Asymmetrical [Ni(dmit)(2)](-) Arrangements Induced by (1R,2R)-Cyclohexanediammonium - Crown Ether Supramolecules

作者：Ye, Qiong^*; Akutagawa, Tomoyuki; Endo, Toru; Noro, Shin-ichiro; Nakamura, Takayoshi; Xiong, Ren-Gen

来源：Inorganic Chemistry, 2010, 49(18): 8591-8600.

DOI：10.1021/ic101253g

• SOLID-STATE DYNAMICS
• CRYSTALLINE MOLECULAR MACHINES
• SUPERCONDUCTOR
• COMPLEXES
• METALS
• CATION
• SALTS
• ROTOR
• DMIT
• 1,3-DITHIOLE-2-THIONE-4,5-DITHIOLATE

Structurally flexible (1R,2R)-cyclohexanediammonium (CHDA(2+)) dication formed hydrogen-bonding supramolecules with [18]crown-6, benzo[18]crown-6 (B[18]crown-6), dibenzo[18]crown-6 (DB[18]crown-6), and dicyclohexano-[18]crown-6 (DCH[18]crown-6) in [Ni(dmit)(2)](-) salts (dmit(2-)=2-thioxo-1,3-dithiole-4,5-dithiolate). The two ammonium moieties of CHDA2+ interacted with the crown ethers to form open-mouth-shaped sandwich-type cationic structures of (CHDA(2+))(crown ethers)(2), that is, (CHDA(2+))([18]crown-6)(2)[Ni(dmit)(2)](2)(-) (1), (CHDA(2+))(B[18]crown-6)(2)[Ni(dmit)(2)](2)(-) (2), (CHDA(2+))(DB[18]crown-6)(2)[Ni(dmit)(2)](2)(-) (3), and (CHDA(2+))(DCH[18]crown-6)(2)[Ni(dmit)(2)](2)(-) (4). The chiral structure of CHDA(2+) induced asymmetrical [Ni(dmit)(2)](-) arrangements in the crystals. A large frequency and temperature dependence of the dielectric response was observed in (CHDA(2+)) B[18]crown-6)(2), due to the pendulum motion of the cyclohexane ring along the nitrogen-nitrogen direction of CHDA(2+). Since the inversion center of the [Ni(dmit)(2)](-) arrangements was lost in the unit cell due to the chiral space group, the salts 1-4 showed rather complicated magnetic behaviors. The temperature-dependent magnetic properties of salts 3 and 4 were explained by the sum of the Cube Weiss and singlet-triplet thermal excitation models, with positive (ferromagnetic) and negative (antiferromagnetic) magnetic exchange energies, respectively.

• 出版日期2010-9-20
• 单位东南大学