43067-26-1Relevant academic research and scientific papers
Synthetically Versatile Nitrogen Acyclic Carbene Stabilized Gold Nanoparticles
Chin, Jia Min,Keppler, Bernhard K.,Rúbio, Guilherme M. D. M.,Reithofer, Michael R.
, p. 15859 - 15862 (2020)
N-heterocyclic carbenes (NHCs) have received significant attention as gold nanoparticle stabilizers due to their strong binding affinity towards gold. However, their tunability is limited by the difficulty in obtaining nonsymmetric NHCs. In this regard, N-acyclic carbenes (NACs) are attractive alternatives due to their high synthetic versatility, allowing easy tuning of their steric and electronic properties towards specific applications. This work reports the first series of stable and monodisperse NAC-functionalized gold nanoparticles. These particles with sizes ranging 3.8 to 11.6 nm were characterized using NMR, UV/Vis and TEM. The nanoparticles display good stability at elevated temperatures and for extended periods both dried or dispersed in a medium, as well as in the presence of exogenous thiols. Importantly, these NAC-stabilized gold nanoparticles offer a promising and versatile alternative to NHC-stabilized gold nanoparticles.
Photophysics and bonding in neutral gold(I) organometallic complexes with an extended aurophilic supramolecular structure
Elbjeirami, Oussama,Yockel, Scott,Campana, Charles F.,Wilson, Angela K.,Omary, Mohammad A.
, p. 2550 - 2560 (2007)
This work represents a synergistic experimental/computational study of the molecular spectroscopy and bonding in Au(CO)Cl in solution and the solid state. The luminescence behavior for crystalline solids is similar for Au(CO)Cl and related (RNC)AuCl complexes that likewise stack in infinite chains, and both exhibit orange-red unstructured phosphorescence bands with extremely large Stokes shifts ((15-20) × 103 cm-1). The long aurophilic distances computed for the ground state (～3.2 A) are contracted in the phosphorescent excited state (～2.6 A), demonstrating excimeric Au-Au covalent bonds. The spectral data suggest phosphorescent species in which the excimeric Au-Au bonding is extended beyond two adjacent molecules in the solid state. Controlling the concentration in frozen solutions attains phosphorescent bands due to dimeric species for which the emission energies are higher (in the blue region) than those for crystalline solids and are reproduced by ab initio calculations. The spectral findings herein suggest that predictive information about the supramolecular structure may be obtained by the luminescnce behavior. This is exemplified by crystals of (1,1,3,3-Me 4BuNC)AuCl, whose red-orange luminsecence anticipated an extended-chain supramolecular structure, which was later verified crystallographically, as the molecules were found to pack in zigzag chains with alternating short (3.418 A) and long (4.433 A) aurophilic distances. Solutions of Au(CO)Cl exhibit negative deviation from Beer's law for, higher-energy monomer bands with the appearance of lower-energy bands at high concentrations due to the dimerization of molecules. Time-dependent density-functional theory (TD-DFT) calculations for monomer and dimer models show good agreement with the experimental spectra and account for the major absorption bands. Ab initio calculations (CCSD(T)/cc-pVTZ) show a blue shift of ～23 cm-1 in the vc=o frequency upon complexation, thus providing the first computational evidence of this anomalous blue shift known experimentally for Au(CO)Cl.
Synthesis of Bioactive N-Acyclic Gold(I) and Gold(III) Diamino Carbenes with Different Ancillary Ligands
Montanel-Pérez, Sara,Elizalde, Raquel,Laguna, Antonio,Villacampa, M. Dolores,Gimeno, M. Concepción
, p. 4273 - 4281 (2019/08/07)
A series of gold(I) and gold(III) N-acyclic diamino carbene (ADC) complexes with different ancillary ligands have been synthesized. The chloride carbene derivatives [Au{C(NHR)(NHCH2py)}Cl] (R = Cy, R = naphthyl, R = xylyl) have been obtained by reaction of 2-picolylamine with the corresponding [AuCl(CNR)]. The gold(I) thiolate derivatives [Au{C(NHR)(NHCH2py)}(Spy)] were prepared by reaction of the chlorido complexes with 2-mercaptopyridine (2-HSpy) in presence of potassium carbonate. The phosphane derivative [Au(pyCH2NH2)(PPh3)](OTf) was obtained by reaction of freshly prepared [Au(OTf)(PPh3)] with 2-picolylamine. The phosphane-carbene complexes [Au{C(NHR)(NHCH2py}(PPh3)](OTf) were obtained from the reaction of picolylamino species with the isocyanide. The gold(III) derivative cis-[Au(C6F5)2(pyCH2NH2)](ClO4) was obtained by the reaction of 2-picolylamine with freshly [Au(C6F5)2(Et2O)2](ClO4). The reaction of the former with CNCy led to complex cis-[Au(C6F5)2{C(NHCy)(NHCH2py)}]ClO4 by a nucleophilic attack of the isocyanide to the amine ligand, thus producing a bidentate C,N acyclic carbene ligand. Cytotoxic studies against the tumor human cell lines Jurkat (T-cell leukaemia), MiaPaca2 (pancreatic carcinoma), A549 (lung carcinoma) and MDA-MB-231 (breast carcinoma) showed moderate to good cytotoxic activity for some of the complexes.
