We have prepared carbon aerogels (CAs) doped with copper through sol-gel polymerization of formaldehyde with the potassium salt of 2,4-dihydroxybenzoic acid, followed by ion exchange with Cu(NO3)2, supercritical drying with liquid CO2, and carbonization at 1050 °C under a N2 atmosphere. The materials were characterized by elemental analysis, nitrogen adsorption, high-resolution transmission electron microscopy, and X-ray diffraction. Results obtained indicate that this approach is an effective method for controlling both the amount and the distribution of a desired metal species within the carbon framework. We also found that carbonization of the copper-doped organic aerogels results in the formation of spherical copper nanoparticles within the carbon framework of the aerogel. The copper nanoparticles have a cubic crystalline structure and range in size from 10 to 50 nm. The Cu-doped CAs retain the overall open cell structure of metal-free CAs, exhibiting high surface areas and pore diameters in the micro-and mesoporic region.

X-ray absorption spectroscopy and X-ray photoemission spectroscopy have been used to examine sulfur−gold bond formation in monolayers derived from a dithiol monomer and related disulfide-containing polyamides. These compounds were designed to allow the molecules to adsorb to gold through two terminal sulfurs, forming surface-attached loops. Element and site-specific density of unoccupied electronic states were probed by X-ray absorption spectroscopy at the C 1s, N 1s, O 1s (K-edge), and S 2p (L2,3-edge) absorption edges. Photoemission measurements of the C 1s, N 1s, O 1s, and S 2p core lines were also used to estimate relative coverage, to confirm layer formation, and to evaluate chemical bonding of the monomer and polyamide to the gold-coated substrates. In the case of the dithiol monomer, the spectroscopic evidence clearly shows that most of the molecules adsorb through a single thiol end. The disulfide-containing precursors, in contrast to the monomer, attach to the surface through both sulfurs to form the anticipated surface-attached loop.

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The C 1s and O 1s core-level photoabsorption spectra of poly͓2-methoxy,5-͑2Ј-ethyl-hexoxy͒-1,4-phenylene vinylene͔ ͑MEH-PPV͒ before and after exposure O 2 and broadband visible light were recorded to determine the degradation pathway for this polymer. The change in the O 1s spectra as a function of exposure demonstrates that the O adds to the polymer chain to form a carbonyl group. Exposure to only O 2 or only light causes no change in the C 1s or O 1s spectra. In the C 1s spectra, the change in the dependence on the photon angle of incidence after exposure demonstrates that O attacks the polymer at the double bond in the vinyl group thereby altering the extended conjugation of the polymer.

Bis(triphenylphosphine)(l,10-phenanthroline-5,6-diolato)platinum(II), (PPh3)2Pt(0',0-PhD), may be prepared by treating 1,10-phenanthroline-5,6-dione with Pt(PPh3)4. The oxygen-bound diolate form of the PhD ligand can coordinate to an additional metal through the nitrogen donor atoms forming a binuclear complex with the (PPh3)2Pt(0',O-PhD) unit serving as a bipyridine-like ligand. Complexes of general form (PPh3)2Pt(O',O-PhD-7V,lV0ML" have been prepared with ML, = PdCl2, Ru(PPh3)2Cl2, and Pt(DBCat). The Pt.Pd and Pt.Ru complexes could not be characterized from elemental analytical data due to the presence of nonstoichiometric solvate molecules; crystallographic structure determinations provided information on both complexes.(PPh^PtCO'O-PhD-MA^OPdC^crystallizes in the orthorhombic space group Pbcn with 2.5 molecules of benzene per complex molecule in a unit cell of dimensions a = 16.175 (5) Á, 6 = 27.792 (6) A, c = 25.801 (7) A, V = 11599 (5) A3, and Z 8.(PPh3)2Pt(0'0-PhD-A,,jV')Ru(PPh3)2Cl2 crystallizes as a mixed toluene-dichloromethane solvate, in the triclinic space group Pi, with unit cell dimensions of a = 15.758 (3) A, b = 15.715 (3) A, c = 19.193 (3) A, a = 82.91 (1)°, ß = 80.41 (l)e, y - 66.89 (1)°, V = 4301 (1) A3, and Z = 2. Structural features of both molecules include similar, planar P2Pt(PhD)MCl2 regions, with additional axial PPh3 ligands for M = Ru, and C-O lengths for the PhD ligand that are typical of catecholate ligands. The electrochemical properties of the complexes consist of first and second electron oxidations of the PhD bridge for all three species, with an additional Run/Rum couple for (PPh3)2Pt(0',0-PhD-MAr')Ru(PPh3)2Cl2 and two additional catecholate oxidations for the DBCat ligand of (PPh3)2Pt(0',O-PhD-/V,7V')Pt(DBCat). Similarities in bonding between L"M(0',0-PhD) species and the bipyridine and 1,10-phenanthroline ligands is described. However, the redox activity of the PhD bridge at potentials near the redox potentials of electroactive metal ions presents an important difference between PhD-bridged complexes and the simple nitrogen donor analogues.