Photopolymerization of Organic Molecular Crystal Nanorods

• Published in: Macromolecules Vol. 40; no. 25; pp. 9040 - 9044
• Main Authors: Al-Kaysi, Rabih O, Dillon, Robert J, Kaiser, J. Michael, Mueller, Leonard J, Guirado, Gonzalo, Bardeen, Christopher J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 11.12.2007
• Subjects: Applied sciences; Exact sciences and technology; Physicochemistry of polymers; Polymerization; Polymers and radiations; Aluminium oxide; Insoluble compound; Cyclopolymerization; Ester polymer; Molecular crystals; Experimental study; Anthracene derivatives; Cyclopolymer; Photopolymerization; Template polymerization; Morphology; Preparation; Diester; Reaction mechanism; Solid polymerization; Nanostructured materials; Optical absorption
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma0717082

The dianthracene molecule 9-anthracenecarboxylic acid, methylene ester (9AC-ME) was synthesized and used to form molecular crystal nanorods using anodized aluminum oxide templates. A high-temperature solvent annealing process generated a crystal polymorph where neighboring monomers had overlapping anthracene moieties. Subsequent exposure to ultraviolet light caused the monomers to undergo a [4 + 4] photocycloaddition reaction, forming highly crystalline polymer nanorods of poly(9AC-ME). The polymer nanorods are flexible, resistant to breakage, and insoluble in organic solvents and strong acid/base solutions. Their molecular structure is characterized by powder X-ray diffraction, solid-state NMR, and UV−vis spectroscopy. Different diameter crystalline polymer nanorods could be fabricated using alumina templates of variable pore diameter.