Addition of: N -nucleophiles to gold(III)-bound isocyanides leading to short-lived gold(III) acyclic diaminocarbene complexes
Anisimova, Tatyana B.,Kinzhalov, Mikhail A.,Guedes Da Silva, M. Fátima C.,Novikov, Alexander S.,Kukushkin, Vadim Yu.,Pombeiro, Armando J. L.,Luzyanin, Konstantin V.
supporting information, p. 3246 - 3250 (2017/07/12)
Reaction of [AuCl3(CNR1)] (R1 = Xyl, Cy, (S)-CHMePh) with amines unexpectedly proceeds via the redox pathway giving gold(i)-isocyanides and imines, while the addition of benzophenone hydrazone to the isocyanide ligand in [
Room-Temperature Hydration of Alkynes Catalyzed by Different Carbene Gold Complexes and their Precursors
Xu, Yun,Hu, Xingbang,Zhang, Shufeng,Xi, Xiuxing,Wu, Youting
, p. 262 - 267 (2016/01/26)
The room-temperature hydration of alkynes catalyzed by NHC-gold(I) (NHC=N-heterocyclic carbene), NAC-gold(I) (NAC=nitrogen acyclic carbene), and isocyanide gold(I) complexes was investigated carefully in the presence of different weakly coordinating anion
Hydration of alkynes at room temperature catalyzed by gold(I) isocyanide compounds
Xu, Yun,Hu, Xingbang,Shao, Jing,Yang, Guoqiang,Wu, Youting,Zhang, Zhibing
supporting information, p. 532 - 537 (2018/04/16)
An effective method using gold(I) isocyanide complexes as catalysts for the transformation of various alkynes to the corresponding ketones is successfully developed. The hydration process proceeds smoothly at room temperature with quite high yield (up to 99%). The catalytic center is the isocyanide-Au(I)+ cation. Further theoretical research reveals a direct hydration mechanism by H2O, and the rate-determining step has an energy barrier of 23.7 kcal mol?1. These results show a good example to reduce unnecessary steps and achieve milder reaction conditions at the same time for the hydration of alkynes.
Efficient one-pot synthesis of unsymmetrical gold(I) N-heterocyclic carbene complexes and their use as catalysts
Hashmi, A. Stephen K.,Yu, Yang,Rominger, Frank
, p. 895 - 904 (2012/04/04)
Eleven different gold(I) complexes of new NHC ligands were prepared in excellent yield, demonstrating the versatility of the new route to NHC complexes. While the influence of electronically different ligands on the synthesis of the catalysts was small, the catalytic activities of the products differed significantly.
Gold(I)-isocyanide and gold(I)-carbene complexes as substrates for the laser decoration of gold onto ceramic surfaces
Heathcote, Robert,Howell, James A. S.,Jennings, Nicola,Cartlidge, David,Cobden, Lisa,Coles, Simon,Hursthouse, Michael
, p. 1309 - 1315 (2007/10/03)
Gold-isocyanide complexes XAu(RNC) (X = halide, pseudohalide, R = alkyl, aryl) and water soluble gold-carbene complexes XAuC(NHPh)[MeN(CH 2CH2O)nMe] (X = Cl, n = 1-11) have been prepared and evaluated as substrates for the direct laser writing of gold decoration onto ceramics. The Royal Society of Chemistry 2007.
