Conformational Analysis and TDDFT Calculations of the Chiroptical Properties of Tris[1,2-propanediolato(2-)-κ O ,κ O ′]-selenium/tellurium and Related Compounds

Wang, Yuekui; Fleischhauer, Jörg; Bausch, Stephan; Sebestian, Milan; Laur, Peter

doi:10.1080/10242430215700

Cited by 8 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the sake of prudence, additional calculations have been performed with different functionals PBE0, O3LYP, TPSSh, and so forth, which exclude the possibility that potential numerical error or functional issue leads to this exception. To best understand the results, the individual contributions of different chiral arrays to the overall ECD spectra were calculated using a scheme reported previously. , The results are also plotted in Figure , where the dashed blue lines indicate the contribution of the Λ octahedral core, the dash dotted magenta lines are for that of the (δδ/δλ/λλ) twists of en ligands, and the dash dotted brown lines for that of the chiral orientation (δ/λ) of the nonaxially symmetric unidentate ligands. Thus, we see that in the case of cis -[Co(en) 2 (CN) 2 ] + , the contribution of the (δδ) twists of the en ligands is much larger than that of the Λ-octahedral core in magnitudes but opposite in sign.…”

Section: Resultsmentioning

confidence: 99%

Theoretical Analysis on the Importance of Achiral Unidentate Ligands to Electronic Circular Dichroism of cis-Bis(ethylenediamine) Cobalt(III) Complexes

et al. 2016

Self Cite

View full text Add to dashboard Cite

Compared with the importance of didentate ligands to chiral chelates, little is known about the influence of unidentate ligands on the chiroptical properties of related chelates. To assess the importance of achiral unidentate ligands to electronic circular dichroism (ECD) spectra, calculations of the excitation energies and oscillator and rotational strengths for all the Λ-enantiomers of bis(ethylenediamine) cobalt(III) complexes cis-[Co(en)2(X)2](n+) (X = Cl(-), CN(-), NH3, N3(-), NO2(-), H2O; n = 1, 3) were performed at the TDDFT/B3LYP/6-311++G(2d,p)//DFT/B3LYP/6-311++G(2d,p) level of theory, including solvent effects. The individual contributions of the chiral arrays, Δ/Λ octahedral core, δ/λ twists of the en ligands, and δ/λ relative orientations of the unidentate ligands to the rotational strengths of related transitions were quantitatively determined and graphically presented. It was found that, for the chelates with nonaxially symmetric unidentate ligands (N3(-), NO2(-), H2O), the chiral orientation (δ/λ) of the unidentate ligands not only dominates the ECD spectra of the Λ-diastereoisomers but also dominates the relative energies in solution with the δ-orientation preferred. For those complexes with axially symmetric unidentate ligands (Cl(-), CN(-), NH3), the inherent dissymmetry within the metal ion-donor atom cluster was found to be unidentate ligand-dependent. The Boltzmann-weighted averaged ECD spectra of the complexes with Λ-octahedral core are in excellent agreement with the observed ones, except that for the diazido complex, they are opposite in sign. This demonstrates that the absolute configuration of the complex cis-(-)-[Co(en)2(N3)2](+) is Δ, not the Λ-form assigned by McCaffery et al. in 1965. These findings not only reveal the importance of unidentate ligands to the ECD spectra of related chelates but also provide an insight for the influence of unidentate ligands on both the inherent dissymmetry and the distributional chirality.

show abstract

Section: Resultsmentioning

confidence: 99%

Theoretical Analysis on the Importance of Achiral Unidentate Ligands to Electronic Circular Dichroism of cis-Bis(ethylenediamine) Cobalt(III) Complexes

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Wang et al137 pioneered the theoretical ECD spectroscopy of octahedral tris ‐(didentate) complexes using TDDFT almost 10 years ago. Jorge et al138 explored the possibility of using TDDFT to elucidate the role of configurational and conformational effects on ECD spectra of tris ‐diamine Co(III) and Rh(III) complexes.…”

