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Copper bis(4-ethyl-3-thiosemicarbazonato) acenaphthenequinone (1) and copper bis(4-methyl-3-thiosemicarbazonato) acenaphthenequinone (2) are synthesized and characterized in solution, in the solid state, and radiolabeled. Serum-protein binding radioassays show good stability in solution and about 25 % binding to protein over 1 h, which is comparable with the hypoxia selective tracer [(64)Cu(ATSM)]. Cyclic voltammetry shows fast and reversible reduction at redox potentials similar to the values known for hypoxia-selective copper compounds. However, despite this, complex 1 does not show any hypoxic-selective uptake in HeLa cells over 1-h standard assays. Possible reasons for this are studied by using the intrinsic fluorescence of the Cu(II) complexes to determine the cellular distributions and uptake mechanism by confocal microscopy. The complexes are found to bind to the external cell membrane and disperse evenly in the cytoplasm only after a very slow cell internalization (>1 h). No significant changes in distribution are observed by fluorescence imaging under hypoxic conditions. The rate of localization in the cytoplasm contrasts with their Zn(II) analogues, which are known to have fast cell uptake (up to 20 min) and a clear localization in lysosomes and mitochondria. The cytotoxicity mechanism of 1 over 24 h against a number of adherent cell lines is seen to be by membrane disruption and is of a comparable magnitude to that of [Cu(ATSM)], as demonstrated by methyl tetrazolium (MTT) and lactate dehydrogenase (LDH) assays.

Seven discrete sugar-pendant diamines were complexed to the {M(CO)(3)}(+) ((99m)Tc/Re) core: 1,3-diamino-2-propyl beta-D-glucopyranoside (L(1)), 1,3-diamino-2-propyl beta-D-xylopyranoside (L(2)), 1,3-diamino-2-propyl alpha-D-mannopyranoside (L(3)), 1,3-diamino-2-propyl alpha-D-galactopyranoside (L(4)), 1,3-diamino-2-propyl beta-D-galactopyranoside (L(5)), 1,3-diamino-2-propyl beta-(alpha-D-glucopyranosyl-(1,4)-D-glucopyranoside) (L(6)), and bis(aminomethyl)bis[(beta-D-glucopyranosyloxy)methyl]methane (L(7)). The Re complexes [Re(L(1)-L(7))(Br)(CO)(3)] were characterized by (1)H and (13)C 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L(2))(CO)(3)Br] and [Re(L(3))(CO)(3)Br], were characterized in the solid state by X-ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H(2)O established that the complexes exist as [Re(L(1)-L(7))(H(2)O)(CO)(3)]Br in aqueous conditions. Radiolabelling of L(1)-L(7) with [(99m)Tc(H(2)O)(3)(CO)(3)](+) afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.

A dinuclear oxo-Mo(V) complex 1 has been prepared which develops an intense absorption in the near-IR region (λ = 1340 nm; ε = 23 000 M-1 cm-1) on reversible one-electron oxidation to [1]+. This has formed the basis of a variable optical attenuator, whereby the intensity of near-IR laser light may be modulated over a range of 50 dB according to the electrical potential applied to the cell.

An approach to a new class of potential radiopharmaceuticals is demonstrated by the labeling of a glucosamine derivative with the tricarbonyls of 99mTc and 186Re. The proligand HL2 (N-(2'-hydroxybenzyl)-2-amino-2-deoxy-D-glucose) was produced by hydrogenation of the corresponding Schiff base and reacted with [NEt4]2[Re(CO)3Br3] to form the neutral complex [(L2)Re(CO)3] in 40% yield. 1H and 13C NMR spectra indicate that the [Re(CO)3] core is bound in a tridentate fashion via the amino N, phenolato O, and C-3 hydroxyl O atoms of the ligand. At the tracer-level, labeling of HL2 with [99mTc(CO)3(H2O)3]+ and [186Re(CO)3(H2O)3]+ was achieved in aqueous conditions in 95 +/- 2% and 94 +/- 3% average radiochemical yields, respectively.

