Adebayo Olajuyigbe A, Abboud Khalil A, Christou George
Department of Chemistry, University of Florida , Gainesville, Florida 32611-7200, United States.
Inorg Chem. 2017 Sep 18;56(18):11352-11364. doi: 10.1021/acs.inorgchem.7b01793. Epub 2017 Aug 30.
The syntheses, structures, and magnetochemical properties are reported for five new Mn clusters: MnO(OPPh)(mpko) (1), MnO(OPPh)(ppko) (2) MnO(OMe)(OPPh)(mpko) (3), [MnMnO(OCMe)(OPPh)(mpko)(HO)] (4), and MnMnO(mpko)(HO)(ClO) (5), where mpko (or ppko) is the anion of methyl (or phenyl) 2-pyridyl ketone oxime. 1 was obtained by carboxylate substitution on MnO(OCMe)(mpko) by treatment with diphenylphosphinic acid (PhPOH). The comproportionation reaction between Mn(ClO) and NBuMnO in the presence of PhPOH and ppkoH in EtOH, or mpkoH in MeOH, led to 2 and 3, respectively. 4 was obtained as was 3, but with phenylphosphonic acid (PhPOH) instead of PhPOH. 5 was obtained by aerial oxidation of Mn(ClO) in the presence of mpkoH. 1 and 2 contain a triangular Mn core, 3 comprises the fusion of two Mn units of 1 by MeO bridges, and 4 has a cagelike structure. 5 is similar to 1 in possessing a triangular core. Variable-temperature, solid-state direct-current (dc) and alternating-current (ac) magnetic data were collected on 1-5: 1 and 2 exhibit ferromagnetic Mn····Mn exchange interactions, S = 6 ground states, and are new single-molecule magnets (SMMs). 3-5 possess S = 4, /, and / ground states, respectively, from dominant antiferromagnetic interactions. Fits of dc magnetization data in the 1.8-10.0 K and 10-70 kG ranges gave D and g values of: -0.29(2) cm and 1.94(1) for 1, -0.38(2) cm and 1.99(1) for 2, -0.29(2) cm and 1.96(1) for 3, -1.26(4) cm and 1.99(2) for 4, -1.41(4) cm and 1.98(2) for 5, where D is the axial zero-field splitting parameter.
报道了五个新的锰簇合物的合成、结构和磁化学性质：MnO(OPPh)(mpko) (1)、MnO(OPPh)(ppko) (2)、MnO(OMe)(OPPh)(mpko) (3)、[MnMnO(OCMe)(OPPh)(mpko)(HO)] (4) 和 MnMnO(mpko)(HO)(ClO) (5)，其中 mpko（或 ppko）是甲基（或苯基）2 - 吡啶基酮肟的阴离子。1 通过用二苯基次膦酸（PhPOH）处理 MnO(OCMe)(mpko) 进行羧酸盐取代反应得到。在乙醇中，PhPOH 和 ppkoH 存在下，或者在甲醇中，mpkoH 存在下，Mn(ClO) 与 NBuMnO 之间的歧化反应分别得到 2 和 3。4 的制备方法与 3 相同，但使用苯基膦酸（PhPOH）代替 PhPOH。5 通过在 mpkoH 存在下对 Mn(ClO) 进行空气氧化得到。1 和 2 含有一个三角形锰核，3 由 1 的两个锰单元通过甲氧基桥连融合而成，4 具有笼状结构。5 与 1 类似，具有三角形核。在 1 - 5 上收集了变温固态直流（dc）和交流（ac）磁性数据：1 和 2 表现出铁磁的 Mn····Mn 交换相互作用，基态 S = 6，是新型单分子磁体（SMMs）。3 - 5 分别具有基态 S = 4、/ 和 /，主要是反铁磁相互作用。在 1.8 - 10.0 K 和 10 - 70 kG 范围内对直流磁化数据的拟合给出了以下 D 和 g 值：1 的为 -0.29(2) cm 和 1.94(1)，2 的为 -0.38(2) cm 和 1.99(1)，3 的为 -0.29(2) cm 和 1.96(1)，4 的为 -1.26(4) cm 和 1.99(2)，5 的为 -1.41(4) cm 和 1.98(2)，其中 D 是轴向零场分裂参数。
