Heats of formation and ionization potentials of some .alpha.-aminoalkyl radicals

Abstract

slow isomerization should be taken into account in 15N NMR studies of arginine and arginyl residues in enzymes at high magnetic fields.The guanidinium group of arginine clearly plays an important role in binding anionic substrates and cofactors at the active sites of a number of enzymes.27 Valuable information on enzymesubstrate complexes and transient intermediates can be obtained by "trapping" them at subzero temperatures in mixed aqueous organic solvents.28 Applications of NMR for "low-temperature" enzymology are just emerging29,30 and the nonequivalence of N1 and N3 resonances of arginine at subzero temperatures may be useful in this connection.

Direct dynamics study on the mechanism and the kinetics of the reaction of CH3NH2 with OH

“…The reaction enthalpies (⌬H 298 0 ) and the relative energies with and without zero-point energy (ZPE) correction of postreactant complex (⌬E c ) and TS ͑⌬E͒ for the two reaction channels calculated at the CCSD(T)/6-311ϩϩG(2d,2p)//CCSD/6-31G(d) level of theory as well as the available experimental reaction enthalpies [42][43][44] 361, 2,961, 2,820, 1,623, 1,473, 1,430, 1,245, 1,130, 1,044, 780 CH 2 NH 2 3,635, 3,533, 3,279, 3,172, 1,716, 1,519, 1,372, 1,234, 972 …”

Mechanisms of the aerobic oxidations catalyzed by N-hydroxyderivatives

“…The reaction mechanism well explains this behavior: the benzyl radical arising from hydrogen abstraction reacts fast with O 2 in a chain process leading to the hydroperoxide (Eqs. (36)- (38)):…”

“…the BDE value of Me 2 C(NH 2 ) H bond, 88.9 kcal/mol [38], is lower than that of the corresponding amide, Me 2 C(NHCOMe) H, 93.1 kcal/mol [6]). However, both effects are still marked enough for the selective aerobic oxidation of the C H bonds in ␣-position to the nitrogen of amides.…”

Photopolymerization Reactions Initiated by a Visible Light Photoinitiating System: Dye/Amine/Bis(trichloromethyl)-Substituted-1,3,5-Triazine

“…[6] Due to their low ionization potentials, they are also very good reducing agents. [31,32] The oxidation potential of the aminoalkyl radical arising from MDEA was evaluated: E ox L -0.6 V/SCE (see above). An efficient interaction between this radical and TA can, therefore, be ruled out because the electron transfer reaction is not favorable (D ET G L +0.35 eV).…”