Synthesis of water-dispersible silver nanoparticles by thermal decomposition of water-soluble silver oxalate precursors.

Silver oxalate, one of the coordination polymer crystals, is a promising synthetic precursor for transformation into Ag nanoparticles without any reducing chemicals via thermal decomposition of the oxalate ions. However, its insoluble nature in solvents has been a great disadvantage, especially for systematic control of crystal growth of the Ag nanoparticles, while such control of inorganic nanoparticles has been generally performed using soluble precursors in homogeneous solutions. In this paper, we document our discovery of water-soluble species from the reaction between the insoluble silver oxalate and N,N-dimethyl-1,3-diaminopropane.

Plasmon-assisted photocurrent generation from silver nanoparticle monolayers combined with porphyrins via their different chain-length alkylcarboxylates.

Three-typed porphyrin derivatives with a different chain-length alkylcarboxylic acid as their peripheral anchor group have been prepared. Anodic photocurrents were observed in a simple system where the porphyrin derivatives were directly anchored on an indium tin oxide (ITO) electrode. Cathodic photocurrents and their plasmon-assisted enhancement appeared from an Ag nanoparticle (Ag NP) composite monolayer combined with the porphyrin derivatives on the ITO electrode.

Molecular nanostamp based on one-dimensional porphyrin polymers.

Surface design with unique functional molecules by a convenient one-pot treatment is an attractive project for the creation of smart molecular devices. We have employed a silane coupling reaction of porphyrin derivatives that form one-dimensional polymer wires on substrates. Our simple one-pot treatment of a substrate with porphyrin has successfully achieved the construction of nanoscale bamboo shoot structures.

New ternary ligands consisting of an N4 bridging ligand and two terpyridines, and their Co(II) and Ni(II) dinuclear complexes. Structure, redox properties, and reaction with acid.

Two ternary ligands consisting of two 2,2′:6′,2′′-terpyridines and one N4-quadridentate μ2,η(2)-bridging ligand were synthesized. The N4 bridge is 1,4-bis(2-pyridyl)phthalazine in ligand 1, and 3,6-bis(2-pyridyl)pyridazine in ligand 2. Two Co(II) dinuclear complexes [(1)Co2(μ-OH)]3+ and [(2)Co2(μ-OH)]3+, and one Ni(II) dinuclear complex [(1)Ni2(μ-Cl)]3+ were obtained.

Syntheses, properties, and photoreactions of the hybrid molecules consisting of a Co(II) mononuclear complex and porphyrins.

New hybrid molecules consisting of mononuclear Co(II) complexes and porphyrin moieties were synthesized and their new photoreactions were examined. Three porphyrins with different meso-substituents (2,6-dimethoxyphenyl, 3,5-di-tert-butylphenyl, and 2,6-difluorophenyl groups) were used to change the redox potentials of the hybrid compounds. The hybrid molecules were prepared by the stepwise condensation of amide bonds.

Syntheses of the terpyridine-bipyridine linked binary ligands and structural and redox properties of their cobalt complexes.

New binary ligands consisting of 2,2':6',2''-terpyridine and 2,2'-bipyridine were synthesized through the linkage of various lengths of the polymethylene chain (1a-1d; n = 3-6, where n is the number of CH(2) units). Their Co(II) complexes, 2a-2d (Cl complexes) and 2a'-2d' (H(2)O complexes), were synthesized. They exclusively formed mononuclear complexes, which could be oxidized to Co(III) complexes in aqueous solutions after prolonged exposure to the air.

Excitation energy flow control in {Ru(2,2'-bipyridine)2}-{pyridylporphyrin}2 systems.

The direction of excitation energy migration is reversed in a system composed of {Ru(bpy)(2)}-{pyridylporphyrin}(2) by the addition of a Zn(2+) ion. The Zn(2+) system shows an excitation-wavelength dependent emission.

Structural, redox, and photophysical studies of the tetra(pyridyl)porphyrin complex containing four (2,2'-bipyridine)(2,2':6',2"-terpyridine)ruthenium(II) groups.

New hybrid complexes of polypyridyl ruthenium and pyridylporphyrins have been prepared by the coordination of pyridyl nitrogens to the ruthenium centers. A 1:4 hybrid complex, [{Ru(bpy)(trpy)}4(mu4-H2Py4P)]8+ ([1]8+) (bpy = 2,2'-bipyridine; trpy = 2,2':6',2"-terpyridine; H2Py4P = 5,10,15,20-tetra(4-pyridyl)porphyrin), has been characterized by the single-crystal X-ray diffraction method. A 1:1 complex, [{Ru(bpy)(trpy)}(H2PyT3P)]2+ ([2]2+) (H2PyT3P = 5-(4-pyridyl)tritolylporphyrin) has also been prepared.