Two novel pyrazine-2-carboxylate titanium complexes were synthesized from an aqueous solution (1) and 1 in N,Ndimethylformamide (DMF) (2). The structure of 2 was determined to be [Ti6O8(C4H3N2 COO)8(C3H7NO)4]• 4C3H7NO• H2O by single-crystal X-ray analysis. Both complexes exhibited solvent adsorptiondesorption accompanying reversible structural change. 1 and 2 were compatible, and 1 was vital for the synthesis of 2. The degassed 1 showed gate adsorption property for water vapor.