Modular One‐Pot Access to π‐Expanded Tetrakis(Phenothiazinyl)‐Silanes With Broadly Tunable Redox and Emission Properties
- 1Institut für Organische Chemie und Makromolekulare Chemie Heinrich‐Heine‐Universität Düsseldorf Düsseldorf Germany
- 2Institut für Anorganische Chemie und Strukturchemie I Heinrich‐Heine‐Universität Düsseldorf Düsseldorf Germany
Abstract
The development of multichromophoric materials with independently tunable redox and emissive properties remains a central challenge in organic materials chemistry. Herein, we report a library of 21 predominantly C3‐connected tetrakis(phenothiazinyl)silanes, accessed principally via a modular one‐pot BLEBS (bromine–lithium exchange–borylation–Suzuki) strategy in moderate to very good yields (15%–87%), featuring systematic variation at the 10‐, 7‐ and 2‐positions of the phenothiazine scaffold, a C1‐connected regioisomeric reference, as well as four distinct linker architectures. Cyclic voltammetry reveals fully reversible first oxidations spanning +0.17 to +0.42 V versus Fc/Fc+, with a linear Hammett correlation (σ p, R 2 = 0.985) for the 7‐substituted subset confirming predictable electronic fine‐tuning. Photophysically, the tetramers exhibit bright fluorescence with quantum yields up to Φ F = 0.90 and emission tunable from deep blue to yellow–green (441–533 nm) through linker engineering. (TD‐)DFT calculations confirm locally excited, phenothiazine‐centered emissive states and quantitatively reproduce the experimental variation in radiative rates via computed oscillator strengths. Notably, 7‐substitution selectively modulates the redox potentials while leaving the optical gap essentially invariant, whereas linker modification primarily governs the emission energy, establishing the tetrakis(phenothiazinyl)silane scaffold as a versatile platform for the largely independent control of electrochemical and photophysical properties.
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BibTeX
@article{merke2026modular,
title = {{Modular One‐Pot Access to π‐Expanded Tetrakis(Phenothiazinyl)‐Silanes With Broadly Tunable Redox and Emission Properties}},
author = {Thomas P. M. Merke and Lysander Presser and Leonard Karl and Christian Ganter and Thomas J. J. Müller},
journal = {Chemistry (Weinheim an Der Bergstrasse, Germany)},
year = {2026},
month = jul,
doi = {10.1002/chem.71368},
url = {https://doi.org/10.1002/chem.71368},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Modular One‐Pot Access to π‐Expanded Tetrakis(Phenothiazinyl)‐Silanes With Broadly Tunable Redox and Emission Properties
AU - Thomas P. M. Merke
AU - Lysander Presser
AU - Leonard Karl
AU - Christian Ganter
AU - Thomas J. J. Müller
PY - 2026
DA - 2026/07/08
JO - Chemistry (Weinheim an Der Bergstrasse, Germany)
DO - 10.1002/chem.71368
UR - https://doi.org/10.1002/chem.71368
AB - The development of multichromophoric materials with independently tunable redox and emissive properties remains a central challenge in organic materials chemistry. Herein, we report a library of 21 predominantly C3‐connected tetrakis(phenothiazinyl)silanes, accessed principally via a modular one‐pot BLEBS (bromine–lithium exchange–borylation–Suzuki) strategy in moderate to very good yields (15%–87%), featuring systematic variation at the 10‐, 7‐ and 2‐positions of the phenothiazine scaffold, a C1‐connected regioisomeric reference, as well as four distinct linker architectures. Cyclic voltammetry reveals fully reversible first oxidations spanning +0.17 to +0.42 V versus Fc/Fc+, with a linear Hammett correlation (σ p, R 2 = 0.985) for the 7‐substituted subset confirming predictable electronic fine‐tuning. Photophysically, the tetramers exhibit bright fluorescence with quantum yields up to Φ F = 0.90 and emission tunable from deep blue to yellow–green (441–533 nm) through linker engineering. (TD‐)DFT calculations confirm locally excited, phenothiazine‐centered emissive states and quantitatively reproduce the experimental variation in radiative rates via computed oscillator strengths. Notably, 7‐substitution selectively modulates the redox potentials while leaving the optical gap essentially invariant, whereas linker modification primarily governs the emission energy, establishing the tetrakis(phenothiazinyl)silane scaffold as a versatile platform for the largely independent control of electrochemical and photophysical properties.
SN - 0947-6539
SN - 1521-3765
ER -