685114-67-4Relevant academic research and scientific papers
Control of intermolecular bonds by deposition rates at room temperature: Hydrogen bonds versus metal coordination in trinitrile monolayers
Sirtl, Thomas,Schloegl, Stefan,Rastgoo-Lahrood, Atena,Jelic, Jelena,Neogi, Subhadip,Schmittel, Michael,Heckl, Wolfgang M.,Reuter, Karsten,Lackinger, Markus
, p. 691 - 695 (2013)
Self-assembled monolayers of 1,3,5-tris(4′-biphenyl-4″- carbonitrile)benzene, a large functional trinitrile molecule, on the (111) surfaces of copper and silver under ultrahigh vacuum conditions were studied by scanning tunneling microscopy and low-energy electron diffraction. A densely packed hydrogen-bonded polymorph was equally observed on both surfaces. Additionally, deposition onto Cu(111) yielded a well-ordered metal-coordinated porous polymorph that coexisted with the hydrogen-bonded structure. The required coordination centers were supplied by the adatom gas of the Cu(111) surface. On Ag(111), however, the well-ordered metal-coordinated network was not observed. Differences between the adatom reactivities on copper and silver and the resulting bond strengths of the respective coordination bonds are held responsible for this substrate dependence. By utilizing ultralow deposition rates, we demonstrate that on Cu(111) the adatom kinetics plays a decisive role in the expression of intermolecular bonds and hence structure selection.
Pure Deep Blue Light-Emitting Diodes from Alternating Fluorene/Carbazole Copolymers by Using Suitable Hole-Blocking Materials
Lu, Jianping,Tao, Ye,D'iorio, Marie,Li, Yuning,Ding, Jianfu,Day, Michael
, p. 2442 - 2449 (2007/10/03)
The influences of the carbazole content on the photophysical, electrochemical, and electroluminescent properties of alternating fluorene/carbazole copolymers PFnCz (n = 1, 2, 3) with well-defined chemical structures have been systematically investigated. The incorporation of carbazole units into the polyfluorene (PF) backbone resulted in a blue shift of both the absorption and photoluminescence (PL) emission peaks, improved PL thermal stability, raised HOMO energy levels, and thus facilitated hole injection into the copolymers. Pure deep blue electroluminescence (EL) with narrow with (full width at the half-maximum) (39-52 nm) and negligible low-energy emission bands was successfully achieved from the PFnCz copolymers by using l,3,5-tris(4′-fluorobiphenyl-4-yl)benzene (F-TBB) as a hole-blocking layer and Alq3 as an electron injection/transporting layer. This device configuration stabilized the blue emission from the PF derivatives. An efficiency of 0.72 cd/A at a luminance of 100 cd/m2 was obtained even with aluminum metal as the cathode.
