Cationic ruthenium(II) pentamethylcyclopentadienyl benzenesulfonamide sandwich complexes have been synthesized and screened for enzymatic inhibition of the physiologically dominant carbonic anhydrase (CA) isozymes: human CA I and II, mitochondrial isozymes VA and VB, and the cancer-associated isozyme IX. The complexes demonstrated weaker binding to CAs compared with typical aromatic sulfonamides, inhibiting the enzyme at high nanomolar concentrations. An in vitro cytotoxic evaluation of the complexes was also undertaken against a range of tumorigenic cell lines and a healthy human cell line. Complexes inhibited the growth of cancerous cells at low micromolar concentrations while expressing lower levels of toxicity towards the normal human cell line. Factors influencing the synthesis, cytotoxicity, and enzyme affinity for this series of organometallic complexes are discussed.

A novel series of ionic Ru(II) arene Cp* sandwich complexes has been synthesized and characterized. Screening results for cytotoxicity against a range of human tumor cell lines and normal human cells indicate that the complexes show promising anticancer activity, which varies with changes in the arene ligand and the anionic counterion.

This article details the preparation and spectroscopic characterization of a focused library of new 18-electron ruthenocenyl complexes incorporating pentasubstituted Cp ester [C 5 (CO 2 R) 5 ] -(for R = Me, Et, n-Pr, n-Bu, 2-Pr, 3-Pent, phenyl, and n-thiopropyl), carboxylic acid [C 5 (CO 2 H) 5 ] -, and carboxylate ligands [C 5 (CO 2 H) 4 (CO 2 )] 2-. Each complex has been characterized using Fourier transform IR and NMR spectroscopy and electrospray mass spectrometry, with single-crystal X-ray structural determinations reported for four complexes: [Ru(η 5 -C 5 H 4 (C 5 (CO 2 CH 3 ) 5 )(η 5 -C 5 (CO 2 -CH , -C 5 H 5 )(η 5 -C 5 (CO 2 C 6 H 5 ) 5 )]. Complexes were also evaluated for in vitro cytotoxic activity against a diverse panel of tumorigenic cell lines and a normal human cell line.

Tetraphenylborate salts of the η 6 -arene Cp * Ru II O-alkyl-N-phenyl carbamate organometallic sandwich complexes, [Cp * Ru(PhNHCO 2 R)]BPh 4 for R = Me (1), Et (2), and n-Pr (3), have been prepared by a facile one-pot reaction between ruthenium trichloride, pentamethylcyclopentadiene, and phenylisocyanate in refluxing alcohol solutions, and have been characterized by Fourier-transform IR and NMR spectroscopy, electrospray mass spectrometry, and single-crystal X-ray structure determinations. In vitro cytotoxicity studies show the complexes to be potent growth inhibitors for a range of tumour cell lines, while expressing significantly lower levels of toxicity towards a normal human fibroblast cell line.