27746-08-3Relevant academic research and scientific papers
Towards Sustainable Catalysis – Highly Efficient Olefin Metathesis in Protic Media Using Phase Labelled Cyclic Alkyl Amino Carbene (CAAC) Ruthenium Catalysts
Nagyházi, Márton,Turczel, Gábor,Balla, áron,Szálas, Gábor,Tóth, Imre,Gál, Gyula Tamás,Petra, Bombicz,Anastas, Paul T.,Tuba, Róbert
, p. 1953 - 1957 (2020/02/15)
New generations of Hoveyda and bis-carbene type of ruthenium-based olefin metathesis catalysts (10 and 12), containing cationic cyclic alkyl amino carbene (CAAC) ligands, have been synthetized. The catalysts show exceptional stability and activity in environmentally benign, protic media. Various olefin metatheses reactions of OH functionalized feedstock (e. g. RCM, ROMP CM) can be carried out at as low as 0.05 mol % catalyst loading in methanol, isopropanol, water or methanol/water solvent mixture, accomplishing the lowest applied catalyst loading reported so far in these media. The facile olefin metathesis of renewable feedstocks including phospholipids (23) and vegetable oils (20) in protic media has also been demonstrated.
Synthesis, photophysical properties, and molecular aggregation of gold(I) complexes containing carbon-donor ligands
Chow, Andy Lok-Fung,So, Man-Ho,Lu, Wei,Zhu, Nianyong,Che, Chi-Ming
, p. 544 - 553 (2011/10/12)
A series of gold(I) complexes with N-heterocyclic carbene (NHC) and acetylide ligands, namely [Au(NHC1)(C≡CAr)] (NHC 1=1-(9-anthracenylmethyl)-3-(n)-butylimidazol-2-ylidene; 1b-1g), [Au(NHC2)(C≡CAr)] (NHC2=1,3-diethylimidazol-2- ylidene; 2b-2f) and [Au(C≡NAr)2]+ (C≡NAr=arylisocyanide; 3a-3f) have been synthesized. At room temperature, most of these gold(I) complexes are emissive in the solid state and in solutions with lifetimes in the nanosecond to submicrosecond regime. The emissions of complexes 1b-1g in solutions are assigned to 1π-π* excited states of the NHC ligand, while that of 2b-2f and 3a-3f are phosphorescent in nature. The intriguing solvatochromism of complex 3a was also investigated. Complexes 1b, 1d, 3a, and 3e aggregate into crystalline nanowires in freshly prepared THF/water dispersions. The X-ray crystallographic data reveal that 1b and 1d possess intermolecular π-π and C-H ... π interactions; while 3a was found to display intermolecular gold(I) ... π interactions. Copyright
Olefin metathesis catalysts bearing a pH-responsive NHC ligand: A feasible approach to catalyst separation from RCM products
Balof, Shawna L.,P'Pool, Steven J.,Berger, Nancy J.,Valente, Edward J.,Shiller, Alan M.,Schanz, Hans-Joerg
experimental part, p. 5791 - 5799 (2009/02/07)
Two novel ruthenium-based olefin metathesis catalysts, H 2ITap(PCy3)Cl2Ru=CH-Ph 12 and H 2ITapCl2Ru=CH-(C6H4-O-iPr) 13 (H2ITap = 1,3-bis(2′,6′-dimethyl-4′- dimethylami
Substituent effects on aromatic stacking interactions
Cockroft, Scott L.,Perkins, Julie,Zonta, Cristiano,Adams, Harry,Spey, Sharon E.,Low, Caroline M. R.,Vinter, Jeremy G.,Lawson, Kevin R.,Urch, Christopher J.,Hunter, Christopher A.
, p. 1062 - 1080 (2007/12/27)
Synthetic supramolecular zipper complexes have been used to quantify substituent effects on the free energies of aromatic stacking interactions. The conformational properties of the complexes have been characterised using NMR spectroscopy in CDCl3, and by comparison with the solid state structures of model compounds. The structural similarity of the complexes makes it possible to apply the double mutant cycle method to evaluate the magnitudes of 24 different aromatic stacking interactions. The major trends in the interaction energy can be rationalised using a simple model based on electrostatic interactions between the π-faces of the two aromatic rings. However, electrostatic interactions between the substituents of one ring and the π-face of the other make an additional contribution, due to the slight offset in the stacking geometry. This property makes aromatic stacking interactions particularly sensitive to changes in orientation as well as the nature and location of substituents. This journal is The Royal Society of Chemistry.
