Tuning of the spin states in trinuclear cobalt compounds of pyridazine by the second simple bridging ligand
Tuning of the spin states in trinuclear cobalt compounds of pyridazine by the second simple bridging ligand
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DOI：
10.1002/ejic.200500741
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发表时间：
2006-04
影响因子：
2.3
通讯作者：
T. Yi;Chang Ho-chol;Song Gao;S. Kitagawa
中科院分区：
文献类型：
--
作者：
T. Yi;Chang Ho-chol;Song Gao;S. Kitagawa
三个新的三核钴（Ⅱ）哒嗪化合物，[Co_3（μ-OH）_2（μ-pdz）_4（pdz）_2（NO_3）_2（H_2 O）_2]·（NO_3）_2·（THF）_2（MeOH）（1），[Co_3（μ-OH）_2（μ-pdz）_4（pdz）_4（NO_3）_2]·[Co_3（μ-OH）_2（μ-pdz）_4（MeOH）_4（NO_3）_4（2），[Co 3（μ-pdz）4（μ-NCS）2（pdz）2（NCS）4]·2 MeOH（3）（pdz =哒嗪）的合成与表征。所有三种化合物的结构由中心对称的三聚体结构单元组成，所述三聚体结构单元由哒嗪配体的两个氮原子和第二小桥接阴离子（1和2中的氢氧根，和3中的末端硫氰酸根）桥接。1和2中的哒嗪配体的两原子桥接模式是不寻常的：每个桥接哒嗪配体提供两个氮供体到两个具有不同键长的金属离子。这导致在两种自旋状态的钴（II）原子在1。磁性测量表明，在3的高自旋金属之间的典型的反铁磁相互作用，但不寻常的磁耦合通过两个高自旋和一个低自旋钴原子内的三聚体1。在低温下，还观察到1的不规则自旋态结构。（© Wiley-VCH Verlag GmbH & Co. KGaA，69451魏因海姆，德国，2006）
Three novel trinuclear cobalt(II) compounds of pyridazine,[Co3(μ-OH)2(μ-pdz)4(pdz)2(NO3)2(H2O)2]·(NO3)2·(THF)·2(MeOH) (1), [Co3(μ-OH)2(μ-pdz)4(pdz)4(NO3)2]·[Co3(μ-OH)2(μ-pdz)4(MeOH)4(NO3)2]·(NO3)4 (2), and [Co3(μ-pdz)4(μ-NCS)2(pdz)2(NCS)4]·2MeOH (3) (pdz = pyridazine), have been synthesized and characterized. The structures of all three compounds consist of centrosymmetric trimer building blocks bridged by the two nitrogen atoms of the pyridazine ligands and the second small bridging anions (hydroxide in 1 and 2, and end-on thiocyanate in 3). The two-atom bridging modes of the pyridazine ligand in 1 and 2 are unusual: each bridging pyridazine ligand affords two nitrogen donors to two metal ions with different bond lengths. This results in two kinds of spin states for the cobalt(II) atoms in 1. Magnetic measurements show a typical antiferromagnetic interaction between the high-spin metals in 3, but an unusual magnetic coupling through two high- and one low-spin cobalt atoms within the trimer in 1. An irregular spin states structure is also observed in 1 at low temperature. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)