Regioselectivity of the interaction of temozolomide with borane and boron trifluoride

Abstract

MP2 and B3LYP calculations are used to predict the most favorable site of temozolomide toward BH 3 and BF 3 which are classical Lewis acids. Binding energies, charge transfers, and bond length perturbations of the temozolomide in various complexes indicate that the N 12 atom is the preferred attack site for BH 3 , while BF 3 prefers the O 17 atom. The interactions are quite strong, as much as 100 kJ/mol for BH 3 and more than 60 kJ/mol for BF 3 . The molecular electrostatic potential surrounding temozolomide is most negative around the O atoms, which is unable to explain the energetic order of binding of the Lewis acids.

H‐bonding and stacking interactions between chloroquine and temozolomide

“…The global minimum of the dimer is stabilized not only by strong dispersion forces between the parallel rings but also by a strong intermolecular NHÁÁO HB. This observation is consistent with previous reports [32,[73][74][75][76][77][78][79][80] that attribute the noncovalent bonding preferences of the TMZ molecule to its terminal amide group.…”

Interactions between temozolomide and guanine and its S and Se-substituted analogues

“…Negative red sections are located around unprotonated N atoms, as well as the O/S/Se atoms. The corresponding MEP around TMZ was previously reported . This MEP in Figure exhibits primary negative potential around its two O atoms, with positive regions around its H atoms and directly above its six‐membered ring.…”

“…H 2 O and HCl, for example, lie exclusively in the plane of the TMZ molecule, and the primary binding mode involves HBs to O and N atoms of TMZ. While also situated in the TMZ plane, Lewis acids BH 3 and BF 3 , engage in direct bonding between B and the O or N atoms of TMZ, also avoiding the region above the aromatic system.…”

“…As a means to focus on certain fundamentals, interactions of TMZ with small molecules have been examined previously by this laboratory, specifically H 2 O, HCl, BH 3 , and . Using the lessons learned, work progressed to larger pharmacological agents chloroquine and quercetin, as well as possible homodimers of TMZ .…”

A theoretical insight into the role of counter anions and their interactions in nitropentaamminecobalt(III) toward linkage isomerism‐induced photochemical motion

“…MEPs and frontier molecular orbitals were computed as reactivity indices to gain insight into the chemical reactivity of [Co(NH 3 ) 5 NO 2 ] 2+ and [Co(NH 3 ) 5 ONO] 2+ isomers. The MEP has been reported as a convenient tool to visualize the anisotropic component of interaction in a complex . The theory of atoms in molecules (AIM), the EDS, and natural bond orbitals (NBO) were employed to analyze chemical bonding.…”