[CrIII(NCMe)6]3+——一种不稳定的三价铬源，可用于形成Cr[M(CN)6]（M = V、Cr、Mn、Fe）普鲁士蓝型磁性材料。

[CrIII(NCMe)6]3+--a labile CrIII source enabling formation of Cr[M(CN)6] (M=V, Cr, Mn, Fe) Prussian blue-type magnetic materials.

作者信息

Nelson Kendric J, Daniels Matthew C, Reiff William M, Troff Shayla A, Miller Joel S

机构信息

Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112-0850, USA.

出版信息

Inorg Chem. 2007 Nov 26;46(24):10093-107. doi: 10.1021/ic7008489. Epub 2007 Oct 24.

DOI:10.1021/ic7008489

PMID:17958356

Abstract

The kinetic inertness of the hexaaquachromium(III) (kH2O=2.4x10(-6) s(-1)) has led to challenges with respect to incorporating CrIII ions into Prussian blue-type materials; however, hexakis(acetonitrile)chromium(III) was shown to be substantially more labile (approximately 10(4) times) and enables a new synthetic route for the synthesis of these materials via nonaqueous solvents. The synthesis, spectroscopic, and physical properties of Cr[M(CN)6] (M=V, Cr, Mn, Fe) Prussian blue analogues synthesized from [CrIII(NCMe)6]3+ and the corresponding [MIII(CN)6]3- are described. All these compounds {(NEt4)0.02CrIII[VIII(CN)6]0.98(BF4)(0.08).0.10MeCN (1), CrIII[CrIII(CN)6].0.16MeCN (2), CrIII[MnIII(CN)6].0.10MeCN (3), and (NEt4)0.04CrIII0.64CrIV0.40[FeII(CN)6]0.40[FeIII(CN)6]0.60(BF4)(0.16).1.02MeCN (4)} are ferrimagnets exhibiting cluster-glass behavior. Strong antiferromagnetic coupling was observed for M=V, Cr, and Mn with Weiss constants (theta) ranging from -132 to -524 K; and in 2, where the strongest coupling is observed (theta=-524 K), the highest Tc (110 K) value was observed. Weak antiferromagnetic coupling was observed for M=Fe (theta=-12 K) leading to the lowest Tc (3 K) value in this series. Weak coupling and the low Tc value observed in 4 were additionally contributed by the presence of both [FeII(CN)6]4- and [FeIII(CN)6]3- as confirmed by 57Fe-Mössbauer spectroscopy.

摘要

六水合铬（III）离子的动力学惰性（kH2O = 2.4×10⁻⁶ s⁻¹）给将CrIII离子掺入普鲁士蓝型材料带来了挑战；然而，六（乙腈）铬（III）表现出明显更高的活性（约10⁴倍），并为通过非水溶剂合成这些材料提供了一条新的合成路线。本文描述了由[CrIII（NCMe）6]³⁺和相应的[MIII（CN）6]³⁻合成的Cr[M（CN）6]（M = V、Cr、Mn、Fe）普鲁士蓝类似物的合成、光谱和物理性质。所有这些化合物{（NEt4）0.02CrIII[VIII（CN）6]0.98（BF4）（0.08）.0.10MeCN（1）、CrIII[CrIII（CN）6].0.16MeCN（2）、CrIII[MnIII（CN）6].0.10MeCN（3）和（NEt4）0.04CrIII0.64CrIV0.40[FeII（CN）6]0.40[FeIII（CN）6]0.60（BF4）（0.16）.1.02MeCN（4）}都是表现出团簇玻璃行为的亚铁磁体。对于M = V、Cr和Mn，观察到强反铁磁耦合，魏斯常数（θ）范围为-132至-524 K；在2中观察到最强的耦合（θ = -524 K），同时观察到最高的Tc（110 K）值。对于M = Fe，观察到弱反铁磁耦合（θ = -12 K），导致该系列中最低的Tc（3 K）值。57Fe-穆斯堡尔光谱证实，4中观察到的弱耦合和低Tc值还归因于[FeII（CN）6]⁴⁻和[FeIII（CN）6]³⁻的同时存在。