1、Article doi: 10.3866/PKU.WHXB201205155 新型螺吡喃衍生物: 离子传感和分子水平的信息处理李颖若 1 张洪涛 2 齐传民 1,* 郭雪峰 2,3,*(1 北京 师范大学化学学院 , 放射性药物教育部重点实验室, 北京100875; 2 北京大学化学与分子工程学院, 北京分子科学国家实验室, 分子动态与稳态结构国家重点 实验室, 北京100871; 3 北京大学工学院先进材料与纳米技术系, 北京100871)摘 要: 为 实 现 金 属 离 子 检 测 和 分 子 水 平 的 信 息 处 理, 合 成 了 一 类 新 型 的 含 有 功 能 配 位 基 团 的
2、 螺 吡 喃 衍 生 物(SP1- SP4). 研 究 发 现: 在 没 有 UV 光 照 的 条 件 下, 金 属 离 子 可 以 促 进 螺 吡 喃 (SP2 和 SP4)开 环 并 形 成 稳 定 可 逆 的 络 合 物 (MC-Mn+). 紫 外 -可 见 吸 收 光 谱 研 究 表 明, 在 UV 光 照 前 加 入 不 同 的 金 属 离 子 会 引 起 SP2 和 SP4 的 光 学 性 质 的 特 征 变 化, 因 此 提 供 了 一 种 简 易 的 通 过 裸 眼 就 能 辨 别 金 属 离 子 的 比 色 方 法. 荧 光 光 谱 研 究 表 明, 这 类 化 合 物 能
3、够 高 灵 敏 高 选 择 性 地 检 测 锌 离 子. 此 外, 基 于 吸 收 光 谱 和 荧 光 光 谱 的 变 化, 这 类 螺 吡 喃 衍 生 物 可 以 用 于 构 建 组 合 的 逻 辑 门, 执 行 分 子 水 平 的 信 息 处 理, 从 而 展 现 了 其 在 化 学 或 环 境 传 感 和 未 来 的 分 子 计 算 机 领 域 的 潜在应用前景.关键词: 螺吡喃; 化学传感; 逻辑门; 紫外-可见吸收光谱; 荧光光谱中图分类号: O641New Spiropyran Derivatives: Ion Sensing and InformationProcessing a
4、t the Molecular LevelLI Ying-Ruo1 ZHANG Hong-Tao2 QI Chuan-Min1,* GUO Xue-Feng2,3,*(1Key Laboratory of Radiopharmaceuticals, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China;2Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry
5、 of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China; 3Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, P. R. China)Abstract: We have designed and synthesized a n
6、ew class of spiropyran derivatives (SP1- SP4) with functional chelating groups, such as pyridine or quinoline moieties and a methoxy group ( OMe), for usein metal ion sensing and information processing at the molecular level. It is notable that metal ions can favor coordination with chelating groups
7、 and facilitate the photoisomerization of spiropyran molecules from the closed form to the open merocyanine form without UV irradiation, thus leading to significant changes in their chemical and physical properties. UV-Vis absorption studies indicated that SP2 and SP4 exhibited metal ion-dependent r
8、eversible binding affinities that result in different hypsochromic shifts for the MC-Mn + complexes. These changes in color can be recognized by eye, thus offering an easy colorimetric method for metal ion detection. Further emission studies distinguished them as promising candidates for Zn2 + detec
9、tion with good sensitivity and selectivity. Moreover, on the basis of their absorption and fluorescence spectra, several combinational logic gates were constructed for information processing at the molecular level. These results demonstrate that spiropyran derivatives with desired functionalities sh
10、ow great potential not only for chemical or environmental sensors, but also for future molecular computing.Received: March 31, 2012; Revised: May 14, 2012; Published on Web: May 15, 2012. Corresponding authors. GUO Xue-Feng, Email: . QI Chuan-Min, Email: .The project was supported by the National Ke
