N-Alkylation of nitriles—I

Electron dynamics with real‐time time‐dependent density functional theory

“…Various investigations have been performed with an adiabatically exact V xc , which neglects all memory effects but is fully nonlocal in space. [23,58,83,84] The adiabatically exact V xc is obtained by inverting the N-particle Schr€ odinger equation for the interacting system, which is a non-trivial endeavor and generally only performed for very simple systems, such as the helium atom and two-electron model systems. It has been shown that during charge transfer the adiabatically exact correlation functional (V c ) reproduces a time-dependent step structure found in the exact V c , but is of the wrong size.…”

“…It has been shown that during charge transfer the adiabatically exact correlation functional (V c ) reproduces a time-dependent step structure found in the exact V c , but is of the wrong size. [23] This leads to incorrect charge-transfer dynamics [23,84] and unphysical peak-shifting in the absorption spectrum. [85] For example, Maitra and co-workers [84,85] have demonstrated a complete lack of charge transfer in a two-electron model system when the adiabatically exact (AE) V xc is used.…”

“…[23] This leads to incorrect charge-transfer dynamics [23,84] and unphysical peak-shifting in the absorption spectrum. [85] For example, Maitra and co-workers [84,85] have demonstrated a complete lack of charge transfer in a two-electron model system when the adiabatically exact (AE) V xc is used. This is shown in Figure 3 where the exact dipole moment displays a clear transfer of charge, while the AE V xc (which includes exact non-local exchange and correlation) does not transfer the charge and, like the adiabatic potential with exact exchange and no correlation (AEXX), only agrees with the exact results at very short times when the system is still close to the reference ground state.…”

“…Exact dipole is shown in black, the adiabatically exact (AE) dipole in red, and the adiabatic exact exchange (AEXX) dipole in pink for closedshell to closed-shell (cs-cs) charge transfer in an asymmetric Hubbard dimer model system. (Reproduced from Ref [84]. with permission from American Physical Society.…”

Elucidating the Pathways of Degradation of Denagliptin

“…Preparation of (3S, 7S, 8aS) Amidine (2) (3S,7S,8aS) amidine (2) was prepared by heating a 2.5 mg/mL solution of denagliptin free base (25.98 mg) in CHCl 3 and FeCl 3 (12.49 mg; mole ratio 1:1.2) at 808C for 2 h by modification of a procedure described in the literature 19 to prevent epimerization. A complex of amidine 2 with FeCl 3 precipitated out of solution and was 98.7% pure after filtration.…”