Shi Jing-Min, Sun You-Min, Liu Zhe, Liu Lian-Dong, Shi Wei, Cheng Peng
Department of Chemistry, Shandong Normal University, Jinan, PR China.
Dalton Trans. 2006 Jan 14(2):376-80. doi: 10.1039/b507723k. Epub 2005 Oct 24.
A new one-dimensional polynuclear copper(II) complex Cu(2)(mu(1,3)-SCN)(2)(mu'(1,3)-SCN)(2)(MPyO)(2)(where MPyO = 4-methylpyridine N-oxide) has been synthesized and its crystal structure determined by X-ray crystallography. In the complex there exist two kinds of bridging coordination modes, namely, mu(1,3)-SCN(-) equatorial-equatorial (EE) bridging ligand and micro'(1,3)-SCN(-) equatorial-axial (EA) bridging ligand. Two micro(1,3)-SCN(-) EE bridging ligands coordinate two copper(II) ions in a binuclear unit, and the S atoms from the micro'(1,3)-SCN(-) EA bridging ligands as axial coordinated atoms link the binuclear units into one-dimensional chains. The ESR spectra have been investigated, and variable temperature (4-300 K) magnetic measurements were analyzed using a binuclear Cu(ii) magnetic interaction formula and indicate the existence of strong antiferromagnetic coupling with 2J=- 216.00 cm(-1) between bridged copper(II) ions. Density functional calculations have been carried out on this binuclear unit, yielding a similar singlet-triplet splitting. The mechanism of strong antiferromangetic interaction is revealed according to the calculations.
合成了一种新型的一维多核铜（II）配合物Cu(2)(μ(1,3)-SCN)(2)(μ'(1,3)-SCN)(2)(MPyO)(2)（其中MPyO = 4-甲基吡啶N-氧化物），并通过X射线晶体学确定了其晶体结构。在该配合物中存在两种桥联配位模式，即μ(1,3)-SCN(-)赤道-赤道（EE）桥联配体和μ'(1,3)-SCN(-)赤道-轴向（EA）桥联配体。两个μ(1,3)-SCN(-) EE桥联配体在双核单元中配位两个铜（II）离子，来自μ'(1,3)-SCN(-) EA桥联配体的S原子作为轴向配位原子将双核单元连接成一维链。研究了ESR光谱，并使用双核Cu（ii）磁相互作用公式对变温（4 - 300 K）磁性测量进行了分析，结果表明在桥联铜（II）离子之间存在强反铁磁耦合，2J = - 216.00 cm(-1)。对该双核单元进行了密度泛函计算，得到了类似的单重态-三重态分裂。根据计算揭示了强反铁磁相互作用的机制。
