Radiation-induced decomposition of the metal-organic molecule Bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II)

The effects of vacuum ultraviolet radiation on the adsorbed copper center molecule bis(4-cyano-2,2,6,6- tetramethyl-3,5-heptanedionato)copper(II) (or Cu(CNdpm)2), (C24H36N2O4Cu, Cu(II)) was studied by photoemission spectroscopy. Changes in the ultraviolet photoemission spectra (UPS) of Cu(CNdpm)2, adsorbed on Co(1 1 1), indicate that the ultraviolet radiation leads to decomposition of Cu(CNdpm)2 and this decomposition is initially dominated by loss of peripheral hydrogen

Radiation-induced decomposition of the metal-organic molecule Bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II)

The effects of vacuum ultraviolet radiation on the adsorbed copper center molecule bis(4-cyano-2,2,6,6- tetramethyl-3,5-heptanedionato)copper(II) (or Cu(CNdpm)2), (C24H36N2O4Cu, Cu(II)) was studied by photoemission spectroscopy. Changes in the ultraviolet photoemission spectra (UPS) of Cu(CNdpm)2, adsorbed on Co(1 1 1), indicate that the ultraviolet radiation leads to decomposition of Cu(CNdpm)2 and this decomposition is initially dominated by loss of peripheral hydrogen

Photofragmentation of \u3ci\u3ecloso\u3c/i\u3e-Carboranes Part 1: Energetics of Decomposition

The ionic fragmentation following B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-dicarbadodecaboranes: orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), and paracarborane (1,12-C2B10H12)] is compared with the energetics of decomposition. The fragmentation yields for all three molecules are quite similar. Thermodynamic cycles are constructed for neutral and ionic species in an attempt to systemically characterize single-ion closo-carborane creation and fragmentation processes. Lower energy decomposition processes are favored. Among the ionic species, the photon-induced decomposition is dominated by BH+ and BH2+ fragment loss. Changes in ion yield associated with core to bound excitations are observed

Photo-fragmentation of the closo-carboranes Part 1: Energetics of Decomposition

The ionic fragmentation following B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-dicarbadodecaboranes: orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), and paracarborane (1,12-C2B10H12)], is compared with the energetics of decomposition. The fragmentation yields for all three molecules are quite similar. Thermodynamic cycles are constructed for neutral and ionic species in an attempt to systemically characterize single ion closo-carborane creation and fragmentation processes. Lower energy decomposition processes are favored. Among the ionic species, the photon induced decomposition isdominated by BH+ and BH2+ fragment loss. Changes in ion yield associated with core to bound excitations are observed

Photo-fragmentation of the closo-carboranes Part 1: Energetics of Decomposition

The ionic fragmentation following B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-dicarbadodecaboranes: orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), and paracarborane (1,12-C2B10H12)], is compared with the energetics of decomposition. The fragmentation yields for all three molecules are quite similar. Thermodynamic cycles are constructed for neutral and ionic species in an attempt to systemically characterize single ion closo-carborane creation and fragmentation processes. Lower energy decomposition processes are favored. Among the ionic species, the photon induced decomposition is dominated by BH+ and BH2+ fragment loss. Changes in ion yield associated with core to bound excitations are observed

Cross linking molecular systems to form ultrathin dielectric layers

Dehydrogenation leads to cross linking of polymer or polymer like formation in very different systems: self-assembled monolayers and in closo -carboranes leading to the formation of semiconducting and dielectric boron carbide. We find evidence of intermolecular interactions for a self-assembled monolayer (SAM) formed from a large molecular adsorbate, [1,1\u27;4\u27,1 -terphenyl]-4,4 -dimethanethiol, from the dispersion of the molecular orbitals with changing the wave vector k and from the changes with temperature. With the formation self assembled molecular (SAM) layer, the molecular orbitals hybridize to electronic bands, with indications of significant band dispersion of the unoccupied molecular orbitals. Although organic adsorbates and thin films are generally regarded as “soft” materials, the effective Debye temperature, indicative of the dynamic motion of the lattice normal to the surface, can be very high, e.g. in the multilayer film formed from [1,1\u27-biphenyl]-4,4\u27-dimethanethiol (BPDMT). Depending on molecular orientation, the effective Debye temperature can be comparable to that of graphite due to the ‘stiffness’ of the benzene rings, but follows the expected Debye-Waller behavior for the core level photoemission intensities with temperature. This is not always the case. We find that a monomolecular film formed from [1,1\u27;4\u27,1 -terphenyl]-4,4 -dimethanethiol deviates from Debye-Waller temperature behavior and is likely caused by temperature dependent changes in molecular orientation. We also find evidence for the increase in dielectric character with polymerization (cross-linking) in spite of the decrease in the HOMO-LUMO gap upon irradiation of TPDMT. The changes in the HOMO-LUMO gap, with cross-linking, are roughly consistent with the band dispersion. The decomposition and cross-linking processes are also accompanied by changes in molecular orientation. The energetics of the three isomeric carborane cage compounds [ closo-1,2-orthocarborane, closo-1,7-metacarborane, closo-1,12-paracarborane (C2B10H12)] decomposition are investigated. Thermodynamic Born-Haber cycles are constructed for neutral and ionic species in an attempt to systemically characterize closo-carborane decomposition process. The decomposition processes are in favor of lower energy decomposition processes. Among the ionic species the photon induced decomposition is dominated by BH+ and BH 2+ fragment loss, and associated with core to bound excitations. It has been observed that dehydrogenation of the closo-carboranes leads to possible cross-linking and formation of a boron rich semiconductor with good dielectric properties

Research on the filters with super-structured fiber gratings

Sampled fiber grating was analyzed with Fourier method and coupled mode theory respectively. Numerical simulation was carried out, the result suggested that sampled rate T could affect the spectral property of the sampled fiber grating. It was found in the research that the interval between two reflective peaks and their number were basically determined by sampling period P when reflective ratio was low. However, when T0. 1, the interval becamerelated to T. The result in this paper queried the conclusion gotten in other papers, in whichthe reflective peaks were always expressed as: Based on the theory in the pa-per, an effective and economical method to fabricate comb-filter was proposed

Amplification and spontaneous emission of Er-doped fiber both in theory and experiment

We took a step forward on the basis of existing deduction, the formula of net gain coefficient of amplification of spontaneous emission of Er-doped fiber was given. Based on the data, which were provided by the reference, we calculated the net gain coefficients for different fiber length pumped at different pump power. Then theoretical curves were drawn. ASE spectra obtained experimentally were in excellent qualitative agreement with the ones obtained from theory. At last, the calculated optimal fiber lengths were given according to several common used wavelengths at the same pump power