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The present work introduces the synthesis and characterization of upper rim dibromo-substituted bis-1,3-diketone calix[4]arenes with hydroxy and propyloxy groups at the lower rim as ligands for Gd3+ and Tb3+ complexes. The dibromo-substitution does not affect 1:1 complex formation with the lanthanide ions arising from their coordination via two 1,3-diketonate groups incorporated at the upper rim of the calix[4]arene. The analysis of the time-resolved luminescence spectra of the Gd3+ complexes clearly demonstrates the notable enhancement of the decay time of the ligand triplet state, while the energy of the triplet state for the new dibromo-bis-1,3-diketones remains practically unchanged versus its non-substituted analogues. The latter tendency points to the heavy-atom effect on the energy transfer from the excited state to vibration levels of the dibromo-substituted ligand resulting in a decreased radiationless decay contribution. Measurements of Tb3+-centered luminescence indicate a better antenna effect (∼1.7) of dibromo-calix[4]arenes compared with its non-substituted counterpart.

Two novel calix[4]arene macrocyclic ligands functionalized with four 1,3-diketone groups at the upper and hydroxyl ( 3 ) or propyloxy-groups ( 6 ) at the lower rims were synthesized and characterized using NMR, IR spectroscopy, mass spectrometry, and elemental analysis. UV–vis spectrophotometry and ESI mass spectrometry studies indicate 1:1 complex formation of ligands 3 and 6 with Ln(III) (Ln=Tb, Yb) in alkaline DMF solutions resulted from coordination of Ln(III) with 1,3-diketonate groups. Luminescence study of Ln(III) complexes with 3 and 6 reveals significant difference in antenna effects of their deprotonated forms on both Tb(III)- and Yb(III)-centered luminescence. Comparison of ligand-centered emission for ligands 3 and 6 points to the latter as more efficient antenna for Tb(III) and Yb(III). Different conformational behavior of ligands 3 and 6 in alkaline media is assumed as a reason for the experimentally observed difference in sensitization pathways in Ln(III) complexes with 3 and 6 .

A series of new calix[4]resorcinarenes (rccc-isomer) and resorcinols functionalized by acetylhydrazone binding fragments have been synthesized. The IR and NMR data and stereochemical behaviour of hydrazones are reported and compared with the results of earlier investigations. The barriers of rotation of hydrazone fragments for some octahydrazone derivatives of calix[4]resorcinarenes and their resorcinol analogues have been determined by NMR-measurements. The complexing behaviour of bis- and octahydrazones has been studied by liquid–liquid extraction towards the s-metal ions (Li+, Na+, K+, Cs+ and Ca2+), p-metal ions (Pb2+), d-metal ions (Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+) and f-metal ions (La3+, Gd3+ and Lu3+). The stoichiometry of complexes and the extraction constants have been determined. It has been established that octahydrazones do not extract alkali metal cations but show excellent selectivity towards transition and soft heavy metal cations (especially Hg2+ or Pb2+).