基于环对苯撑/柱[5]芳烃超分子体系的动态白光精准调控
Dynamic Precision Regulation of White Light Based on the Supramolecular System of Cycloparaphenylene/Pillar[5]arene
摘要: 基于柱芳烃、环对苯撑等大环主体的白光发射体系在超分子化学领域占据着重要作用。我们设计了一种基于二四苯乙烯–咔唑和N-萘二酸酐的D-π-A型客体分子(TCPN),通过主客体相互作用将其与柱[5]芳烃(P5)、[10]环对苯撑([10]CPP)和[12]环对苯撑([12]CPP)进行自组装,可以构建多组分超分子动态白光发射体系。在该体系中,发射黄色荧光的TCPN和P5的混合物与绿色荧光的[10]CPP以及蓝色荧光的[12]CPP按照特定比例进行组合。这种独特的组合方式不仅可以实现从单色荧光到白光发射的高效转换,还赋予了整个体系优异的动态可调荧光发射特性。
Abstract: Supramolecular systems based on macrocyclic hosts such as pillar[n]arenes and cycloparaphenylenes play an important role in the field of supramolecular chemistry for their white-light emission. We designed a D-π-A type guest molecule (TCPN) based on 1,4-bis(anthracen-9-yl)benzene and N-naphthalic anhydride. Through host-guest interactions, we assembled it with pillar[5]arene (P5), [10]cycloparaphenylene ([10]CPP), and [12]cycloparaphenylene ([12]CPP) to construct a multicomponent supramolecular dynamic white-light-emitting system. In this system, the mixture of TCPN and P5, which emits yellow fluorescence, combined with [10]CPP that emits green fluorescence and [12]CPP that emits blue fluorescence in a specific proportion, can achieve efficient conversion from monochromatic fluorescence to white light emission based on the condition of solvent evaporation, demonstrating excellent dynamically tunable fluorescent emission characteristics.
文章引用:张迁, 刘冬霞, 樊彦青, 阿布都热西提·阿布力克木. 基于环对苯撑/柱[5]芳烃超分子体系的动态白光精准调控[J]. 化学工程与技术, 2025, 15(3): 111-123. https://doi.org/10.12677/hjcet.2025.153010

1. 引言

白光作为人们日常生活中最重要的光源之一,其在照明、显示、传感、生物成像等领域具有广泛的应用前景[1] [2]。传统白光发射材料通常依赖于多种发光组分的物理混合[3],其发光性能往往受限于复杂的制备工艺、较差的稳定性和有限的动态可调性。近年来,超分子化学的快速发展为构建新型白光发射材料提供了全新的思路[4]-[6]。作为第五代大环化合物,具有柱状空腔的柱[5]芳烃(pillar[5]arene)因其

Figure 1. Dynamic white-light emission based on the host-guest supramolecular system of cycloparaphenylene/pillar[5]arene

1. 基于环对苯撑/柱[5]芳烃主客体超分子体系实现动态白光发射

富电子空腔结构、优异的主客体络合能力和易于功能化等特点,在超分子化学领域得到了广泛应用[7]-[11]。柱[5]芳烃可以络合多种客体分子(如长烷烃链、阳离子染料和π-共轭分子)以形成稳定的主客体络合物[12] [13],这为超分子白光体系的构建提供了机遇。此外,由苯环通过对位首尾连接形成的环对苯撑[14] (Cycloparaphenylenes, CPPs)凭借独特的环状π-共轭结构和尺寸依赖的光物理特性而备受关注,其共轭程度和电子性质随环尺寸的变化而改变[15]-[17]。然而单分子CPPs因其分子内电荷转移等原因通常难以实现白光发射体系的构建,因此需要引入其他功能单元实现多组分发光体系的调控[18] [19]。例如,2023年,北京师范大学江华教授课题组[20]利用基于柱[5]芳烃和CPP的异位双碳纳米环与客体分子之间的主客体相互作用,实现了可控的包括白光在内的多颜色荧光发射体系的构建。受此启发,本文通过CPPs、柱[5]芳烃以及第三种客体分子(四苯乙烯基衍生物——一种基于二四苯乙烯–咔唑和N-萘二酸酐的客体分子TCPN)之间的主客体相互作用,从溶液到固体实现了包括白光在内的多颜色动态荧光发射的精准调控。在该体系中,发射黄色荧光的TCPN和柱[5]芳烃(P5)的络合物(TCPN-P5),与具有绿色荧光的[10]CPP以及蓝色荧光的[12]CPP按照特定比例进行组合,不仅可以实现从单色荧光到白光发射的高效转换,还赋予了整个体系优异的动态可调荧光发射特性(图1)。这一研究不仅有助于深化对超分子发光机制的理解,也为开发新型智能光电功能材料提供了重要参考。

