Ge-Fe Carbonyl Cluster Compounds: Ionic Liquids-Based Synthesis, Structures, and Properties

ChemistryOpen. 2021 Feb;10(2):171-180. doi: 10.1002/open.202000254. Epub 2020 Nov 23.

Abstract

Nine Ge-Fe carbonyl cluster compounds are prepared via ionic liquids-based synthesis. This includes the novel compounds [EMIm][Fe(CO)3 I(GeI3 )], [EHIm][Fe(CO)3 I(GeI3 )], [BMIm][GeI2 {Fe(CO)4 }2 (μ-I)][AlCl4 ]2 , [GeI2 {Fe(CO)4 }2 (μ-I)][Fe(AlBr4 )3 ], [BMIm]2 [(FeI2 )0.75 {Fe(CO)2 I(GeI3 )2 }2 ], and [EHIm][Fe(CO)4 (GeI2 )2 Fe(CO)3 GeI3 ] as well as the previously reported compounds (Fe(CO)4 (GeI3 )2 , FeI4 {GeI3 Fe(CO)3 }2 , and Ge12 {Fe(CO)3 }8 (μ-I)4 (EMIm: 1-ethyl-3-methylimidazolium, EHIm: 1-ethylimidazolium, BMIm: 1-butyl-3-methylimidazolium). With this series of compounds, a comparison of synthesis conditions and structural features is possible and, for instance, allows correlating the composition and structure of the respective Ge-Fe carbonyl cluster compounds with the type and acidity of the ionic liquid. With [EMIm][{GeI3 }2 Fe(CO)3 I], moreover, we can exemplarily show the thermal decomposition as a single-source precursor in the ionic liquid, resulting in bimetallic Ge-Fe nanoparticles with small size and narrow size distribution (7.0±1.4 nm).

Keywords: Ge−Fe systems; cluster compounds; crystal structures; ionic liquids; nanoparticles.