29892-37-3Relevant academic research and scientific papers
Novel gold(I)- and gold(III)-N-heterocyclic carbene complexes: Synthesis and evaluation of their anticancer properties
Rana, Bidyut Kumar,Nandy, Abhishek,Bertolasi, Valerio,Bielawski, Christopher W.,Das Saha, Krishna,Dinda, Joydev
, p. 2544 - 2548 (2014)
A novel Au(III)-N-heterocyclic carbene organometallic complex supported by two N-heterocyclic carbene (NHC) ligands was synthesized from Au(SMe 2)Cl and 1-methyl-2-pyridin-2-yl-2H-imidazo[1,5-a]pyridin-4-ylium hexafluorophosphate via a Ag intermediate. X-ray crystallography revealed the first example of a square planar geometry adopted by a Au(III) species stabilized by two NHCs and two chloride ligands. The aforementioned Au(I)- and Au(III)-NHC complexes were found to be more potent than cisplatin against the HCT 116, HepG2, A549, and MCF7 cell lines.
DISSOLUTION OF METALLIC GOLD IN DMSO-RX SYSTEMS. THE CONCEPT OF A DONOR-ACCEPTOR ELECTRON TRANSFER SYSTEM
Nifontova, G. A.,Lavrent'ev, I. P.
, p. 391 - 397 (1992)
The complexing of gold during dissolution of gold powder in donor-acceptor organic and aqueous-organic Au0-DMSO-RX systems (where R = H or Bu, and X = Cl or Br) was studied.Ten complexes were produced, and their compositions and IR spectra in the 4000-200 cm-1 range were determined.The data obtained were interpreted in terms of the concept of donor-acceptor electron transfer systems. Keywords: metal, gold, dissolution, organic media, DMSO, RX, gold complexes, production, donor-acceptor electron tranfer (DAET) systems, concept.
Synthesis, Characterization, and in vitro Cytotoxicity of Gold(I) Complexes of 2-(Diphenylphosphanyl)ethylamine and Dithiocarbamates
Sulaiman, Adam A. A.,Altaf, Muhammad,Isab, Anvarhusein A.,Alawad, Abdullah,Altuwaijri, Saleh,Ahmad, Saeed
, p. 1454 - 1459 (2016)
Gold(I) complexes of 2-(diphenylphosphanyl)ethylamine or (2-aminoethyl)diphenylphosphine (AEP), and dithiocaarbamates (R2NCS2) were prepared by the reaction of these ligands with (CH3)2S-AuCl in dichloromethane.
A synchronous nucleation and passivation strategy for controllable synthesis of Au36(PA)24: unveiling the formation process and the role of Au22(PA)18 intermediate
Ma, Xiaoshuang,Ma, Guanyu,Qin, Lubing,Chen, Guangxu,Chen, Shaowei,Tang, Zhenghua
, p. 1777 - 1784 (2020)
Despite the recent progress on controllable synthesis of alkynyl-protected Au nanoclusters, the effective synthetic means are very limited and the cluster formation process still remains puzzling. Here, we develop a novel synchronous nucleation and passivation strategy to fabricate Au36(PA)24 (PA=phenylacetylenyl) nanoclusters with high yield. In Au36(PA)24 formation process, Au22(PA)18 as key intermediate was identified. Meanwhile, Au22(PA)18 can be synthesized under a low amount of reductant, and by employing more reductants, Au22(PA)18 can turn into Au36(PA)24 eventually. Moreover, the structure evolution from Au22(PA)18 to Au36(PA)24 is proposed, where four Au13 cuboctahedra can yield one Au28 kernel. Finally, the ratiocination is verified by the good accordance between the predicted intermediate/product ratio and the experimental value. This study not only offers a novel synthetic strategy, but also sheds light on understanding the structural evolution process of alkynyl-protected Au nanoclusters at atomic level.
Electropolymerization of Metal Clusters Establishing a Versatile Platform for Enhanced Catalysis Performance
Cai, Jinmeng,Gong, Chun-Hua,Han, Zhen,Li, Si,Li, Yao,Mak, Thomas C. W.,Wang, Qian-You,Wang, Shan,Wang, Yi-Man,Zang, Shuang-Quan
supporting information, (2022/01/20)
Atomically precise metal clusters are attractive as highly efficient catalysts, but suffer from continuous efficiency deactivation in the catalytic process. Here, we report the development of an efficient strategy that enhances catalytic performance by electropolymerization (EP) of metal clusters into hybrid materials. Based on carbazole ligand protection, three polymerized metal-cluster hybrid materials, namely Poly-Cu14cba, Poly-Cu6Au6cbz and Poly-Cu6Ag4cbz, were prepared. Compared with isolated metal clusters, metal clusters immobilizing on a biscarbazole network after EP significantly improved their electron-transfer ability and long-term recyclability, resulting in higher catalytic performance. As a proof-of-concept, Poly-Cu14cba was evaluated as an electrocatalyst for reducing nitrate (NO3?) to ammonia (NH3), which exhibited ≈4-fold NH3 yield rate and ≈2-fold Faraday efficiency enhancement compared to that of Cu14cba with good durability. Similarly, Poly-Cu6Au6cbz showed 10 times higher photocatalytic efficiency towards chemical warfare simulants degradation than the cluster counterpart.
