Reaction of Nd-III and Er-III nitrate salts with a 1,3,5-tris(dipicolylamine)-triazine (dpat) ligand yielded two unprecedented examples of [Ln(NO3)(6/5)](3-/2-) (Ln = Nd, Er) moieties completely encapsulated by the ligands. They are found in the two new complexes, [(H(3)dpat)(2)][(Nd(NO3)(6))(2)]center dot 2CH(3)CN (1), and the related [(H(3)dpat)(2)][(Er(NO3)(5))(3)]center dot 3CH(3)CN center dot H2O (2). The structures of the complexes are similar and they crystallize in the triclinic P-1 space group with a = 12.1630(3), b = 12.2694(3), c = 17.6357(5) angstrom, V = 2611.10(12) angstrom(3), and a = 14.3372(4), b = 17.1271(4), c = 25.2207(7) angstrom, V = 5934.7(3) angstrom(3), respectively. Anion-pi interactions, which are reported here for the first time for Ln(III) ion complexes, hydrogen bonding interactions and pi-pi stacking support the formation of the encapsulated species. Evidence of the protonated dpat ligand in 1 and 2 was found through isolation of (H(2)dpat)(NO3)(2). Finally, the pH-dependent ability of the ligand to extract La(III )and nitrate ions from aqueous into toluene solution is demonstrated.