Electronic Structures of Late versus Early Transition Metal Imido Complexes from 15N NMR Signatures DOI Creative Commons
Yuya Kakiuchi, Christophe Copéret

Helvetica Chimica Acta, Journal Year: 2024, Volume and Issue: 107(11)

Published: Oct. 27, 2024

Abstract Imido ligand is a ubiquitous motif in organometallic chemistry, serving roles spanning from ancillary ligands to reactive sites. The nature of M=N bond highly depended on the metal centres and their d‐electron configuration, with late transition (TM) imido complexes exhibiting contrasting features when compared early TM analogues. Envisioning uncover general electronic descriptor for ligands, we computationally investigate solid‐state 15 N NMR signatures various central metals, geometries counts, compare them against these corresponding systems. spectroscopic are mostly driven by presence filled, π‐symmetry orbitals complexes, suggesting development high‐lying π(M=N) low‐lying σ/σ * (M=N) orbitals. This contrasts what observed reported systems, which σ‐type determine signature. Noteworthily, Ni‐ Pd‐imido formal d 10 configurations exhibit asymmetric nitrogen‐15 signature extremely deshielded principal components, because antibonding π orbitals, consistent high reactivity. sensitive response sites further highlights that chemical shift useful reactivity descriptor.

Language: Английский

Solid-State Nuclear Magnetic Resonance Spectroscopy for Surface Characterization of Metal Oxide Nanoparticles: State of the Art and Perspectives DOI Creative Commons
Pan Gao, Yi Ji, Guangjin Hou

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Metal oxide materials have found wide applications across diverse fields; in most cases, their functionalities are dictated by surface structures and properties. A comprehensive understanding of the intricate features is critical for further design, optimization, applications, necessitating multi-faceted characterizations. Recent advances solid-state nuclear magnetic resonance (ssNMR) spectroscopy significantly extended its detailed analysis multiple metal nanoparticles, offering unparalleled atomic-level information on structures, properties, chemistries. Herein, we present an overview current state art from NMR perspective. We begin with a brief introduction to contemporary ssNMR methodologies. Subsequently, introduce provide reviews different techniques characterizations local disorders, defects, active sites, acidity as well revelation mechanisms behind some intriguing chemistries that occur surfaces, referencing representative recent studies. Finally, address challenges beyond status perspectives future development application advanced methodologies this emerging field.

Language: Английский

Citations

1
Ti-catalyzed 1,2-Diamination of Alkynes Using 1,1-Disubstituted Hydrazines DOI
Partha Karmakar, Yuya Kakiuchi, Jae‐Kwan Kim

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 20, 2025

Ti-catalyzed alkyne diamination and hydrohydrazination proceed through a common N-aminoazatitanacyclobutene intermediate. These reactions have historically existed as processes catalyzed by distinct molecular Ti compounds, with several reports for only single example diamination. Here, we demonstrate that diamidoamine catalyst, (NNN)Ti(═NNR2) (1, (NNN)H2 = N-methyl-N',N″-bis(trimethylsilyl)diethylenetriamine; R alkyl, aryl), is capable of catalyzing both hydrohydrazination, where the selectivity dictated simple changes to reaction conditions. This approach capitalizes on fact there are entropic differences at branch point between (unimolecular) (bimolecular). discovery leads an expanded substrate scope provides understanding how structure-activity relationships can impact relative rates (selectivity) hydrohydrazination. relationships, anchored 15N NMR descriptors, were then used design novel, highly active, selective (NNNSiMe2Ph)Ti(═NNR2) (1f), which contains bulkier flanking amide ligands. More broadly, these results suggest this strategy may be applied more generally catalysts uncover new 1,1-disubstituted hydrazines.

Language: Английский

Citations

0
Electronic Structures of Late versus Early Transition Metal Imido Complexes from 15N NMR Signatures DOI Creative Commons
Yuya Kakiuchi, Christophe Copéret

Helvetica Chimica Acta, Journal Year: 2024, Volume and Issue: 107(11)

Published: Oct. 27, 2024

Abstract Imido ligand is a ubiquitous motif in organometallic chemistry, serving roles spanning from ancillary ligands to reactive sites. The nature of M=N bond highly depended on the metal centres and their d‐electron configuration, with late transition (TM) imido complexes exhibiting contrasting features when compared early TM analogues. Envisioning uncover general electronic descriptor for ligands, we computationally investigate solid‐state 15 N NMR signatures various central metals, geometries counts, compare them against these corresponding systems. spectroscopic are mostly driven by presence filled, π‐symmetry orbitals complexes, suggesting development high‐lying π(M=N) low‐lying σ/σ * (M=N) orbitals. This contrasts what observed reported systems, which σ‐type determine signature. Noteworthily, Ni‐ Pd‐imido formal d 10 configurations exhibit asymmetric nitrogen‐15 signature extremely deshielded principal components, because antibonding π orbitals, consistent high reactivity. sensitive response sites further highlights that chemical shift useful reactivity descriptor.

Language: Английский

Citations

0