2. 实验部分

2.1. 合成路线

Figure 2. Synthetic route of TCPN

2. TCPN的合成路线

主体分子[12]CPP[10]CPPP5B4-Bu和客体分子TCPN的合成路线(图2~5)。反应条件:a, n-BuLi, THF, 0˚C; 2 h, P-toluenesulfonic acid, toluene, reflux, 10 h, yield: 90% (two steps); b, n-BuLi, THF, Isopropoxyboronic acid pinacol ester, −78˚C, 1 h, yield: 80%; c, Pd(PPh3)4, K2CO3, Ar, 1,4-dioxane/H2O (5/1), 90˚C, 12 h, yield: 71%; d, imidazole, 140˚C, Ar, 4.5 h, yield: 91%; e, Pd2 (dba)3, X-phos, t-BuOK, toluene, 115˚C, Ar, 12 h, yield: 85%. f, PIDA, dry MeOH, r.t., 48 h, yield: 58%; g, n-BuLi, THF, −78˚C, 6 h, MeI, NaH, 0˚C~r.t., 8 h, yield: 74%; h, n-BuLi, THF, −78˚C, 3 h, MeI, NaH, 0˚C~r.t., 12 h, yield: 65%; i, n-BuLi, THF, Isopropoxyboronic acid pinacol ester, −78˚C, 1 h, yield: 80%; j, Pd(PPh3)4, K2CO3, Ar, THF/H2O (5/1), 110˚C, 24 h, yield: 58%; k, Bpin-Bpin, Pd2(dba)3, X-phos, KOAc, 1,4-dioxane, 110˚C, 16 h, yield: 60%; l, Pd(PPh3)4, K2CO3, Ar, 1,4-dioxane/H2O:(5/1), 110˚C, 72 h; m, SnCl2, HCl, THF, r.t., 12 h, yield: 27% (two steps). n, Pd (PPh3)4, K2CO3, Ar, THF/H2O (5/1), 110˚C, 24 h, yield: 86%; o, Bpin-Bpin, Pd2(dba)3, X-phos, KOAc, 1,4-dioxane, 110˚C, Ar, 16 h, yield: 60%; p, Pd(PPh3)4, K2CO3, Ar, dioxane/H2O (5:1), 110˚C, 72 h; q, SnCl2, HCl, THF, r.t., 24 h, yield: 31% (two steps). r, (CH2O)n, TfOH, DCM, r. t., 5 h, yield: 54%; s, NaOH, HCHO, 120˚C, 12 h, then Diphenyl ether, toluene, 250˚C, reflux, yield: 90%; t, AlCl3, toluene, DCM, r. t. 1 h, yield: 85%; u, 1-Bromobutane, NaH, MeCN, 85˚C, 12 h, yield: 67%。

Figure 3. Synthetic route of [12]CPP

3. [12]CPP的合成路线

Figure 4. Synthetic route of [10]CPP

4. [10]CPP的合成路线

Figure 5. Synthetic route of P5 and B4-Bu

5. P5B4-Bu的合成路线

2.2. 材料表征

TPE-Br白色固体,90%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.23 − 7.18 (m, 2H), 7.15~7.05 (m, 9H), 7.01 (d, J = 2.6 Hz, 6H), 6.91~6.85 (m, 2H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 143.38, 143.29, 143.19, 142.67, 141.57, 139.62, 132.96, 131.27, 131.21, 130.83, 127.86, 127.76, 127.66, 126.68, 126.62, 126.57, 120.43。

TPE-Bpin白色固体,80%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.54 (d, J = 7.9 Hz, 2H), 7.09 (dd, J = 6.0, 3.4 Hz, 9H), 7.05~6.98 (m, 8H), 1.32 (s, 12H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 146.75, 143.68, 143.58, 143.50, 141.36, 140.83, 134.07, 131.34, 131.31, 130.68, 127.71, 127.61, 126.50, 126.42, 83.68, 24.88。