11、y Basic Research Program of China (973) (2009CB623703, 2012CB921404), National Natural Science Foundation of China (20833001, 51121091, 2112016, 21071022), and Foundation for the Author of National Excellent Doctoral Dissertation of Higher Education, China (2007B21).国 家 重 点 基 础 研 究 发 展 规 划 项 目 (973)
12、 (2009CB623703, 2012CB921404), 国 家 自 然 科 学 基 金 (20833001, 51121091, 2112016, 21071022)及 全 国高等学校优秀博士论文作者专项基金(2007B21)资助 Editorial office of Acta PhysicoChimica SinicaVol.282472 Acta Phys. Chim. Sin. 2012Key Words: Spiropyran; Chemical sensor; Logic gate; UV-Vis absorption spectrum; Fluorescentspectru
13、m1 IntroductionPhotochromic compounds have been extensively investigat- ed in recent years for their high potential applications in opti- cally rewritable storage,1 optical switching,2 chemical3 and bio- logical4 sensings. In particular, considerable attention has been paid to spiropyran molecules,
14、one of the most promising fami- lies of photochromic compounds, because of their unique opti- cal and physical properties.5- 10 The stimulus-induced transfor- mation of the ring-closed structure of spiropyrans (SPs) into their fully -conjugated isomeric merocyanine forms (MCs) re- sults not only in
15、the variations of absorption spectra, but also in the profound alterations of other physical and chemical prop- erties of the system, such as the dipole moments, nonlinear op- tic properties, emission spectra, and macroscopic properties (for example, conductance, rheological property, and surface we
16、ttability). By taking advantage of these remarkable charac- teristics of SPs, a number of spiropyran derivatives containing diverse functional groups have so far been designed and used as molecular sensors and molecular switches.11- 17Among the remarkable characteristics of SPs, one unique feature i
17、s that the photogenerated open merocyanine form pro- cesses the charge-separated zwitterionic state with a free nega- tively-charged oxygen atom, which can further interact with ex- ternal stimuli through dipole- dipole interactions and coordina- tion chemistry (Scheme 1). Recently, several groups h
18、ave suc- cessfully utilized this for the purpose of optically detecting met- al ions,18- 20 anions,21 nucleobases,22 amino acids,23 and DNA,24 etc. In this study, a new class of spirobenzopyrans SP2 andSP4 bearing electron-donating OMe group and pyridine orquinoline moiety as binding sites were desi
19、gned and synthe- sized (Scheme 1). We will explore the changes in their chemi- cal and physical properties upon addition of different metal ions before and after UV irradiation and show the capability ofselectively detecting metal ions with high sensitivity and con-structing logic gates for informat
20、ion processing at the molecu- lar level.25- 312 ExperimentalFunctional spirobenzopyran derivatives SP1- SP4 were syn- thesized as shown in Scheme 2. Compounds 2-1 and 2-2 were prepared by modification of the procedure reported by Raymo and Giordani32 bearing OH as a functional group for the fol- low
