Abstract
The adduct of piperazine, o-phthalic acid and water (1:2:2), C20H26N2O10, crystallizes in the monoclinic space group P21/c with a = 6.129(1), b = 12.810(2), c = 13.137(2)Å, β = 95.87(1)°, V = 1026.0(3)Å3, Z = 2. The piperazinium adopts a chair comformer, and is tied with the hydrogen orthophthalate via a hydrogen bond of the N-H…O type. Because of bifurcated hydrogen bonding of C(sp3)H-O [3.0801(17) and 3.1408(18)Å] and the shortest hydrogen bond of C(sp3)H-O [2.9758(17)Å], C(sp3)H-O hydrogen bonds play important roles in stablizing the title adduct.