CB-2TPE白色固体,71%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 8.19 (d, J = 8.7 Hz, 3H), 8.06 (s, 1H), 7.65 (d, J = 8.2 Hz, 2H), 7.50 (d, J = 8.5 Hz, 2H), 7.44 (d, J = 8.1 Hz, 5H), 7.31 (d, J = 8.6 Hz, 2H), 7.18~7.03 (m, 30H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 143.81, 142.12, 140.98, 140.61, 139.43, 139.18, 138.47, 132.98, 131.85, 131.45, 131.37, 128.67, 127.77, 127.67, 127.62, 126.46, 126.37, 126.26, 125.98, 125.30, 123.19, 122.90, 118.71, 112.38, 112.11, 110.92. ESI-MS: calculated for [C64H45N+H]+, 828.3625; found 828.3699。

N-Br淡黄色固体,91%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 8.64 (d, J = 7.3 Hz, 2H), 8.28 (d, J = 8.3 Hz, 2H), 7.80 (t, J = 7.8 Hz, 2H), 7.67 (d, J = 8.2 Hz, 2H), 7.21 (d, J = 8.2 Hz, 2H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 164.12, 134.45, 134.39, 132.57, 131.71, 130.42, 128.48, 127.05, 122.72, 122.56. ESI-MS: calculated for [C18H10BrNO2+Na]+, 373.9787; found 373.9788。

TCPN黄色固体,1.1 g,85%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 8.72 (d, J = 7.2 Hz, 2H), 8.32 (d, J = 8.8 Hz, 4H), 7.89~7.75 (m, 4H), 7.63 (dd, J = 23.9, 8.7 Hz, 6H), 7.49 (d, J = 7.9 Hz, 4H), 7.21~6.99 (m, 34H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 164.42, 143.91, 143.84, 142.05, 140.90, 140.68, 140.45, 139.54, 137.86, 134.53, 134.17, 133.35, 131.84, 131.48, 131.38, 130.43, 128.60, 127.79, 127.66, 127.61, 127.42, 127.15, 126.47, 126.43, 126.32, 125.49, 124.18, 122.71, 118.61, 110.30. ESI-MS: calculated for [C18H10BrNO2+H]+, 1099.4258; found 1099.4290。

C2-Br白色固体,58%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.48 (d, J = 8.7 Hz, 2H), 7.32 (d, J = 8.6 Hz, 2H), 6.74 (d, J = 10.2 Hz, 2H), 6.41 (d, J = 10.2 Hz, 2H), 3.41 (s, 3H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 185.26, 149.89, 137.42, 131.87, 130.34, 127.48, 122.44, 76.19, 52.89。

C3-Br-Cl白色固体,74%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.43 (d, J = 8.5 Hz, 2H), 7.29 (q, J = 8.8 Hz, 4H), 7.24 (d, J = 8.5 Hz, 2H), 6.08 (s, 4H), 3.41 (s, 6H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 142.29, 141.73, 133.35, 133.27, 131.46, 128.51, 127.71, 127.36, 121.66, 74.39, 74.33, 51.99。

C3-2Br白色固体,65%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.46~7.39 (m, 4H), 7.26~7.21 (m, 4H), 6.07 (s, 4H), 3.42 (d, J = 6.1 Hz, 6H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ= 142.29, 133.76, 133.31, 132.90, 131.49, 131.39, 128.44, 127.81, 127.73, 125.91, 121.71, 74.42, 52.02。

C3-Cl-Bpin白色固体,80%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.76 (d, J = 7.9 Hz, 2H), 7.38 (d, J = 6.6 Hz, 2H), 7.32 (d, J = 8.7 Hz, 2H), 7.29~7.23 (m, 2H), 6.08 (dd, J = 24.8, 10.3 Hz, 4H), 3.42 (s, 6H), 1.34 (s, 12H). 13C NMR (150 MHz, CDCl3, 298 K, ppm): δ = 146.3, 142.0, 135.1, 133.7, 133.5, 133.1, 128.6, 127.6, 125.4, 83.9, 75.0, 74.6, 52.1, 25.0。

C9-2Cl白色固体,58%;1H NMR (600 MHz, CDCl3, 298 K, ppm): δ = 7.68~7.57 (m, 12H), 7.45~7.44 (m, 4H), 7.36~7.34 (m, 4H), 7.30~7.26 (m, 4H), 6.24~6.00 (m, 12H), 3.51~3.36 (m, 18H). 13C NMR (151 MHz, CDCl3, 298 K, ppm): δ = 142.17, 141.99, 140.33, 140.08, 139.39, 139.07, 133.12, 133.07, 133.04, 129.49, 128.49, 127.49, 127.15, 127.11, 126.79, 126.37, 74.65, 74.63, 52.02。

