Eleven adducts from 4-methylbenzo[d]thiazol-2-amineand Carboxylic Acids via Classical H-bonds and Noncovalent Associations

Abstract Cocrystallization of4-methylbenzo[d]thiazol-2-amine with an array of carboxylic acids got a total of 11 crystalline adducts. The 11 adducts have been examined by XRD, IR and EA, the melting points of all adducts were also gauged.Their structural and supramolecular aspects are fully analyzed. The result reveals that among the investigated crystalline solids1-4, 6-7 and 9-10 the aryl N in thiazole cores are protonated when the organic acids are deprotonated and the crystal packing is interpreted by the strong charge-assisted N-H⋯O H-bond from the NH+ and the carboxylates. 5, 8 and 11 are cocrystals sustained by the neutral N-H⋯O/O-H⋯N H-bonds. Except the N-H⋯O H-bonds, the O-H···OH-bonds were also present at 3, 6, 7 and 9-11. 1 has the additional N-H···S H-bonds.The O-H···S H-bond was created in 10. 1 and 5 contained the N-H···N H-bond. 4 showed the N-H···Cl H-bond.Further analysis of the crystal packing of the adducts told that a different set of additional O-H···C,C-C,O-C, O-O, O-S,Cl-O, Cl-Cl, Cl-S, Br-Br,CH3-N, CH-O/CH2-O/CH3-O, CH3-Cl/CH-Cl, C-π, CH3-CH3/CH3-CH/CH-CH, NH-π, CH3-π/CH2-π/CH-π, Cl-π andπ-π contacts contribute to the stabilization and expansion of the totalstructures. For the interplay of the various weak nonbonding contacts these structures took on homo/hetero supramolecular synthons.The recognition of the base-acid in all the multicomponent crystalsis based on thetypical R22(8) synthon. Due to the cooperation of these weak bonds,1-11 display 1D-3D motifs.