Theoretical studies on the reaction of mono- and ditriflate derivatives of 1,4:3,6-dianhydro-d-mannitol with trimethylamine—Can a quaternary ammonium salt be a source of the methyl group?

Abstract

DFT studies on the mechanism of the formation of "gemini" quaternary ammonium salts in the reaction of 1,4:3,6-dianhydro-D-mannitol ditriflate derivative with trimethylamine and its subsequent conversion to tertiary amine through the methyl-transfer reaction are discussed. Two alternative reaction pathways are presented in the gas phase and in ethanol. Additionally, the transformation of the monotriflate derivative of 1,4:3,6-dianhydro-D-mannitol into the single quaternary ammonium salt is presented. Two functionals (B3LYP, M062X) and two basis sets (6-31+G** and 6-311++G**) were used for the calculations. The effect of the substituent attached to the five-membered rings at the C2 (and/or C5) carbon atom on the activation barrier is described. The trimethylammonium group bond to the five-membered ring greatly reduces the activation barrier height. The preferred reaction pathway for the conversions was established. Including the London dispersion in the calculations increases the stabilization of all the points on the potential energy surface in relation to individual reactants.

Effect of solvation on the aggregation-induced luminescence of tetraphenylethene derivatives

“…It can be inferred that there may be some kind of stable combination between THF and TPE-(α-NH 2 ) 2 in the water-THF mixture ( f w = 90%). Accordingly, we studied the structures of TPE-(α-NH 2 ) 2 -solvent–H 2 O using the M06-2X 18 density functional in combination with the SMD water model. 19 In Table 1, it is shown that the binding energy of the TPE-(α-NH 2 ) 2 –solvent–H 2 O combination in the structure Ini is different from that of the structure Fin (Ini represents the situation that the solvent molecule is closer to the TPE-(α-NH 2 ) 2 molecule.…”

Synthesis of n‐alkylated quaternary ammonium chitosan and its long‐term antibacterial finish for rabbit hair fabric

“…Those acquaintance from claiming quaternary ammonitic salt assemblies with solid hydration capacity in the position about hydroxyl aggregations camwood likewise expand the dissolvability for chitosan subsidiaries. [16][17][18][19] It is worth mentioning that most of the existing studies use trimethylammonium quaternary ammonium salt as antibacterial agent, [20][21][22] while there are few studies on the application of triethyl quaternary ammonium salt in fabric antibacterial finishing. Due to electron pusher effect, triethyl quaternary ammonium salt has more stable positive charge on N atom, which theoretically has stronger cationic and antibacterial properties than trimethylammonium quaternary ammonium salt.…”