C9-2Bpin白色固体,58%;1H NMR (600 MHz, CDCl3, 298 K, ppm): δ = 7.76 (d, J = 8.2 Hz, 4H), 7.55~7.50 (m, 12H), 7.44 (dd, J = 13.8, 8.3 Hz, 8H), 6.25~6.03 (m, 12H), 3.49~3.44 (m, 18H), 1.31 (s, 24H). 13C NMR (100 MHz, CDCl3, 298 K, ppm): δ = 146.36, 142.48, 142.39, 140.01, 140.00, 134.90, 133.31, 133.26, 127.13, 127.09, 126.39, 125.31, 83.75, 74.94, 74.68, 52.00, 51.95, 24.82, 24.55。

[12]CPPtwo steps, 25 mg, 27%; 1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.52 (s, 48H) [15]

C7-2Cl白色固体,86%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.68~7.65 (m, 4H), 7.63~7.59 (m, 4H), 7.50~7.45 (m, 4H), 7.40~7.35 (m, 4H), 7.32~7.28 (m, 4H), 6.21~6.16 (m, 4H), 6.13~6.08 (m, 4H), 3.46 (d, J = 5.8 Hz, 12H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 142.32, 141.98, 139.99, 139.63, 133.67, 133.39, 133.08, 128.48, 127.47, 127.43, 127.04, 126.42, 77.32, 77.00, 76.68, 74.63, 74.49, 52.03, 52.01。

C7-2Bpin白色固体,60%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.78 (d, J = 8.2 Hz, 4H), 7.67 (d, J = 5.6 Hz, 4H), 7.59 (d, J = 8.3 Hz, 4H), 7.49 (d, J = 8.4 Hz, 4H), 7.45 (d, J = 8.2 Hz, 4H), 6.14 (d, J = 4.8 Hz, 8H), 3.46 (d, J = 5.2 Hz, 12H), 1.34 (s, 24H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ= 156.36, 141.35, 139.62, 139.07, 134.93, 134.65, 134.51, 133.35, 131.02, 129.52, 129.10, 127.43, 127.16, 126.49, 125.34, 83.75, 74.97, 74.79, 54.03, 52.08, 50.89, 29.69, 24.86。

[10]CPPtwo steps, 31%; 1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 7.56 (s, 40H) [15]

P5白色固体,54%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 6.77 (s, 10H), 3.78 (s, 10H), 3.65 (s, 30H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 150.75, 128.21, 114.02, 55.74, 29.61。

B4-Bu白色固体,66%;1H NMR (400 MHz, CDCl3, 298K, ppm): δ = 6.93~6.74 (m, 12H), 4.05 (s, 8H), 3.66 (t, J = 6.4 Hz, 8H), 1.74~1.59 (m, 8H), 1.45~1.33 (m, 8H), 0.84 (t, J = 7.4 Hz, 12H). 13C NMR (101 MHz, CDCl3, 298K, ppm): δ = 155.45, 134.21, 128.83, 123.64, 73.11, 32.39, 29.79, 19.28, 13.95。

3. 结果与讨论

我们通过设计并合成了一种D-π-A型客体分子TCPN,其中二四苯乙烯–咔唑为供体单元,N-萘二酸酐为受体单元。通过主客体相互作用,将发射黄色荧光的TCPN-P5混合物与发射绿色荧光的[10]CPP、发射蓝色荧光的[12]CPP按特定比例混合时,可以形成一种动态超分子白光发射体系。这种体系不仅具有优异的可调性,还能通过调节各组分的比例实现对白光发射特性的精准调控。柱[5]芳烃凭借其刚性富电子的大环空腔可以与缺电子分子形成主客体络合物,同时其也拥有可以容纳π-共轭芳香类衍生物的显著能力。此外,环对苯撑的π-共轭空腔使其能够与四苯乙烯之间形成较强的π-π相互作用[21],这种相互作用是主客体络合的关键驱动力之一。通过CPPs与四苯乙烯的主客体相互作用,一定程度上可以限制四苯乙烯的空间扭转。客体分子中N-萘二酸酐基团可以与P5形成优异的主客体络合物,而四苯乙烯基团则与CPPs具有较强的亲和性。这种独特的设计不仅充分发挥了各组分的光学特性,还通过精确的分子间相互作用实现了白光发射的高效调控,为开发高性能超分子发光材料提供了新的思路和策略。

