Template synthesis and structure of mono- and trisubstituted ribbed-functionalized iron(II) clathrochelates

• Published in: Inorganica Chimica Acta 2005, Vol.358 (1), p.131-146
• Main Authors: Voloshin, Yan Z., Varzatskii, Oleg A., Palchik, Aleksei V., Vorontsov, Ivan I., Antipin, Mikhail Yu, Lebed, Ekaterina G.
• Format: Article
• Language: English
• Subjects: Clathrochelates; Iron complexes; Macrocyclic compounds
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2004.08.008

The template condensation of three methylchloroglyoximate molecules with phenylboronic acid and with BF 3 · O(C 2H 5) 2 on an iron(II) ion afforded reactive trichloride phenylboron- and fluoroboron-capped precursors, respectively. The monochloride FeBd 2(CH 3ClGm)(BF) 2 precursor (where Bd 2− and CH 3ClGm 2− are α-benzyldioxime and methylchloroglyoxime dianions) was synthesized by condensation of macrocyclic iron(II) α-benzyldioximate FeBd 2(BF 2) 2(CH 3CN) 2 with CH 3ClGmH 2. Mono- and trifunctionalized amine, alkylsulfide, and arylsulfide clathrochelate iron(II) tris-dioximates were prepared starting from these precursors by nucleophilic substitution reactions. The complexes obtained were characterized using elemental analysis, PD mass, IR, UV–Vis, 1H, 13C NMR, and 57Fe Mössbauer spectra, and X-ray crystallography. An encapsulated low-spin iron(II) ion was found to have distorted trigonal-prismatic coordination N 6-environment in all clathrochelates synthesized. The template condensation of three methylchloroglyoximate molecules with phenylboronic acid and with BF 3 · O(C 2H 5) 2 on an iron(II) ion afforded reactive trichloride phenylboron- and fluoroboron-capped precursors, respectively. The monochloride FeBd 2(CH 3ClGm)(BF) 2 precursor (where Bd 2− and CH 3ClGm 2− are α-benzyldioxime and methylchloroglyoxime dianions) was synthesized by condensation of macrocyclic iron(II) α-benzyldioximate FeBd 2(BF 2) 2(CH 3CN) 2 with CH 3ClGmH 2. Mono- and trifunctionalized amine, alkylsulfide, and arylsulfide clathrochelate iron(II) tris-dioximates were prepared starting from these precursors by nucleophilic substitution reactions. The complexes obtained were characterized using elemental analysis, PD mass, IR, UV–Vis, 1H, 13C NMR, and 57Fe Mössbauer spectra, and X-ray crystallography. An encapsulated low-spin iron(II) ion was found to have distorted trigonal-prismatic coordination N 6-environment in all clathrochelates synthesized.