分子基长余辉材料具有结构多样、发光颜色丰富、可设计性强、生物兼容性好等优势，在光学防伪、加密、光学开关、生物医学等领域具有广泛的应用前景。目前已报道的长余辉材料多表现出单一、稳定的余辉发射，限制了多种场景的应用。多模式响应型长余辉材料作为分子基长余辉材料的重要分支，通常表现出动态可调的余辉寿命、强度、颜色等，可作为额外的视觉监测参数，具有更高的研究与应用价值。

本论文以构筑多模式响应型长余辉材料为研究目标，考虑到金属或卤素的重原子效应以及配合物对有机磷光体的限域作用，使用含N/O杂原子的配体构筑了多例具有可调室温磷光（Room-temperature phosphorescence, RTP）的金属-有机配合物，并对其结构及RTP性能进行表征。具体工作如下：

一、以缺电子的联吡啶和富电子的甲酸为配体成功制备了兼具光致变色和RTP的系列金属-有机框架（Metal-organic frameworks, MOFs）——M(HCOO)₂(4,4'-bipy) （4,4'-bipy=4,4’-联吡啶; M=Cd, MOF-Cd; Zn, MOF-Zn）。MOF-Zn/Cd的室温磷光可利用光致变色行为动态调控：变色前呈现亮黄色余辉，变色后余辉消失；余辉可通过加热恢复，开/关过程可多次循环。基于可逆光致变色动态操纵RTP特性，进一步设计了多重加密模型，证实了在多模信息安全领域的应用前景。利用同构MOFs发光-光致变色性能的差异，通过外延生长法制备了具有多模块的核壳异质结MOF-Co@Zn和MOF-Mn@Zn。异质结在单晶水平上显示出不同的发光和光致变色行为，同时在异质结中实现了光致变色操控磷光，呈现出时间-空间双分辨的颜色和发光变化。

二、选用具有能量转移潜力的D(+)-樟脑酸（D-Cam）和1,3,5-三（1-咪唑基）-苯（tib）与锌自组装，获得了一例三模动态可调余辉的MOF——[Zn₃(D-Cam)₃(tib)₂]·2H₂O (MOF-1)。MOF-1表现出宽范围的激发波长、时间和温度依赖的RTP，余辉覆盖蓝色到橙色。理论计算表明，在MOF-1中电子云分布相对分散，赋予了材料多色可调的余辉。利用其长余辉特性，成功将MOF-1应用于多重加密防伪模型。

三、将卤素原子引入金属-有机长余辉体系，获得了两例具有激发波长、时间依赖的室温磷光金属-有机卤化物（Metal-organic halides, MOHs）——ZnX₂(bpp)（bpp=1,3-二（4-吡啶基）丙烷; X = Cl, MOH-1; Br; MOH-2）。动态多色余辉可归因于配体bpp的自身发射及bpp与卤素原子相互作用的结果，这启发我们向磷光体系中引入适当卤素原子可以作为一种制备动态多色余辉材料的方法。实验和理论计算表明，ZnX₂对超长室温磷光至关重要：(a) 配位聚合物中的Zn-N键和X…π键给bpp分子提供了一个相对稳固的环境，抑制了非辐射跃迁；(b) 由于重原子效应，配位聚合物的自旋轨道耦合相对于bpp大大增强；(c) 卤素和bpp配体之间存在电荷转移（XLCT）。此外，我们还证实了这类材料有望用于信息传递、多重加密防伪、装饰品等领域。

四、选用兼具刚性基团和柔性基团的1-（3-氨基丙基）咪唑（apim）为配体构筑了系列具有室温磷光卤化镉基配位聚合物（Coordination polymers, CPs）——(H-apim)CdCl₃和(apim)CdCl₂（CdX-apim1和CdX-apim2，X=Cl, Br）。系列CPs表现出不同寿命、不同颜色（从青色到红色）的余辉，这归因于卤素原子、配体配位方式及柔性基团的共平面构型不同。有趣的是，CdCl-apim1和CdX-apim2均显示出激发波长依赖的RTP性质，这归因于咪唑/apim自身的发射及其与卤素原子相互作用的结果。理论计算证实在CdCl-apim1中氨丙基没有参与发光，只包含金属到配体的电荷转移（MLCT）和XLCT两种辐射跃迁方式；在CdCl-apim2中氨丙基参与发光，不仅包含MLCT和XLCT过程，还包含扭曲的分子内电荷转移（TICT）。此外，利用系列CPs设计了多重防伪和信息加密模型，证实了此类材料在多个领域的应用前景。这项工作不仅合成了系列具有激发波长依赖的RTP CPs，且实现了全色谱RTP。

Molecular long afterglow materials have attracted widespread attention due to their potential applications in optical anti-counterfeiting, encryption, optical switch, biomedicine and other fields. To date, most long afterglow materials exhibit invariable emission, which limit the application in various scenarios. The multi-mode responsive afterglow materials are a new type of photofunctional materials with tunable afterglow (such as lifetime, intensity, color, etc.), which can be regarded as additional visual monitoring parameters, showing a higher value for research and application.

