Premium
Tricyanidoferrates(−IV) and Ruthenates(−IV) with Non‐Innocent Cyanido Ligands
Author(s) -
Jach Franziska,
Wagner Frank R.,
Amber Zeeshan H.,
Rüsing Michael,
Hunger Jens,
Prots Yurii,
Kaiser Martin,
Bobnar Matej,
Jesche Anton,
Eng Lukas M.,
Ruck Michael,
Höhn Peter
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202103268
Subject(s) - raman spectroscopy , crystallography , chemistry , alkali metal , microcrystalline , oxidation state , metal , physics , organic chemistry , optics
Exceptionally electron‐rich, nearly trigonal‐planar tricyanidometalate anions [Fe(CN) 3 ] 7− and [Ru(CN) 3 ] 7− were stabilized in LiSr 3 [Fe(CN) 3 ] and AE 3.5 [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 LiSr 3 [Fe(CN) 3 ] crystallizes in P6 3 /m, the polar space group P6 3 with three‐fold cell volume for AE 3.5 [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 CN 1.67− ligands and a closed‐shell d 10 configuration for Fe, that is, Fe 2− .