Alkaloids as Ligands. 2. Synthesis and Characterization of Iron(II) Halide Complexes Containing L-sparteine

Abstract

Iron(II) compounds of l-sparteine, sp, are four-coordinate, pseudotetrahedral complexes of the type Fe(sp)X2, where X is Cl, Br, or I. The infrared spectra suggest that sp adopts an all-chair conformation in these complexes. Furthermore, the infrared spectra show four bands below 600 cm-1, two of which are halide sensitive. These absorptions have been assigned to iron-ligand stretching modes. X-ray powder patterns of Fe(sp)Cl2 and Fe(sp)Br2 are identical to the analogous pseudotetrahedral cobalt(II) compounds. These iron compounds have room temperature magnetic moments close to 5.3 µB and display a characteristics low-intensity absorption near 4000 cm-1 which has been assigned to the 5E → 5T2 ligand-field transition. Mössbauer effect spectral results indicate the quadrupole interaction is approximately 2.9 mm/s. The chemical isomer shift increases from 1.03 to0 1.25 to 1.29 mm/s (relative to α-iron foil) for the chloride, bromide, and iodide complexes respectively. The latter two values are among the highest observed for tetrahedral iron(II) complexes.

Department(s)

Chemistry

International Standard Serial Number (ISSN)

0020-1693

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1978 Elsevier Limited, All rights reserved.

Publication Date

01 Feb 1978

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