Abstract：
The salts bis(2-amino-3-methylpyridinium) fumarate dihydrate, 2C6H9N2+·C4H2O22-·2H2O (I), and 2-amino-3-methylpyridinium 5-chlorosalicylate, C6H9N2+·C7H4ClO3- (II), were synthesized from 2-amino-3-methylpyridine with fumaric acid and 5-chlorosalicylic acid, respectively. The crystal structures of these salts were characterized by single-crystal X-ray diffraction, revealing protonation in I and II by the transfer of a H atom from the acid to the pyridine base. In the crystals of both I and II, N-H...O interactions form an R22(8) ring motif. Hirshfeld surface analysis distinguishes the interactions present in the crystal structures of I and II, and the two-dimensional (2D) fingerprint plot analysis shows the percentage contribution of each type of interaction in the crystal packing. The volumes of the crystal voids of I (39.65 Å3) and II (118.10 Å3) have been calculated and reveal that the crystal of I is more mechanically stable than II. Frontier molecular orbital (FMO) analysis predicts that the band gap energy of II (2.6577 eV) is lower compared to I (4.0035 eV). The Quantum Theory of Atoms In Molecules (QTAIM) analysis shows that the pyridinium-carboxylate N-H...O interaction present in I is stronger than the other interactions, whereas in II, the hydroxy-carboxylate O-H...O interaction is stronger than the pyridinium-carboxylate N-H...O interaction; the bond dissociation energies also confirm these results. The positive Laplacian [∇2ρ(r) > 0] of these interactions shows that the interactions are of the closed shell type. An in-silico ADME (Absorption, Distribution, Metabolism and Excretion) study predicts that both salts will exhibit good pharmacokinetic properties and druglikeness.
摘要：
富马酸二(2-氨基-3-甲基吡啶鎓)盐二水合物，2C6H9N2+·C4H2O22-·2H2O(I),和2-氨基-3-甲基吡啶5-氯水杨酸盐，C6H9N2+·C7H4ClO3-(II),由2-氨基-3-甲基吡啶与富马酸和5-氯水杨酸合成，分别。通过单晶X射线衍射对这些盐的晶体结构进行了表征。通过将H原子从酸转移到吡啶碱，揭示了I和II中的质子化。在I和II的晶体中，N-H...O相互作用形成R22(8)环基序。Hirshfeld表面分析区分了I和II晶体结构中存在的相互作用，二维（2D）指纹图谱分析显示了晶体堆积中每种类型的相互作用的百分比贡献。已计算出I（39.65°3）和II（118.10°3）的晶体空隙的体积，并表明I的晶体比II的机械稳定性更高。前沿分子轨道（FMO）分析预测，II（2.6577eV）的带隙能量低于I（4.0035eV）。分子中原子的量子理论(QTAIM)分析表明,吡啶-羧酸盐N-H..存在于I中的相互作用比其他相互作用更强，而在II中，羟基羧酸盐O-H。..O相互作用比吡啶-羧酸盐N-H强。..O相互作用；键离解能也证实了这些结果。这些相互作用的正拉普拉斯[*2ρ(r)>0]表明相互作用是闭壳型的。硅内ADME(吸收，Distribution,代谢和排泄）研究预测，两种盐都将表现出良好的药代动力学特性和药物相似性。
