摘要
1-Methylpiperazine was employed to crystallize with 2,4-dihydroxybenzoic acid and 1,8-naphthalene acid, affording two multi-component hydrogen-bonding salts [（C5H14N2）^2＋-（C7H5O4）2^·H2O]（1） and [（C5H14N2）^2＋（C12H6O4）^2-.2H2O]（2）. These two forms of salts are both monoclinic systems with space group P21/c（14）. The lattice parameters of salts 1 and 2 are a=1.32666（10） nm, b=0.90527（7） nm, c=1.67107（13） nm, β=103.125（1）° and a=1.4950（2） nm, b=0.75242（15） nm, c=1.6563（3） nm, β=92.834（2）°, respectively. Expected classical hydrogen bonds N-H...O and O-H...O appear in the chargetransfer salts, and asymmetric units of these two forms both contain water molecules which play a significant role in building novel supramolecular architectures. Robust hydrogen-bond interactions between 1-methylpiperazine and aromatic acid provide sufficient driving force to direct the two crystals to three-dimensional structures. Weak interactions C-H-O emerging in salts 1 and 2 further enhance their crystal structures. As a consequence, hydrogen-bonding interactions in these compounds afford diverse 3D net supramolecular architectures. Thermal stability of these compounds was investigated by thermogravimetric analysis（TGA）.
1-Methylpiperazine was employed to crystallize with 2,4-dihydroxybenzoic acid and 1,8-naphthalene acid, affording two multi-component hydrogen-bonding salts [（C5H14N2）^2＋-（C7H5O4）2^·H2O]（1） and [（C5H14N2）^2＋（C12H6O4）^2-.2H2O]（2）. These two forms of salts are both monoclinic systems with space group P21/c（14）. The lattice parameters of salts 1 and 2 are a=1.32666（10） nm, b=0.90527（7） nm, c=1.67107（13） nm, β=103.125（1）° and a=1.4950（2） nm, b=0.75242（15） nm, c=1.6563（3） nm, β=92.834（2）°, respectively. Expected classical hydrogen bonds N-H...O and O-H...O appear in the chargetransfer salts, and asymmetric units of these two forms both contain water molecules which play a significant role in building novel supramolecular architectures. Robust hydrogen-bond interactions between 1-methylpiperazine and aromatic acid provide sufficient driving force to direct the two crystals to three-dimensional structures. Weak interactions C-H-O emerging in salts 1 and 2 further enhance their crystal structures. As a consequence, hydrogen-bonding interactions in these compounds afford diverse 3D net supramolecular architectures. Thermal stability of these compounds was investigated by thermogravimetric analysis（TGA）.
基金
Supported by the National Natural Science Foundation of China（Nos.51372125, 21203106）, the Fund of the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, China（No.2013-34）, and the Scientific and Technical Development Project of Qingdao City, China（No. 13-1-4-184-jch）.
