Department of Inorganic Chemistry, National Taras Shevchenko University, Volodymyrska Street 64, Kyiv 01601, Ukraine.
Inorg Chem. 2010 Jun 21;49(12):5460-71. doi: 10.1021/ic1000123.
Two new tetranuclear complexes, [Zn(2)Cr(2)(NCS)(4)(Dea)(2)(HDea)(2)].4DMSO (1; DMSO = dimethyl sulfoxide) and [Zn(2)Cr(2)(NCS)(4)(Dea)(2)(HDea)(2)].2CH(3)CN (2), were prepared from zinc oxide, Reinecke's salt, NH(4)[Cr(NCS)(4)(NH(3))(2)].H(2)O, ammonium thiocyanate, and a nonaqueous solution of diethanolamine (H(2)Dea) in a reaction carried out under open air. Both compounds have similar centrosymmetric crystal structures based on a tetranuclear {Zn(2)Cr(2)(mu(3)-O)(2)(mu-O)(4)} core. Variable-temperature magnetic susceptibility measurements of 1 and 2 show weak antiferromagnetic coupling between chromium centers. The magnetic data and high-field, high-frequency electron paramagnetic resonance spectra were analyzed in terms of the spin Hamiltonian H = JS(1).S(2) - j(S(1).S(2) + mu(B)B{g(1)}S(1) + D(Cr){S(z1)(2) - S(1)(S(1) + 1)/3} + E(Cr)(S(x1)(2) - S(y1)(2)) + mu(B)B{g(2)}S(2) + D(Cr){S(z2)(2) - S(2)(S(2) + 1)/3} + E(Cr)(S(x2)(2) - S(y2)(2)) + D(12){S(z1)S(z2) - S(1).S(2)/3} + E(12)(S(x1)S(x2) - S(y1)S(y2)) with J = 13.7 cm(-1), j = 1.1 cm(-1), D(Cr) = 0.3864 cm(-1), E(Cr) = -0.1104 cm(-1), D(12) = -0.1873 cm(-1), and E(12) = -0.0155 cm(-1) for 1 and J = 9.4 cm(-1), j = 0.8 cm(-1), D(Cr) = 0.3564 cm(-1), E(Cr) = -0.0647 cm(-1), D(12) = -0.1850 cm(-1), and E(12) = -0.0112 cm(-1) for 2. Density functional theory (DFT) calculations were employed to calculate the zero-field splitting on Cr(3+) ions. Calculations of the exchange integrals J were attempted by using the "broken-symmetry" DFT method.
两个新的四核配合物，[Zn(2)Cr(2)(NCS)(4)(Dea)(2)(HDea)(2)].4DMSO(1; DMSO=二甲亚砜)和[Zn(2)Cr(2)(NCS)(4)(Dea)(2)(HDea)(2)].2CH(3)CN(2)，是由氧化锌、雷尼镍盐、NH(4)[Cr(NCS)(4)(NH(3))(2)].H(2)O、硫氰酸铵和非水二乙醇胺(Dea)在开放空气中进行反应制备的。两种化合物都具有基于四核{Zn(2)Cr(2)(mu(3)-O)(2)(mu-O)(4)}核的相似的中心对称晶体结构。1 和 2 的变温磁化率测量显示了铬中心之间的弱反铁磁耦合。磁数据和高频、高磁场电子顺磁共振谱用自旋哈密顿量 H = JS(1).S(2) - j(S(1).S(2) + mu(B)B{g(1)}S(1) + D(Cr){S(z1)(2) - S(1)(S(1) + 1)/3} + E(Cr)(S(x1)(2) - S(y1)(2)) + mu(B)B{g(2)}S(2) + D(Cr){S(z2)(2) - S(2)(S(2) + 1)/3} + E(Cr)(S(x2)(2) - S(y2)(2)) + D(12){S(z1)S(z2) - S(1).S(2)/3} + E(12)(S(x1)S(x2) - S(y1)S(y2)) 进行了分析，其中 J = 13.7 cm(-1)，j = 1.1 cm(-1)，D(Cr) = 0.3864 cm(-1)，E(Cr) = -0.1104 cm(-1)，D(12) = -0.1873 cm(-1)，E(12) = -0.0155 cm(-1)对于 1 和 J = 9.4 cm(-1)，j = 0.8 cm(-1)，D(Cr) = 0.3564 cm(-1)，E(Cr) = -0.0647 cm(-1)，D(12) = -0.1850 cm(-1)，E(12) = -0.0112 cm(-1)对于 2。密度泛函理论(DFT)计算被用来计算 Cr(3+)离子的零场分裂。通过使用“破对称”DFT 方法尝试了交换积分 J 的计算。
