NMR and quantum chemical studies on association of 2,6-bis(acylamino)pyridines with selected imides and 2,2′-dipyridylamine

Abstract

Association constants of 2,6-bis(alkylcarbonylamino)pyridines (alkyl = methyl or ethyl) and their perfluoroalkyl analogues with succin-and maleimide as well as with 2,2 0 -dipyridylamine (complementary DAD and ADA hydrogen bonding motifs are responsible for formation of the associates) have been determined by NMR titrations and quantum chemical calculations. Interactions of 2,6-bis (alkylcarbonylamino)pyridines with imides differ by character from these of perfluoroalkyl analogues. Such large difference was not observed for the 2,2 0 -dipyridylamine associates. Since fluorine atoms cause carbonylamino groups to be stronger hydrogen bond donors, perfluorinated species of this type were found to be more stable. Single crystal X-ray structures of 2,6-bis(trifluoromethylcarbonylamino)pyridine and 2,6-bis(pentafluoroethylcarbonylamino)pyridine have been also determined.

The influence of CH bond polarization on the self-association of 2-acylaminopyrimidines by NH/CH···O/N interactions: XRD, NMR, DFT, and AIM study

“…1) gave crystals for X-ray structure determination after slow evaporation of CDCl 3 in NMR tube. Compounds were characterized also by 1 H, 13 C, and 15 N NMR spectroscopy and by elemental analysis (see ESM).…”

“…It has been shown how hydrogen bonding can be used in designing the shape of aggregate [5][6][7] in solution and in solid state [8]. Generally, non-covalent intermolecular interactions are influenced by steric effects [9][10][11][12], electronic repulsion [11,13], position of the heteroatoms in the ring [14][15][16], and cooperative effects [17]. The atoms able to compete for hydrogen bonds (basic or acidic centers) are responsible for the conformational flexibility of NH-CO bond in amides [18][19][20].…”

Understanding the Effects of Preorganization, Rigidity, and Steric Interactions in Synthetic Barbiturate Receptors

“…The macrocyclic pre-organization found in most prototypical synthetic barbiturate receptors results in high guest binding affinities ranging from 10 4 − 10 5 M -1 . 16,22 In addition to binding barbiturates, this class of receptors accommodates other guests with the appropriate complementary hydrogen-bonding arrays including uracils, 23-26 thymines, 23-24,26-30 succinimides, 24,31 glutarimides, 18,24,32 cyanuric acids, 23,33-35 and dipyridine-2-ylamines, 31-32 demonstrating the versatility of the receptor scaffolds. This diversity has resulted in the use of synthetic barbiturate receptors in different applications including catalysis, 36-38 electrooptical materials, 34-35,39 and supramolecular dendrimers.…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 21, 2010) and the discipline

“…With the purpose to study the triple hydrogen bonds, which are expected to strengthen the association especially with the perfluoroalkyl derivatives, interactions between 2,6-bis(alkylcarbonylamino)pyridines with succin-and maleimide and with 2,2 0 -dipyridylamine were investigated in the following paper by Ośmiałowski et al [263] using NMR and DFT approach. In addition, also X-ray single crystal structures of 2,6-bis(trifluoromethylcarbonylamino)pyridine and 2,6-bis(pentafluoroethylcarbonylamino)pyridine have been determined.…”