Reaction of Imidazole and 2-Methylimidazole with Copper(II) Salts and Certain Acids

Abstract

Composition of biligand compounds Cu(C 3 H 4 N 2 , C 4 H 6 N 2 ) x ( ) 2 • nH 2 O obtained by reaction of aqueous suspensions of prepared poorly soluble copper(II) benzoate Cu(C 7 H 5 O 2 ) 2 • 3H 2 O and nicotinate Cu(C 6 H 4 NO 2 ) 2 • H 2 O with imidazole and 2-methylimidazole has been determined. Mono-and biligand salts have been analyzed and their thermal decomposition has been studied. IR spectroscopy has shown the participation of pyridine nitrogen of imidazole and carboxylic groups of aromatic acids in binding to copper(II) ion. Composition and stability of copper(II) benzoate complex, solubility constant for salt Cu(C 7 H 5 O 2 ) 2 • 3H 2 O at ionic strength I = 0.1 have been determined by solubility method, pH potentiometry, and photometry. Co-crystals/salts of composition C 3 H 4 N 2 • C 7 H 6 O 2 (pH 8.0), C 3 H 4 N 2 • C 6 H 5 NO 2 (pH 7.4) and 3(C 4 H 6 N 2 ) • C 19 H 19 O 6 N 7 • 2H 2 O (pH ~7) have been prepared and studied by thermogravimetric analysis. X-ray powder diffractograms have been recorded for initial compounds and their reaction products (imidazole-benzoic acid, 2-methylimidazole-folic acid systems).

Salts of barbituric and 2-thiobarbituric acids with imidazole: polymorphism, supramolecular structure, thermal stability and water solubility

“…For instance, Skorik et al obtained imidazolium salts with nicotinic (HIm + Nic − , pH synthesis 7.4, Δp K a = 2.85) and benzoic (HIm + Benz − , pH synthesis 8.0, Δp K a = 3.68) acids at the molar ratio of acid : Im equal to 1 : 2 and 1 : 3, respectively. 39 As the authors note, the molar ratio of the components in the synthesized salts generally corresponds to the basicity of the selected acid. Indeed, H 2 (T)BA behave mainly as monobasic acids and exist in the form of H(T)BA − in a wide pH range (Fig.…”

“…There are data on imidazolium salts with benzoic acid and its derivatives, 39,41–43 various dicarboxylic acids, 44–49 nicotinic and folic acids. 39,50 In addition, the following H 2 (T)BA cocrystals with 1-hydroxy-4,5-dimethyl-imidazole-3-oxide (HIMO) have been described: (H 2 TBA) 0.5 ·(HIMO) 0.5 , (H 2 BA) 0.5 ·(HIMO) 0.5 and (H 2 TBA) 0.5 ·(H 2 BA) 0.5 (in general, (H 2 TBA) 1− x (H 2 BA) x ). 51,52…”

“…Imidazole (C 3 H 4 N 2 , Im) and its derivatives exhibit a broad range of biological activities; therefore, they play an important role in medicinal and pharmaceutical chemistry. 39 It is a planar 5-membered heterocycle containing two nitrogen atoms in its molecular structure (Fig. 2): one nitrogen behaves as a pyrroletype nitrogen {N-H (position 1) and the other one shows close resemblance to a pyridine-type nitrogen {N-(position 3).…”

“…Imidazole has amphoteric properties with a pronounced predominance of the basic ones: a weak acid due to N(1) atom (pK a B14), a base due to N(3) (pK a = 7.04). 40 There are data on imidazolium salts with benzoic acid and its derivatives, 39,[41][42][43] various dicarboxylic acids, [44][45][46][47][48][49] nicotinic and folic acids. 39,50 In addition, the following H 2 (T)BA cocrystals with 1-hydroxy-4,5-dimethyl-imidazole-3-oxide (HIMO) have been described: (H 2 TBA) 0.5 Á(HIMO) 0.5 , (H 2 BA) 0.5 Á(HIMO) 0.5 and (H 2 TBA) 0.5 Á(H 2 BA) 0.5 (in general, (H 2 TBA) 1Àx (H 2 BA) x ).…”

“…40 There are data on imidazolium salts with benzoic acid and its derivatives, 39,[41][42][43] various dicarboxylic acids, [44][45][46][47][48][49] nicotinic and folic acids. 39,50 In addition, the following H 2 (T)BA cocrystals with 1-hydroxy-4,5-dimethyl-imidazole-3-oxide (HIMO) have been described: (H 2 TBA) 0.5 Á(HIMO) 0.5 , (H 2 BA) 0.5 Á(HIMO) 0.5 and (H 2 TBA) 0.5 Á(H 2 BA) 0.5 (in general, (H 2 TBA) 1Àx (H 2 BA) x ). 51,52 To the best of our knowledge, there are currently no reports of the cocrystals, salt cocrystals or salts formation in the 'H 2 BA-Im' and 'H 2 TBA-Im' systems.…”