Synthesis of L-Au(I)-CF2H Complexes and Their Application as Transmetalation Shuttles to the Difluoromethylation of Aryl Iodides
García-Domínguez, Patricia
supporting information, p. 2923 - 2928 (2021/09/07)
We describe herein two alternative protocols to efficiently prepare difluoromethylgold(I) complexes bearing ancillary ligands with different electronic and steric properties. LAu-OX (X = H andt-Bu) species, formed in the presence of base, have been identified as intermediate complexes involved in these transformations. The application of these compounds as “CF2H transmetalation shuttles” from gold to palladium has been demonstrated in a Pd-catalyzed difluoromethylation reaction of aryl iodides, in which the Au-to-Pd transfer of “CF2H” is feasible under stoichiometric conditions. These findings will pave the way for catalytic manifolds in gold chemistry.
Metal cage coordination compound and preparation method thereof, and catalyst
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Paragraph 0080; 0082; 0084, (2019/11/04)
The invention relates to a metal cage coordination compound and a preparation method thereof, and a catalyst. The metal cage coordination compound of the invention is prepared by assembling gold trichloride and a triphenylphosphine cage ligand composed of dynamic imine via a coordination bond; and the triphenylphosphine cage ligand contains a plurality of imine bonds and is thus soluble in many common organic solvents (such as dichloromethane) and not soluble in methanol or n-hexane. The above metal cage coordination compound is used as a catalyst for participation in an organic reaction, andcan function as a homogeneous catalyst during a reaction; and after the reaction, the metal cage coordination compound can be precipitated by adding methanol or n-hexane and then recycled through recovery via filtration or other manners, so production cost is lowered.
Balancing Bulkiness in Gold(I) Phosphino-triazole Catalysis
Zhao, Yiming,Wakeling, Matthew G.,Meloni, Fernanda,Sum, Tze Jing,van Nguyen, Huy,Buckley, Benjamin R.,Davies, Paul W.,Fossey, John S.
supporting information, p. 5540 - 5548 (2019/08/07)
The syntheses of a series of 1-phenyl-5-phosphino 1,2,3-triazoles are disclosed, within which, the phosphorus atom (at the 5-position of a triazole) is appended by one, two or three triazole motifs, and the valency of the phosphorus(III) atom is completed by two, one or zero ancillary (phenyl or cyclohexyl) groups respectively. This series of phosphines was compared with tricyclohexylphosphine and triphenylphosphine to study the effect of increasing the number of triazoles appended to the central phosphorus atom from zero to three triazoles. Gold(I) chloride complexes of the synthesised ligands were prepared and analysed by techniques including single-crystal X-ray diffraction structure determination. Gold(I) complexes were also prepared from 1-(2,6-dimethoxy)-phenyl-5-dicyclohexyl-phosphino 1,2,3-triazole and 1-(2,6-dimethoxy)-phenyl-5-diphenyl-phosphino 1,2,3-triazole ligands. The crystal structures thus obtained were examined using the SambVca (2.0) web tool and percentage buried volumes determined. The effectiveness of these gold(I) chloride complexes to serve as precatalysts for alkyne hydration were assessed. Furthermore, the regioselectivity of hydration of but-1-yne-1,4-diyldibenzene was probed.
Mechanism of Photoredox-Initiated C-C and C-N Bond Formation by Arylation of IPrAu(I)-CF3 and IPrAu(I)-Succinimide
Kim, Suhong,Toste, F. Dean
supporting information, p. 4308 - 4315 (2019/01/25)
Herein, we report on the photoredox-initiated gold-mediated C(sp2)-CF3 and C(sp2)-N coupling reactions. By adopting gold as a platform for probing metallaphotoredox catalysis, we demonstrate that cationic gold(III) complexes are the key intermediates of the C-C and C-N coupling reactions. The high-valent gold(III) intermediates are accessed by virtue of photoredox catalysis through a radical chain process. In addition, the bond-forming step of the coupling reactions is the reductive elimination from cationic gold(III) intermediates, which is supported by isolation and crystallographic characterization of key Au(III) intermediates.
Diastereoselective synthesis, structure and reactivity studies of ferrocenyloxazoline gold(i) and gold(II) complexes
Holz, Julia,Ayerbe García, Marta,Frey, Wolfgang,Krupp, Felix,Peters, René
, p. 3880 - 3905 (2018/03/21)
In the last few decades, gold complexes have demonstrated huge potential for soft Lewis acid catalysis. Despite the intensive research on Au complexes and planar chiral metallacycles, enantiopure ferrocenylgold complexes have-surprisingly-not been reported until the studies presented in this article. Herein, we report the asymmetric synthesis of planar chiral ferrocenyl Au(i) complexes. These dinuclear species form helically chiral ten-membered (NCCCAu)2 rings stabilized by aurophilic interactions. In supramolecular solid state structures, linear, zigzag or helical Au(i) wires with regular Au?Au separations were observed. The dissolved dinuclear entities could be oxidized by Au(i) to unique ferrocenyl Au(ii) complexes featuring short Au(ii)-Au(ii) bonds, while the ferrocene core remained intact. However, our initial studies revealed the issue of configurational lability of the ferrocenyl Au(ii) complexes in terms of the element of planar chirality in the presence of the gold source, (Me2S)AuCl. This was successfully addressed by a systematic study implementing permanent σ-donor ortho-protecting groups such as methyl and trimethylsilyl, which impede an epimerization event. Oxidation of the dinuclear Au(i) complexes was also accomplished by oxidative addition reactions with halogenated solvents, preferably CHCl3. Additional reactivity studies revealed that dinuclear Au(ii) dihalide complexes are also formed with reactive alkylhalides such as iodomethane, benzylbromide and benzyliodide. Interestingly, the whole spectral range of colors (violet, blue, green, yellow, and red) is covered by the title complexes depending on the Au oxidation state and the anionic ligands in the Au(ii) complexes. This appears to be quite unusual for ferrocenes, which typically adopt orange to red colors in a non-oxidized state.
