Dodson Grace (hosetoast9)
From our computational results, we explain the observed unusual dependence of the rate constant of covalent complex formation, kobs, on the ARS concentration. The latter depends both on the non-covalent binding step with the equilibrium constant, Ki, and on the rate constant of covalent adduct formation, kinact. The calculated ratio kinact/Ki = 213 M-1 s-1 reproduces the corresponding experimental value of 250 ± 30 M-1 s-1 for the interaction of ARS-853 with KRASG12C. Electron density analysis in the reactive region demonstrates that covalent bond formation occurs efficiently according to the Michael addition mechanism, which assumes the activation of the C[double bond, length as m-dash]C bond of ARS-853 by a water molecule and Lys16 in the binding site of KRASG12C. We also refine the kinact and Ki constants of the ARS-107 compound, which shares common features with ARS-853, and show that the decrease in the kinact/Ki ratio in the case of ARS-107 is explained by changes in both Ki and kinact constants.A novel and convenient photo-mediated halogenated spirocyclization of N-(p-methoxyaryl)propiolamides has been developed. The photolysis of phenyliodine bis(trifluoroacetate) (PIFA) as an iodination reagent led to iodinated ipso-cyclization under the irradiation of a xenon lamp, while brominated ipso-cyclization or chlorinated ipso-cyclization was achieved by irradiating a mixture of PIFA and KBr/KCl under a blue LED. The present protocol simply utilizes light as the safe and clean energy source and doesn't require any external photocatalyst providing various 3-halospiro[4,5]trienones in good to excellent yields (up to 93%).Three-dimensional graphene (3D GR)-based hybrids have received significant attention due to their unique structures and promising applications in supercapacitors. In this paper, 3D GR with small pore sizes has been prepared by chemical vapor deposition using commercial nickel nanowires as the template. After nitric acid treatment, the hydrophilicity of 3D GR improved. Polyaniline nanowire arrays (PANI NWAs) have been successfully grown on its surface by in situ polymerization to obtain hybrid PANI NWA/3D GR. The results show that PANI NWAs with a length of ∼300 nm vertically grow on 3D GR with a pore diameter of ∼2 μm. The small pore size of 3D GR not only improves the mechanical properties of 3D GR, but also provides numerous sites for the growth of PANI NWAs. Meanwhile, PANI NWAs provide a shorter ion diffusion path and larger contact area with the electrolyte. Due to the unique structure, the hybrid exhibits a high specific capacitance of 789.9 F g-1 at 10 mV s-1. When it is assembled into a symmetric supercapacitor, it exhibits an energy density of 32.2 W h kg-1 at a power density of 793.3 W kg-1 and maintains a good cycle stability of 90% after 5000 cycles at 1.0 A g-1.Gas-phase coordination complexes of actinyl(v) cations, AnO2+, provide a basis to assess fundamental aspects of actinide chemistry. Electrospray ionization of solutions containing an actinyl cation and sulfonate anion CH3SO2- or C6H5SO2- generated complexes [(AnVO2)(CH3SO2)2]- or [(AnVO2)(C6H5SO2)2]- where An = Np or Pu. Collision induced dissociation resulted in C-S bond cleavage for methanesulfinate to yield [(AnVO2)(CH3SO2)(SO2)]-, whereas hydrolytic ligand elimination occurred for benzenesulfinate to yield [(AnVO2)(C6H5SO2)(OH)]-. These different fragmentation pathways are attributed to a stronger C6H5-SO2-versus CH3-SO2- bond, which was confirmed for both the bare and coordinating sulfinate anions by energies computed using a relativistic multireference perturbative approach (XMS-CASPT2 with spin-orbit coupling). The results demonstrate shutting off a ligand fragmentation channel by increasing the strength of a particular bond, here a sulfinate C-S bond. The [(AnVO2)(CH3SO2)(SO2)]- complexes produced by CID spontaneously react with O2 to eliminate SO2, yielding [(AnO2)(CH3SO2)(O2)]-, a process previously reported for An = U and found