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Dalton Transactions

The international journal for inorganic, organometallic and bioinorganic chemistry



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Dalton Trans., 2009, 10466 - 10473, DOI: 10.1039/b909213g

Systematic investigation of an array of TCNQ lanthanide complexes: synthesis, structure and magnetic properties

Juwen Zhang, Pengfei Yan, Guangming Li, Guangfeng Hou, Masayuki Suda and Yasuaki Einaga

An array of TCNQ (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane) lanthanide complexes, namely, [Ln2(TCNQ)4(H2O)10(EtOH)2][2TCNQ]·xH2O [Ln = La ( 1, x = 5), Pr ( 2, x = 3)], [Ln2(TCNQ)4(H2O)10][2TCNQ]·yH2O [Ln = Gd ( 3, y = 6), Dy ( 4, y = 5)] and [Ln(TCNQ)2(H2O)6][TCNQ]·H2O·MeOH [Ln = Er ( 5), Lu ( 6)], have been synthesized by salt-elimination reactions. X-ray crystallographic analysis indicates that 1–6 are discrete ion complexes. Cations of 1–4 adopt a dimer structure, while cations of 5 and 6 display a monomer structure. The magnetic study proposes that an antiferromagnetic interaction between TCNQ radicals exists in 1–6. The depopulation of the Stark levels for 2 and 5 leads to a continuous decrease in mT when the samples are cooled from 300 K to 2 K. The desolvated 3, namely, 3a exhibits a unique magnetic conversion from the magnetic disordering to the magnetic ordering at 4 K. 4 shows a ferromagnetic coupling between paramagnetic centers.

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