The three new complexes Tp(Py)Ln(CH3CO2)2(H2O) (Ln = Eu (1), Gd(2), or Tb (3)) were prepared and characterized crystallographically. In the crystal lattices of these complexes, separate molecules are connected in infinite chains by π-stacking interactions. Complexes 1 and 3 display intense photoluminescence and triboluminescence (red and green respectively), while compound 3 exhibits electroluminescence commencing at 9 V in an ITO/PVK/3/Al device (ITO = indium-tin oxide, PVK = poly(N-vinylcarbazole)). A series of Eu/Tb-doped Gd compounds was prepared by cocrystallization from mixtures of 1 and 2 or 2 and 3, respectively. It was shown that π-stacking interactions are involved in increasing the efficiency of energy transfer from the gadolinium complex to emitting [Tp(Py)Eu](2+) or [Tp(Py)Tb](2+) centers, and this energy transfer occurs through hundreds of molecules, resembling the process of energy harvesting in chloroplast stacks.

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A series of brightly luminescent new mononuclear TpLn(An)(HO) (where An = carboxylate anion, Ln = Eu or Tb and Tp = tris(3-(2'-pyridyl)pyrazolyl)borate) and dinuclear (TpLn)pma(MeOH) (Ln = Eu, Tb, pma = tetraanion of pyromellitic acid) complexes were prepared and characterized by X-ray crystallography. Within each series the compounds possess similar molecular structures, which differ only by the nature of the carboxylate anions. The quantum efficiencies for metal-centered emission of the complexes were up to 29(3)% for Eu and 53(5)% for the Tb compounds and significantly depend on the electronic structure of the additional ligand (i.e. the carboxylate). The aliphatic carboxylate compounds' luminescence quantum yields were all similar, but different from those for the aromatic ones. The complexes with trifluoroacetate and pentafluorobenzoate unexpectedly displayed lower quantum efficiencies compared to those with the corresponding non-fluorinated analogues. Energy transfer from Tb to Eu occurs in a mixture of (TpEu)(pma)(TbTp)(MeOH), (TpEu)(pma)(MeOH) and (TpTb)(pma)(MeOH) but is not very efficient. The Tb-compounds displayed green electroluminescence, and both the Eu and Tb complexes exhibited bright metal-centered red (Eu) or green (Tb) triboluminescence.