两种Mn12单分子磁体的单晶55Mn核磁共振谱。

Single-crystal 55Mn NMR spectra of two Mn12 single-molecule magnets.

作者信息

Harter Andrew G, Chakov Nicole E, Roberts Brian, Achey Randy, Reyes Arneil, Kuhns Philip, Christou George, Dalal Naresh S

机构信息

Department of Chemistry and Biochemistry and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA.

出版信息

Inorg Chem. 2005 Apr 4;44(7):2122-4. doi: 10.1021/ic050048j.

DOI:10.1021/ic050048j

PMID:15792441

Abstract

The initial application is reported of single-crystal 55Mn NMR spectroscopy, and associated orientation dependence studies, to single-molecule magnets (SMMs). The studies were performed on two members of the Mn12 family of SMMs, [Mn12O12(O2CMe)16(H2O)4].2MeCO2H.4H2O (Mn12-Ac) and [Mn12O12(O2CCH2Br)16(H2O)4].4CH)Cl) (Mn12-BrAc). Single-crystal spectra give a dramatic improvement in the spectral resolution over oriented powder spectra, allowing the clear observation of quadrupolar splittings, the determination of quadrupole coupling parameters (e2qQ), and an assessment of the symmetry-lowering perturbation of the core of Mn12-Ac by hydrogen-bonding interactions with lattice solvate molecules of crystallization. The results emphasize the utility of single-crystal NMR studies to probe the cores of these magnetic molecules.

摘要

据报道，首次将单晶55Mn核磁共振光谱法及相关取向依赖性研究应用于单分子磁体（SMMs）。研究针对SMMs的Mn12家族的两个成员进行，即[Mn12O12(O2CMe)16(H2O)4].2MeCO2H.4H2O（Mn12-Ac）和[Mn12O12(O2CCH2Br)16(H2O)4].4CH)Cl)（Mn12-BrAc）。与取向粉末光谱相比，单晶光谱的光谱分辨率有显著提高，能够清晰观察到四极分裂，确定四极耦合参数（e2qQ），并评估Mn12-Ac核心与晶格溶剂化结晶分子的氢键相互作用对对称性降低的扰动。结果强调了单晶核磁共振研究在探测这些磁性分子核心方面的实用性。