21、ing reaction step. The pyridine or quinoline moiety was then linked to compounds 2-1 and 2-2 using EDCI/DMAP (EDCI: 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, DMAP:4-dimethylaminopyridine) esterification reaction to give SP1-SP4 as yellow crystals in high yield (90%).2.1 1-(2-hydroxyethyl)-2,3,
22、3-trimethylindoliumbro- mide (1)Under nitrogen atmosphere, a mixture of 2,3,3-trimethyl-3H-indole (4.77 g, 30.0 mmol) and 2-bromoethanol (4.50 g,36.0 mmol) in dry CH CN (30 mL) was heated under reflux for312 h. Removal of CH3CN and excess of 2-bromoethanol under the reduced pressure gave a dark purp
23、le residue. Repeated washing with anhydrous ether gave compound 1 (7.85 g,92.1%) as a white solid. All the reagents used are AR grade.1H NMR (DMSO-d6, 400 MHz): 1.55 (s, 6H), 3.38 (s, 3H),3.87 (t, 2H, J=6.8 Hz), 4.60 (t, 2H, J=6.8 Hz), 7.60- 7.64 (m,2H), 7.84- 7.87 (m, 1H), 7.94- 7.98 (m, 1H). Fouri
24、er transform mass spectroscopy (FTMS): m/z=204.1, M-Br+.2.2 2-(3,3-dimethyl-6-nitrospiro chromene-2,2-indolin-1-yl) ethanol (2-1)Under nitrogen atmosphere, Compound 1 (1.14 g, 4.0 mmol) and 2-hydroxy-5-nitrob-enzaldehyde (0.80 g, 4.8 mmol) were dissolved in dry tetrahydrofuran (THF) (25 mL). The sol
25、ution was heated to reflux then triethylamine (0.49 g, 4.8 mmol) inScheme 1 Illustrations of the reversible structural transformations of SP2 and SP4 in responses to light, heat, and metal ionsNo.10 LI Ying-Ruo et al.: New Spiropyran Derivatives: Ion Sensing and Information Processing at the Molecul
26、ar Level 2473Scheme 2 Synthesis of spirobenzopyrans SP1- SP4THF (5 mL) was added dropwise. The mixture was refluxedfor 4 h. The solvent was removed by evaporation under re- duced pressure. The crude residue was recrystallized from ab- solute ethanol giving compound 2-1 (1.30 g, 92.2%) as red pur- pl
27、e crystals.1H NMR (CDCl3, 400 MHz): 1.20 (s, 3H), 1.29 (s, 3H),3.33- 3.50 (m, 2H), 3.68- 3.77 (m, 2H), 5.89 (d, 1H, J=13.6Hz), 6.67 (d, 1H, J=10.4 Hz), 6.76 (d, 1H, J=12.4 Hz),6.87- 6.93 (m, 2H), 7.10 (d, 1H, J=9.0 Hz), 7.20 (t, 1H, J=10.0Hz ), 7.99- 8.04 (m, 2H). FTMS: m/z=353.1, M+H+.2.3 2-(8-meth
28、oxy-3,3-dimethyl-6-nitrospirochromene-2,2-indolin-1-yl) ethanol (2-2)Compound 2-2 was prepared according to a procedure simi- lar to compound 2-1. After column chromatography on silica gel with ethyl acetate/petroleum (60- 90 C) (1:1, V/V) as elu- ent, compound 2-2 was obtained as dark blue crystals
29、 (3.82 g,91.6%).1H NMR (CDCl3, 400 MHz): 1.18 (s, 3H), 1.29 (s, 3H),3.35- 3.43 (m, 2H), 3.51- 3.63 (m, 2H), 3.78 (s, 3H), 5.82 (d,1H, J=14.0 Hz), 6.65 (d, 1H, J=10.4 Hz), 6.84- 6.90 (m, 2H),7.08 (d, 1H, J=10.0 Hz), 7.15- 7.21 (m, 1H), 7.63 (d, 1H, J=3.6Hz), 7.69 (d, 1H, J=3.6 Hz). FTMS: m/z=383.2, M
30、+H+.2.4 2-(3,3-dimethyl-6-nitrospiro chromene-2,2- indolin-1-yl)ethylpicolinate (SP1)5.96 (d, 1H, J=10.4 Hz), 6.73 (d, 1H, J=8.4 Hz), 6.79 (d, 1H,J=8.0 Hz), 6.87- 6.92 (m, 2H), 7.09 (d, 1H, J=6.4 Hz),7.19- 7.23 (m, 1H), 7.46- 7.49 (m, 1H), 7.80-7.84 (m, 1H),7.95- 7.98 (m, 2H), 8.06 (d, 1H, J=7.2 Hz)
