Hexagonal Supramolecular Architectures from Ferrocenium Cations Incorporating [Ni(mnt)2]− Columns: Structures and Properties of [Alkylferrocene][Ni(mnt)2]− Charge-Transfer Complexes (mnt=maleonitriledithiolate)

• Published in: Chemistry : a European journal Vol. 13; no. 6; pp. 1872 - 1881
• Main Authors: Mochida, Tomoyuki, Koinuma, Takeo, Akasaka, Takahiro, Sato, Michiko, Nishio, Yutaka, Kajita, Koji, Mori, Hatsumi
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.01.2007; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; Chemistry, Multidisciplinary; crystal engineering; magnetic properties; metallocenes; Physical Sciences; pi interactions; Science & Technology; self-assembly; TRANSFER SALTS; CRYSTAL-STRUCTURE; POLYMORPHISM; CO; pi interactions; metallocenes; TRANSITION; self-assembly; DECAMETHYLFERROCENIUM SALTS; PHASE; magnetic properties; MAGNETIC-PROPERTIES; NI; COORDINATION POLYMERS; crystal engineering
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200601275

The crystal architecture, magnetic properties, and thermodynamic properties of [n‐butylferrocene][Ni(mnt)2] (1), [tert‐butylferrocene][Ni(mnt)2] (2), [1,1′‐diethylferrocene][Ni(mnt)2] (3), and [1,1′‐diisopropylferrocene][Ni(mnt)2] (4) were investigated (mnt=maleonitriledithiolate). These complexes exhibit a unique supramolecular structure in which the ferrocenium cations constitute honeycomb‐like assembled structures surrounding columns of the anions. For 1, the cations form a dimer through a very short intermolecular ferrocene–ferrocene distance of 3.28 Å, which mediates an antiferromagnetic interaction with a singlet–triplet energy gap of 5 K. First‐order phase transitions occur in 1–3 at 364, 361, and 350 K, respectively, accompanied by thermal hysteresis. Hexagonal columns: The charge‐transfer salts of [Ni(mnt)2]− and alkylferrocenium cations exhibit hexagonal architectures of cations surrounding anion columns (see figure). A short intermolecular ferrocene–ferrocene contact (3.28 Å) was found in the n‐butylferrocene salt, which mediates an intermolecular antiferromagnetic interaction (2J=−5 K). These complexes exhibit first‐order phase transitions at high temperatures.