Syntheses And Properties Of TCNQ And Its Alkyl Derivative Metal Complexes

Three series of TCNQ and its alkyl derivative lanthanide complexes, [Ln2(TCNQ)4(H2O),o(EtOH)2][2TCNQ]·xH2O [Ln= La (1, x= 5), Pr (2, x= 3)], [Ln2(TCNQ)4(H2O)12][2TCNQ]·yMeOH·zH2O [Ln= Ce (3, y= 1, z= 3), Nd (4, y= 2, z = 4), Sm (5, y= 2, z= 3)], [Ln2(TCNQ)4(H2O)10][2TCNQ]·yH2O [Ln= Gd (6, w= 6), Dy (7, w= 5)], [Ln(TCNQ)2(H2O)6][TCNQ]·H2O·MeOH [Ln= Er (8), Lu (9)], [Ln(DMTCNQ)2(H2O)7][DMTCNQ] [Ln= La (10), Pr (11)], [Ln(DMTCNQ)2(H2O)6-(CH3OH)][DMTCNQ]-4H2O [Ln= Gd (12), Dy (13)], [Ln(DMTCNQ)2(H2O)6]-[DMTCNQ]·H2O·CH3OH [Ln= Er (14), Lu (15)], [Ln(DETCNQ)(H2O)8]-[2DETCNQ]·2H2O [Ln= La (16), Pr (17)], [Ln(DETCNQ)(H2O)7][2DETCNQ] [Ln= Gd (18), Dy (19)] and [Ln(DETCNQ)(H2O)7][2DETCNQ]·5H2O [Ln= Er (20), Lu (21)], have been synthesized by reactions of LiTCNQ/LiDMTCNQ/LiDETCNQ (TCNQ = 7,7,8,8-tetracyano-p-quinodimethane, DMTCNQ= 2,5-dimethyl-7,7,8,8-tetracyano-p-quinodimethane, DETCNQ= 2,5-diethyl-7,7,8,8-tetracyano-p-quinodi-methane) with LnCl3·nH2O in this dissertation.The molecular structures of 1-10,12 and 18 were determinated by X-ray single crystal diffraction analysis.1-10,12 and 18 are all discrete ion compounds. The cations of 1-7 are dimeric, while the cations of 8-10,12 and 18 are mononuclear. In 1-7, three TCNQ·- radical anions are coordinated to lanthanide ions, In 8-10 and 12, two TCNQ·-or DMTCNQ·- radical anions are coordinated to lanthanide ions. In 18, only one DETCNQ·- radical anion is coordinated to lanthanide ion.The molecular magnetic investigation indicates that theπ-πantiferromagnetic interactions between TCNQ·- radical anions exist in 1-9. The thermal depopulation of the Stark levels influences the magnetic behaviors of 2 and 8.6 exhibits a magnetic conversion from the magnetic disordering to the magnetic ordering at 4 K upon desolvation. The ferromagnetic coupling between paramagnetic centers exists in 7. The antiferromagnetic interactions between spin carriers exist in 12 and 18.The electrochemical study shows that 1-21 all undergo a reversible one-electron oxidation process and a reversible one-eletron reduction process. The electrochemical HOMO-LOMO gaps of 1-9,10-15 and 16-21 are close to the electrochemical HOMO-LOMO gaps of TCNQ·-, DMTCNQ·- and DETCNQ·-, respectively. The electrochemical properties of 1-21 are all chemically and electrochemically reversible.