Sixteen new 3d–4f binuclear complexes have been obtained using two Schiff-base ligands, Hvalampy and Hvalaepy, derived from the reaction of o-vanillin and 2-aminomethyl-pyridine or 2-(2-aminoethyl)-pyridine, respectively. Hvalaepy ligand: [Zn(valaepy)₂Sm(O₂NO)₃]·CH₃CN 1; [Ni(valaepy)₂Eu(O₂NO)₃(H₂O)]·CH₃CN 2; [Ni(valaepy)₂Gd(O₂NO)₃(H₂O)]·CH₃CN 3; [Ni(valaepy)₂Dy(O₂NO)₃(H₂O)]·CH₃CN 4; [Ni(valaepy)₂Ho(O₂NO)₃(H₂O)]·CH₃CN 5; [Cu(valaepy)₂Eu(O₂NO)₃]·CH₃CN 6; [Cu(valaepy)₂Gd(O₂NO)₃]·CH₃CN 7; Hvalampy ligand: [Zn(valampy)₂Pr(O₂NO)₃]·CH₃CN 8, [Zn(valampy)₂Sm(O₂NO)₃]·CH₃CN 9; [Zn(valampy)₂Gd(O₂NO)₃]·CH₃CN 10; [Zn(valampy)₂Tb(O₂NO)₃]·CH₃CN 11; [Zn(valampy)₂Dy(O₂NO)₃]·CH₃CN 12; [Zn(valampy)₂Eu(O₂NO)₃]·CH₃CN 13; [Ni(valampy)₂La(O₂NO)₃(H₂O)₂]·2H₂O 14, [Ni(valampy)₂Sm(O₂NO)₃(H₂O)₂]·2H₂O 15; [Ni(valampy)₂Eu(O₂NO)₃(H₂O)]·2CH₃CN 16. The crystal structures of the sixteen compounds can be described as resulting from the coordination of two valaepy⁻ (or valampy⁻) ligands to the 3d metal ions through two phenoxo oxygen atoms and nitrogen atoms, arising from the pyridyl and azomethynic groups. In all these compounds the 3d and 4f metal ions are bridged by the phenoxo oxygen atoms. The comparative analysis of the crystal structures shows several differences, which arise mainly from the stereochemical preference of the 3d metal ions. These ions arrange the two organic ligands in positions that favour or not the coordination of the methoxy groups to the lanthanide ions. The magnetic properties of compounds 2, 3, 4, 5, 7, 14, 15, and 16 have been investigated. The exchange interactions between Ni^II and Gd^III in 3, and between Cu^II and Gd^III in 7 were found to be ferromagnetic (J_NiGd = 1.56 cm⁻¹; J_CuGd = 4.94 cm⁻¹; H = −JS_GdS_M). For the 3d–4f binuclear complexes derived from the Hvalampy ligand (namely 8–13) the photoluminescence (PL) properties were investigated in the Vis spectral region. The results provide evidence for the relatively stronger antenna effect in 9 and 11 compared to 8, 12 and 13.

The synthesis and crystal structures of five radical cation salts based on the organic donors bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF), racemic ethylenedithio-methyl-oxazoline-tetrathiafulvalene (EDT-TTF-MeOx) and the enantiopure (S,S,S,S) and (R,R,R,R) tetramethyl-bis(ethylenedithio)tetrathiafulvalene (TMBEDT-TTF) and the D₃-symmetric anion tris(tetrachlorobenzenediolato)phosphate(V) (TRISPHAT) are reported. The salts are formulated as [BEDT-TTF][(rac)-TRISPHAT]·CH₂Cl₂ (1), [BEDT-TTF][(rac)-TRISPHAT]·2CH₃CN (2), [(rac)-EDT-TTF-Ox][(rac)-TRISPHAT]·CH₃CN (3), [(S,S,S,S)-TMBEDT-TTF][(rac)-TRISPHAT]·2CH₃CN (4), and [(R,R,R,R)-TMBEDT-TTF][(rac)-TRISPHAT]·2CH₃CN (5). The donors are fully oxidized and self-assemble in dyads inserted in the channels generated by the packing of the TRISPHAT anions. Magnetic and EPR measurements performed on compounds 1 and 2 clearly indicate weak interactions within the dimers in compound 1, characterized by a very narrow line in the EPR spectrum, while the radicals are strongly coupled in compound 2.

N-Acylhydrazones have been described as responsive compounds to a wide variety of triggers that are able to induce reversible structural changes. These reversible constitutional, conformational or configurational changes caused by physical or chemical stimuli are useful tools in designing molecular switches. We report herein bis-N-acylhydrazones as new switchable-light emissive molecules triggered by light and/or solvents. The emissive properties could be explained by phototautomerisation (Excited State Intramolecular Proton Transfer) and by formation of aggregates (Aggregation-Induced Emission). We investigated the influence of structural particularities brought in by electron-donor or electron-withdrawing substituents as well as the requirement of several hydrazone bonds in the molecular structure for the generation of light.