Amine-Responsive Adaptable Nanospaces: Fluorescent Porous Coordination Polymer for Molecular Recognition

• Published in: Angewandte Chemie International Edition Vol. 53; no. 44; pp. 11772 - 11777
• Main Authors: Haldar, Ritesh, Matsuda, Ryotaro, Kitagawa, Susumu, George, Subi J., Maji, Tapas Kumar
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 27.10.2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Amines; Amines - metabolism; charge transfer; Chemical bonds; Coordination polymers; Emission; Encapsulation; Energy transfer; Energy Transfer - physiology; molecular recognition; Nanostructure; Naphthalene; Platforms; Recognition; supramolecular encapsulation; X-ray diffraction; X-Ray Diffraction - methods; X-ray diffraction; energy transfer; molecular recognition; supramolecular encapsulation; charge transfer
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201405619

Flexible and dynamic porous coordination polymers (PCPs) with well‐defined nanospaces composed of chromophoric organic linkers provide a scaffold for encapsulation of versatile guest molecules through noncovalent interactions. PCPs thus provide a potential platform for molecular recognition. Herein, we report a flexible 3D supramolecular framework {[Zn(ndc)(o‐phen)]⋅DMF}n (o‐phen=1,10‐phenanthroline, ndc=2,6‐napthalenedicarboxylate) with confined nanospaces that can accommodate different electron‐donating aromatic amine guests with selective turn‐on emission signaling. This system serves as a molecular recognition platform through an emission‐readout process. Such unprecedented tunable emission with different amines is attributed to its emissive charge‐transfer (CT) complexation with o‐phen linkers. In certain cases this CT emission is further amplified by energy transfer from the chromophoric linker unit ndc, as evidenced by single‐crystal X‐ray structural characterization. It all stacks up: A supramolecular host with a nano‐coordination space built up by the assembly of a 1D coordination polymer has been synthesized for encapsulation and recognition of various aromatic amine guest molecules through an emission‐readout process. In some cases, the charge‐transfer emission is enhanced by energy transfer from the chromophoric naphthalene linker unit.