Orange Luminescence and Structural Properties of Three Isostructural Halocyclohexylisonitrilegold(I) Complexes
White-Morris, Rochelle L.,Olmstead, Marilyn M.,Balch, Alan L.,Elbjeirami,Omary, Mohammad A.
, p. 6741 - 6748 (2008/10/08)
The preparation of three isonitrile complexes (CyNC)AuICl, (CyNC)AuIBr and (CyNC)AuIl, along with their structural and spectral characterization, are reported. X-ray crystal structures reveal that these crystallize in the same space group and have closely related structures. The structures involve pleated chains of linear, two-coordinate monomers that are arranged in a head-tail fashion. However, these chains vary significantly in the degree of aurophilic interactions among the individual molecules. Thus, (CyNC)AuICl forms infinite chains with alternating Au...Au distances of 3.3894(7) and 3.5816(7) A. Within the chains of (CyNC)AuIBr, however, the alternation of Au...Au distances is more pronounced so that there are dimers, with an Au...Au distance of 3.4864(9) A, and neighboring gold centers at 3.7036(9) A. In (CyNC)Au Il, the gold-gold contacts do not lie within the range of significant aurophilic bonding. The closest Au...Au distance is 3.7182(11) A while every other Au...Au distance is 3.9304(12) A. The steric factor of the X ligand and dipole-dipole interactions between the antiparallel complexes is much more significant than aurophilic interactions in governing the self-association of the complexes in this series. The colorless crystals of each solid display an orange luminescence band with a strikingly large Stokes' shift (～21 000 cm-1, 2.6 eV). However, considerable care had to be taken to ensure that the crystals used for the study of the luminescence were free of a surface impurity that produced a turquoise-green luminescence in (CyNC)AuICl. The diffuse reflectance spectra for the solids show a similar three-band pattern in the 200-330 nm range.
The effect of hard and soft donors on structural motifs in (isocyanide)gold(I) complexes
Wilton-Ely, James D. E. T.,Ehlich, Hendrik,Schier, Annette,Schmidbaur, Hubert
, p. 3216 - 3232 (2007/10/03)
Treatment of the (isocyanide)gold(I) species LAuCl (L =′BuNC, 2,6-Me2C6H3NC) with 4-mercaptobenzoic acid in the presence of NaOMe yields the complexes [Au(4-SC6H4CO2H)L] in good yield. Reaction of LAuCl with 2-HSQn (Qn = quinoline) and 2-HSPy (Py = pyridine) under the same conditions provides the thiolato compounds [Au(2-SQn)L] and [Au(2-SPy)L], respectively. A structural investigation of the pyridylthiolato compound revealed chains of molecules with alternating medium and long Au-Au interactions. Treatment of this compound with HBF4 results in the cationic species [Au(2-HSPy)(2,6-Me2C6H3NC)]+ as the BF4- salt. The same product is obtained on reaction of [AuCl(2,6-Me2C6H3NC)] with AgOTf followed by HSPy. Treatment of the gold(I) halide compounds LAuCl (L =′BuNC, 2,6-Me2C6H3NC) with potassium 1,3,4-thiadiazole-2,5-dithiolate (KSSSK) leads to the isolation of dinuclear thiolatogold complexes [(AuL)2(SSS)]. These products go on to form insoluble polymers through loss of isocyanide on standing in solution. A single crystal of [{Au(′BuNC)}2(SSS)] was obtained and the subsequent structural analysis revealed one of the most complicated networks known based solely on aurophilic interactions. A good comparison to the 'soft' S-donation of the thiolato ligands was provided by the synthesis of a number of nitratogold(I)complexes with the anion bound through the 'hard' O-donor. Reaction of iPrNC and CyNC with Au(tht)Cl provided the complexes [AuCl(iPrNC)] and [AuCl(CyNC)], respectively. These compounds were found to yield the respective nitrato species [Au(NO3)iPrNC)] and [(Au(NO3)(CyNC)] on treatment with AgNO3. The nitrato complexes yielded single crystals enabling a structural investigation to be carried out. While [Au(NO3)(CyNC)] has a more conventional structure with dimers aligned into strings with alternating short and long aurophilic bonding, [Au(NO3)(iPrNC)] has a unique structure based on strings of alternating, corner-sharing Au6 and Au8 units with short Au-Au contacts in edge-sharing Au3 triangles.
