Dyeing polymorphs: The MALDI host 2,5-dihydroxybenzoic acid
Dyeing polymorphs: The MALDI host 2,5-dihydroxybenzoic acid
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DOI：
10.1021/cg060887w
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发表时间：
2007-03-01
影响因子：
3.8
通讯作者：
Kahr, Bart
中科院分区：
文献类型：
--
作者：
Cohen, Dawn E.;Benedict, Jason B.;Kahr, Bart
采用染料甲基红对基质辅助激光解吸电离质谱（MALDI-MS）宿主2,5-二羟基苯甲酸的伴生多态性进行了区分。红色和紫色晶体通过检查很容易分离。它们分别对应于已知的形式I (P2(1)/c, a = 4.9110(3)埃，b = 11.8280(7)埃，c = 11.0580(6)埃，beta = 91.059（3)度，V = 642.22埃(3)）和形式II (P2(1)/c, a = 5.5610(2)埃，b = 4.8690(1)埃，c = 23.6880(8)埃，beta = 100.191（1)度，V = 631.27埃(3)）。通过对二羟基苯甲酸和甲基红共晶的x射线结构、混合晶体的线性二色性测量和力场计算，探讨了差异着色的机理。讨论了观测结果与MALDI机制研究的相关性。
The dye methyl red was used to distinguish concomitant polymorphs of the matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) host, 2,5-dihydroxybenzoic acid. Red and purple crystals were readily separated by inspection. They corresponded to the known Form I (P2(1)/c, a = 4.9110(3) angstrom, b = 11.8280(7) angstrom, c = 11.0580(6) angstrom, beta = 91.059(3)degrees, V = 642.22 angstrom(3)) and Form II (P2(1)/c, a = 5.5610(2) angstrom, b = 4.8690(1) angstrom, c = 23.6880 (8) angstrom, beta = 100.191(1)degrees, V = 631.27 angstrom(3)), respectively. X-ray structures of cocrystals of dihydroxybenzoic acids and methyl red, measurements of the linear dichroism of mixed crystals, and force-field calculations were used to investigate the mechanism of differential coloring. The relevance of the observations to investigations of the MALDI mechanism are discussed.