Abstract
AbstractThe synthesis of 5,10,15,20‐tetrakis((5,10‐bis((2‐hexyldecyl)oxy)dithieno[3,2‐c:3′,2′‐h][1,5]naphthyridin‐2‐yl)ethynyl)porphyrin zinc(II) (Por4NT), a near‐infrared (NIR) emitting compound, comprising a zinc porphyrin core linked with triple bonds through its meso positions to four 5,10‐bis((2‐hexyldecyl)oxy)dithieno[3,2‐c:3′,2′‐h][1,5]naphthyridine (NT) arms is reported. Por4NT featured high solubility in common non‐polar solvents, which is ideal for easy processing through solution techniques, and high photoluminescence (PL) efficiency of ≈30% in dilute toluene solution. It also exhibited a strong tendency for aggregation because of its flat conformation, and this aggregation resulted in a strong redshifted emission and a drop in PL efficiency. A well‐matched PBDTSi‐BDD‐Py “host” terpolymer is therefore designed, which is capable of mitigating the aggregation of the Por4NT “guest”. An optimized blend of the host, guest, and an ionic‐liquid electrolyte is utilized as the active material in a light‐emitting electrochemical cell (LEC), which delivered strong NIR radiance of 134 µW cm‐2 with a long wavelength maximum at 810 nm at a low drive voltage of 5.0 V. The attainment of the strong NIR emission from the host–guest LEC is attributed to a tuned aggregation of the Por4NT emitter, which resulted in the desired aggregation‐induced redshift of the emission at a reasonably retained efficiency.
Highlights
Materials that emit in the near-infrared (NIR) range are critical for the realization of a wide range of applications in, for example, optical communication, security authentication, and medicine,[1] with the latter applications in part effectuated by the NIR window between 700–1000 nm of biological tissue.[2]
Zn was selected as the porphyrin core metal over, e. g., Pt or Pd, because of its abundance, low toxicity, and low price.[31]
The porphyrin core was further metallated by reaction with zinc acetate dihydrate to afford ZnP-TIPS4.[30]. Desilylation of ZnP-TIPS4 with TBAF followed by Sonogashira coupling of the intermediate with NT monobromide afforded Por4NT, as depicted in Scheme S2, Supporting Information
Summary
Materials that emit in the near-infrared (NIR) range are critical for the realization of a wide range of applications in, for example, optical communication, security authentication, and medicine,[1] with the latter applications in part effectuated by the NIR window between 700–1000 nm of biological tissue.[2]. Porphyrins are organic compounds employed by nature for a number of different tasks, notably for photosynthesis[26] and for oxygen transport in the blood stream.[27] They have been employed as emitters in OLEDs.[28] The optical properties of porphyrins can be modified to achieve emission in the NIR region via the selection of the central metal atom and by the modification of the chemical constituents attached to the meso and β positions of the porphyrin core.[4,29] Recently, we reported the synthesis of a star-shaped diketopyrrolopyrrole-substituted Zn porphyrin that delivered deep NIR emission with a peak wavelength of 900 nm when introduced in an LEC device.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
