Oxidovanadium Complexes of 2, 2′‐Bipyridine, 1, 10 Phenanthroline, and p‐Nitro‐o‐aminophenol – Radical versus Nonradical States. Issue 3 (4th January 2016)

• Record Type: Journal Article
• Authors: Shit, Madhusudan; Bera, Sachinath; Maity, Suvendu; Maji, Subrata; Weyhermüller, Thomas; Ghosh, Prasanta
• Is Part Of: European journal of inorganic chemistry. Issue 3(2016)
• Page Start: 330
• Page End: 338
• Publication Date: 2016-01-04
• Subjects: Oxidovanadium -- Ligand effects -- Radicals -- Structure elucidation -- Electronic structure; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201501246
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: 2, 2′‐Bipyridine (bpy), 1, 10‐phenanthronline (phen) and p ‐nitro‐ o ‐aminophenol ( NO2 LH2 ) oxidovanadium complexes of the types [(LONO 2– )(VO)(bpy)] (1 ), [(LONO 2– )(VO)(phen)] (2 ) and [(LONO 2– )(VO)( NO2 LISQ · – )][NHEt3 ] (3 – NHEt3 + ; NO2 LISQ · – = p ‐nitro‐ o ‐iminobenzosemiquinonate radical) were isolated with ( E )‐2‐(3‐hydroxy‐3‐phenyltriaz‐1‐en‐1‐yl)benzoic acid (LONO H2 ) as a coligand. The single‐crystal X‐ray bond parameters and electron paramagnetic resonance (EPR) spectra authenticated that1 and2 are the oxidovanadium(IV) complexes of bpy and phen, whereas3 – is the NO2 LISQ · – complex of oxidovanadium(IV) and undergoes reversible one‐electron oxidation and reduction at lower potentials. Density functional theory (DFT) calculations established that the closed‐shell‐singlet (CSS) solution of3 – is unstable owing to open‐shell‐singlet (OSS) perturbation. The CSS → OSS charge‐transfer transition that appears at λ = 632 nm is absent for1 and2 . Complex3 is a hybrid of the [(LONO 2– )(VO 2+ )( NO2 LIQ )] ( NO2 LIQ = p ‐nitro‐ o ‐iminobenzoquinone) and [(LONO 2– )(VO 3+ )( NO2 LISQ · – )] states, whereas3 2– is an oxidovanadium(IV) complex of the type [(LONO 2– )(VO 2+ )( NO2 LAP 2– )] 2– ( NO2 LAP 2– = p ‐nitro‐ o ‐amidophenolato). Abstract : Oxidovanadium(IV) complexes of 2, 2′‐bipyridine, 1, 10‐phenanthronline and the p ‐nitro‐ o ‐iminobenzosemiquinonate radical are reported. The3 – → 3 and3 – → 3 2– conversions are reversible owing to the formation of p ‐nitro‐ o ‐iminobenzoquinone and p ‐nitro‐ o ‐amidophenolato complexes.