A series of pyrrole-indolin-2-ones were synthesized, and their inhibition profile for Aurora kinases was studied. The potent compound 33 with phenylsulfonamido at the C-5 position and a carboxyethyl group at the C-3' position selectively inhibited Aurora A over Aurora B with IC50 values of 12 and 156 nM, respectively. Replacement of the carboxyl group with an amino group led to compound 47, which retained the activity for Aurora B and lost activity for Aurora A (IC50=2.19 microM). Computation modeling was used to address the different inhibition profiles of 33 and 47. Compounds 47 and 36 (the ethyl ester analogue of 33) inhibited the proliferation of HCT-116 and HT-29 cells and suppressed levels of the phosphorylated substrates of Aurora A and Aurora B in the Western blots.

Iron tris(2-methylpyridyl)amine (TPA) and iron 1-(bis(2-methylpyridyl)amino)-2-methyl-2-propanoate (BPyA) salts are characterized as water oxidation catalysts (WOCs) using sodium periodate. Under the conditions used, these complexes serve as homogeneous WOCs as demonstrated via kinetic analysis and dynamic light scattering (DLS). The Fe(BPyA) salt serves as both a mononuclear and dinuclear catalyst, with the mononuclear form showing higher catalytic activity. Based on the H/D kinetic isotope effect and pH dependence, the rate determining step (RDS) in water oxidation (WO) by Fe(BPyA) is nucleophilic attack by water during O-O bond formation. In contrast, Fe(TPA) shows complex kinetic behavior due to the formation of multiple oxidation states of the complex in solution, each of which exhibits catalytic activity for WO. The RDS in WO by Fe(TPA) follows an equilibrium established between monomeric and dimeric forms of the catalyst. Under acidic conditions formation of the monomer is favored, which leads to an increase in the WO rate.

A μ-oxido-bridged triruthenium complex (RuT(2+)), formed by air-oxidation of a previously reported monoruthenium water oxidation catalyst (WOC), serves as an efficient photochemical WOC with the turnover frequency (TOF) and turnover number (TON) 0.90 s(-1) and 610, respectively. The crystal structures of RuT(2+) and its one-electron oxidized RuT(3+) are also reported.

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Three chloro(4'-(N-methylpyridinium)-2,2':6',2''-terpyridine)platinum(ii) (abbreviated as ) derivatives tethered to a single alkyl viologen unit (-(CH2)n-CH2-N(+)C5H4-C5H4N(+)-CH3; abbreviated as -, where n = 1, 3, and 4), i.e., , have been synthesized and investigated in detail. It is shown that the turnover number (TON) for the photocatalytic H2 evolution from water in the presence of a sacrificial electron donor EDTA (ethylenediaminetetraacetic acid disodium salt) is dramatically improved by the attachment of a single alkyl unit (TON = 21.5-25.2, 12 h). Spectrophotometric studies reveal that the photoirradiation of in the presence of EDTA initially leads to the formation of a 1-electron-reduced species, and then to a 2-electron-reduced species, where reductive quenching of a photoexcited species is a major path to the reduced photoproduct in each step. Electrochemical studies show that two consecutive 1-electron reductions at the unit are nearly overlapped with the corresponding reductions at the unit. The 1-electron-reduced species can be thus expressed as either or , while the 2-electron-reduced one as . Moreover, the latter products behave as stacked species involving three types of π-dimer sites, ()2, ()2, and ()(), and do not drive thermal H2 evolution according to the reaction: + 2H(+) → + H2. The H2 evolution from water photocatalyzed by has been found to occur via formation of 3-electron-reduced species; + EDTA + hν → (or ) + EDTA(ox), and (or ) + 2H(+) → (or ) + H2.