Reversible crystal state structural phase transitions molecular materials without metal have been received increasing interest recently. Here we successfully synthesized a novel ternary neutral co-crystallized organic adduct hexamethylenetetramine·1-adamantane carboxylic acid·chloroform, 1, which accompanies with an interesting reversible phase transition close to the zero temperature (263 K). We confirmed this reversible phase transition by its switchable thermal dielectric behaviors and unit cell constants anomalies around the phase transition temperature (T_c). X-ray single crystal diffraction analysis above (1-RTP) and below (1-LTP) T_c suggests that the order-disorder motion from the adamantane ring in 1-adamantane carboxylic acid triggered the reversible phase transition.

没有金属的可逆晶态结构相变分子材料近来受到越来越多的关注。在这里，我们成功地合成了一种新型三元中性共结晶有机加合物六亚甲基四·1-金刚烷羧酸·氯仿，1，它与一个有趣的可逆相变接近零的温度（263 K）伴随。我们通过其可切换的热介电特性和相变温度（T _c）附近的晶胞常数异常来确认这种可逆的相变。高于（1-RTP）和低于（1-LTP）T _c的X射线单晶衍射分析 这表明1-金刚烷羧酸中金刚烷环的无序运动触发了可逆相变。