Efficient Access to 5‐Bromo‐ and 5, 6‐Dibromophenanthroline Ligands. Issue 32 (31st August 2017)

• Record Type: Journal Article
• Authors: Stumper, Anne; Pilz, Thomas David; Schaub, Markus; Görls, Helmar; Sorsche, Dieter; Peuntinger, Katrin; Guldi, Dirk; Rau, Sven
• Is Part Of: European journal of inorganic chemistry. Issue 32(2017)
• Page Start: 3799
• Page End: 3810
• Publication Date: 2017-08-31
• Subjects: Ruthenium -- Bromine -- N ligands -- Cross‐coupling -- Synthesis design; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201700548
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : Bromo‐functionalized precursor molecules are essential for generating desired target compounds through cross‐coupling reactions. Herein we show an improved synthetic route, feasible at low temperatures and affording high yields, to the ligands 5‐bromo‐1, 10‐phenanthroline (1 ) and 5, 6‐dibromo‐1, 10‐phenanthroline (2 ). The corresponding ruthenium complexes, containing various equivalents of ligand2, are easily accessible in high yields, including the analogue of tris‐homoleptic [Ru(bpy)3 ] 2+ (bpy = 2, 2′‐bipyridine), [Ru(2 )3 ] 2+ . X‐ray diffraction analyses have provided detailed information on the structures of the ligands and their corresponding metal complexes. An investigation of the electrochemical properties has provided detailed information on the 3 MLCT state localized on2 . We show the conversion of heteroleptic ruthenium complexes of these ligands in Suzuki cross‐coupling reactions whereas the ligands did not undergo reaction under the same conditions. Abstract : Improved syntheses of 5‐bromo‐ and 5, 6‐dibromo‐1, 10‐phenanthroline are presented. A series of their Ru II –polypyridine complexes have been prepared and converted through Suzuki cross‐coupling reactions. All the complexes have been characterized. A correlation between the number of bromine substituents and the photophysical and electrochemical properties of ruthenium complexes has been explored.