Department of Chemistry, Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC.
J Am Chem Soc. 2012 Jun 20;134(24):9848-51. doi: 10.1021/ja302009h. Epub 2012 Jun 7.
Four photoluminescent dye crystals, TPB-n (n = 1-3) and TPCH, have been synthesized in isolation from carbon-carbon coupling of 4,4'-trimethylene-dipyridine (tmdp) in the absence of organic solvent and catalyst via in situ one-pot metal/ligand oxidative-dehydrogenation reactions. Large crystals have been obtained and readily separated from reaction products without the need for purification. Their structures were characterized: TPB and TPCH represent two dissimilar oxidized forms of tmdp dimers; TPCH was less oxidized but accompanied with partial hydrolysis with molecular formula further confirmed by FAB-MASS analysis. They exhibit distinct photoluminescence (PL) with quantum efficiency measured up to 42%. TPB-2 and TPB-3 are two polymorphic dihydrates, stimuli-responsive toward photoluminescence color changes; both can transform to TPB-1 upon gentle heating. Importantly, the three TPB-n crystals establish the first tetrapyridyl-type ligands adapted by metal phosphates to create a cationic luminescent framework, NTHU-12. This study serves as an inspiring route beyond conventional C-C bond formation reactions and has generated four tmdp dimers in isolation. The facile syntheses have resulted in ample production of a rare type of tetrapyridyl ligands, leading to the discovery of the first positively charged hybrid topology in nanoporous solids. The features of the four luminescent tmdp dimers and NTHU-12 embodied in synthesis, structure, and optical property are reported.
四种光致发光染料晶体，TPB-n（n=1-3）和 TPCH，已经通过在不存在有机溶剂和催化剂的情况下，通过原位一锅金属/配体氧化脱氢反应，从 4,4'-亚甲基二吡啶（tmdp）的碳-碳偶联中分离出来合成。已经获得了大晶体，并可以从反应产物中轻易分离出来，而无需进行纯化。它们的结构已被表征：TPB 和 TPCH 代表 tmdp 二聚体的两种不同氧化形式；TPCH 的氧化程度较低，但伴随着部分水解，分子公式进一步通过 FAB-MASS 分析得到证实。它们表现出明显的光致发光（PL），量子效率高达 42%。TPB-2 和 TPB-3 是两种晶型二水合物，对光致发光颜色变化有响应；两者都可以在温和加热下转化为 TPB-1。重要的是，这三种 TPB-n 晶体建立了第一个被金属磷酸盐适应的四吡咯型配体，以创建一个阳离子发光骨架，NTHU-12。这项研究为超越传统的 C-C 键形成反应提供了一条鼓舞人心的途径，并成功地分离出了四种 tmdp 二聚体。简便的合成导致了大量稀有类型的四吡咯配体的生产，从而发现了第一个在纳米多孔固体中带正电荷的混合拓扑结构。报道了四种发光 tmdp 二聚体和 NTHU-12 的合成、结构和光学性质的特点。
