2- (5), or 3-D (6−10) solid-state networks of
hydrogen bonding and π−π stacking interactions in the crystal. Isostructural 7−9 exhibit a 2-D hydrogen
bonding network that promotes topotaxial growth of single crystals of their isostructural family and generates
crystal composites with two (11) and three (12) different components. Furthermore, 7−9 can also form
crystalline solid solutions (M,M‘)(NPBA)2(NO3)2(MeOH)2 (M, M‘ = Co2+, Ni2+, or Zn2+, 13−16), where
mixtures of Co2+, Ni2+, and Zn2+ share the same crystal lattice in different proportions to allow the formation
of materials with modulated magnetic moments. Finally, we report the effects that multidimensional
noncovalent networks exert on the magnetic moments between 2 and 300 K of 1-D (4), 2-D (5), and 3-D
(7, 8, 10, and 13−16) paramagnetic networks.