The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Laura Turculet - One of the best experts on this subject based on the ideXlab platform.
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selective ni catalyzed hydroboration of co2 to the Formaldehyde Level enabled by new psip ligation
Organometallics, 2017Co-Authors: Luke J Murphy, Helia Hollenhorst, Robert Mcdonald, Michael J Ferguson, Michael D Lumsden, Laura TurculetAbstract:The synthesis and characterization of group 10 metal pincer complexes supported by a new bis(indolylphosphino)silyl ligand are described, including the synthesis of Ni, Pd, and Pt hydride species. Solution NMR and single-crystal X-ray data revealed that a significant amount of structural variability is possible for such hydride complexes, particularly in the case of Ni, where terminal Ni-H as well as complexes involving η2-SiH coordination are both accessible and may even coexist, in ratios dependent on factors such as the nature of additional coligands, including N2 from the reaction atmosphere, as well as solvent and temperature. Nickel and palladium hydride complexes of this new ligand were found to exhibit divergent selectivity in the catalytic hydroboration of CO2 with pinacolborane (HBPin). While the Pd catalyst exhibited moderate activity for CO2 hydroboration to the formate Level, the analogous Ni species exhibited unprecedented selectivity (97%) for hydroboration of CO2 to the Formaldehyde Level ...
López-serrano Joaquín - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic Studies on the Selective Reduction of CO2 to the Aldehyde Level by a PBP-Supported Nickel Complex
'American Chemical Society (ACS)', 2016Co-Authors: Rios Pablo, Rodríguez Amor, López-serrano JoaquínAbstract:This work describes a thorough investigation of the mechanism of a highly selective hydrosilylation of CO2 to the Formaldehyde Level catalyzed by a bis(phosphino)boryl (PBP)Ni(II) complex in the presence of B(C6F5)3. CO2 activation by insertion into the Ni–H bond of the catalyst precursor 2 is shown to occur very easily, because of the trans influence exerted by the boryl ligand. During catalysis, the limiting step is B(C6F5)3 dissociation from the active species (PBP)Ni–OCHO·B(C5F6)3 (4), which controls the amount of free borane that can lead to over-reduction to methane. Free borane activates the silane by formation of [R3Si–H···B(C6F5)3], which can then transfer the silylium (R3Si+) fragment to the oxygen atoms of the Ni formate and Ni acetal intermediates. The ion pair [(PBP)Ni][HB(C6F5)3] (5) is the key species that activates CO2 in the catalytic cycle (and silylformate in a second step) with [HB(C6F5)3]− as the source of hydride. Hydride transfer to [(PBP)Ni–OCO]+ is virtually barrierless, whereas hydride transfer to [(PBP)Ni–OCHOSiR3]+ has the second-highest energy barrier of the process (25.2 kcal mol–1). Therefore, the (PBP)Ni framework is instrumental in both reduction steps of the catalysis and controls the selectivity of the reaction by sequestering B(C6F5)3Peer reviewe
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Mechanistic Studies on the Selective Reduction of CO2 to the Aldehyde Level by a PBP-Supported Nickel Complex
'American Chemical Society (ACS)', 2016Co-Authors: Rios Pablo, Rodríguez Amor, López-serrano JoaquínAbstract:This work describes a thorough investigation of the mechanism of a highly selective hydrosilylation of CO2 to the Formaldehyde Level catalyzed by a bis(phosphino)boryl (PBP)Ni(II) complex in the presence of B(C6F5)3. CO2 activation by insertion into the Ni–H bond of the catalyst precursor 2 is shown to occur very easily, because of the trans influence exerted by the boryl ligand. During catalysis, the limiting step is B(C6F5)3 dissociation from the active species (PBP)Ni–OCHO·B(C5F6)3 (4), which controls the amount of free borane that can lead to over-reduction to methane. Free borane activates the silane by formation of [R3Si–H···B(C6F5)3], which can then transfer the silylium (R3Si+) fragment to the oxygen atoms of the Ni formate and Ni acetal intermediates. The ion pair [(PBP)Ni][HB(C6F5)3] (5) is the key species that activates CO2 in the catalytic cycle (and silylformate in a second step) with [HB(C6F5)3]− as the source of hydride. Hydride transfer to [(PBP)Ni–OCO]+ is virtually barrierless, whereas hydride transfer to [(PBP)Ni–OCHOSiR3]+ has the second-highest energy barrier of the process (25.2 kcal mol–1). Therefore, the (PBP)Ni framework is instrumental in both reduction steps of the catalysis and controls the selectivity of the reaction by sequestering B(C6F5)3Ministerio de Economía, Industria y Competitividad CTQ2013-45011-P and CTQ2014-51912-REDCJunta de Andalucía FQM-212
You Wan - One of the best experts on this subject based on the ideXlab platform.
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urine Formaldehyde Level is inversely correlated to mini mental state examination scores in senile dementia
Neurobiology of Aging, 2011Co-Authors: Zhiqian Tong, Jinling Zhang, Wenhong Luo, Weishan Wang, Hongjun Luo, Jiangning Zhou, You WanAbstract:It is widely known that exogenous Formaldehyde exposure induces human cognitive impairment and animal memory loss; and recent studies show that Formaldehyde at pathological Levels induces A beta deposition and misfolding of tau protein to form globular amyloid-like aggregates. Endogenous Formaldehyde may be a marker for progressive senile dementia.
