التفاصيل البيبلوغرافية
| العنوان: |
Employing Long-Range Inductive Effects to Modulate Metal-to-Ligand Charge Transfer Photoluminescence in Homoleptic Cu(I) Complexes. |
| المؤلفون: |
Rosko MC; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States., Espinoza EM; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States., Arteta S; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States., Kromer S; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States., Wheeler JP; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States., Castellano FN; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States. |
| المصدر: |
Inorganic chemistry [Inorg Chem] 2023 Feb 20; Vol. 62 (7), pp. 3248-3259. Date of Electronic Publication: 2023 Feb 07. |
| نوع المنشور: |
Journal Article |
| اللغة: |
English |
| بيانات الدورية: |
Publisher: American Chemical Society Country of Publication: United States NLM ID: 0366543 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1520-510X (Electronic) Linking ISSN: 00201669 NLM ISO Abbreviation: Inorg Chem Subsets: PubMed not MEDLINE; MEDLINE |
| أسماء مطبوعة: |
Original Publication: [Easton, Pa.] American Chemical Society. |
| مستخلص: |
Four Cu(I) bis (phenanthroline) photosensitizers formulated from a new ligand structural motif ( Cu1-Cu4 ) coded according to their 2,9-substituents were synthesized, structurally characterized, and fully evaluated using steady-state and time-resolved absorption and photoluminescence (PL) measurements as well as electrochemistry. The 2,9-disubstituted-3,4,7,8-tetramethyl-1,10-phenanthroline ligands feature the following six-membered ring systems prepared through photochemical synthesis: 4,4-dimethylcyclohexyl ( 1 ), tetrahydro-2H-pyran-4-yl (2 ), tetrahydro-2H-thiopyran-4-yl ( 3 ), and 4,4-difluorocyclohexyl ( 4 ). Universally, these Cu(I) metal-to-ligand charge transfer (MLCT) chromophores display excited-state lifetimes on the microsecond time scale at room temperature, including the three longest-lived homoleptic cuprous phenanthroline excited states measured to date in de-aerated CH 2 Cl 2 , τ = 2.5-4.3 μs. This series of molecules also feature high PL quantum efficiencies (Φ PL = 5.3-12% in CH 2 Cl 2 ). Temperature-dependent PL lifetime experiments confirmed that all these molecules exhibit reverse intersystem crossing and display thermally activated delayed PL from a 1 MLCT excited state lying slightly above the 3 MLCT state, 1050-1490 cm -1 . Ultrafast and conventional transient absorption measurements confirmed that the PL originates from the MLCT excited state, which remains sterically arrested, preventing an excessive flattening distortion even when dissolved in Lewis basic CH 3 CN. Combined PL and electrochemical data provided evidence that Cu1-Cu4 are highly potent photoreductants ( E ox * = -1.73 to -1.62 V vs Fc +/0 in CH 3 CN), whose potentials are altered solely based on which heteroatoms or substituents are resident on the 2,9-appended ring derivatives. It is proposed that long-range electronic inductive effects are responsible for the systematic modulation observed in the PL spectra, excited-state lifetimes, and the ground state absorption spectra and redox potentials. Cu1-Cu4 quantitatively follow the energy gap law, correlating well with structurally related cuprous phenanthrolines and are also shown to triplet photosensitize the excited states of 9,10-diphenylanthracene with bimolecular rate constants ranging from 1.61 to 2.82 × 10 8 M -1 s -1 . The ability to tailor both photophysical and electrochemical properties using long-range inductive effects imposed by the 2,9-ring platforms advocates new directions for future MLCT chromophore discovery. |
| تواريخ الأحداث: |
Date Created: 20230207 Date Completed: 20230222 Latest Revision: 20230222 |
| رمز التحديث: |
20231215 |
| DOI: |
10.1021/acs.inorgchem.2c04315 |
| PMID: |
36749829 |
| قاعدة البيانات: |
MEDLINE |
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