New dithiolene derivatives as coordination chromophores: structural, spectroscopic, electrochemical, Hirshfeld surface analyses, and in-vitro cytotoxicity

Seven substituted dithiolene systems with acetylacetonate, 3, 4-dimethylpyrazole (HPz), and 3, 4-dimethoxybenzyl moieties were synthesized by nucleophilic substitution, cyclocondensation, and transchalcogenation reactions. The seven compounds were characterized by NMR and X-ray diffraction techniques. The single-crystal X-ray diffraction analysis revealed that 4, 5-bis (2, 4-dioxopentan-3-yl) sulfanyl-1, 3-dithiol-2-one, C13H14O5S4 or DMIO (acac) 2, and 4, 5-bis (3, 5-dimethylpyrazol-4-yl) sulfanyl-1, 3-dithiole-2-thione methanol monosolvate, C13H14N4S5·CH3OH or DMIT (HPz) 2, crystallized in the triclinic P1 and monoclinic P21/n space groups, respectively, while 4, 5-bis (3, 4-dimethoxybenzyl) sulfanyl-1, 3-dithiole-2-thione, C21H22O4S5 or DMIT (3, 4-dimethoxybenzyl) 2, and 4, 5-bis (3, 4-dimethoxybenzyl) sulfanyl-1, 3-dithiol-2-one, C21H22O5S4 or DMIO (3, 4-dimethoxybenzyl) 2, crystallized in the monoclinic space groups P21/n and P21/c, respectively. Methyl 4- (5- ({[4- (methoxycarbonyl) phenylmethylsulfanyl) -2-sulfanylidene-1, 3-dithiol-4-yl]sulfanyl}methyl) benzoate, C21H18O4S5 or DMIT (4-methylbenzoate) 2, and methyl 4- (5- ({[4- (methoxycarbonyl) phenylmethylsulfanyl) -2-oxo-1, 3-dithiol-4-yl]sulfanyl}methyl) benzoate, C21H18O5S4 or DMIO (4-methylbenzoate) 2, crystallized in the orthorhombic P212121 and monoclinic P21/n space groups, respectively. Similarly, 4- (5-{[ (4-carboxyphenyl) methylsulfanyl-2-oxo-1, 3-dithiol-4-yl) sulfanyl]methyl}benzoic acid, C19H14O5S4 or DMIO (4-methylbenzoic acid) 2, crystallized in the monoclinic space group P21/c. The molecular packings of the seven crystalline compounds were stabilized by a variety of intermolecular O. . . H, H. . . H, C. . . H, S. . . H, S. . . S, S. . . O, and N. . . H interactions, depending on the substituent group. Hirshfeld surface analysis confirmed the presence of the above-mentioned interactions and the percentage contributions of the interatomic contacts were determined by 2D fingerprint plots in the total Hirshfeld surface. Studies of the antiproliferative activity against the NCI-60 cell line panel were performed for selected 2-oxo-1, 3-dithiole-4, 5-dithiolate (DMIO) derivatives.