Photoluminescence of as‐synthesized and heat‐treated phenyl‐containing polysilylcarbodiimides: role of crosslinking and free carbon formation in polymer‐derived ceramics. (31st October 2013)

• Record Type: Journal Article
• Authors: Mera, Gabriela; Menapace, Ilaria; Widgeon, Scarlett; Sen, Sabyasachi; Riedel, Ralf; Laine, Richard M.
• Is Part Of: Applied organometallic chemistry. Volume 27:Number 11(2013:Nov.)
• Page Start: 630
• Page End: 638
• Publication Date: 2013-10-31
• Subjects: Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.2993
• Languages: English
• ISSNs: 0268-2605

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>For the first time, photoluminescence properties of four polysilylcarbodiimides, comprised of a phenyl pendant group attached at the silicon atom and a second substituent being either phenyl (<bold>S1</bold>), methyl (<bold>S2</bold>), hydrogen (<bold>S3</bold>) or vinyl (<bold>S4</bold>), are reported. Distinctive fluorescence emissions are detected in the polymers with one phenyl group at the silicon atom (<bold>S2</bold>, <bold>S3</bold> and <bold>S4</bold>), due to a phenyl excimer emission. The polymer with two phenyl groups attached at the same silicon atom (<bold>S1</bold>) shows, besides the phenyl excimer emission, also a vibrationally structured emission stemming from the Ph‐SiX<sub>2</sub>‐Ph unit. Moreover, the polysilylcarbodiimides were heat‐treated at different temperatures up to 500°C in argon flow. In this case, the amount of crosslinking is identified to be responsible for a bathochromic shift of the maximum emission spectra with increasing annealing temperature. After annealing at 300°C, polymers <bold>S2</bold> and <bold>S3</bold> present a red‐shifted emission due to <named-content id="d21e626" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">rearrangement reactions</named-content> of the basic polymer structure. Furthermore, the presence of free carbon formed during the annealing procedure in the form of polycyclic <named-content id="d21e629" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">aromatic hydrocarbons</named-content>, as well‐defined fragments of graphene, are proven to contribute to the photoluminescence properties of the heat‐treated polysilylcarbodiimides. Copyright © 2013 John Wiley & Sons, Ltd.</p> </abstract>