High-performance, lightweight coaxial cable from carbon nanotube conductors.

Coaxial cables have been constructed with carbon nanotube (CNT) materials serving as both the inner and outer conductors. Treatment of the CNT outer and inner conductors with KAuBr(4) was found to significantly reduce the attenuation of these cables, which demonstrates that chemical agents can be used to improve power transmission through CNT networks at high frequencies (150 kHz-3 GHz). For cables constructed with a KAuBr(4)-treated CNT outer conductor, power attenuation per length approaches parity with cables constructed from metallic conductors at significantly lower weight per length (i.

Carbon nanotube wires and cables: near-term applications and future perspectives.

Wires and cables are essential to modern society, and opportunities exist to develop new materials with reduced resistance, mass, and/or susceptibility to fatigue. This article describes how carbon nanotubes (CNTs) offer opportunities for integration into wires and cables for both power and data transmission due to their unique physical and electronic properties. Macroscopic CNT wires and ribbons are presently shown as viable replacements for metallic conductors in lab-scale demonstrations of coaxial, USB, and Ethernet cables.

Platinum(II) terpyridyl acetylide complexes on platinized TiO(2): toward the photogeneration of H(2) in aqueous media.

New platinum(II) terpyridyl acetylide complexes having the ability to bind to TiO(2) have been synthesized and assayed in their ability to sensitize platinized titanium dioxide for the photogeneration of H(2) using visible light (lambda > 410 nm). Specifically, the complexes [Pt(tpy-phen-COOH)(C[triple bond]C-C(6)H(5))]Cl (1), where tpy-phen-COOH = 4'-(4-carboxyphenyl)-[2,2';6',2'']terpyridine and C[triple bond]C-C(6)H(5) = phenylacetylide, and [Pt(tpy-COOH)(C[triple bond]C-C(6)H(5))]Cl (2), where tpy-COOH = 4'-carboxy-2,2';6',2''-terpyridine, were prepared to investigate the effectiveness of attachment and proximity to the TiO(2) surface on hydrogen yield. Both complexes 1 and 2 sensitize the photogeneration of hydrogen, but produce fewer turnovers than the unbound chromophore, [Pt(ttpy)(C[triple bond]C-C(6)H(5))]PF(6) (5).

Cyclometalated 6-phenyl-2,2'-bipyridyl (CNN) platinum(II) acetylide complexes: structure, electrochemistry, photophysics, and oxidative- and reductive-quenching studies.

Three cyclometalated 6-phenyl-4-(p-R-phenyl)-2,2'-bipyridyl (CNN-Ph-R) Pt(II) acetylide complexes, Pt(CNN-Ph-R)(CCPh), where R = Me (1), COOMe (2), and P(O)(OEt)(2) (3), have been synthesized and studied. Compounds 1 and 3 have been structurally characterized by single crystal X-ray crystallography and are found to exhibit distorted square planar geometries about the Pt(II) ions. The electrochemical properties of the compounds, as determined by cyclic voltammetry, have also been examined.

Platinum(II) terpyridyl-acetylide dyads and triads with nitrophenyl acceptors via a convenient synthesis of a boronated phenylterpyridine.

Four new Pt(II) terpyridyl acetylide complexes which possess a covalently linked nitrophenyl moiety were prepared and studied. Specifically, the chromophore-acceptor (C-A) dyads reported here include [Pt(ptpy-ph-p-NO(2))(C[triple bond]C-C(6)H(5))](PF(6))(3) (1), where ptpy-ph-p-NO(2) = 4'-{4-(4-nitrophenyl)-phenyl}-[2,2';6',2'']terpyridine, and C[triple bond]C-C(6)H(5) = phenylacetylide and [Pt(ptpy-ph-m-NO(2))(C[triple bond]C-C(6)H(5))](PF(6))(2) (2), where ptpy-ph-m-NO(2) = 4'-(4-m-nitrophenyl-phenyl)-2,2';6',2''-terpyridine, as well as the related donor-chromophore-acceptor (D-C-A) triads [Pt(ptpy-ph-p-NO(2))(C[triple bond]C-C(6)H(4)CH(2)-PTZ)]PF(6) (3), where C[triple bond]C-C(6)H(4)CH(2)-PTZ = 4-ethynylbenzyl-N-phenothiazine, and [Pt(ptpy-ph-m-NO(2))(C[triple bond]C-C(6)H(4)CH(2)-PTZ)]PF(6) (4). Transient absorption spectroscopy and electrochemical analyses were used to characterize these compounds.

Photoinduced electron transfer in platinum(II) terpyridyl acetylide chromophores: reductive and oxidative quenching and hydrogen production.

A series of luminescent platinum(II) terpyridyl acetylide complexes, ([Pt(tpy)(CCPh)]ClO4 (1) and [Pt(ttpy)(CC-p-C6H4R)]ClO4, where tpy=terpyridine, ttpy=4'-p-tolylterpyridine, R=H, Cl, Me) (2-4) were studied with regard to excited-state quenching by dialkylated bipyridinium cations as electron acceptors and triethanolamine (TEOA) as an electron donor and the photogeneration of hydrogen from systems containing the chromophore, the dialkylated bipyridinium cations, TEOA, and colloidal Pt as a catalyst. The dialkylated bipyridinium cations include methyl viologen (MV2+) and a series of diquats prepared from 2,2'-bipyridine or 4,4'-dimethyl-2,2'-bipyridine. The quenching rates for the diquats for one of the chromophores (2) are close to the diffusion-controlled limit.

Solution behavior of a novel biopharmaceutical drug candidate: a gonadotropin-toxin conjugate.

There is little known about the solution structure and stability of peptide-protein conjugates, which comprise a new class of potential biopharmaceutical agents. This study describes the solution behavior of gonadotropins-releasing hormone (GnRH) chemically conjugated to pokeweed antiviral protein (PAP). The conjugate adopts a well-defined conformation across a pH range of 4 to 8.

Photocatalytic generation of hydrogen from water using a platinum(II) terpyridyl acetylide chromophore.

The cationic complex [Pt(tolylterpyridine)(phenylacetylide)]+ has been used as a photosensitizer for the reduction of aqueous protons in the presence of a sacrificial electron donor to make H2. In this system, triethanolamine (TEOA) acts as the sacrificial reducing agent, methyl viologen (MV2+) serves as an electron transfer agent, and colloidal Pt stabilized by polyacrylate functions as the catalyst for H2 generation. The Pt(II) chromophore undergoes both oxidative and reductive quenching, but H2 is only seen when both TEOA and MV2+ are present.