Near-infrared fluorescence of silicon phthalocyanine carboxylate esters

Seven silicon(IV) phthalocyanine carboxylate esters (SiPcs, 1–7 ) with non-, partially- and per-fluorinated aliphatic (linear or branched at the alpha-carbon) and aromatic ester groups have been synthesized, their solid-state structures determined and their optoelectronic properties characterized. The SiPcs exhibit quasi-reversible oxidation waves (vs. Fc+/Fc) at 0.58–0.75 V and reduction waves at −0.97 to −1.16 V centered on the phthalocyanine ring with a narrow redox gap range of 1.70–1.75 V. Strong absorbance in the near-infrared (NIR) region is observed for 1–7 with the lowest-energy absorption maximum (Q band) varying little as a function of ester between 682 and 691 nm. SiPcs 1–7 fluorescence in the near-infrared with emission maxima at 691–700 nm. The photoluminescence quantum yields range from 40 to 52%. As a function of esterification, the SiPcs 1–7 exhibit moderate-to-good solubility in chlorinated solvents, such as 1,2-dichlorobenzene and chloroform.

Citation

Pal , A K , Varghese , S , Cordes , D B , Slawin , A M Z , Samuel , I D W & Zysman-Colman , E 2017 , ' Near-infrared fluorescence of silicon phthalocyanine carboxylate esters ' , Scientific Reports , vol. 7 , 12282 . https://doi.org/10.1038/s41598-017-12374-8

Publication

Scientific Reports

Status

Peer reviewed

DOI

https://doi.org/10.1038/s41598-017-12374-8

ISSN

2045-2322

Type

Journal article

Rights

© The Author(s) 2017. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Description

EZ-C acknowledges the University of St Andrews for financial support. We are grateful to the EPSRC for financial support from grant EP/M02105X/1 and the European Research Council for financial support from grant 321305. I.D.W.S. acknowledges a Royal Society Wolfson Research Merit Award.