Dynamic measurements of aqueous lanthanide triflate-catalyzed reactions using luminescence decay.
نویسندگان
چکیده
There is tremendous interest in water-compatible lanthanide triflate-based catalysts for carbon-carbon bond forming reactions; however, poor understanding of their aqueous mechanism severely limits the ability to increase the utility of these catalysts. Here, we report dynamic measurements of the water-coordination number of lanthanide triflate-based catalysts using luminescence-decay measurements in a range of aqueous systems. This unique characterization method is a reliable, convenient, and fast approach to analyze lanthanide-based catalysts in aqueous systems.
منابع مشابه
A new class of ligands for aqueous, lanthanide-catalyzed, enantioselective Mukaiyama aldol reactions.
The development of aqueous methods for generating enantiopure β-hydroxy carbonyl compounds is an important goal because these subunits compose many bioactive compounds and the ability to synthesize these groups in water has environmental and cost benefits. In this communication, we report a new class of ligands for aqueous, lanthanide-catalyzed, asymmetric Mukaiyama aldol reactions for the synt...
متن کاملThe role of water in lanthanide-catalyzed carbon-carbon bond formation.
Luminescence-decay measurements in combination with high-performance liquid chromatography analyses were used to study the relationship between rates of catalysis and water-coordination numbers of europium-based precatalysts in the aqueous Mukaiyama aldol reaction. A correlation between reactivity and water-coordination number was observed and is reported here.
متن کاملSpeciation of Eu(III) hydroxo complexes in aqueous DMSO studied by direct excitation luminescence spectroscopy and their catalytic activity in phosphodiester cleavage.
Data from potentiometric titrations of Eu(CF(3)SO(3))(3) by Me(4)NOH in 80% v/v DMSO/water agree equally well with formation of two sets of hydroxo complexes: either Eu(2)OH(5+) and Eu(OH)(n)(3-n) (n = 1-3) or Eu(2)OH(5+), Eu(2)(OH)(2)(4+), Eu(2)(OH)(5)(+) and Eu(OH)(3). Studies using direct excitation luminescence spectroscopy and time-resolved decay measurements of Eu(III) solutions containin...
متن کاملLanthanide-based time-resolved luminescence immunoassays
The sensitive and specific detection of analytes such as proteins in biological samples is critical for a variety of applications, for example disease diagnosis. In immunoassays a signal in response to the concentration of analyte present is generated by use of antibodies labeled with radioisotopes, luminophores, or enzymes. All immunoassays suffer to some extent from the problem of the backgro...
متن کاملProbing the Influence of Disorder on Lanthanide Luminescence Using Eu-Doped LaPO4 Nanoparticles
Lanthanide-doped nanocrystals (NCs) differ from their bulk counterparts due to their large surface to volume ratio. It is generally assumed that the optical properties are not affected by size effects as electronic transitions occur within the well-shielded 4f shell of the lanthanide dopant ions. However, defects and disorder in the surface layer can affect the luminescence properties. Trivalen...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of the American Chemical Society
دوره 131 18 شماره
صفحات -
تاریخ انتشار 2009