Table 1. Photophysical properties of P5, [10]CPP, [12]CPPP, TCPN

1. P5[10]CPP[12]CPPPTCPN的光物理性能

成分

λex/nm

λem/nm

荧光寿命/ns

P5

295

334

2.1

[10]CPP

338

492

6.6

[12]CPP

339

469

2.4

TCPN

334

331/514/660

2.0

P5-TCPN-[10]CPP-[12]CPP

350

465

4.2

Figure 6. UV-Vis and fluorescence emission spectra of P5[10]CPP[12]CPPTCPN

6. P5[10]CPP[12]CPPTCPN的紫外–可见和荧光发射光谱

首先,我们利用紫外–可见吸收光谱、荧光发射光谱实验对主体分子P5[10]CPP[12]CPP、客体分子TCPN进行了光物理性能研究,其中柱[5]芳烃和TCPN在溶液中表现出较弱的荧光发射,但是在固体状态下,TCPN表现出增强的荧光发射,其本身固体黄色荧光多段发射特性可以为白光发射贡献长波长光谱组分。[10]CPP[12]CPP在二氯甲烷中具有较强的荧光发射,分别发射出绿色和蓝色荧光[15] (图6表1)。

Figure 7. X-ray structure of TCPN and SEM image of the crystal surface

7. TCPN的单晶结构和晶体表面的SEM图

为了更全面地了解TCPN的多功能特性,我们对TCPN的单晶结构和分子堆积方式进行深入研究。通过二氯甲烷/正己烷溶液缓慢结晶法,成功获得TCPN单晶,其外观为明亮的黄色针状。TCPN的晶相为单斜晶系,P21/c空间群并且其不对称单元中包含一个TCPN分子。对于TCPN的晶体结构,两个交叉排列的分子在晶体结构中形成紧密的分子间堆积(图7(a))。此外,我们对此黄色针状的TCPN晶体进行进一步的扫描电镜测试,发现TCPN呈现一种实心的柱状结构,与单晶结构显示的堆积形式一致(图7(b)~(e))。

Figure 8. (a) (b) COSY and NOESY spectra of TCPN-P5-[10]CPP; (c) (d) COSY and NOESY spectra of TCPN-P5-[12]CPP (400 MHz, 298 K in CDCl3)

8. (a) (b) TCPN-P5-[10]CPP的COSY和NOESY光谱;(c) (d) TCPN-P5-[12]CPP的COSY和NOESY光谱(400 MHz, 298 K in CDCl3)

由于柱[5]芳烃优异的主客体包结性能以及CPP优异的光物理性能,我们以其为主体分子,以TCPN为客体分子通过主客体相互作用构建主客体络合物。首先,将TCPNP5的主客体络合物(TCPN-P5)分别与[10]CPP[12]CPP制备了主客体络合物,并通过2D NMR研究了TCPNP5[10]CPP[12]CPP之间的主客体相互作用。COSY和NOESY实验中,TCPNP5[10]CPP以1:1:1混合时可以观察到TCPN[10]CPP氢质子之间的相关峰(图8(a)~(b))。其中,[10]CPP与四苯乙烯基团氢质子也存在明显相关峰,同时柱[5]芳烃则与N-萘二酸酐基团氢质子也存在相关性。上述结果明确证实了主客体络合物内组分的空间接近性以及并为络合物的形成提供了强有力的证据。不仅如此,当TCPNP5[12]CPP以1:1:1比例混合时,其COSY和NOESY实验也显示出明显的相关性(图8(c)~(d))。总之,上述结果证明TCPNP5[10]CPP[12]CPP之间可以通过主客体相互作用实现超分子荧光发射体系的构建。

Figure 9. SEM images of the dynamic white-light emission system

9. 动态白光发射体系的SEM谱图

我们通过扫描电镜SEM实验进一步验证了主客体络合物的形成(图9),结果表明TCPN在混合溶剂挥发后呈现出一种粒径 < 1 μm的微小密集球珠状结构,P5表现为粒径5 μm~10 μm的的规则立方体结构,[10]CPP[12]CPP表面呈现多褶皱的层状结构,动态白光体系TCPN-P5-[10]CPP-[12]CPP在混合溶剂挥发后主要表现为一种粒径50 μm~100 μm的规则立方体块状结构。因此,上述结果表明动态白光体系TCPN-P5-[10]CPP-[12]CPP主客体组装体的成功构建。

