Castellanos-García Laura J, Agudelo Brian Castro, Rosales Hernando F, Cely Melissa, Ochoa-Puentes Christian, Blanco-Tirado Cristian, Sierra Cesar A, Combariza Marianny Y
Escuela de Química, Universidad Industrial de Santander, Bucaramanga, Santander, Colombia.
Departamento de Química, Universidad Nacional de Colombia, Bogotá, Colombia.
J Am Soc Mass Spectrom. 2017 Dec;28(12):2548-2560. doi: 10.1007/s13361-017-1783-z. Epub 2017 Sep 6.
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. Graphical Abstract ᅟ.
苯撑乙烯低聚物（PVs）在有机电子学这一不断发展的领域中具有出色的光物理特性，适用于多种应用。然而，PVs也是多功能分子，其光学和物理化学性质可通过结构调控来调整。我们报告了八种PV衍生物的合成、光物理和质谱表征，这些衍生物具有作为紫外基质辅助激光解吸电离（UV-MALDI）电子转移（ET）基质的潜在价值。紫外-可见光谱分析表明，在紫外区域存在强特征吸收带，且在355 nm处的摩尔吸光率与传统质子（CHCA）和ET（DCTB）MALDI基质相似或更高。大多数PVs表现出高于0.5的非辐射量子产率（φ），表明热衰减良好。通过电子传播理论（EPT）计算的PVs电离势值（IP）范围为6.88至7.96 eV，使这些低聚物成为ET电离基质的良好候选物。PVs的激光解吸电离（LDI）分析表明，在正离子模式下仅存在自由基阳离子（M），不存在簇、加合物或质子化物种；此外，PVs的M阈值能量低于DCTB。我们还测试了四种选定的PVs作为ET MALDI基质对从卟啉、酞菁到多环芳烃等分析物的性能。与LDI相比，四种PVs中的两种显示信噪比提高了1961%至304%，激光能量阈值为0.17 μJ至0.47 μJ，而DCTB为0.58 μJ。使用PV基质还可实现更低的检测限（低飞摩尔范围），而LDI的检测限范围为皮摩尔至纳摩尔。图形摘要ᅟ
