Macrobicyclic d-metal tris-dioximates obtained by cross-linking with p-block elements Part I. Template synthesis and properties of macrobicyclic boron-containing iron(II) dioximates

The synthesis and characterization of a number of new boron-containing macrobicyclic iron(II) complexes of the general composition FeD3(BR)2, where D2− = dioxime anion; R  OH, F, alkyl, alkoxyl, are reported. Infrared, visible, (1H, 13C, 11B) NMR and Mossbauer spectra were examined. The molecular structure of the macrobicyclic complexes was proved by Mossbauer spectroscopy data. The complexes show the geometry of a distorted trigonal prism with different distortion angles in the range 20–30°. The ‘macrocyclic’ effects manifested themselves by a decrease in IS value in Mossbauer spectra, increase in Debye temperature and molar extinction coefficient and reduction in the width of charge transfer band due to a decrease in the non-rigidity of the complex molecule.