### Infrared Spectral Identification of Isomers of Chromium(III) Propylenediamine ComplexesInfrared Spectral Identification of Isomers of Chromium(III) Propylenediamine Complexes

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 Author Sakabe, Yuzuru ♦ Ogura, Haruo Source J-STAGE Content type Text Publisher The Japan Society for Analytical Chemistry Language English
 Subject Keyword Infrared spectra ♦ chromium(III) complex ♦ identification ♦ characterization ♦ ethylenediamine ♦ propylenediamine Abstract The infrared (IR) spectra of isomers of dicyanobis(propylenediamine)chromium(III) chloride and related complexes have been measured over the range of 4000 to $290cm^{-1}$ in order to determine the characteristic frequencies available for identification of the isomers. Our results suggest that the desired distinctive frequencies exist mainly in the C=N stretching band at $2145-2131cm^{-1},$ the vibrations in the region $838-830cm^{-1},$ the Cr-N stretching vibrations in the region $590-431cm^{-1},$ and the Cr-C stretching or Cr-C≡N bending vibrations in the region $408-320cm^{-1}.$ These frequencies have enabled: 1) a distinction between $cis-(+)_{589}-[Cr(CN)_{2}(d-pn)(l-pn)]Cl$ and the diastereoisomeric isomers, such as $cis-(-)_{589}-[Cr(CN)_{2}(d-pn)_{2}]Cl$ or $cis-(+)_{589}-[Cr(CN)_{2}(l-pn)_{2}]Cl$ (pn=propylenediamine=1, 2-diaminopropane); 2) the identification of the geometric isomers of $Λ-cis-(-)_{589}-[Cr(CN)_{2}(d-pn)_{2}]Cl$ which results from differences in the relative position of the methyl groups of propylenediamine ligands, and 3) the discrimination of ethylenediamine complexes from that of propylenediamine. In these paramagnetic Cr(III) complexes, the measurement of NMR spectra is made worthless due to the influence of the large magnetic moment of unpaired electrons. Accordingly, the importance of the structural information obtained by IR measurements is very high in their identification. ISSN 09106340 Learning Resource Type Article Publisher Date 1992-02-10 e-ISSN 13482246 Journal Analytical Sciences(analsci1985) Volume Number 8 Issue Number 1 Page Count 4 Starting Page 63 Ending Page 66