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

Abstract

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.

DFT study of the Jahn–Teller effect in Cu(II) chelate complexes

“…Energy differences between elongated forms, as well as between the regular symmetrical configuration for all the four isomers correspond to the recent theoretical investigations on tris(ethylenediamine) complexes [11,12]. Large difference between the energies of elongated and compressed forms for each isomer, (0.58±0.02×10…”

“…[11] or Wang et all. [12] who investigated the influence of the different conformations of the chelate rings on the CD spectra of [Ru(en) 3 ] 2+ . On the other hand, for tris(ethyleneglicol) complexes there are no computational studies so far, and they were always considered to be completely analogues to tris(ethylenediamine) complexes.…”

Computational study of chiral molecules with high intrinsic hyperpolarizabilities

“…Time-dependent density functional theory (TDDFT) has emerged as currently the most applied method for calculating electronic transition energies due to its balance between accuracy and efficiency [48][49][50][51][52].…”

Synthesis and Structural Characterization of 2-Hydroxy-5- (Phenyldiazenyl) Benzaldehyde Oxime - A Theoretical Approach

“…The interest for benzothiazole azo dyes as disperse and cationic dyes for textile application is growing [16]. In recent years, with the development of density functional theory and especially the improvement of time-dependent density functional theory [17], properties of both ground-and excited-states for mediumsized metal complexes can be calculated at the first-principle level with good accuracy [18,19]. To get better insight into the geometry and the electronic structure geometry optimizations of the ground and excitedstates were carried out by means of DFT calculations.…”