TY - JOUR
T1 - Ring-Puckering Motion of Azetidinium Cations in a Metal-Organic Perovskite [(CH 2 ) 3 NH 2 ][M(HCOO) 3 ] (M = Zn, Mg) - A Thermal and 1 H NMR Relaxation Study
AU - Asaji, Tetsuo
AU - Ito, Yoshiharu
AU - Fujimori, Hiroki
AU - Zhou, Biao
N1 - Publisher Copyright:
© Copyright 2019 American Chemical Society.
PY - 2019/2/21
Y1 - 2019/2/21
N2 - A metal-organic perovskite which consists of four-membered-ring ammonium (azetidinium), magnesium, and formate ions [(CH 2 ) 3 NH 2 ][Mg(HCOO) 3 ] was synthesized. Differential scanning calorimetry revealed a first-order phase transition at T c = 288 K. Besides a sharp anomaly at T c , a broad Schottky-type anomaly was observed at 273 K. Temperature dependences of spin-lattice and dipolar spin-lattice relaxation times T 1 and T 1D were determined. In the low-temperature phase, short and long T 1 -values were observed. T 1D showed a minimum of 0.15 ms at around 220 K, which can be assigned to the ring-puckering motion of the azetidinium cation. Compared with the previously reported zinc analogue [(CH 2 ) 3 NH 2 ][Zn(HCOO) 3 ], energy separation between the two molecular conformations associated with the ring-puckering motion and inhomogeneity that occurred in the crystals at low temperatures are discussed.
AB - A metal-organic perovskite which consists of four-membered-ring ammonium (azetidinium), magnesium, and formate ions [(CH 2 ) 3 NH 2 ][Mg(HCOO) 3 ] was synthesized. Differential scanning calorimetry revealed a first-order phase transition at T c = 288 K. Besides a sharp anomaly at T c , a broad Schottky-type anomaly was observed at 273 K. Temperature dependences of spin-lattice and dipolar spin-lattice relaxation times T 1 and T 1D were determined. In the low-temperature phase, short and long T 1 -values were observed. T 1D showed a minimum of 0.15 ms at around 220 K, which can be assigned to the ring-puckering motion of the azetidinium cation. Compared with the previously reported zinc analogue [(CH 2 ) 3 NH 2 ][Zn(HCOO) 3 ], energy separation between the two molecular conformations associated with the ring-puckering motion and inhomogeneity that occurred in the crystals at low temperatures are discussed.
UR - http://www.scopus.com/inward/record.url?scp=85061530199&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b11789
DO - 10.1021/acs.jpcc.8b11789
M3 - Article
AN - SCOPUS:85061530199
SN - 1932-7447
VL - 123
SP - 4291
EP - 4298
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 7
ER -