Figure 10. Dynamic white-light-emitting system TCPN-P5-[10]CPP-[12]CPP

10. TCPN-P5-[10]CPP-[12]CPP构建的动态白光发射体系

通过主客体相互作用将TCPNP5进行自组装形成具有黄色荧光的混合溶液(TCPN-P5, DCM/PE = 1:1),随着体系中溶剂的挥发,在365 nm LED下显示出从淡蓝色到黄色甚至黄绿色的荧光发射(图10(a))。然后将体系与发射绿色荧光的[10]CPP和发射蓝色荧光的[12]CPP按摩尔比为10:10:1:1的比例混合,可以构建具有优异可调性的动态超分子白光发射体系(图10(b))。重要的是,我们在溶剂完全挥发的混合物中重新滴加体积比1:1的二氯甲烷/石油醚混合溶液,上述动态白光发射体系的变化过程可以重现。

Figure 11. Control experiments at different molar ratios

11. 不同摩尔比下的对照实验

Figure 12. Solvent evaporation fluorescence titration experiment

12. 溶剂挥发荧光滴定实验

为精细调控上述白光发射体系,我们对TCPNP5[10]CPP[12]CPP这四种化合物的摩尔比从5:5:1:1~10:10:1:1~20:20:1:1进行了系统调节(图11),并对不同比例下的稳定性进行测试。结果表明,当TCPNP5[10]CPP[12]CPP的摩尔比为5:5:1:1时,上述体系仅表现出蓝绿色荧光,随着溶剂的挥发,其一直保持蓝色荧光发射,无法实现白光发射的调控,当溶剂完全挥发时,其荧光发射消失;而当提升摩尔比为10:10:1:1时,体系表现出随溶剂挥发而出现持续时间较长的白光发射;当进一步增加摩尔比至20:20:1:1时,虽然可以观察到溶剂挥发导致的白光发射,但与10:10:1:1的比例相比,其白光发射的持续时间显著缩短。基于以上结果,我们发现摩尔比为10:10:1:1为实现动态白光的最佳主客体组装比例。此外,我们对不同溶剂和不同浓度下的白光发射体系进行系统验证(表2),通过探究多种不同混合溶剂下的构建情况,只有二氯甲烷/石油醚的混合溶液可以构建白光发射体系;而通过改变二氯甲烷和石油醚的浓度从1×104 M~1 × 106 M都具有白光发射。

Table 2. White light emission system under different solvents and concentrations

2. 不同溶剂和不同浓度下白光发射体系构建

溶剂

浓度

是否白光

二氯甲烷/石油醚

1 × 105 M

乙酸乙酯/正己烷

1 × 105 M

四氢呋喃/水

1 × 105 M

甲苯/乙醇

1 × 105 M

1,4-二氧六环/甲醇

1 × 105 M

二氯甲烷/石油醚

1 × 106 M

二氯甲烷/石油醚

1 × 104 M

因此,我们对摩尔比为10:10:1:1的超分子白光发射体系进行了荧光滴定实验(图12),结果表明随着溶剂的逐渐挥发,该超分子体系在470 nm处的荧光强度逐渐增强。但当体系开始出现白光发射时,其荧光强度开始减弱;随着白光发射逐渐消失时,550 nm处的荧光强度逐渐增强。此外,为了验证柱[5]芳烃在该超分子白光发射体系中的重要性,我们以功能化杯[4]芳烃(B4-Bu)替代柱[5]芳烃进行主客体络合物以及白光发射体系的构建。结果表明,含有杯[4]芳烃(B4-Bu)的主客体络合物并不能随着溶剂挥发而表现出白光发射,从而证实了柱[5]芳烃在该体系中的关键作用(图10(c))。由于随着溶剂挥发,部分析出固体粘结在比色皿表面,严重影响荧光测试使得无法绘制CIE图,采用拍摄照片和视频的方式记录白光发射体系的构建。由于配置4 mL摩尔比为10:10:1:1的超分子白光发射溶液,随着溶剂自然挥发可以保持超过5 h的白光发射。

