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From the reaction of various 6-indolylfulvenes (1a−f) with Super Hydride (LiBEt3H), followed by transmetalation with titanium tetrachloride (TiCl4), six indolyl-substituted titanocenes, bis[(1-methylindol-2-yl)cyclopentadienyl]titanium(IV) dichloride (3a), bis[(1-methyl-5-methoxyindol-2-yl)cyclopentadienyl]titanium(IV) dichloride (3b), a dihydrochloride derivative of bis[(1-methyl-3-dimethylaminomethylindol-2-yl)cyclopentadienyl]titanium(IV) dichloride (3c), bis[(1-methylindol-3-yl)cyclopentadienyl]titanium(IV) dichloride (3d), bis[(1-methyl-5-methoxyindol-3-yl)cyclopentadienyl]titanium(IV) dichloride (3e), and bis[(1-methylmethoxyindol-3-yl)cyclopentadienyl]titanium(IV) dichloride (3f), were obtained. The six titanocenes 3a−f were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines in order to determine their IC50 values. Titanocenes 3a−f were found to have IC50 values of 47 (±9), 15 (±2), 8.2 (±1.9), 21 (±5), 11 (±1), and 170 (±40) μM, respectively.

From the reaction of 6-(p-methoxyphenyl) fulvene (1a), 6-(p-N,N-dimethylaminophenyl) fulvene (1b) and 6-(3,4-dimethoxyphenyl) fulvene (1c) with LiBEt3H, lithiated cyclopentadienide intermediates (2a–c) were synthesised. These intermediates were then transmetallated to tin with SnCl4 to yield tetra-substituted bis(cyclopentadienyl)tin dichloride complexes (3a–c). Further reaction with tin tetrachloride yielded the benzyl-substituted derivatives bis-[(p-methoxybenzyl)cyclopentadienyl] tin(IV) dichloride (4a), bis-[(p-N,N-dimethylaminobenzyl)cyclopentadienyl] tin(IV) dichloride (4b), and bis-[(3,4-dimethoxyphenyl)cyclopentadienyl] tin(IV) dichloride (4c). Preliminary antibacterial tests were carried out using the Kirby–Bauer disk-diffusion method, in which 4a–c showed little to no activity against the Gram-negative bacterium Escherichia coli, but medium activity against Gram-positive bacteria (MRSA, MSSA). In addition, the organotin complexes had their cytotoxicity investigated through preliminary in vitro testing on the LLC-PK (pig kidney epithelial) cell line in order to determine their IC50 values. Compound 4c showed no cytotoxic activity, while 4a and 4b were found to have IC50 values of 15 and 205 μM, respectively.