CAS: 149817-62-9; 4'-Bromo-2,2':6',2''-Terpyridine

主要参考文献

参考标题:The Synthesis Of 4′-Aryl Substituted Terpyridines By Suzuki Cross-Coupling Reactions: Substituent Effects On Ligand Fluorescence
作者:Wendy Goodall,Kerstin Wild,Kathryn J. Arm,J. A. Gareth Williams
摘要:Several 4A€²-Aryl-Substituted 2,2A€²:6A€²,2A€³-Terpyridines (Tpy-C6H4R) Have Been Prepared By Palladium-Catalysed Cross-Coupling Of 4A€²-Bromoterpyridine Or 4A€²-Triflate-Terpyridine (Triflate = Trifluoromethylsulfonyloxy) With Aryl Boronic Acids Or Esters, Rc6H4B(Or′)2 (R = H, M-Nh2, P-Cho, -No2, -Cn, -Nme2, -Nph2). The New Ligand 4A€²-Mesitylterpyridine (Mesityl = 2,4,6-Trimethylphenyl) Was Prepared In The Same Way. Similarly, 4A€²-Bromophenylterpyridine (Tpy-ï•-Br) Has Been Cross-Coupled With Aryl Halides To Generate Several New Biaryl-Substituted Terpyridines (Tpy-ï•-C6H4R Where R = H, P-Cn, Nme2, Nph2), Together With Two Related Compounds With Pendent 3- Or 4-Pyridyl Groups (Tpy-ï•-C6H4-Py). For Selected Compounds, The Alternative Coupling Strategy Of Reaction Of A Terpyridine-4-Boronate Or Terpyridine-4-Phenylboronate With The Appropriate Aryl Halide Has Also Been Investigated (E.G. To Prepare Tpy-ï•-C6H4No2), But Was Generally Found To Be Less Satisfactory. All Of The Compounds Are Fluorescent In The Uv Region Of The Spectrum, The Biaryl-Substituted Compounds Being Only Slightly Red-Shifted Compared To The Monoaryl Systems, But With The Further Red-Shift That Accompanies Protonation Being More Significant For The Former. Fluorescence Lifetimes In Solution Are In The Range 1A€“5 Ns. The Emission Spectra Of The Aminobiphenyl-Substituted Compounds (Tpy-ï•-C6H4Nr″2, Where R″ = Me Or Ph) Display A Large Red-Shift With Increasing Solvent Polarity, Suggesting The Involvement Of An Intramolecular Charge Transfer State, As Found Previously For The Two Analogues Omitting The Phenyl Ring (Tpy-C6H4Nr″2). In Contrast To The Latter, However, Protonation Or Binding Of A Lewis Acidic Metal Ion To The Aminobiphenyl Compounds Serves To Quench Almost Completely Their Emission.

合成参考文献

摘要:Spitzner, D., Science of Synthesis, (2005) 15, 180.