Silver atom and strand numbers in fluorescent and dark Ag:DNAs

2012 ◽  
Vol 48 (46) ◽  
pp. 5748 ◽  
Author(s):  
Danielle Schultz ◽  
Elisabeth G. Gwinn
Keyword(s):  

Zeeman spectroscopy is not practicable for the investigation of the structure of electronic conventional states which give rise to broad optical absorption bands in solids. We have investigated the application of Faraday rotation and circular dichroism techniques to absorption bands of neutral silver atoms and F centres in alkali halides. These centres give rise to optical absorption bands due to transitions of the type 2 S → 2 P which are 2000 to 6000 cm -1 in width because, in part, of strong coupling to lattice phonons. A discussion is given of information which may be obtained concerning the electonic states involved in the 2 S → 2 P transition by analysis of the magneto-optical effects by the method of moments. It is shown, for example, that the spin-orbit coupling constant of the 2 P state of the silver atom is reduced from 613 cm -1 in the free state to 365 cm -1 in KCl, to 102 cm -1 in KBr and to an unmeasurably small value in KI. This cancellation of spin-orbit interaction of the silver atom is assigned to symmetry allowed admixtures of lattice ion wavefunctions into the 2 P state.


2021 ◽  
Vol 13 (1) ◽  
pp. 21-30
Author(s):  
O.K. Sharutina ◽  

By mixing solutions of tris(2-methoxy-5-bromophenyl)antimony and silver nitrate in a methanol : acetonitrile mixture (1:1 vol.), nitrato-O,O'-(acetonitrile)[tris(2-methoxy-5-bromophenyl)antimony]silver complex with the general formula [(C6H3ОMe-2-Br-5)3SbAg(μ2-NO3)(Ме3CN)]2•2[(C6H3ОMe-2-Br-5)3SbAgNO3(Ме3CN)] (1) has been obtained. An addition of silver nitrate solution in the methanol : acetonitrile mixture to the tris(2-methoxy-5-bromophenyl)antimony dioxane solution has led to the formation of a small amount of dark crystals of the ionic complex [(2-MeО-5-Br-C6H3)3SbAg(H2O)Sb(C6H3Br-5-OMe-2)3]+[(2-MeО-5-Br-C6H3)3SbAg(m-NO3)3 AgSb(C6H3Br-5-OMe-2)3]-×3C4H8O2 (2). Complexes 1 and 2 have been characterized by IR spectroscopy, and their structures have been determined by X-ray diffraction analysis. The IR spectra of complexes 1 and 2 contain the bands characterizing the Sb-O, Sb-C, С≡N-, and NO3-group band vibrations. X-ray diffraction analysis of the complexes has been carried out on an automatic four-circle D8 Quest Bruker diffractometer (МоКα radiation, λ = 0.71073 Å, graphite monochromator) at 293 K. Crystallographic characteristics of 1: triclinic, P-1 space group, a = 9.32(3), b = 17.50(7), c = 17.97(5) Å, a = 97.56(14), β = 92.90(19), g = 99.45(19) grad., V = 2859(16) Å3, Z = 2, rcalc = 2.069 g/cm3, 2: monoclinic, С2/с space group, a = 17.417(14), b = 21.041(15), c = 32.01(2) Å, a = 90, β = 97.79(3), g = 90 grad., V = 11624(15) Å3, Z = 4, rcalc = 2.006 g/cm3. In the monomeric and dimeric molecules of crystal 1, nitrate ligands are chelating and bridging, respectively. In the cation of complex 2, the silver atom is bonded to two antimony ligands, the third coordination site is occupied by a water molecule. In the dimeric anion there are one antimony ligand and three bridging nitrate groups surrounding each silver atom.


1997 ◽  
Vol 52 (2) ◽  
pp. 301-304 ◽  
Author(s):  
Alexander Sladek ◽  
Hubert Schmidbaur

Abstract Treatment of tris[(triphenylphosphine)gold(I)]-sulfonium tetrafluoroborate with AgBF4 (molar ratio 2:1) in tetrahydrofuran affords a hepta-nuclear mixed-metal cluster trication {[(Ph3P)6Au6AgS2](thf)}3+ as the tetrafluorobor­ate salt. The crystal structure of the compound has been determined by X-ray diffraction. The sil­ver atom is found in a bridging position between the two Au3S units with short contacts to both sulfur atoms and to three out of six gold atoms. The coordination sphere of the silver atom is complemented by a tetrahydrofuran molecule. In di(tri)chlorom ethane solutions there is rapid site exchange of the silver coordination as shown by virtual equivalence of the phosphine ligands on the NMR time scale at ambient temperature.


Author(s):  
S.D. Tošić ◽  
V.I. Kelemen ◽  
D. Šević ◽  
V. Pejčev ◽  
D.M. Filipović ◽  
...  

1993 ◽  
Vol 07 (01n03) ◽  
pp. 374-378 ◽  
Author(s):  
Naoshi SUZUKI ◽  
Tatsuya TESHIMA ◽  
Kazuko MOTIZUKI

Self-consistent LAPW band calculations have been carried out systematically for intercalation compounds M 1/3 TiS 2 (M=transition metal, silver, alkali metal) in order to clarify bonding nature between the guest atoms and the host TiS 2. In transition-metal intercalates the guest 3d states hybridize with the S 3p states as well as the Ti 3d states. As the result covalent bonds are formed between the guest 3d and S 3p states, conserving the covalent bonds between the Ti 3d and S 3p states of the host. In Ag 1/3 TiS 2 the Ag 4d states hybridize strongly with the S 3p state and destroy the host covalent bonds between the Ti 3d and S 3p states. In Li 1/3 TiS 2 and K 1/3 TiS 2 there is little hybridization between the guest 2s or 4s states and the host Ti 3d or S 3p states. Cohesive properties of M 1/3 TiS 2 compounds, including stacking structures of the guest atoms, are discussed on the basis of the total energy calculation.


1980 ◽  
Vol 102 (26) ◽  
pp. 7702-7709 ◽  
Author(s):  
S. A. Mitchell ◽  
J. Farrell ◽  
G. A. Kenney-Wallace ◽  
G. A. Ozin

2016 ◽  
Vol 18 (14) ◽  
pp. 9497-9503 ◽  
Author(s):  
Xun-Lei Ding ◽  
Dan Wang ◽  
Rui-Jie Li ◽  
Heng-Lu Liao ◽  
Yan Zhang ◽  
...  

The single Au atom can be adsorbed on both V and O sites of vanadium oxide clusters with quite large binding energies, illustrating the stabilization of noble atoms in single-atom catalysts.


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