Chen Jia-Mei, Zhuang Xiao-Mei, Yang Li-Zi, Jiang Long, Feng Xiao-Long, Lu Tong-Bu
MOE Laboratory of Bioinorganic and Synthetic Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, China.
Inorg Chem. 2008 Apr 21;47(8):3158-65. doi: 10.1021/ic702143d. Epub 2008 Mar 5.
The crystal structures of [Co 2L(Cl)](ClO 4) 3 ( 1), [Co 2L(Br)](ClO 4) 3 ( 2), [Co 2L(OH)(OH 2)]I 3 ( 3), and [Co 2L (1)(Cl)](ClO 4) 3 ( 4), the density functional theory calculations, as well as the binding constants of [Co 2L] (4+) toward Cl (-) and Br (-) and of [Co 2L (1)] (4+) toward Cl (-), are reported in this paper (L = N[(CH 2) 2NHCH 2(C 6H 4- p)CH 2NH(CH 2) 2] 3N, L (1) = N[(CH 2) 2NHCH 2(C 6H 4- m)CH 2NH(CH 2) 2] 3N). The rigid dicobalt(II) cryptate [Co 2L] (4+) shows the recognition of Cl (-) and Br (-) but not of F (-) and I (-), because of the size matching to its rigid cavity. We also found that the relative rigid tripodal skeleton of L than that of L (1) results in the higher affinity of [Co 2L] (4+) toward Cl (-). Magnetic susceptibility measurements of 1 and 2 indicate that the two Co(II) atoms in the cryptates are antiferromagnetically coupled through the Cl (-)/Br (-) bridge, with g = 2.19, J = -13.7 cm (-1) for 1, and g = 2.22, J = -17.1 cm (-1) for 2.
本文报道了Co₂L(Cl)₃（1）、Co₂L(Br)₃（2）、[Co₂L(OH)(OH₂)]I₃（3）和Co₂L(¹)(Cl)₃（4）的晶体结构、密度泛函理论计算结果，以及Co₂L对Cl⁻和Br⁻、Co₂L(¹)对Cl⁻的结合常数（L = N[(CH₂)₂NHCH₂(C₆H₄ - p)CH₂NH(CH₂)₂]₃N，L(¹) = N[(CH₂)₂NHCH₂(C₆H₄ - m)CH₂NH(CH₂)₂]₃N）。刚性双钴(II)穴合物Co₂L因其刚性空腔大小匹配而表现出对Cl⁻和Br⁻的识别，但对F⁻和I⁻无识别作用。我们还发现L相对于L(¹)具有相对刚性的三脚架骨架，这导致Co₂L对Cl⁻具有更高的亲和力。对1和2的磁化率测量表明，穴合物中的两个Co(II)原子通过Cl⁻/Br⁻桥发生反铁磁耦合，对于1，g = 2.19，J = -13.7 cm⁻¹，对于2，g = 2.22，J = -17.1 cm⁻¹。
