title: Synthesis, photophysical and electrochemical properties of a mixed bipyridyl-phenanthrolyl ligand Ru(II) heteroleptic complex having trans-2-methyl-2-butenoic acid functionalities.
abstract: In this work, two ligands: 4-(trans-2-Methyl-2-butenoic acid)-2,2'-bipyridine) (L(1)) and 5-(trans-2-methyl-2-butenoic acid)-1,10-phenanthroline (L(2)), with the corresponding mixed-ligand heteroleptic Ru(II) complex were synthesized and characterized by FT-IR, 1H-, 13C-NMR spectroscopy and elemental analysis. The influence of the mixed functionalized polypyridyl ruthenium(II) complex on the photophysical and electrochemical properties were investigated and compared to individual single-ligand homoleptic complexes. Interestingly, the mixed-ligand complex formulated as [RuL(1)L(2)(NCS)(2)] exhibits broad and intense metal-to-ligand charge transfer (MLCT) absorption with a high molar extinction coefficient (λ(max) = 514 nm, ε = 69,700 M(-1) cm(-1)), better than those of individual single-ligand complexes, [Ru(L(1))(2)(NCS)(2)] and [Ru(L(2))(2)(NCS)(2)], and a strong photoluminescence intensity ratio in the red region at λ(em) = 686 nm. The electrochemical properties of the complex indicated that the redox processes are ligand-based.
authors.affiliation: Department of Chemistry, Faculty of Science and Agriculture, University of Fort Hare, PMB X1314, Alice 5700, South Africa. aadeloye@ufh.ac.za
authors.forename: Adewale O
authors.initials: AO
authors.lastname: Adeloye
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D018360:Crystallography, X-Ray; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D010618:Phenanthrolines / Q000138:chemical synthesis* / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: C570554:4-(trans-2-methyl-2-butenoic acid)-2,2'-bipyridine; C570555:5-(trans-2-methyl-2-butenoic acid)-1,10-phenanthroline; D008024:Ligands; D010618:Phenanthrolines; D015082:2,2'-Dipyridyl; D012428:Ruthenium