A new ligand system incorporating the 4-pyridonyl group as a substituent in 1,8-naphthalimide compounds is presented, with the pyridone group acting as both an electron donor for the internal charge transfer (ICT) fluorescence process and as a metal binding moiety. After establishing the solution-state photophysical properties of the new pyridyl and carboxyphenyl derivatives L1 and HL2, respectively, we have prepared and characterised four crystalline d-block metal complexes containing the 4-(4-pyridonyl)-1,8-naphthalimide residue. Complex 1, a discrete mononuclear Ag(I) complex, and complexes 2 and 3, both one-dimensional Zn(II) coordination polymers, all exhibit striking photoluminescence in the crystalline phase, the nature of which can be related to the solid-state behaviour of the pyridone substituent. Complex 4, a permanently porous Cu(II) material, shows no photoluminescence, but instead reveals a rare and intriguing inclined 2D → 3D polyrotaxane architecture, an unusual class of mechanically interlocked network in which the particular coordination chemistry of the pyridone group facilitates alternating looped and linear structural features.

中文翻译：

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4-吡啶基作为基于1,8-萘二甲酰亚胺的光致发光和机械联锁配位化合物的多功能电子供体†

提出了一种新的配体系统，该系统在1，8-萘二甲酰亚胺化合物中引入了4-吡啶基作为取代基，吡啶酮基既充当内部电荷转移（ICT）荧光过程的电子供体，又充当金属结合部分。分别建立了新的吡啶基和羧苯基衍生物L1和HL2的溶液态光物理性质后，我们制备并表征了四种含有4-（4-吡啶基）-1,8-萘二甲酰亚胺残基的d-嵌段金属配合物。络合物1，一个离散的单核Ag（I）络合物，以及络合物2和3，都是一维Zn（II））配位聚合物，都在结晶相中表现出惊人的光致发光，其性质可能与吡啶酮取代基的固态行为有关。复合物4是一种永久多孔的Cu（II）材料，没有显示光致发光，而是显示了一种稀有且引人入胜的倾斜2D→3D聚轮烷结构，这是一种罕见的机械互锁网络，其中吡啶酮基团的特殊配位化学促进了交替环和线性结构特征。