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.
[Cr (III)F(NCMe) 5](BF 4) 2.MeCN ( 1) was synthesized from a prolonged dissolution of [Cr (III)(NCMe) 6](BF 4) 3 in MeCN via fluoride abstraction from BF 4 (-). Complex 1 exhibits a crystal field splitting, Delta o, of 17 470 cm (-1) and is a nonaqueous source of Cr (III)F (2+). The reaction of 1 with (NEt 4) 3[Cr (III)(CN) 6] formed a new Prussian-blue-like magnetic material of (NEt 4) 0.04[Cr (III)F] 1.54[Cr (III)(CN) 6](BF 4) 0.12.0.10(MeCN) ( 2) composition. Complex 2 magnetically orders at a critical temperature, T c, of 85 K and at 2 K exhibits magnetic hysteresis with a coercive field, H cr, of 60 Oe and a remanent magnetization, M rem, of 1880 emuOe/mol.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.