Complexes [Ca(H 2 O) 2 (Dmf@CB[6])(Bdc)] · DMF · 4H 2 O (I) and [Ca(H 2 O) 3 (Dmf@CB[6])]Cl 2 · 2H 2 O (II) are synthesized by the heating (95°C) of a mixture of calcium chloride and cucurbit[6]uril (CB[6]) in a mixture of dimethylformamide (DMF) and water with the addition of terephthalic acid (H 2 Bdc) in the case of complex I or triethylamine for complex II. The compounds are characterized by X ray diffraction analysis, IR spectroscopy, and thermogravimetric and elemental analyses. The luminescence spectra are also recorded. According to the X ray diffraction data, the calcium atom is coordinated by the oxygen atoms of the cucurbit[6]uril molecule, water molecules, and terephthalate anion (for I). The internal cavity of the cav itand is occupied by DMF.