A homologous heterospin series of mononuclear lanthanide/TCNQF(4) organic radical complexes.
A homologous heterospin series of mononuclear lanthanide/TCNQF(4) organic radical complexes.
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DOI：
10.1039/b922219g
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发表时间：
2010-04
影响因子：
4
通讯作者：
Nazario Lopez;Hanhua Zhao;A. Prosvirin;W. Wernsdorfer;K. Dunbar
中科院分区：
文献类型：
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作者：
Nazario Lopez;Hanhua Zhao;A. Prosvirin;W. Wernsdorfer;K. Dunbar
三价稀土离子（M（III）= La，Pr，Nd，Sm，Eu，Gd，Dy，Ho，Er和Yb）与2，3，5，6-四氟-7，7，8，8-四氰基对苯醌二甲烷（TCNQF（4））自由基阴离子反应生成一类单核配合物{M[（TCNQF（4））]（2）[H（2）O]（x）}。（TCNQF（4））（3H（2）O），x = 6，7.阳离子配合物{M（III）（[TCNQF（4）]（-））（2）[H（2）O]（x）}（+）与一个[TCNQF（4）]（-）自由基阴离子和三个水分子共结晶。其中一个配位的[TCNQF（4）]（-）自由基与未配位的[TCNQF（4）]（-）自由基发生π-π堆积相互作用，导致（（TCNQF（4））（2））（2-）π-二聚体的反铁磁耦合。第二配位的[TCNQF（4）]（-）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化合物磁秩序在4.4 K和一小部分的Gd和Dy样品进行磁有序分别在3.7 K和4.3 K由于部分脱水（间隙水分子的损失）。抗磁性金属离子用于产生磁性稀释的Gd和Dy化合物，其不表现出任何磁有序的迹象。
Reactions between trivalent rare earth ions (M(III) = 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 (TCNQF(4)) produce a family of mononuclear complexes {M[(TCNQF(4))](2)[H(2)O](x)}.(TCNQF(4))(3H(2)O), x = 6, 7. The cationic complex {M(III)([TCNQF(4)](-) )(2)[H(2)O](x)}(+) cocrystallizes with one [TCNQF(4)](-) radical anion and three water molecules. One of the coordinated [TCNQF(4)](-) radicals is involved in pi-pi stacking interactions with the uncoordinated [TCNQF(4)](-) radicals which leads to the antiferromagnetic coupling for these ((TCNQF(4))(2))(2-)pi-dimers. The second coordinated [TCNQF(4)](-) remains as a radical ligand and is not involved in pi-pi 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.