Preparation, Characterization, Electrochemistry, and Infrared Spectro­electrochemistry of Ruthenium ­Nitrosyl Porphyrins Containing η1‐O‐Bonded Axial Carboxylates. Issue 4 (5th January 2016)

• Record Type: Journal Article
• Authors: Awasabisah, Dennis; Xu, Nan; Gautam, Krishna P. Sharmah; Powell, Douglas R.; Shaw, Michael J.; Richter‐Addo, George B.
• Is Part Of: European journal of inorganic chemistry. Issue 4(2016)
• Page Start: 509
• Page End: 518
• Publication Date: 2016-01-05
• Subjects: Redox chemistry -- Spectroelectrochemistry -- Cyclic voltammetry -- Porphyrinoids -- Ruthenium -- Nitrosyl ligands; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201501115
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: The synthesis, characterization and redox behavior of eight low‐spin nitrosyl carboxylate compounds (por)Ru(NO)[η 1 ‐OC(=O)R] [por = T( p ‐OMe)PP: R = Me (1 ), i Pr (2 ), t Bu (3 ), p ‐C6 H4 NO2 (4 ), Fc (5 ), CF3 (8 ); por = TTP: R = Fc (6 )] and [T( p ‐OMe)PP]Ru(NO)(OC6 HF4 ) (7 ) are reported. The compounds are moderately stable in air as solids. Their IR (KBr) spectroscopic data show υNO' s in the 1839–1861 cm –1 range. The X‐ray crystal structures of compounds1, 2, 5 –7, and8 have been determined, and reveal linear RuNO linkages for these formally {RuNO} 6 complexes. The redox behavior of the compounds at a Pt working electrode were studied in CH2 Cl2 with NBu4 PF6 as supporting electrolyte. The compounds display reversible first oxidations. IR spectroelectrochemistry of compounds1 –4, 7 and8 revealed porphyrin‐centered oxidations, whereas the ferrocenylcarboxylate compounds revealed first oxidations at the ferrocenyl moiety followed by second oxidations at the porphyrin macrocycles. Reductions of these compounds are accompanied by loss of the axial ligands. Abstract : The redox behavior of a representative set of Ru porphyrin nitrosyls with η 1 ‐ O ‐carboxylate ligands reveal that the first oxidations occur at the porphyrin macrocycles. Appending redox‐active ferrocenylcarboxylates to the (por)Ru(NO) centers alters the oxidation behavior such that the first oxidations occur on the ferrocenyl moieties. X‐ray crystallographic data were obtained for six of these derivatives that show essentially linear RuNO linkages consistent with their {RuNO} 6 descriptions.