- 作者: 蔡惠蓮、卓庭義、楊振宜、吳清水、李錦祥、王瑜
- 作者服務機構: Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan, R.O.C.
- 中文摘要: The reaction of [Mn12O12(Oac)16(H2O)4]·4H2O·2HOAc with Cl3CCO2H in dichloromethane leads to formation of mixed-valence trinuclear oxo-centered [Mn3O(O2CCCl3)6(H2O)3]·2H2O (1). Complex 1 crystallizes in two forms; the monoclinic and hexagonal systems. [Mn3O(O2CCCl3)6(H2O)3]·3H2O (1a) crystallizes in hexagonal, space group P63/m (295 K) with a = 10.0741(1) A, c = 22.8668(4) A, and z = 2. [Mn3O(O2CCCl3)6(H2O)3]·0.5C6H14 (1b) crystallizes in monoclinic, space group P21/n (150 K) with a = 11.8258(2) A, b = 41.9370(5) A, c = 25.9619(4) A , β = 95.297(1)o, and z = 12. Complex 1 possesses an oxo-centered Mn3O unit with peripheral ligands provided by bridging trichloroacetate and terminal H2O groups. Each manganese ion is distorted octahedral, and consideration of overall charge of the trinuclear unit necessitates a mixed-valence MnIIMnIII2 description. Magnetization measurement at 2.0 K up to 70 kG indicates the mixed ground state S = 3/2 and S = 1/2 for complex 1. X-band EPR spectra measured at 4.0-100.0 K on polycrystalline sample of complex 1. There is a transition centered at g ? 4, which decreases in intensity with increasing temperature. Also, there is a transition centered at g ? 2, which does not disappear with increasing temperature.
- 英文摘要: --
- 中文關鍵字: Trinuclear manganese complex; Mixed-valence complex; Crystal structure; Magnetochemistry; Magnetic exchange coupling; EPR.
- 英文關鍵字: --