Reactions between trivalent rare earth ions (MIII = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er and Yb) and the radical anion of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (TCNQF4) produce a family of mononuclear complexes M[(TCNQF4)]2[H2O]x}·(TCNQF4)(3H2O), x = 6, 7. The cationic complex MIII([TCNQF4]−˙)2[H2O]x}+ cocrystallizes with one [TCNQF4]−˙ radical anion and three water molecules. One of the coordinated [TCNQF4]−˙ radicals is involved in π–π stacking interactions with the uncoordinated [TCNQF4]−˙ radicals which leads to the antiferromagnetic coupling for these ((TCNQF4)2)2−π-dimers. The second coordinated [TCNQF4]−˙ remains as a radical ligand and is not involved in π–π interactions. Magnetic studies indicate that the Sm compound magnetically orders at 4.4 K and that a fraction of the Gd and Dy samples undergo magnetic ordering at 3.7 K and 4.3 K respectively due to partial dehydration (loss of interstitial water molecules). Diamagnetic metal ions were used to generate magnetically dilute Gd, and Dy compounds that do not exhibit any signs of magnetic ordering.
三价稀土离子(MIII = La、Pr、Nd、Sm、Eu、Gd、Dy、Ho、Er 和 Yb)与 2,3,5,6-四
氟-7,7,8 自由基阴离子之间的反应, 8-四
氰基醌二
甲烷 (TCNQF4) 产生一系列单核配合物 M[(TCNQF4)]2[H2O]x}·(TCNQF4)(3H2O), x = 6, 7。 阳离子配合物 MIII([TCNQF4]−˙ )2[H2O]x}+ 与一个 [TCNQF4]−˙ 自由基阴离子和三个
水分子共结晶。配位的 [TCNQF4]−˙ 自由基之一参与与未配位的 [TCNQF4]−˙ 自由基的 π–π 堆积相互作用,从而导致这些 ((TCNQF4)2)2−π-二聚体的反
铁磁耦合。第二个配位的 [TCNQF4]−˙ 仍然作为自由基
配体,不参与 π-π 相互作用。磁性研究表明,Sm 化合物在 4.4 K 下发生磁有序化,而一部分 Gd 和 Dy 样品由于部分脱
水(间隙
水分子损失)而分别在 3.7 K 和 4.3 K 下发生磁有序化。抗磁性
金属离子用于生成磁性稀释的 Gd 和 Dy 化合物,这些化合物不表现出任何磁有序迹象。