The synthesis and spectroscopic characterization of the mononuclear uranium complex [((ArO)(3)tacn)U(III)(NCCH(3))] is reported. The uranium(III) complex reacts with organic azides to yield uranium(IV) azido as well as uranium(V) imido complexes, [((ArO)(3)tacn)U(IV)(N(3))] and [((ArO)(3)tacn)U(V)(NSi(CH(3))(3))]. Single-crystal X-ray diffraction, spectroscopic, and computational studies of thi...

Titanium(IV) complexes exhibit high potential as anti-tumor agents, particularly due to their low intrinsic toxicity and cytotoxicity toward cisplatin resistant cells. Nevertheless, Ti(IV) complexes generally undergo rapid hydrolysis that previously hampered their utilization as anticancer drugs. We recently overcame this difficulty by developing a highly stable Ti(IV) complex that is based on ...

The ability of 3-hydroxypyridin-4-ones (CP), a family of bidentate orally effective iron chelators, to remove iron and to prevent iron-induced lipid peroxidation was studied in beating rat myocardial cells in culture. The iron (III) binding constant (log beta 3) of all CP compounds is 36, but their lipophilicity may be modified by altering the length of the R2 substituent on the ring nitrogen. ...

A new hexadentate, tripodal 8-hydroxyquinoline ligand (QH3) and its trivalent metal chelates (MQ, M=Al3+, Ga3+, In3+) with hemicage structures have been prepared and the electrochemical and photophysical properties systematically studied. The hemicage structure of the metal complexes was characterized by 1H NMR, indicating a pure facial geometry, in contrast to their uncaged cousins with 8-hydr...

New amphiphilic and spin-labile Mn(III) complexes based on dianionic N(4)O(2)-hexadentate sal(2)trien or sal(2)bapen ligands, which contain OC(6)H(13), OC(12)H(25), or OC(18)H(37) alkoxy substituents at different positions of the salicylidene unit were prepared (H(2)sal(2)trien = N,N'''-bis(salicylidene)-1,4,7,10-tetraazadecane, H(2)sal(2)bapen = N,N'''-bis(salicylidene)-1,5,8,12-tetraazadodeca...

Four isomorphic tetranuclear lanthanide complexes, namely [Ln4(L)2(HL)2(NO3)2(OH)2](NO3)2·4H2O (Ln = Dy (1); Tb (2); Ho (3); Er (4)), constructed using hexadentate salen-type ligand N,N'-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine, have been isolated. X-ray crystallographic analysis reveals that all of the complexes 1-4 are of discrete tetranuclear structure with a unique {Ln4O8} core in...

A highly sensitive and simple colorimetric assay for the detection of Fe3+ ions was developed using gold nanoparticles (AuNPs) conjugated with glycol chitosan (GC). The Fe3+ ion coordinates with the oxygen atoms of GC in a hexadentate manner (O-Fe3+-O), decreasing the interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry showed that the bound Fe3+ was c...

A series of hexadentate ditopic receptors incorporating benzimidazole moieties have been designed, which are fitted with phosphonic acid or phosphoethylester coordinating units. In addition, poly(oxyethylene) pendants have been introduced on the benzimidazole backbone of two ligands to increase water solubility. The ligands self-assemble with lanthanide ions under stoichiometric conditions, yie...