Solving the total structures of gold nanoclusters is of critical importance for understanding their electronic, optical and catalytic properties. Herein, we report the X-ray structure of a charge-neutral Au24(SCH2Ph-(t)Bu)20 nanocluster. This structure features a bi-tetrahedral Au8 kernel protected by four tetrameric staple-like motifs. Electronic structure analysis is further carried out and the optical absorption spectrum is interpreted. The Au24(SCH2Ph-(t)Bu)20, Au23(S-c-C6H11)16 and Au25(SCH2CH2Ph)18 nanoclusters constitute the first crystallographically characterized "trio".

Thiolato-protected gold nanoclusters have acquired wide applications; however, on the fundamental science end there is still a lack of deep understanding of their high stability. Recent success in transforming the highly robust biicosahedral Au38(SCH2CH2Ph)24 nanocluster into an extremely stable tetrahedral Au36(SPh-(t)Bu)24 nanocluster raises an important question: Is the transformation due to the bulkiness effect of SPh-(t)Bu or the electronic conjugation effect of the aromatic ligand as opposed to the nonaromatic SCH2CH2Ph? Toward this goal, we report our success in the crystallization of a nonaromatic thiolato-protected Au36(SC5H9)24 nanocluster (where, SC5H9 = cyclopentanethiolato). Comparison of Au36(SC5H9)24 with the aromatic thiolato-protected Au36(SPh-(t)Bu)24 nanocluster rules out the thought that the face-centered cubic, tetrahedral structure of Au36(SPh-(t)Bu)24 is dictated by the aromatic ligand; it also reveals that the electronic conjugation effect in aromatic ligand makes the S-C bond shorter and stronger, and this affects the S-Au bonds, resulting in a larger separation between the staple motifs and the inner Au28 kernel. Overall, this work sheds some light on the major question of the specific roles of thiol ligand in determining the cluster size and structure.

No abstract

No abstract

This letter focuses on the first result of the preparation and the swelling behavior of a novel hybrid gelatin hydrogel with carbon nanotubes. A novel hybrid gelatin hydrogel with carbon nanotubes was synthesized by a physical mixing method. The structure of the novel hydrogel obtained was characterized by SEM. Besides, the swelling behavior of the synthesized hydrogel was measured at two different temperatures. The results indicate that carbon nanotubes added could maintain the stability of the hybrid hydrogel without cross‐linking at 37 °C. This suggests that the hybrid gelatin hydrogel with carbon nanotubes could be used in biomedical field. Besides, its application in protein separation is discussed.SEM image of the gelatin‐MWNTs hybrid gel at 10 000 × magnification.magnified imageSEM image of the gelatin‐MWNTs hybrid gel at 10 000 × magnification.

ERRATUMThe online version of the original article can be found at http://dx

No abstract

No abstract