Alkaloids as Ligands. 1. Synthesis and Characterization of Three Cobalt(II) Pseudohalide Compounds Containing L-sparteine
Abstract
The alkaloid l-sparteine (sp) combines with cobalt(II) cyanate, thiocyanate, and selenocyanate to form pseudotetrahedral, N-bonded four-coordinate complexes of the type Co(sp)(NCX)2 (X = O, S, or Se). Their electronic spectra indicate that Co(Sp)(NCSe)2 is nearly tetrahedral whereas Co(sp)(NCO)2 and Co(Sp)(NCS)2·1/2H2O are more severely distorted from tetrahedral geometry. This distortion is observed in the low-symmetry splitting of the ν2 and ν3 ligand field transitions which is ca. twice as large in the isocyanate and isothiocyanate complexes as in the isoselenocyanate complex which exhibits a splitting of ca. 2000 cm-1 for ν2 and 1000 cm-1 for ν3. Apparently the isoselenocyanate complex maintains a nearly regular tetrahedral geometry by changing the conformation of the A ring of l-sparteine from the chair to the boat conformation. Pseudohalide stretching and bending modes are identified and found to be similar to those of other complexes containing nitrogen-coordinated pseudohalides. For the isocyanate, isothiocyanate, and isoselenocyanate compounds cobalt-tertiary nitrogen stretching frequencies are 465, 498, and 473 cm-1, respectively. Below 400 cm-1 two cobalt-pseudohalide nitrogen stretching bands for each compound are identified.
Recommended Citation
J. T. Wrobleski and G. J. Long, "Alkaloids as Ligands. 1. Synthesis and Characterization of Three Cobalt(II) Pseudohalide Compounds Containing L-sparteine," Inorganic Chemistry, vol. 16, no. 3, pp. 704 - 709, American Chemical Society (ACS), Mar 1977.
The definitive version is available at https://doi.org/10.1021/ic50169a041
Department(s)
Chemistry
International Standard Serial Number (ISSN)
0020-1669
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 1977 American Chemical Society (ACS), All rights reserved.
Publication Date
01 Mar 1977
