81795-79-1Relevant articles and documents
Oligo p-Phenylenevinylene Derivatives as Electron Transfer Matrices for UV-MALDI
Castellanos-García, Laura J.,Agudelo, Brian Castro,Rosales, Hernando F.,Cely, Melissa,Ochoa-Puentes, Christian,Blanco-Tirado, Cristian,Sierra, Cesar A.,Combariza, Marianny Y.
, p. 2548 - 2560 (2017/12/12)
Phenylenevinylene oligomers (PVs) have outstanding photophysical characteristics for applications in the growing field of organic electronics. Yet, PVs are also versatile molecules, the optical and physicochemical properties of which can be tuned by manipulation of their structure. We report the synthesis, photophysical, and MS characterization of eight PV derivatives with potential value as electron transfer (ET) matrices for UV-MALDI. UV-vis analysis show the presence of strong characteristic absorption bands in the UV region and molar absorptivities at 355 nm similar or higher than those of traditional proton (CHCA) and ET (DCTB) MALDI matrices. Most of the PVs exhibit non-radiative quantum yields (φ) above 0.5, indicating favorable thermal decay. Ionization potential values (IP) for PVs, calculated by the Electron Propagator Theory (EPT), range from 6.88 to 7.96 eV, making these oligomers good candidates as matrices for ET ionization. LDI analysis of PVs shows only the presence of radical cations (M+.) in positive ion mode and absence of clusters, adducts, or protonated species; in addition, M+. threshold energies for PVs are lower than for DCTB. We also tested the performance of four selected PVs as ET MALDI matrices for analytes ranging from porphyrins and phthalocyanines to polyaromatic compounds. Two of the four PVs show S/N enhancement of 1961% to 304% in comparison to LDI, and laser energy thresholds from 0.17 μJ to 0.47 μJ compared to 0.58 μJ for DCTB. The use of PV matrices also results in lower LODs (low fmol range) whereas LDI LODs range from pmol to nmol. [Figure not available: see fulltext.].
Understanding the unconventional effects of halogenation on the luminescent properties of oligo(phenylene vinylene) molecules
Sun, Chun-Lin,Li, Jun,Geng, Hong-Wei,Li, Hui,Ai, Yong,Wang, Qiang,Pan, Shan-Lin,Zhang, Hao-Li
supporting information, p. 3091 - 3100 (2014/01/06)
It is commonly known that halogenation tends to decrease the luminescence quantum yield of an organic dye, owing to the high electronegativity and heavy-atom effect of the halogen atom. However, based on an investigation of the effects of halogenation on the luminescence of the oligo(phenylene vinylene) (OPV) framework, we demonstrate that halogenation can have positive impact on the solid-state fluorescence and electrochemiluminescence (ECL) properties of OPV derivatives. The chlorinated OPV exhibits a very high solid-state fluorescence quantum yield (91 %), whilst the brominated analogue gives the highest ECL emission intensity. Time-dependent density functional theory calculations, natural bond orbital analysis, and natural transition orbital analysis were performed to assist the understanding of the origin of these positive halogenation effects, which provide insight into the rational design of highly luminescent halogenated organic materials for solid-state devices and ECL applications. Copyright
Solid state behaviour of vinyl quinones
Irngartinger,Lichtenthaeler,Herpich,Stadler
, p. 349 - 360 (2007/10/03)
2,5-Bisvinyl-1,4-benzoquinones 1 and 2-vinyl-1,4-benzoquinones 2 substituted with aryl or ester end groups have been synthesized. The 2,5-bisstyryl-1,4-benzoquinones 1 (R=phenyl, p-tolyl, o-tolyl) crystallize with a 7 angstrom-stacking axis. But only for the o-tolyl derivative the contacts between the vinyl groups are close enough to allow a four-center type photopolymerization. The ester derivative 1 (R=COOEt) has a layer structure and can be photooligomerized in the crystal. The generated cyclobutane subgroups have twofold symmetry. The vinylquinones 2 (R=aryl) may be dimerized photochemically in the crystal at the vinyl groups to centrosymmetric cyclobutanes. Crystals with 4 angstrom stacking axis are also photoreactive.