Luke J Murphy - One of the best experts on this subject based on the ideXlab platform.
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selective ni catalyzed hydroboration of co2 to the Formaldehyde Level enabled by new psip ligation
Organometallics, 2017Co-Authors: Luke J Murphy, Helia Hollenhorst, Robert Mcdonald, Michael J Ferguson, Michael D Lumsden, Laura TurculetAbstract:The synthesis and characterization of group 10 metal pincer complexes supported by a new bis(indolylphosphino)silyl ligand are described, including the synthesis of Ni, Pd, and Pt hydride species. Solution NMR and single-crystal X-ray data revealed that a significant amount of structural variability is possible for such hydride complexes, particularly in the case of Ni, where terminal Ni-H as well as complexes involving η2-SiH coordination are both accessible and may even coexist, in ratios dependent on factors such as the nature of additional coligands, including N2 from the reaction atmosphere, as well as solvent and temperature. Nickel and palladium hydride complexes of this new ligand were found to exhibit divergent selectivity in the catalytic hydroboration of CO2 with pinacolborane (HBPin). While the Pd catalyst exhibited moderate activity for CO2 hydroboration to the formate Level, the analogous Ni species exhibited unprecedented selectivity (97%) for hydroboration of CO2 to the Formaldehyde Level ...
Nurindang Marzuki - One of the best experts on this subject based on the ideXlab platform.
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electrochemical biosensor immobilization of Formaldehyde dehydrogenase with nafion for determination of Formaldehyde from indian mackerel rastrelliger kanagurta fish
Current Analytical Chemistry, 2012Co-Authors: Nurindang Marzuki, Fatimah Abu Bakar, Abu Bakar Salleh, Nor Azah Yusof, Shafiquzzaman SiddiqueeAbstract:An electrochemical biosensor was developed based on Formaldehyde dehydrogenase immobilized with Nafion membrane for determination of Formaldehyde in fish. The enzyme was immobilized through the entrapment technique and measured based on the reduction of I²-nicotinamide adenine dinucleotide. The response time of the Formaldehyde biosensor was <1 min, with an optimum pH of 8. The optimum enzyme loading and NAD + concentrations were found at 30 mg/mL and 0.5 mM, respectively. Using the Formaldehyde biosensor, a linear response of Formaldehyde showed a range of 0.1 to 10 ppm and a detection limit of 0.016 ppm. In application of Nash method, the samples were stored at 4°C ± 1 for 10 days. With the two combined methods, a linear correlation coefficient with R ² = 0.9982 (y = 0.956x - 0.014) was found. The developed Formaldehyde biosensor showed a good reproducibility, long storage stability (more than 6 months stored at 4°C), and also effective monitoring of Formaldehyde Level in Indian mackerel (Rastrelliger kanagurta) fish.
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Development of Enzyme-Based Biosensor for the Detection of Formaldehyde in Fish
2011Co-Authors: Nurindang MarzukiAbstract:Usage of Formaldehyde as preservative in fish by fisherman in order to maintain its fresh look and avoid microbial spoilage is a big risk to consumer’s health. Moreover, its capability to induce carcinogen at certain Level arises endeavour to create simple, sensitive and rapid device for Formaldehyde determination. Therefore, a novel detection method based on amperometric biosensor coupled with an enzyme, Formaldehyde dehydrogenase (FDH) has been developed. To maximize the reaction rate, the enzyme acts as biorecognition was immobilized in Nafion membrane which chemically modified on gold electrode. The enzyme required nicotinamide adenide dinucleotide (NAD+) as a cofactor which then reduced to NADH at -0.2 volt during enzymatic reaction. Through the electrode this physiochemical changes were converted into electric signal which correlated with Formaldehyde concentration. The current measurement was analysed using a computer connected to the transducer. The optimized Formaldehyde biosensor displayed a linear response over the range of 1 to 10 ppm Formaldehyde with correlation coefficient (R2) equals to 0.9865 (RSD 0.05) at 1, 5 and 10 ppm of Formaldehyde (n = 10). For selectivity and interferences by ratio study, it was discovered that the biosensor response retained its specificity for Formaldehyde and did not respond to equivalent additions of methanol and also ethanol and gave the percentage of Formaldehyde recovered ranging from 99.0% to 99.8%. The developed biosensor has been applied for monitoring Formaldehyde Level in Indian Mackerel (Rastrelliger kanagurta) where the samples stored for ten days at temperature of 4oC ± 1 and were compared to Formaldehyde Levels determined by the conventional Nash method. As the result, the two methods showed a linear correlation coefficient with R2 = 0.9937 (y = 0.0542x - 0.0256) and has no significant different (p > 0.05). For determination of Formaldehyde in fish tissue, the percentage of Formaldehyde recovery was found at the range of 68.3 to 86.25 (RSD ≤ 10.81%) after spiked with 1, 5 and 10 ppm of Formaldehyde. It also showed stable measurement reading of 90% from the initial value after six months (stored at 4oC). Another advantage of the constructed biosensor in this work is the assembly of the basic requirements for simplicity, reusability and reagentless system. Thus, it is a promising tool and has a potential application for fast and direct Formaldehyde detection in fish.