1,4,7-TRIAZACYCL[3.3.3]AZINE - BASICITY, PHOTOELECTRON-SPECTRUM, PHOTOPHYSICAL PROPERTIES
1,4,7-TRIAZACYCL[3.3.3]AZINE - BASICITY, PHOTOELECTRON-SPECTRUM, PHOTOPHYSICAL PROPERTIES
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DOI：
10.1021/ja00261a004
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发表时间：
1986-01-08
影响因子：
15
通讯作者：
WIRZ, J
中科院分区：
文献类型：
--
作者：
LEUPIN, W;MAGDE, D;WIRZ, J
1，4，7-三氮杂环[3.3.3]氮杂环(1，R=H)及其2，5，8-三甲基衍生物1(R=Me)的合成分两步进行，即氨与丙烯醛(R=H)或巴豆醛(R=Me)的缩合反应和产物在Pd/C催化剂上的脱氢反应。用波谱方法(~1H和~(13)C核磁共振谱、自由基阴离子的ESR、PES和UV/Vis吸收与发射)对对称的紫色杂环1进行了表征。母体1(R=H)在从正己烷到水的所有溶剂中都是中等可溶和稳定的，在日益酸性的溶液中，三个外围的N原子依次质子化(pKa=3.46，-2.2，-7.2)。当甲基取代(1，R=H.fwdarw)时，随着溶剂极性的增加和质子化程度的增加，观察到第一吸收带显著的蓝移。R=Me)，甚至在与三个苯并基(1.fwdarw.三环喹唑啉(2))。化合物1从第二激发单线态S2产生微弱的蓝色荧光发射，vphi.f=(5.+-.1).时代。10-4(R=H)，.vphi。.simeq.1.泰晤士报。10-4(R=Me)，以及来自S1的很弱的红色荧光。最低的单重态和三重态S1和T1之间的能量差非常小(ΔE<；10kJ/mol)，并且T1的寿命非常短(3.ta.<；1微秒)。描述.pi的简单MO模型。环[3.3.3]的电子结构氮杂很好地使三氮杂衍生物1的物理和化学性质合理化。
1,4,7-Triazacycl[3.3.3] azine (1, R = H) and its 2,5,8-trimethyl derivative 1 (R = Me) are formed in two steps, the condensation of ammonia with acrolein (R = H) or crotonaldehyde (R = Me) and dehydrogenation of the product on Pd/C catalyst. The symmetrical (C3h), purple-colored heterocycles 1 have been characterized by spectroscopic methods (1H and 13C NMR, ESR of the radical anions, PES, and UV/vis absorption and emission). Parent 1 (R = H) is moderately soluble and stable in all solvents from hexane to water, and the three peripheral N atoms are sequentially protonated in increasingly acidic solutions (pKa = 3.46, -2.2, -7.2). A pronounced blue shift of the first absorption band is observed with increasing solvent polarity, with increasing protonation, upon methyl substitution (1, R = H .fwdarw. R = Me), and even upon fusion with three benzo groups (1 .fwdarw. tricycloquinazoline (2)). Compounds 1 give rise to a weak blue fluorescence emission from the second .pi..pi.* excited singlet state S2, .vphi.f = (5 .+-. 1) .times. 10-4 (R = H), .vphi. .simeq. 1 .times. 10-4 (R = Me), as well as a very weak red fluorescence from S1. The energy gap between the lowest .pi..pi.* excited singlet and triplet states, S1 and T1, is very small (.DELTA. E < 10 k J/mol) and the lifetime of T1 is unusually short (3.tau. < 1 .mu.s). A simple MO model describing the .pi. electronic structure of cycl[3.3.3.] azines serves well to rationalize the physical and chemical properties of the triaza derivatives 1.