73954-58-2

Stable coinage metal nanoparticles (NPs) have been synthesized individually in an aqueous alkaline solution from the corresponding metal salts as precursors using the condensation product (CP) of salicylaldehyde and triethylenetetramine as a reagent. Silver and gold NPs are obtained with and without light illumination but UV irradiation is essential for Cu(0)NP formation. During nanoparticle formation the CP is oxidized to OCP which eventually becomes a fluorophore and also a stabilizer for the in situ produced NPs. It has been observed that silver and gold particle formation kinetics is accelerated by UV exposure. Thus the ease of evolution of coinage metal NP formation relates to their nobility. The as prepared OCP solutions containing coinage metals exhibit a fluorescence contrast behaviour (fluorescence enhancement by Cu and Ag; quenching by AuNP) due to the match and mismatch of wave vectors. The electric field evident from the FDTD simulation abreast of the scattering cross section of the NPs governed from Mie theory as a consequence of surface plasmon coupled emission (SPCE), near field electromagnetic intensity enhancement and lightening rod effect concentrating the electric field around the fluorophore are responsible for the Cu and AgNPs stimulated fluorescence. Again, lossy surface waves are anticipated for efficient quenching by the AuNPs. The most unprecedented observation is 'Turn On' fluorescence which is reported here as a result of the substitution of Au(0) or Cu(0) by Ag(0). Finally, the preferential fluorescence enhancement helps the selective detection of Ag(I) and Cu(II) well below the US Environmental Protection Agency (EPA) permissible level by tuning the experimental conditions. The Royal Society of Chemistry 2014.

Two novel homodinuclear isomorphous lanthanide(III) complexes [Ln(api)]2 (where Ln = Pr and Nd for 1 and 2, respectively) with Schiff base anion api3- {H3api = 2-(2-hydroxyphenyl)-1,3- bis[4-(2-hydroxyphenyl)-3-azabut-3-en

A series of Schiff’s base derivatives was rationally designed, synthesized, and evaluated as multi-function agents for the treatment of Alzheimer’s disease (AD). The results revealed that compound 3b was a novel multifunctional agent. It acted as a highly selective monoamine oxidase-B inhibitor (IC50 = 8.4 nM), which was explained by the docking study. Compound 3b also was an antioxidant agent (2.3 eq) and could significantly inhibit self-induced Aβ1-42 aggregation (31.8%). Meanwhile, compound 3b was a selective metal chelator and could inhibit Cu2+-induced Aβ1-42 aggregation (62.3%). Furthermore, compound 3b presented good neuroprotective effects on H2O2-induced PC12 cell injury. More importantly, compound demonstrated good blood brain barrier permeability and druglike properties. Therefore, compound 3b, a promising multi-targeted active molecule, offers an attractive starting point for further study in the drug-discovery process against AD.[Figure not available: see fulltext.].

Three novel copper(II) and zinc(II) complexes based on salicylaldehyde-imine ligands, namely [Cu(HL1)(CH3CH2OH)]·(CH3COO) (1), [Zn3(HL1)2(CH3COO)4] (2), and [Zn2(L2)]·

A series of binuclear dysprosium compounds, namely, [Dy(api)]2 (1), [Dy(api)]2·2CH2Cl2 (2), [Dy(Clapi)]2·2C4H8O (3), and [Dy(Clapi)]2·2C3H6O (4)

Dinuclear phenoxo-bridged nickel complexes [Ni2(L1)H2O(CH3COO)](1) and [Ni2(L2)H2O(CH3COO)](2) (where L1H3° = 2-(2′-hydroxyphenyl)-1,3-bis[4-(2-h

Crown-ether like interaction of two neutral [Cu2(μ-OH)(μ- L1)] (H3L1 = 2-(2′-hydroxyphenyl)-1,3- bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) fragments, around a central Na+ cation as self-assembly template, led to the formation of [Na{Cu2(μ-OH)(μ-L1)}2]ClO4 (1). Di-tert-butyl group substituted H3L2 {2-(3,5-di-tert-butyl-2-hydroxyphenyl)-1,3-bis[4-(3,5-di-tert-butyl-2- hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine} conversely yields only [Cu2(μ-OH)(μ-L2)]·1.5H2O (2), by discarding aggregation around the Na+ ion. The crown-ether type aggregate 1 exhibits ferromagnetic interactions within the double oxido-phenoxido [Cu2] fragments and weak antiferromagnetic interactions are mediated by the O?Na+?O bridges. Complex 2 registers only weak antiferromagnetic interactions within the oxido-phenoxido bridged [Cu2] entity. UV-visible and emission titration spectroscopy establish the interaction of cationic complex 1 with calf thymus DNA in Tris buffer and it cleaves supercoiled pBR322 DNA from in situ generated ROS.