Hydrates of N-(Anthracen-9-ylmethyl)-3-(1H-imidazolium-1-yl)propan-1-ammonium Zinc(II) or Cobalt(II) 2,6-pyridinedicarboxylate: Inter-conversions, assembling and utilities.

Same volume of solutions of different concentrations yielding different crystalline hydrates. [Display omitted] • Hydrates of divalent Co and Zn complexes and their interconversions are presented. • Crystallization of different hydrates from same components but at different concentrations. • Top-down as well as bottom-up of unit cells explain interconversions among these hydrates. • Stacking differences plays a major role in interconversions. • Aggregation induced emissions of hydrates of zinc complexes are presented. Different hydrates [(H 3 anthraimmida)M(26pdc) 2 ]⋅nH 2 O⋅mCH 3 OH {(M = Co; n, m = 4, 0 or n, m = 4.5: 0 or n, m = 2, 2 and M = Zn; n, m = 4, 0 or n, m = 1, 1.5) N-(anthracen-9-ylmethyl)-3-(1H-imidazolium-1-yl)propan-1-amommonium cation (H 3 anthraimmida), 2,6-pyridinedicarboxylates (26pdc)} of N-(anthracen-9-ylmethyl)-3-(1H-imidazolium-1-yl)propan-1-ammonium zinc(II) or cobalt(II) 2,6-pyridinedicarboxylate were crystallized from solutions of same reacting components but each at different concentration. Among these hydrates, the ones having methanol also as solvent of crystallization were metastable, easily transformed to corresponding tetrahydrate. The crystals of the metastable hydrate of zinc complex (monoclinic) transformed to tetrahydrate (triclinic) by halving of unit cell dimension of the metastable form. This transformation was observed under an optical microscope in real time. The transformation of the metastable hydrate of the cobalt complex also resulted the corresponding tetrahydrate. In this case, the unit-cell of the metastable form was doubled than the unit-cell dimension of the corresponding tetrahydrate. The crystals of the metastable form of the zinc complex (monoclinic) transformed to the tetrahydrate (triclinic) though a top-down approach, whereas the crystals of the metastable hydrate of the cobalt complex underwent a bottom-up approach. Diffused light scattering studies have revealed that the average particle sizes of the metastable hydrate of the zinc or cobalt complex dissolved in methanol, were decreased or increased upon addition of water to the solution. The zinc complexes in methanol showed aggregation induced emission enhancement at 415 nm upon addition of water. [ABSTRACT FROM AUTHOR]