The synthesis and physical characterization of a series of lanthanide (Ln(III)) and nickel (Ni(II)) mixed trimetallic complexes with the heptadentate (N(4)O(3)) amine phenol ligand H(3)trn [tris(2'-hydroxybenzylaminoethyl)amine] has been accomplished in order to extend our understanding of how amine phenol ligands can be used to coaggregate d- and f-block metal ions and to investigate further the magnetic interaction between these ions. The one-pot reaction in methanol of stoichiometric amounts of H(3)trn with NiX(2).6H(2)O (X = ClO(4), NO(3)) followed by addition of the corresponding LnX(3).6H(2)O salt, and then base, produces complexes of the general formula [LnNi(2)(trn)(2)]X.nH(2)O. The complexes were characterized by a variety of analytical techniques. Crystals of five of the complexes were grown from methanol solutions and their structures were determined by X-ray analysis: [PrNi(2)(trn)(2)(CH(3)OH)]ClO(4).4CH(3)OH.H(2)O, [SmNi(2)(trn)(2)(CH(3)OH)]NO(3).4CH(3)OH.2H(2)O, [TbNi(2)(trn)(2)(CH(3)OH)]NO(3).4CH(3)OH.3H(2)O, [ErNi(2)(trn)(2)(CH(3)OH)]NO(3).6CH(3)OH, and [LuNi(2)(trn)(2)(CH(3)OH)]NO(3).4.5CH(3)OH.1.5H(2)O. The [LnNi(2)(trn)(2)(CH(3)OH)](+) complex cation consists of two octahedral Ni(II) ions, each of which is encapsulated by the ligand trn(3)(-) in an N(4)O(2) coordination sphere with one phenolate O atom not bound to Ni(II). Each [Ni(trn)](-) unit acts as a tridentate ligand toward the Ln(III) ion via two bridging and one nonbridging phenolate donors. Remarkably, in all of the structurally characterized complexes, Ln(III) is seven-coordinate and has a flattened pentagonal bipyramidal geometry. Such uniform coordination behavior along the whole lanthanide series is rare and can perhaps be attributed to a mismatch between the geometric requirements of the bridging and nonbridging phenolate donors. Magnetic studies indicate that ferromagnetic exchange occurs in the Ni(II)/Ln(II) complexes where Ln = Gd, Tb, Dy, Ho, or Er.

Anion templation is used to assemble novel redox-active bis-ferrocene functionalised rotaxane self-assembled monolayers (SAMs) on to gold electrode surfaces; after template removal, the unique SAM rotaxane binding domain is capable of selectively sensing chloride ions electrochemically.

Nanomedicine is an interdisciplinary field, still in its infancy, where an accurate scientific assessment of potential risks and benefits is urgently needed, as is the engagement of end users and the public in this facet of the nanotechnology debate. There is increasing interest in improving our understanding of the interactions between nanomaterials and living systems, with regard to both the underlying chemistry and the physics of effects on the nanoscale. Ultimately, such knowledge promises new vistas for designing the 'smart' medicines of the future, of which targeted personalized drugs are the holy grail. Imaging and therapeutic components, including metallic radioisotopes, semiconductor quantum dots and magnetic materials, may be used to construct 'nanocarriers' (by encapsulation or conjugation) by rapid and simple (covalent and supramolecular) chemistry. The biomedical functions of the resulting materials are as yet largely unexplored. Encapsulation in nanocarriers could achieve delivery of the reagents (imaging and therapeutic drugs) to the sites of action in the body, while minimizing systemic toxicity and enzymatic degradation. These functional systems have the potential to become a general solution in drug delivery. Here we review recent developments concerning the applications of nanoparticles, including carbon nanotubes, as synthetic scaffolds for designing nanomedicines. This article will also focus on how understanding and design at the molecular level could help interdisciplinary teams develop research towards new diagnostics and therapeutics both in the short and the long term.