Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2013 Jan 7;14(1):964-78.
doi: 10.3390/ijms14010964.

VCD studies on chiral characters of metal complex oligomers

Hisako Sato  1 , Akihiko Yamagishi
Affiliations
Review

VCD studies on chiral characters of metal complex oligomers

Hisako Sato et al. Int J Mol Sci. .

Abstract

The present article reviews the results on the application of vibrational circular dichroism (VCD) spectroscopy to the study of stereochemical properties of chiral metal complexes in solution. The chiral characters reflecting on the vibrational properties of metal complexes are revealed by measurements of a series of β-diketonato complexes with the help of theoretical calculation. Attention is paid to the effects of electronic properties of a central metal ion on vibrational energy levels or low-lying electronic states. The investigation is further extended to the oligomers of β-diketonato complex units. The induction of chiral structures is confirmed by the VCD spectra when chiral inert moieties are connected with labile metal ions. These results have demonstrated how VCD spectroscopy is efficient in revealing the static and dynamic properties of mononuclear and multinuclear chiral metal complexes, which are difficult to clarify by means of other spectroscopes.

PubMed Disclaimer

Figures

Figure 1
Figure 1
The vibrational circular dichroism spectra of the optically resolved enantiomers of F2 in CDCl3. Solid and dotted lines correspond to P1 and P2 as shown in Scheme 1, respectively, (modified from [22]).
Figure 2
Figure 2
The vibrational circular dichroism spectra of the optically resolved enantiomers of racemic types (upper left and right) and meso-type (under) in CDCl3. Solid and dotted lines correspond to less and more retained enantiomers, respectively. It should be noted that the peak intensity for the meso-type dimers is ten times lower than that for the racemic dimers (modified from [21]).
Scheme 1
Scheme 1
Four possible enantiomeric pairs represented by (F1) Δ–ΛΛΛ/Λ–ΔΔΔ F2 Δ–ΛΛΔ/Λ–ΔΔΛ F3 Λ–ΛΛΔ/Δ–ΔΔΛ and (F4 Λ–ΛΛΛ/Δ–ΔΔΔ, respectively (modified from [22]).
Scheme 2
Scheme 2
ΔΔ- (or ΛΛ-)[Ru(III)(acac)2(S-dabe or R-dabe)Ru(III)(acac)2] or ΔΔ- (or ΛΛ-)[Ru(III)(acac)2(R-dabe or S-dabe)Ru(III)(acac)2] (racemic type) and ΔΛ-[Ru(III)(acac)2(S-dabe or R-dabe)Ru(III)(acac)2] (meso-type) with non-symmetrical orthogonal bridging ligands.
Chart 1
Chart 1
(a) [M(III)(acac)3] (acac = acetylacetonato, M = Ru, Cr, Co, Rh, Ir and Al); (b) [M(III)(acac)2(dbm)] (M = Ru, Cr, and Co) (modified from [15]). (a) (b)
Chart 2
Chart 2
(a) (−)-tfac = (−)-3-trifluoroacetylcamphorato); (b) Δ- or Λ-[Ru((−)- or (+)-tfac)n(acac)3−n] (n = 1, 2 and 3, (−)- or (+)-tfac = (−)- or (+)-3-trifluoroacetylcamphorato and acac = acetylacetonato ) (modified from [16]).
Chart 3
Chart 3
(a) one-handed, (b) two-handed and (c) three-handed tectons (modified from [19,52]).
Chart 4
Chart 4
(a) [{Ru(III)(acac)2(taet)}2Ni(tmen)]; (b) [{Ru(III)(acac)(taet)2Ni(II)(tmen)} n{Ni(II)(tmen)}](ClO4)2 (modified from [19]).
Chart 5
Chart 5
Star-burst type tetranuclear complexes, Δ-(or Λ-)[{Δ-(or Λ-)Ru(III)(acac)2 (taet)}3Ru(III)] from three-handed tecton (modified from [22]).
Chart 6
Chart 6
Structures of (a) 1,2-diacetyl-1,2-dibenzoylethane (dabeH2) and (b) [Ru(III)(acac)2(dabe)Ru(III)(acac)2] (modified from [21]).
See this image and copyright information in PMC

References

    1. Amouri H., Gruselle M. Chirality in Transion Metal Chemsitry. Wiley; West Sussex, UK: 2008. pp. 121–232.
    1. Riehl J.P., Kaizaki S. Absolute Chiral Structures of Inorganic Compounds. In: Bakac A., editor. Physical Inorganic Chemistry. Wiley; Hoboken, NJ, USA: 2010. pp. 143–197.
    1. Kaizaki S. Applications of Electronic Circular Dichroism to Inorganic Sterochemsitry. In: Berova N., Polavarapu P.L., Nakanishi K., Woody R.W., editors. Comprehensive Chiroptical Spectroscopy. Vol. 2. Wiley; Hoboken, NJ, USA: 2012. pp. 451–471.
    1. Canary J.W., Dai Z. Dynamic Stereochemistry and Chiroptical Spectroscopy of Metallo-Organic Compounds. In: Berova N., Polavarapu P.L., Nakanishi K., Woody R.W., editors. Comprehensive Chiroptical Spectroscopy. Vol. 2. Wiley; Hoboken, NJ, USA: 2012. pp. 251–287.
    1. Nafie L.A. Infrared Vibrational Optical Activity: Measurement and Instrumentation. In: Berova N., Polavarapu P.L., Nakanishi K., Woody R.W., editors. Comprehensive Chiroptical Spectroscopy. Vol. 1. Wiley; Hoboken, NJ, USA: 2012. pp. 115–146.

LinkOut - more resources