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Capturing the Heptaniobate {Nb 7 O 22 } 9 – Anion by Covalent Bond Formation: Synthesis, Crystal Structure, and Selected Properties of {[Fe(cyclam)] 3 Nb 7 O 22 }· ≈ 19 H 2 O
Author(s) -
MüscherPolzin Philipp,
Näther Christian,
Bensch Wolfgang
Publication year - 2020
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201900276
Subject(s) - cyclam , crystallography , crystal structure , octahedron , molecule , chemistry , ion , natural bond orbital , ligand (biochemistry) , covalent bond , crystal (programming language) , inorganic chemistry , metal , organic chemistry , biochemistry , programming language , receptor , computer science
The new compound {[Fe(cyclam)] 3 Nb 7 O 22 } · ≈ 19 H 2 O ( I ) was synthesized at room temperature reacting aqueous solutions of K 8 {Nb 6 O 19 } · 16 H 2 O, Fe(NO 3 ) 3 · 9 H 2 O and cyclam (1,4,8,11‐tetraazacyclotetradecane). In the crystal structure the heptaniobate {Nb 7 O 22 } 9– anion is observed which is expanded by three [Fe(cyclam)] 3+ complexes, thus suppressing further condensations into larger aggregates. The complexes are solely bound to the three terminal O 2– anions of the NbO 6 octahedron which expands the hexaniobate {Nb 6 O 19 } 8– anion to form the heptaniobate cluster. The two O atoms in the FeN 4 O 2 octahedron are in cis position leading to a severe distortion of the cyclam ligand with one of the CH 2 –CH 2 –CH 2 –N–CH 2 –CH 2 fragments being rotated by about 90°. The {[Fe(cyclam)] 3 Nb 7 O 22 } units are arranged to form channels which host the crystal water molecules. The crystal water molecules can be removed by thermal treatment. Storing the sample on air the pristine sample is recovered.