Two New Proton Transfer Salts of Benzo[d]thiazol-2-amine with Different Aromatic Acids

Two new proton transfer salts (HABT)⁺(SA)⁻ (1) and (HABT)⁺₂(ADSA)²⁻·2H₂O (2) were synthesized from the reaction of benzo[d]thiazol-2-amine (2-aminobenzothiazole) (ABT) with 2-hydroxybenzoic acid (salicylic acid) (HSA) and 2-aminobenzene-1,4-disulfonic acid (H₂ADSA), respectively. The molecular structures of these salts were carried out by elemental analysis, X-ray diffraction crystallography, FTIR and UV–Vis techniques Single-crystal X-ray analysis of the compounds revealed proton transfer from acidic moieties to basic moieties to form salts with intermolecular hydrogen bond motifs R₂²(8) for 1 and R₃³(10) for 2. The intramolecular hydrogen bond creates the cyclic S(6) motif in both structures (1 and 2). For salt 1, crystallization took place in the P2(1)/c space group of the monoclinic system, and for salt 2 in the P-1 space group of the triclinic system. The antibacterial and antifungal properties of the compounds are assayed against various Gram positive bacteria {Bacillus subtilis, Listeria monocytogenes (ATCC 7644), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (NRRL B-767)}, Gram negative bacteria {Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853)} and fungus {Candida albicans (F89)}. Minimum inhibitory concentrations (MIC) of synthesized salts were compared with antibacterial (levofloxacin cefepime, vancomycin) and antifungal (Fluconazole) reference compounds.

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