Five-coordinate iridium(III) complex with ΔΛ chirality.

The coordinatively unsaturated bis-chelated iridium(III) complex, [Ir(2-Bubzq)Cl] (2-BubzqH = 2-butyl-benzo[]quinoline), denoted as complex 1, was obtained by reacting iridium(III) trichloride with 2-BubzqH in a 1 : 2 molar ratio. The results were in contrast to the common view that a chlorine-bridged dimer, [Ir(L)Cl] (L = bis-chelate ligand), is formed under the corresponding conditions. A single-crystal X-ray diffraction structural analysis revealed that complex 1 has a five-coordinate geometry with a distorted square pyramidal configuration.

Effects of geometrical isomerism on emissive behaviour of heteroleptic cyclometalated Ir(III) complexes.

In this study, we report the emissive properties of a heteroleptic cyclometalated Ir(iii) complex, [Ir(bzq)2(PBO)] (bzqH = benzo[h]quinoline; PBOH = 2-(2-hydroxyphenyl)benzoxazole). The complex, [Ir(C^N)2(N^O)], was synthesised and optically resolved using a chiral column. Two geometrical isomers, trans-(N,N) and cis-(N,N) isomers, were obtained as the major and minor products in an enantiopure form, respectively.

Vibrational circular dichroism towards asymmetric catalysis: chiral induction in substrates coordinated with copper(II) ions.

Cu(ii) complexes containing RR- or SS-2,2'-isopropylidene-bis(4-phenyl-2-oxazoline) (denoted as [Cu(RR- or SS-oxa)]2+) are known to catalyse many asymmetric organic reactions. Herein, the source of enantioselectivity was investigated by vibrational circular dichroism (VCD) spectroscopy. An achiral β-diketonato ligand (denoted as LH), such as 1-phenyl-1,3-butanedione and dibenzoylmethane, was added to form [Cu(RR- or SS-oxa)L]+.

Enantiomeric Excess Dependent Splitting of NMR Signal through Dynamic Chiral Inversion and Coligand Exchange in a Coordination Complex.

Nuclear magnetic resonance (NMR) spectroscopy cannot be used to discriminate enantiomers, and NMR resonances of enantiomeric mixtures are generally not affected by enantiomeric excess (). Here, we report that a coordination complex (·2Zn·3), where is a salen-like prochiral ligand and is an exchangeable acetate coligand, exhibits symmetrical splitting of one of the H NMR resonances of with the degree of splitting linearly proportional to of the chiral guest coligand , 2-phenoxypropionic acid. Despite the well-defined chirality in the crystal structure of ·2Zn·3, concurrent fast chiral inversion and coligand exchange in solution renders ·2Zn·3 the primary example of prochiral solvating agent (-CSA) based on a coordination complex.

Stereoselective interactions as manifested by vibrational circular dichroism spectra: the interplay between chiral metal complexes co-adsorbed in a montmorillonite clay.

Vibrational circular dichroism (VCD) spectroscopy was applied to study intermolecular interactions on the surface of a clay mineral. A montmorillonite clay loaded with two kinds of chiral molecules was prepared. Firstly a cationic ruthenium(ii) complex, Δ- or Λ-[Ru(phen)3]2+ (phen = 1,10-phenanthroline), was ion-exchanged into sodium montmorillonite (denoted as [Ru(phen)3]2+/mont).

Solid state vibrational circular dichroism towards molecular recognition: chiral metal complexes intercalated in a clay mineral.

Vibrational circular dichroism (VCD) spectroscopy was applied to study chirality recognition in the interlayer space of a clay mineral. Clay intercalation compounds including two kinds of chiral molecules were prepared. Firstly a cationic metal complex, Δ- or Λ-[Ru(phen)] (phen = 1,10-phenanthroline), was ion-exchanged into sodium montmorillonite.

Vibrational circular dichroism and single crystal X-Ray diffraction analyses of [Ir(bzq)(phen)] (bzq = benzo[h]quinoline; phen = 1,10-phenanthroline): absolute configuration and role of CH-π interaction in molecular packing.

Vibrational circular dichroism (VCD) spectra are measured for dichloromethane solutions of the resolved enantiomers of [Ir(bzq)(phen)] (bzqH = benzo[h]quinoline; phen = 1,10-phenanthroline). The absolute configuration of each enantiomer is determined by comparing the experimental and theoretical spectra. The result is in accord with the results of the X-ray single crystallographic analysis on the enantiomeric crystal.