Temperature-induced reversible structural phase transition of N-chloromethyl-1,4-diazabicyclo[2.2.2]octonium trichloroaquo-manganese(II)

Autor: Deng-Deng Huang, Li-Zhuang Chen, Qi-Jian Pan, Jia-Zhen Ge
Rok vydání: 2014
Předmět:
Zdroj: Journal of Molecular Structure. 1072:307-312
ISSN: 0022-2860
DOI: 10.1016/j.molstruc.2014.05.041
Popis: A novel mononuclear metal–organic compound, N-chloromethyl-1,4-diazabicyclo-[2.2.2]octonium trichloroaquomanganese (II), Mn(LCH 2 Cl) (H 2 O) Cl 3 ( 1 ) (L + CH2Cl = N-chloromethyl-1,4-diazabicyclo[2.2.2]octonium ion) was synthesized. Differential scanning calorimetry (DSC) measurement detected that this compound underwent a reversible phase transition at ca. 187.5 K with a hysteresis of 1.5 K width, The single crystal X-ray diffraction data suggested that the phase transition undergoes from a room temperature paraelectric phase with a space group of Pnma ( a = 18.219(1) A, b = 8.945(6) A, c = 8.191(5) A, V = 1334.9(2) A 3 and Z = 4) to a low temperature paraelectric one with a space group of P2 1 /n ( a = 8.117(2) A, b = 17.956(5) A, c = 8.923(2) A, β = 91.819(3)°, V = 1299.9(6) A 3 and Z = 4), and symmetry breaking occurred with an Aizu notation of mmmF2/m. The ordering of twisting motions of dabco ring may drive the phase transition.
Databáze: OpenAIRE