Two Polymorphs of (Anilinium)(18-Crown-6)[Ni(dmit)2]: Structure and Magnetic Properties

✍ Scribed by Sadafumi Nishihara; Tomoyuki Akutagawa; Tatsuo Hasegawa; Shigeki Fujiyama; Toshikazu Nakamura; Takayoshi Nakamura

• Book ID: 102606815
• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 341 KB
• Volume: 168
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2002.9764

✦ Synopsis

Two polymorphs of monovalent [Ni(dmit) 2 ] À (dmit 2À =2thioxo-1,3-dithiole-4,5-dithiolate) crystals A and B, (anilinium)(18-crown-6)[Ni(dmit) 2 ], were prepared, and the structure and magnetic properties were investigated. In these crystals, the [Ni(dmit) 2 ] À molecules form dimers, which arranged into chains between the supramolecular cation structure (anilinium)(18crown-6). In crystal A, supramolecular cation formed a regular stack, inducing ladder structure of [Ni(dmit) 2 ], whose magnetism had been well fitted by spin ladder equation with the spin gap of D ¼ 190 K. Crystal B is ca. 3% more densely packed compared to crystal A. Due to the dense packing, supramolecular cation stack is distorted, which prevented the intermolecular interaction between [Ni(dmit) 2 ] À dimers in direction corresponds to the ladder-leg direction in crystal A. Reflecting the [Ni(dmit) 2 ] À arrangement, crystal B showed a temperature dependence of magnetic susceptibility well reproduced by the singlet-triplet thermal activation model, whose antiferromagnetic exchange interaction (2J) was 140 K.