31、, 8.74 (d, 1H, J=4.8Hz). 13C NMR (CDCl3, 100 MHz): 165.05, 159.32, 149.87,147.72, 146.46, 141.06, 137.03, 135.75, 128.41, 127.92,127.05, 125.92, 125.19, 122.76, 121.86, 121.83, 119.97,118.45, 115.53, 106.78, 106.49, 63.30, 52.87, 42.21, 25.86,19.85. FTMS: m/z=458.15, M+H+.2.5 2-(8-methoxy-3,3-dimeth
32、yl-6-nitrospiro chromene-2,2-indolin-1-yl) ethyl picolinate (SP2)SP2 was prepared according to a procedure similar to SP1. Compound 2-2 was used instead of compound 2-1. SP2 was obtained as yellow crystals (0.64 g, 88.9%).1H NMR (CDCl3, 400 MHz): 1.15 (s, 3H), 1.27 (s, 3H),3.58- 3.66 (m, 1H), 3.73 (
33、s, 3H), 3.74- 3.80 (m, 1H), 4.56 (t,2H, J=6.6 Hz), 5.93 (d, 1H, J=10.4 Hz), 6.78 (d, 1H, J=7.6Hz), 6.83- 6.90 (m, 2H), 7.08 (d, 1H, J=6.4 Hz), 7.17- 7.21 (m, 1H), 7.45- 7.48 (m, 1H), 7.56 (d, 1H, J=2.8 Hz), 7.66 (d,1H, J=2.4 Hz), 7.65- 7.66 (m, 1H), 8.02 (d, 1H, J=7.6 Hz),8.73 (d, 1H, J=5.6 Hz). 13C
34、 NMR (CDCl3, 100 MHz): 164.10,149.84, 149.03, 147.73, 147.33, 146.42, 140.45, 136.99,135.79, 128.36, 127.73, 126.99, 125.15, 121.88, 121.84,119.68, 118.18, 115.30, 107.72, 106.70, 106.33, 63.27, 56.12,52.84, 41.97, 25.98, 19.79. FTMS: m/z=488.19, M+H+.2.6 2-(3,3-dimethyl-6-nitrospiro chromene-2,2- i
35、ndolin-1-yl) ethylisoquinol-ine-3-carboxylate (SP3)SP3 was prepared according to a procedure similar to SP1. Quinoline-2-carboxylic was used instead of acid picolinic acid. SP3 was obtained as light yellow crystals (0.69 g, 90.6%).1H NMR (CDCl3, 400 MHz): 1.20 (s, 3H), 1.40 (s, 3H),3.45- 3.54 (m, 1H
36、), 3.81- 3.91 (m, 1H), 4.64- 4.69 (m, 2H),6.37 (d, 1H, J=14.4 Hz), 6.77 (d, 1H, J=10.4 Hz), 6.85- 6.90 (m, 2H), 7.08 (d, 1H, J=10.0 Hz), 7.15- 7.19 (m, 1H), 7.22 (d,1H, J=11.6 Hz), 7.66- 7.71 (m, 1H), 7.81- 7.87 (m, 1H),Under nitrogen atmosphere, compound 2-1 (0.35 g, 1.0mmol), picolinic acid (0.12
37、g, 1.0 mmol), EDCI (0.38 g, 2.0mmol), DMAP (0.01 g, 0.1 mmol) were dissolved into dry di- chloromethane (15 mL). The reaction mixture was stirred at room temperature overnight. Evaporation of the solvent gave a brown tar. The obtained brown tar was dissolved into ethyl ace- tate, washed with H2O thr
38、ee times, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave a light brown residue. The crude residue was recrystallized from ethyl acetate/n-hexane giving SP1 (0.82 g, 90.5% ) as a light yellow crystals.1H NMR (CDCl3, 400 MHz): 1.15 (s, 3H), 1.29 (s, 3H),3.55- 3.63 (m, 1H),
39、 3.68- 3.74 (m, 1H), 4.55- 4.58 (m, 2H),Vol.282474 Acta Phys. Chim. Sin. 20127.89- 7.93 (m, 2H), 8.02 (d, 1H, J=4.0 Hz), 8.16 (d, 1H, J=11.6 Hz), 8.28- 8.33 (m, 2H). 13C NMR (CDCl3, 100 MHz):Table 1 Calculated rate constants and conversions ofSP1- SP4 at 293 K165.37,135.78,127.64,159.41,130.58,125.8
40、7,147.67,130.44,122.72,147.57,129.34,122.27,146.46,128.79,121.88,141.00,128.28,120.95,137.29,127.93,119.94,Compound KUV/s- 1 Kdark/s- 1 Kvisible/s- 1 e/%SP1SP2SP3SP4(1.10.1)10- 2 (9.20.1)10- 3 (8.90.1)10- 3(9.80.1)10- 3(1.30.1)10- 3 (1.40.1)10- 2 (1.70.1)10- 3(1.40.1)10- 2(7.20.1)10- 3 (1.10.1)10- 1