此外,我们进行了多组对照实验验证了动态白光发射体系构建过程中TCPNP5[10]CPP[12]CPP的重要性。例如,在相同浓度下分别考察了不同化合物或络合物在不同溶剂中的表现,即TCPN的单独DCM溶剂、TCPN的VDCM/VPE = 1:1的混合溶液等12种对照实验。结果表明,TCPN在随着DCM/PE混合溶液挥发的过程中,并不能显示出白光发射;而对TCPNP5[10]CPP[12]CPP这四种化合物以其中两种任意组合时,也没有白光发射;当对TCPNP5[10]CPP[12]CPP四种化合物分别进行任意三个组合时,TCPN-[10]CPP-[12]CPP在随着DCM/PE混合溶液挥发的过程中,显示出短暂的类白光发射(图13)。

Figure 13. Comparative experiments on the dynamic white-light-emitting system

13. 动态白光发射体系的对照试验

4. 总结

综上所述,本文构建了一系列基于环对苯撑和柱[5]芳烃的多组分超分子动态白光发射体系。通过结合特定尺寸CPPs不同颜色荧光发射的特性,以及柱[5]芳烃较强的主客体络合能力,我们合理设计了一种新型超分子组装策略,实现对白光发射的精准调控,并赋予其动态响应特性。以二四苯乙烯–咔唑和N-萘二酸酐的D-π-A型为客体分子(TCPN),与P5、具有绿色荧光的[10]CPP和蓝色荧光的[12]CPP按摩尔比10:10:1:1通过主客体相互作用实现了多组分超分子络合物的构建,同时实现了以溶剂挥发为条件的可调性的超分子动态白光发射体系的构建。这一研究不仅有助于深化对超分子发光机制的理解,还为开发新型智能光电功能材料提供了重要参考。同时也为柱芳烃和环对苯撑的独特性质的开发开辟了新的途径,有助于白光发射器件的创新和优化。

