Crystal Structure and Dielectric Property of ( p ‐CH 3 OC 6 H 4 NH 3 ) + (18‐crown‐6)·H 2 PO 4 – ·2H 3 PO 4

One novel organic‐inorganic hybrid compound, ( p ‐CH 3 OC 6 H 4 NH 3 ) + (18‐crown‐6) · H 2 PO 4 – · 2H 3 PO 4 ( 1 ) (( p ‐CH 3 OC 6 H 4 NH 3 ) + = 4‐methoxyphenylammonium; 18‐crown‐6 = 1, 4, 7, 10, 13, 16‐hexaoxacyclooctadecane), has been synthesized and characterized by IR spectroscopy, thermogravimetric analysis and single crystal X‐ray diffraction. In the structure, the organic ( p ‐CH 3 OC 6 H 4 NH 3 ) + (18‐crown‐6) supermolecular cation layer and inorganic phosphate anion layer arrange alternately. Temperature‐ and frequency‐dependent dielectric constants of compound 1 show no distinct dielectric anomalies, suggesting no phase transition within the measured temperature range (100–380 K). A high dielectric constant of 442.3 at a low frequency of 200 Hz suggests slow molecular motion and/or space charge polarization rather than fast electronic motion.