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Updated: Nov 7, 2025
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Tricyanidoferrates(-IV) and Ruthenates(-IV) with Non-Innocent Cyanido Ligands
Franziska Jach1,2, Frank R Wagner1, Zeeshan H Amber3
1Max-Planck-Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, 01187, Dresden, Germany.
Abstract:
Exceptionally electron-rich, nearly trigonal-planar tricyanidometalate anions [Fe(CN)3 ]7- and [Ru(CN)3 ]7- were stabilized in LiSr3 [Fe(CN)3 ] and AE3.5 [M(CN)3 ] (AE=Sr, Ba; M=Fe, Ru). They are the first examples of group 8 elements with the oxidation state of -IV. Microcrystalline powders were obtained by a solid-state route, single crystals from alkali metal flux. While LiSr3 [Fe(CN)3 ] crystallizes in P63 /m, the polar space group P63 with three-fold cell volume for AE3.5 [M(CN)3 ] is confirmed by second harmonic generation. X-ray diffraction, IR and Raman spectroscopy reveal longer C-N distances (124-128 pm) and much lower stretching frequencies (1484-1634 cm-1 ) than in classical cyanidometalates. Weak C-N bonds in combination with strong M-C π-bonding is a scheme also known for carbonylmetalates. Instead of the formal notation [Fe-IV (CN- )3 ]7- , quantum chemical calculations reveal non-innocent intermediate-valent CN1.67- ligands and a closed-shell d10 configuration for Fe, that is, Fe2- .
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