基金项目

本研究得到中国博士后科学基金(2024MD764022)和国家自然科学基金(22161046)的资助。

NOTES

*通讯作者。

参考文献

[1] Park, S., Kwon, J.E., Kim, S.H., Seo, J., Chung, K., Park, S., et al. (2009) A White-Light-Emitting Molecule: Frustrated Energy Transfer between Constituent Emitting Centers. Journal of the American Chemical Society, 131, 14043-14049.
https://doi.org/10.1021/ja902533f
[2] Xie, Z., Chen, C., Xu, S., Li, J., Zhang, Y., Liu, S., et al. (2015) White‐Light Emission Strategy of a Single Organic Compound with Aggregation-Induced Emission and Delayed Fluorescence Properties. Angewandte Chemie International Edition, 54, 7181-7184.
https://doi.org/10.1002/anie.201502180
[3] Findlay, N.J., Bruckbauer, J., Inigo, A.R., Breig, B., Arumugam, S., Wallis, D.J., et al. (2014) An Organic Down‐Converting Material for White‐Light Emission from Hybrid LEDs. Advanced Materials, 26, 7290-7294.
https://doi.org/10.1002/adma.201402661
[4] Lou, X., Song, N. and Yang, Y. (2019) Enhanced Solution and Solid‐State Emission and Tunable White‐Light Emission Harvested by Supramolecular Approaches. ChemistryA European Journal, 25, 11975-11982.
https://doi.org/10.1002/chem.201902700
[5] Yang, H., Li, Z., Liu, P., Sun, X., Wang, Z., Yao, H., et al. (2020) Metal-Free White Light-Emitting Fluorescent Material Based on Simple Pillar[5]arene-Tripodal Amide System and Theoretical Insights on Its Assembly and Fluorescent Properties. Langmuir, 36, 13469-13476.
https://doi.org/10.1021/acs.langmuir.0c02120
[6] Li, Q., Liu, Y., Liu, P., Shangguan, L., Zhu, H. and Shi, B. (2020) Solvent-Controlled Assembly of Pillar[5]arene-Based Supramolecular Networks via π-π Interactions for White Light Modulation. Organic Chemistry Frontiers, 7, 399-404.
https://doi.org/10.1039/c9qo01383k
[7] Ogoshi, T., Kanai, S., Fujinami, S., Yamagishi, T. and Nakamoto, Y. (2008) PARA-Bridged Symmetrical Pillar[5]arenes: Their Lewis Acid Catalyzed Synthesis and Host-Guest Property. Journal of the American Chemical Society, 130, 5022-5023.
https://doi.org/10.1021/ja711260m
[8] Ogoshi, T., Yamagishi, T. and Nakamoto, Y. (2016) Pillar-Shaped Macrocyclic Hosts Pillar[n]arenes: New Key Players for Supramolecular Chemistry. Chemical Reviews, 116, 7937-8002.
https://doi.org/10.1021/acs.chemrev.5b00765
[9] Wu, D., Li, Y., Shen, J., Tong, Z., Hu, Q., Li, L., et al. (2018) Supramolecular Chemotherapeutic Drug Constructed from Pillararene-Based Supramolecular Amphiphile. Chemical Communications, 54, 8198-8201.
https://doi.org/10.1039/c8cc04334e
[10] Chen, J. and Chen, P. (2019) Pillar[5]arene-Based Resilient Supramolecular Gel with Dual-Stimuli Responses and Self-Healing Properties. ACS Applied Polymer Materials, 1, 2224-2229.
https://doi.org/10.1021/acsapm.9b00516
[11] Zhu, H., Li, Q., Khalil-Cruz, L.E., Khashab, N.M., Yu, G. and Huang, F. (2021) Pillararene-Based Supramolecular Systems for Theranostics and Bioapplications. Science China Chemistry, 64, 688-700.
https://doi.org/10.1007/s11426-020-9932-9
[12] Jiang, B., Wang, W., Zhang, Y., Lu, Y., Zhang, C., Yin, G., et al. (2017) Construction of π‐Surface‐Metalated Pillar[5]arenes Which Bind Anions via Anio-π Interactions. Angewandte Chemie, 129, 14630-14634.
https://doi.org/10.1002/ange.201707209
[13] Butkiewicz, H., Hyziuk, P., Kosiorek, S., Sashuk, V., Zimnicka, M.M. and Danylyuk, O. (2024) Carboxylated Pillar[5]arene Cavity Accommodates Organic Cations in the Host-Guest Complexes. Tetrahedron, 162, Article ID: 134117.
https://doi.org/10.1016/j.tet.2024.134117
[14] Hirst, E.S. and Jasti, R. (2012) Bending Benzene: Syntheses of [n]cycloparaphenylenes. The Journal of Organic Chemistry, 77, 10473-10478.
https://doi.org/10.1021/jo302186h
[15] Darzi, E.R. and Jasti, R. (2015) The Dynamic, Size-Dependent Properties of [5]-[12]Cycloparaphenylenes. Chemical Society Reviews, 44, 6401-6410.
https://doi.org/10.1039/c5cs00143a
[16] Zhao, H., Ma, Y., Cao, L., Huang, S., Zhang, J. and Yan, X. (2019) Synthesis and Photophysical Properties of Chalcophenes-Embedded Cycloparaphenylenes. The Journal of Organic Chemistry, 84, 5230-5235.
https://doi.org/10.1021/acs.joc.9b00207
[17] Guo, Q., Qiu, Y., Wang, M. and Fraser Stoddart, J. (2021) Aromatic Hydrocarbon Belts. Nature Chemistry, 13, 402-419.
https://doi.org/10.1038/s41557-021-00671-9
[18] Zhang, X., Liu, H., Zhuang, G., Yang, S. and Du, P. (2022) An Unexpected Dual-Emissive Luminogen with Tunable Aggregation-Induced Emission and Enhanced Chiroptical Property. Nature Communications, 13, Article No. 3543.
https://doi.org/10.1038/s41467-022-31281-9
[19] Li, X.N., Liu, L., Jia, L.Y., et al. (2025) Acceptor Engineering of Quinone-Based Cycloparaphenylenes via Post-Synthesis for Achieving White-Light Emission in Single-Molecule. Nature Communications, 16, Article No. 467.
[20] Fan, Y., Fan, S., Liu, L., Guo, S., He, J., Li, X., et al. (2023) Efficient Manipulation of Förster Resonance Energy Transfer through Host-Guest Interaction Enables Tunable White-Light Emission and Devices in Heterotopic Bisnanohoops. Chemical Science, 14, 11121-11130.
https://doi.org/10.1039/d3sc04358d
[21] Tang, H., Gu, Z.W., Ding, H.F., Li, Z.B., Xiao, S.Y., Wu, W. and Jiang, X.Q. (2019) Nanoscale Crystalline Sheets and Vesicles Assembled from Nonplanar Cyclic π-Conjugated Molecules. Research, 2019, Article ID: 1953926.
https://doi.org/10.34133/2019/1953926