41、 (7.10.1)10- 3(8.90.1)10- 256.46.750.38.7118.54, 115.52, 106.75, 106.65, 63.54, 52.97, 42.30, 25.88,19.88. FTMS: m/z=508.17, M+H+.2.7 2-(8-methoxy-3,3-dimethyl-6-nitrospirochromene-2,2-indolin-1-yl) ethyl isoquinoline-3-carboxylate (SP4)SP4 was prepared according to a procedure similar to SP1. Compo
42、und 2-2 was used instead of compound 2-1 and quino- line-2-carboxylic was used instead of acid picolinic acid. SP4 was obtained as yellow crystals (0.72 g, 90.1%).1H NMR (CDCl3, 400 MHz): 1.17 (s, 3H), 1.27 (s, 3H),3.65- 3.70 (m, 1H), 3.72 (s, 3H), 3.80- 3.87 (m, 1H),4.58- 4.66 (m, 2H), 6.10 (d, 1H,
43、 J=10.4 Hz), 6.82 (d, 1H, J=7.6 Hz), 6.86 (d, 1H, J=10.4 Hz), 6.88 (t, 1H, J=7.4 Hz), 7.08 (d, 1H, J=6.4 Hz), 7.21 (t, 1H, J=7.6 Hz), 7.53 (d, 1H, J=2.4Hz), 7.64 (d, 1H, J=2.4 Hz), 7.67 (t, 1H, J=8.0 Hz), 7.81 (t,1H, J=7.6 Hz), 7.88 (d, 1H, J=9.2 Hz), 8.09 (d, 1H, J=8.8 Hz),8.27 (d, 2H, J=8.4 Hz). 1
44、3C NMR (CDCl3, 100 MHz): 165.31,KUV: the rate constant for the conversions of SP to MC upon UV irradiation;Kdark: the rate constant for the conversions of MC to SP in the dark;Kvisible: the rate constant for the conversions of MC to SP under visible irradiation;e: the calculated conversions- 1) unde
45、r visible irradiation are still larger than those for MC1 to SP1 (7.20.1)10- 3 s- 1) and MC3 to SP3 (7.10.1)10- 3 s- 1), separately. On the basis of kinetic data listed in Table 1, the calculated conversions (e) of SP2 and SP4 are 6.7% and8.7% , respectively, which are much smaller than the cases fo
46、rSP1 and SP3 (56.4% and 50.3% , respectively), indicating that the introduction of OMe apparently shifts the SP/MC equi- librium to favor the closed form of spiropyrans and thus de- crease the stability of the open form most likely due to the in- crease of the electron density of the phenoxide ion u
47、nit affect-ed by the electron-donating OMe group.3.2 Sensing properties19149.12,135.82,127.60,107.68,147.70,130.56,122.33,106.67,147.54,130.39,121.86,147.32,129.28,120.92,146.42,128.73,119.64,140.40,128.26,118.28,137.22,127.73,115.28,Fig.1 and Fig.S5 (Supporting Information) show the absorp-tion spe
48、ctra of SP1- SP4 (5.0 10- 5 mol L- 1) in ethanol in the absence and the presence of 1 equivalent (equiv.) of different106.51, 63.50, 56.11, 52.95, 42.05, 25.97,19.79. FTMS: m/z=538.17, M+H+.3 Results and discussion3.1 Photochromic propertiesPrevious reports demonstrated that the introduction of an e
49、lectron-withdrawing group (e.g., NO2, CF3) into the ben-zene ring enhances the stability of the open form of SPs33,34whereas an electron-donating group (e.g., t-Bu, OMe) pro- duces a more stable photostationary closed form.35,36 To gather the kinetic data of SP1- SP4 to evaluate the effect of OMe on the properties of spiropyrans, we monitored the evolutions of