Section: Applicationsmentioning

confidence: 99%

Circular dichroism: electronic

Warnke

Furche

2011

WIREs Comput Mol Sci

121

129

View full text Add to dashboard Cite

First‐principles calculations of electronic circular dichroism (ECD) are widely used to determine absolute configurations of chiral molecules. In addition, ECD is a sensitive probe for the three‐dimensional molecular structure, making ECD calculations a useful tool to study conformational changes. In this review, we explain the origin of ECD and optical activity using response theory. While the quantum‐mechanical underpinnings of ECD have been known for a long time, efficient electronic structure methods for ECD calculations on molecules with more than 10–20 atoms have become widely available only in the past decade. We review the most popular methods for ECD calculation, focusing on time‐dependent density functional theory. Although single‐point vertical ECD calculations yield useful accuracy for conformationally rigid systems, inclusion of finite‐temperature effects is necessary for flexible molecules. The scope and limitations of modern ECD calculations are illustrated by applications to helicenes, fullerenes, iso‐schizozygane alkaloids, paracyclophanes, β‐lactams, and transition metal complexes. © 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 00 1–17 DOI: 10.1002/wcms.55 This article is categorized under: Electronic Structure Theory > Density Functional Theory

show abstract

“…In recent decades, however, with the development of density functional theory (DFT) and especially the improvement of timedependent density functional theory (TDDFT), 5 properties of excited states for larger molecules can be calculated at the first principle level with good accuracy. [6][7][8] This makes it possible to perform such an analysis, as proposed and demonstrated by Wang 9 et al in 2002. For this reason, the optical and chiroptical properties of some well-studied transition metal complexes also have been explored recently by Ziegler's group [10][11][12][13] using the TDDFT method.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Analysis of the Individual Contributions of Chiral Arrays to the Chiroptical Properties of Tris-diamine Ruthenium Chelates

Wang

et al. 2009

J. Am. Chem. Soc.

Self Cite

View full text Add to dashboard Cite

Calculations of the excitation energies, oscillator and rotational strengths, and the CD spectra of 16 diastereoisomers of the tris-diamine ruthenium chelates [Ru(en)(3)](2+), [Ru(pn)(3)](2+), and [Ru(bn)(3)](2+) have been performed at the TDDFT/B3LYP/LanL2DZ+6-31G* level including solvent effects. The individual contributions of the chiral arrays, Delta/Lambda octahedral core, delta/lambda twists of the ligand rings, and R/S chiral carbons to the rotational strengths of related transitions have been quantitatively determined and graphically presented. It was found that the three chiral arrays Delta, delta and S each make their contributions to the CD spectra of the chelates with the sign alternated between negative and positive from long wavelength to short, but the intensities of the extrema are different for different chiral arrays. By simply combining the contributions of related chiral arrays in the chelates, all CD spectra of the 16 isomers obtained at the TDDFT level can be well reproduced, and those of the other conformers can also be well predicted, as expected. These findings not only make it possible to determine the absolute configurations and conformations of related chelates in solution from their CD spectra but also provide a deep insight into the chiroptical properties of the chelates.

show abstract

Conformational Analysis and TDDFT Calculations of the Chiroptical Properties of Tris[1,2-propanediolato(2-)-κ O ,κ O ′]-selenium/tellurium and Related Compounds

Cited by 8 publications

References 0 publications

Theoretical Analysis on the Importance of Achiral Unidentate Ligands to Electronic Circular Dichroism of cis-Bis(ethylenediamine) Cobalt(III) Complexes

Theoretical Analysis on the Importance of Achiral Unidentate Ligands to Electronic Circular Dichroism of cis-Bis(ethylenediamine) Cobalt(III) Complexes

Circular dichroism: electronic

Theoretical Analysis of the Individual Contributions of Chiral Arrays to the Chiroptical Properties of Tris-diamine Ruthenium Chelates

Contact Info

Product

Resources

About