0000000000494463
AUTHOR
Ying-zi Han
Highly Robust but Surface-Active : An N-Heterocyclic Carbene-Stabilized Au25 Nanocluster
Surface organic ligands play a critical role in stabilizing atomically precise metal nanoclusters in solutions. However, it is still challenging to prepare highly robust ligated metal nanoclusters that are surface-active for liquid-phase catalysis without any pre-treatment. Now, an N-heterocyclic carbene-stabilized Au25 nanocluster with high thermal and air stabilities is presented as a homogenous catalyst for cycloisomerization of alkynyl amines to indoles. The nanocluster, characterized as [Au25(iPr2-bimy)10Br7]2+ (iPr2-bimy=1,3-diisopropylbenzimidazolin-2-ylidene) (1), was synthesized by direct reduction of AuSMe2Cl and iPr2-bimyAuBr with NaBH4 in one pot. X-ray crystallization analysis …
Tertiary Chiral Nanostructures from C‐H∙∙∙F Directed Assembly of Chiroptical Superatoms
Chiral hierarchical structures are universal in nature, whereas quite challenging to mimic in man-made synthesis. We report herein the synthesis and structure of tertiary chiral nanostructures with 100% optical purity. A novel synthetic strategy, using chiral reducing agent, R and S -BINAPCuBH 4 (BINAP is 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl), is developed to access to atomically precise, intrinsically chiral [Au 7 Ag 6 Cu 2 ( R - or S -BINAP) 3 (SCH 2 Ph) 6 ]SbF 6 nanoclusters in one-pot synthesis. The clusters represent the first tri-metallic superatoms with inherent chirality and fair stability. Both metal distribution (primary) and ligand arrangement (secondary) of the enantiomer…
From Symmetry Breaking to Unraveling the Origin of the Chirality of Ligated Au13Cu2 Nanoclusters
A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au13Cu2, into an enantiomeric pair by breaking (lowering) the overall molecular symmetry with the ligands. Using an achiral diphosphine, a racemic [Au13Cu2(DPPP)3(SPy)6]+ was prepared which crystallizes in centrosymmetric space groups. Using chiral diphosphines, enantioselective synthesis of an optically pure, enantiomeric pair of [Au13Cu2((2r,4r)/(2s,4s)‐BDPP)3(SPy)6]+ was achieved in one pot. Their circular dichroism (CD) spectra give perfect mirror images in the range of 250–500 nm with maximum anisotropy factors of 1.2×10−3. DFT calculations provided good correlations wit…
Highly Robust but Surface‐Active: An N‐Heterocyclic Carbene‐Stabilized Au 25 Nanocluster
Surface organic ligands play a critical role in stabilizing atomically precise metal nanoclusters in solutions. However, it is still challenging to prepare highly robust ligated metal nanoclusters that are surface-active for liquid-phase catalysis without any pre-treatment. Now, an N-heterocyclic carbene-stabilized Au25 nanocluster with high thermal and air stabilities is presented as a homogenous catalyst for cycloisomerization of alkynyl amines to indoles. The nanocluster, characterized as [Au25 (i Pr2 -bimy)10 Br7 ]2+ (i Pr2 -bimy=1,3-diisopropylbenzimidazolin-2-ylidene) (1), was synthesized by direct reduction of AuSMe2 Cl and i Pr2 -bimyAuBr with NaBH4 in one pot. X-ray crystallization…
From Symmetry Breaking to Unraveling the Origin of the Chirality of Ligated Au13 Cu2 Nanoclusters
A general method, using mixed ligands (here diphosphines and thiolates) is devised to turn an achiral metal cluster, Au13 Cu2 , into an enantiomeric pair by breaking (lowering) the overall molecular symmetry with the ligands. Using an achiral diphosphine, a racemic [Au13 Cu2 (DPPP)3 (SPy)6 ]+ was prepared which crystallizes in centrosymmetric space groups. Using chiral diphosphines, enantioselective synthesis of an optically pure, enantiomeric pair of [Au13 Cu2 ((2r,4r)/(2s,4s)-BDPP)3 (SPy)6 ]+ was achieved in one pot. Their circular dichroism (CD) spectra give perfect mirror images in the range of 250-500 nm with maximum anisotropy factors of 1.2×10-3 . DFT calculations provided good corre…
CCDC 2096619: Experimental Crystal Structure Determination
Related Article: Hui Shen, Zhen Xu, Lingzheng Wang, Ying-Zi Han, Xianhu Liu, Sami Malola, Boon K. Teo, Hannu Häkkinen, Nanfeng Zheng|2021|Angew.Chem.,Int.Ed.|60|22411|doi:10.1002/anie.202108141
CCDC 2096621: Experimental Crystal Structure Determination
Related Article: Hui Shen, Zhen Xu, Lingzheng Wang, Ying-Zi Han, Xianhu Liu, Sami Malola, Boon K. Teo, Hannu Häkkinen, Nanfeng Zheng|2021|Angew.Chem.,Int.Ed.|60|22411|doi:10.1002/anie.202108141
CCDC 1916156: Experimental Crystal Structure Determination
Related Article: Hui Shen, Guocheng Deng, Sami Kaappa, Tongde Tan, Ying-Zi Han, Sami Malola, Shui-Chao Lin, Boon K. Teo, Hannu Häkkinen, Nanfeng Zheng|2019|Angew.Chem.,Int.Ed.|58|17731|doi:10.1002/anie.201908983