In this paper, we focus on the construction of multi-mode responsive long afterglow materials. Considering the heavy atom effect of metals or halogens and the limiting effect on organic phosphors, several metal-organic complexes with tunable room-temperature phosphorescence (RTP) were constructed using ligands containing N/O heteroatoms, and their structures and optical properties were characterized. The details are as follows:

(1) A series of metal-organic frameworks (MOFs)——M(HCOO)₂(4,4'-bipy) (4,4’-bipy=4,4-bipyridine; M=Cd, MOF-Cd; Zn, MOF-Zn) with both photochromic and long-lived RTP were successfully synthesized by introducing electron-deficient bipyridine and electron-rich formic acid. MOF-Zn/Cd exhibit dynamic and tunable persistent luminescence upon photo-stimulus, which show bright yellow afterglow that gradually disappears after further irradiation. The afterglow can be easily recovered, and the switching RTP on/off process can be recycled for several times. Benefiting from the dynamic manipulating RTP via reversible photochromism, a multiple encryption demo was facilely obtained. Taking advantage of the difference in luminescence and photochromism of isomorphic MOFs, the multiblock core–shell heterojunctions, MOF-Co@Zn and MOF-Mn@Zn, have been prepared through an epitaxial growth process, and achieved spatio-temporal resolved photo-controllable persistent luminescence in heterojunctions.

(2) D(+)-camphoric acid and 1,3,5-tris(1-imidazolyl)-benzene with energy transfer potential were selected to construct a zinc-based MOF-[Zn₃(D-Cam)₃(tib)₂]·2H₂O (MOF-1) with triple-mode tunable long-persistent luminescence. MOF-1 shows obvious excitation wavelength-, time- and temperature-dependent phosphorescence, covering blue and red region. Theoretical calculations show that the dispersive electronic states distributed in MOF-1, which endow an opportunity to achieve triple-mode dependent color-tunable afterglow. Utilizing its long afterglow, a multiple encryption model was successfully designed, proving that MOF-1 can be applied in information encryption and anti-counterfeiting fields.

(3) Two metal-organic halides (MOHs) with excitation wavelength- and time-dependent RTP, ZnX₂(bpp) (bpp = 1,3-di(4-pyridyl)propane, X=Cl, MOH-1; Br; MOH-2), were synthesized by introducing halogen atoms. The dynamic multicolor afterglow can be attributed to the emission of bpp and the interaction between bpp and halogen atoms. Therefore, the introduction of metal halides into phosphors could be a facile way to develop highly tunable dynamic afterglow materials. Experiments and theoretical calculations show that ZnX₂ is essential for ultra-long RTP: (a) The Zn-N bonds and X... π bonds in the coordination polymer provide a relatively rigid environment for bpp molecules and inhibit the non-radiative transition; (b) Due to the heavy atom effect, the spin-orbit coupling of the coordination polymer is greatly enhanced compared with bpp; (c) Charge transfer occurs between halogen and bpp ligand (XLCT). In addition, we also confirmed that such materials can be used in information communication, encryption, anti-counterfeiting, decoration and other fields.

(4) Using 1-(3-aminopropyl)imidazole (apim) with both rigid and flexible groups as ligands, a series of CdX₂-based coordination polymers (CPs)——(H-apim)CdCl₃ and (apim)CdCl₂ (CdX-apim1 and CdX-apim2, X=Cl, Br) with RTP were constructed. CPs exhibit different duration and colors (from cyan to red), which can be due to the differences in halogen atoms, coordination modes, and the coplanar configuration of flexible groups. Interestingly, CdCl-apim1 and CdX-apim2 exhibit excitation wavelength-dependent RTP properties, which can be attributed to the emission of imidazole/apim and its interaction with halogen atoms. In addition, theoretical calculations confirm that the aminopropyl groups in CdCl-apim1 do not participate in luminescence, and only includes two radiative transitions: metal to ligand charge transfer (MLCT) and XLCT; While aminopropyl groups in CdCl-apim2 participate in luminescence, including not only MLCT and XLCT processes, but also twisted intramolecular charge transfer (TICT). In addition, multiple anti-counterfeiting and information encryption models have been designed using these CPs, confirming the application prospects of such materials in many fields. This work not only prepared a series of excitation wavelength-dependent RTP CPs, but also achieved full-color RTP in these CPs.