cg1c00459_si_001.pdf (1.23 MB)
Structural Landscape of Zn(II) and Cd(II) Coordination Compounds with Two Isomeric Triimidazole Luminophores: Impact of Crystal Packing Patterns on Emission Properties
journal contribution
posted on 2021-06-01, 12:40 authored by Marina S. Fonari, Victor Ch. Kravtsov, Victor Bold, Elena Lucenti, Elena Cariati, Daniele Marinotto, Alessandra ForniThe
interplay of different
Zn(II) and Cd(II) salts with two luminescent triimidazole ligands,
triimidazo[1,2-a:1′,2′-c:1″,2″-e][1,3,5]triazine (L1) and its positional isomer triimidazo[1,2-a:1′,2′-c:1″,5″-e][1,3,5]triazine
(L2), in solvothermal synthetic conditions resulted in
mono-, bi-, and polynuclear Zn(II) and Cd(II) coordination compounds
with diverse metal/luminophore(L1,L2)/anion/water
ratios, [Zn(H2O)6](NO3)2(L1)2 (1), [Zn(H2O)4(L1)2](NO3)2(H2O)2 (2), [Cd(H2O)4(L1)2](NO3)2(H2O)2 (3), [Zn(L1)(NO3)(H2O)3](NO3) (4),
[Cd(L1)2(NO3)2(H2O)2] (5, 6), [Cd2(bdc)(L1)2(NO3)2(H2O)4]·2H2O (7), [Zn(H2O)4(L2)2](NO3)2 (8), [Cd(L2)2(NO3)2(H2O)] (9), [Zn(L2)2(CH3COO)2]
(10), [Cd(L2)2(CH3COO)2(Im)0.75(H2O)0.25]·0.5(H2O) (11), [Zn(Cl)2(L1)(H2O)] (12), {[Zn(Cl)2(L1)]·1/6(L1·H2O)}n (13), and [Cd(L2)6]2[Cd(H2O)6](ClO4)6·7(H2O) (14). Herein, for the
first time, the Zn and Cd coordination compounds with L1 and L2 luminophores as inner-sphere ligands have been
obtained and structurally characterized. The structural landscape
includes inclusion compound 1, supramolecular isomers 1–3, isomorphs 2 and 3, polymorphs 5 and 6, and one-dimensional
coordination polymer 13. In discrete complexes, both
luminophores coordinate to the metals in monodentate mode; in 13, L1 acts as a bidentate bridging ligand giving
rise to the structure extension. Since the crystal packing and stacking
patterns of the luminophore molecules are important factors underlying
the aggregation induced emission, the finite and infinite stacking
motifs registered in the crystal structures 1–14 are reported. All compounds reveal an emissive response
upon irradiation under the UV–vis lamp. The best performing
compounds in the series, namely, 4, 5, and 10, have been fully spectroscopically characterized.
