Katsuaki Konishi

Over recent years, research on the structures and properties of ligand-protected gold cluster molecules has gained significant interest. The crystal structure information accumulated to date has revealed the structural preference to adopt closed polyhedral geometries, but the use of multidentate ligands sometimes leads to the formation of exceptional structures. This Account describes results of our studies on diphosphine-coordinated [core+ exo]-type gold clusters featuring extra gold atoms outs

Cores and effect: A post-synthetic approach using a diphosphine ligand gave two Au8 clusters with unique core geometries based on edge-shared gold tetrahedron motifs (see picture). Although the clusters have isomeric cores, they have different colors and different optical properties. These differences are shown to depend on the core geometries. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or ty

Abstract 2,3‐bis(diphenylphosphino)butane enantiomers (chiraphos, L) used as chiral auxiliaries results in the preferential formation of an unprecedented Au 24 framework with inherent chirality. The crystal structure of [Au 24 L 6 Cl 4 ] 2+ ( 1 ) has a square antiprism‐like octagold core twinned by two helicene‐like hexagold motifs, where the inherent chirality is associated with the helical arrangement. The clusters carrying ( R , R )‐ and ( S , S )‐ diphosphines had right‐ and left‐handed stra

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAsymmetric epoxidation of olefins catalyzed by manganese complexes of chiral "strapped" porphyrins with diastereotopic faces. A novel strategy for stereochemical modeling of the active site of cytochrome P-450Katsuaki Konishi, Kenichiro Oda, Kei Nishida, Takuzo Aida, and Shohei InoueCite this: J. Am. Chem. Soc. 1992, 114, 4, 1313–1317Publication Date (Print):February 1, 1992Publication History Published online1 May 2002Published inissue 1 February 1992

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA Novel Anion-Binding Chiral Receptor Based on a Metalloporphyrin with Molecular Asymmetry. Highly Enantioselective Recognition of Amino Acid DerivativesKatsuaki Konishi, Kazuyuki Yahara, Hiroshi Toshishige, Takuzo Aida, and Shohei InoueCite this: J. Am. Chem. Soc. 1994, 116, 4, 1337–1344Publication Date (Print):February 1, 1994Publication History Published online1 May 2002Published inissue 1 February 1994https://pubs.acs.org/doi/10.1021/ja00083a019htt

An organometallic Au13 cluster having two σ-bonded acetylide ligands was synthesized and its structure was determined by X-ray crystallography. Absorption spectral studies indicated the presence of electronic coupling between the superatomic Au13 core and the acetylide π-orbitals, which was supported by theoretical considerations.

The porphyrin–prophyrin distance and the spatial requirements of the porphyrin substituents are parameters that influence the rotatability of the ligands in metal bis(porphyrinate)s (shown on the right): the chiral cerium complexes were much easier to racemize than the zirconium complexes. The porphyrin ligands in the latter rotate in response to H+.

A large turn-on effect in the form of a notable photoluminescence (PL) enhancement was observed for an oligo(ethylene glycol)-appended CdS cluster molecule with a Cd10S16 core upon mixing with CuI in water (see graphic). Analysis by the Job method and size-exclusion chromatography suggested that the turn-on response, which was found to be specific for CuI, is associated with the formation of a CuI-containing multicluster network. Supporting information for this article is available on the WWW un

A novel container complex in which a 1.4 nm gold cluster is confined within a hexaporphyrin cage was synthesized; the cage showed notable confinement capability for the cluster core, but allowed the interpenetration of small molecules into the interstitial space.

Recent advances in the crystal structure determination of ligand-protected metal clusters have revealed that their electronic structures and optical features are essentially governed by the nuclearity and geometries of the inorganic frameworks. In this Perspective, we point out the definite effects of the exterior ligand moieties on the properties of small gold clusters. On the basis of systematic experimental studies on the optical properties of Au₈ and Au₁₃ clusters with

2,3-bis(diphenylphosphino)butane enantiomers (chiraphos, L) used as chiral auxiliaries results in the preferential formation of an unprecedented Au₂₄ framework with inherent chirality. The crystal structure of [Au₂₄ L₆ Cl₄ ]²⁺ (1) has a square antiprism-like octagold core twinned by two helicene-like hexagold motifs, where the inherent chirality is associated with the helical arrangement. The clusters carrying (R,R)- and (S,S)- diphosphines

Amphiphile Porenwände erleichtern die reversible Sorption von kurzkettigen Alkoholen durch das mikroporöse organisch-anorganische 1D-Hybrid [1-Na]3[PW12O40], das aus dem Calix[4]aren-Na+-Komplex 1-Na+ (R1=R2=H) und dem Polyoxowolframat-Ion [PW12O40]3− aufgebaut ist. Das analoge, mit 2-Na+ (R1=tBu, R2=CH2CO2Et) erhaltene Aggregat hat eine mikroporöse 3D-Architektur.

It is well known that alkynes act as π-acids in the formation of complexes with metals. We found unprecedented attractive Au-π interactions in diacetylene-modified [core+exo]-type [Au₈ ]⁴⁺ clusters. The 4-phenyl-1,3-butadiynyl-modified cluster has unusually short Au-C_α distances in the crystal structure, revealing the presence of attractive interactions between the coordinating C≡C moieties and the neighboring bitetrahedral Au₆ core, which is further s

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChiral N-substituted porphyrins related to heme inactivation products. First crystallographic determination of absolute stereochemistry and correlation with circular dichroismKatsuaki Konishi, Yoshinori Takahata, Takuzo Aida, Shohei Inoue, and Reiko KurodaCite this: J. Am. Chem. Soc. 1993, 115, 3, 1169–1170Publication Date (Print):February 1, 1993Publication History Published online1 May 2002Published inissue 1 February 1993https://pubs.acs.org/doi/10.