In:
European Journal of Inorganic Chemistry, Wiley, Vol. 2013, No. 18 ( 2013-06-12), p. 3178-3184
Abstract:
Perfluoroarylation of a known iron(II) diiodoclathrochelate precursor and its new n ‐butylboron‐capped hexaiodomacrobicyclic analog with pentafluorophenylcopper(I) gave the first iron(II) cage complexes with inherent perfluoroaryl substituent(s). The complexes synthesized were characterized by elemental analysis, MALDI‐TOF mass spectrometry, IR, UV/Vis, 1 H, 11 B, 19 F, and 13 C{ 1 H} NMR spectroscopy, and X‐ray crystallography. The encapsulated iron(II) ions in the X‐rayed hexaiodo‐ and di‐ and hexa(pentafluorophenyl)ated iron(II) clathrochelates are located almost in the centers of their FeN 6 coordination polyhedra. The geometry of the hexaiodoclathrochelate precursor is trigonal prismatic (TP, distortion angle φ = 4.5°), whereas the perfluoroarylated iron(II) clathrochelates are intermediate between a TP and a trigonal antiprism (TAP) ( φ ≈ 25°). This rotation and expansion from TP to TAP polyhedra causes horizontal spreading, and the heights h decrease from 2.40 to 2.33–2.35 Å. Anodic ranges of the cyclic voltammograms (CVs) for the pentafluorophenylated iron(II) clathrochelates contain one‐electron waves of the metal‐centered Fe 2+/3+ oxidation, which are quasireversible in the cyclic voltammetry (CV) timescale. The potentials for the mono‐ and difunctionalized clathrochelates are only slightly different, as a result of steric hindrance between two pentafluorophenyl substituents in the same chelate ribbed fragment decreasing their conjugation with the polyazomethine clathrochelate framework and lowering the electronic effects. The cathodic ranges of these CVs contain irreversible waves for encapsulated metal‐centered Fe 2+/+ reduction to anionic forms of the cage complexes that are unstable on the CV timescale.
Type of Medium:
Online Resource
ISSN:
1434-1948
,
1099-0682
DOI:
10.1002/ejic.v2013.18
DOI:
10.1002/ejic.201300189
Language:
English
Publisher:
Wiley
Publication Date:
2013
detail.hit.zdb_id:
1475009-0