| 1. |
- Hicks, R. G., et al.
(författare)
-
Strong supramolecular-based magnetic exchange in pi-stacked radicals. Structure and magnetism of a hydrogen-bonded verdazyl radical : hydroquinone molecular solid
- 2001
-
Ingår i: Journal of the American Chemical Society. ; 123:29, s. 7154-7159
-
Tidskriftsartikel (refereegranskat)abstract
- The X-ray crystal structure and magnetic properties of a molecular crystal consisting of 1,5-dimethyl-3-(2-pyridyl)-6-oxoverdazyl radical and hydroquinone (pyvd:hq) are presented. The structure contains a two-dimensional network of hydrogen bonds involving the hydroquinones and the pyridine ring of the pyvd radical. The radicals adopt an unusual head-over-tail (antiparallel) jr-stacked array perpendicular to the hydrogen-bonded planes. The variable-temperature magnetic susceptibility data can be modeled using a one-dimensional antiferromagnetic chain model, with J = -58 cm(-1). The strength of the magnetic coupling is very unusual because there are no close intermolecular radical-radical contacts to provide conventional pathways for magnetic interactions. A pathway for coupling is proposed involving the mediation of magnetic exchange interactions between radical centers by the pyridine rings. Density functional calculations on the pyvd radical, as well as aggregates thereof based on the X-ray structure, have been employed in attempts to understand the possible mechanisms by which the strong magnetic interactions are achieved.
|
|
| 2. |
|
|
| 3. |
- Li, K., et al.
(författare)
-
MBE-based SiGe/Si heterojunction multilayer structures
- 2001
-
Ingår i: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 227-228, s. 744-748
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, SiGe/Si multilayer heterostructures prepared by molecular beam epitaxy (MBE) are described with the aim of manufacturing SiGe heterojunction bipolar transistors (HBTs). Based on the simulations made by Medici, device structures have been designed and grown. The quality of the MBE layered structures has been characterized by reflection high-energy electron diffraction, X-ray diffraction, secondary ion mass spectrometry and spreading resistance. Furthermore, SiGe-HBTs have been fabricated. Promising DC and RF results of processed HBT devices have been obtained. © 2001 Elsevier Science B.V.
|
|
| 4. |
|
|
| 5. |
- Sun, S. G., et al.
(författare)
-
Studies on a series of rhenium(I) bipyridyl photosensitive dyes
- 2004
-
Ingår i: Youji huaxue. - 0253-2786. ; 24:8, s. 953-956
-
Tidskriftsartikel (refereegranskat)abstract
- A series of rhemium(I) 2,2'-bipyridyl complexes [fac-(4,4'-di-COOEt-bpy)Re(CO)(3)(Xpy)PF6] (bpy = 2, 2'-bipyridine; py = pyridine; X = 3-methyl, 3-hydroxy, 3-amino, H) were synthesized. Their electrochemical properties, ground state electronic spectra and emission spectra were studied in acetonitrile. As the X group became more electron donating from H to 3-methyl, 3-hydroxy or 3-amino, the Re(II/I) oxidation potentials declined, the MLCT absorption maximum of the complex was changed little, the emission maximum blue-shifted, and the emission intensity and the fluorescence lifetime were decreased.
|
|
| 6. |
- Sun, S. G., et al.
(författare)
-
Synthesis of rhenium(I) bipyridyl and ruthenium(II) tris-bipyridyl photosensitive dyes used for solar cells
- 2004
-
Ingår i: Gaodeng xuéxiào huàxué xuébào. - 0251-0790. ; 25:1, s. 67-70
-
Tidskriftsartikel (refereegranskat)abstract
- There has been a growing effort to convert solar energy into electricity in recent years. In order to get a stable solar cell system and acquire a high incident photon-to-current conversion efficiency(IPCE), two novel rhenium(I) bipyridyl and ruthenium(II) tris-bipyridyl photosensitive dyes were synthesized, the ethoxycarbonyl group in the dyes could be employed for covalently linking to the surface of the nanostructured TiO2. Their structures, photophysical and electrochemical properties were studied. The UV-Vis absorption maxima were 382 and 476 nm; emission maxima were 622 and 672 nm, respectively. The Re(I/II) oxidation potential is significantly positive than that of Ru(II/III) which provides a larger driving force for electron transfer. The results show that they both have proper redox potentials, enough stability and are suitable for being used as photosensitizers of solar cells.
|
|
| 7. |
- Sun, S. G., et al.
(författare)
-
Synthesis of two novel rhenium(I) bipyridyl photosensitive dyes
- 2004
-
Ingår i: Chinese Chemical Letters. - 1001-8417 .- 1878-5964. ; 15:8, s. 965-968
-
Tidskriftsartikel (refereegranskat)abstract
- Two novel rhenium(I) 2, 2'-bipyridyl complexes, [(4,4'-di-COOEt-bipy) Re(CO)3 (NCCH3)PF6] and [(4,4'-di-COOEt-bipy) Re (CO)(3) (NCS)], a model complex [(4,4'-di-COOEt-bipy) Re (CO)(3) (pyridine)PF6], were synthesized. Their ground state electronic spectra and emission spectra were measured in acetonitrile. The MLCT absorption maximum of the complex exhibited a considerable red shift as the ligand changed from pyridine to CNCH3, or SCN.
|
|
| 8. |
|
|
