Synthesis, Structure, and Redox Properties of Nonsymmetric 6-Oxoverdazyls.

Nonsymmetric 6π-electron ("oxidized") 6-oxoverdazyls have been synthesized for the first time. After formal incorporation of a hydrogen atom, the corresponding 7π-electron neutral verdazyl radical is generated. The 7π radical can undergo a further electrochemically reversible reduction to an 8π anion.

Stabilization and One Electron Reduction of a Silicon Analogue of a Carboxylic Acid Anhydride.

Reaction of the 1,2-disilylenes {( Am)Si} ( Am=[(NDip) CAr] , Dip=2,6-diisopropylphenyl, Ar=4-C H Bu (Ar') 1 a or Ph 1 b) and two abnormal N-heterocyclic silylenes, ( Am)SiOCSi{(NDip) CAr} (Ar=Ar' 3 a or Ph 3 b) with N O led to formation of unprecedented examples of uncoordinated silicon analogues of carboxylic acid anhydrides, ( Am)(O=)SiOSi(=O)( Am) (Ar=Ar' 2 a or Ph 2 b). Both compounds have been fully characterized, and the mechanism of formation of one explored using DFT calculations. Reduction of sila-acid anhydride 2 a with a dimagnesium(I) compound, [{( Nacnac)Mg} ] ( Nacnac=[(MesNCMe) CH] , Mes=mesityl), led to the one-electron reduction of the anhydride and formation of a magnesium complex of a sila-acid anhydride radical anion [( Nacnac)Mg{(OSi( Am)} O] 5.

A one-pot reduction route to bimetallic manganese 1,8-naphthyridine complexes.

Reaction of the dinucleating ligand 2,7-bis(6-methyl-2-pyridyl)-1,8-naphthyridine (L) with the Mn and Mn precursors MnBr(CO) and MnCl resulted in the formation of the monometallic complexes [MnBr(CO)(L)] (1) and [MnCl(L)] (3). In both cases, formation of bimetallic manganese complexes could be achieved by reduction with KC, yielding the carbonyl-bridged complex [Mn(CO)(L)] (2) and the helicate complex [Mn(L)] (4), respectively. EPR results demonstrate that 4 represents a novel, weakly antiferromagnetically coupled homovalent dimer ( = -0.

One- and two-electron reductions of a bulky BODIPY compound.

The redox reaction between a bulky BODIPY and a magnesium(I) reducing agent leads to the formal one-electron reduction of the BODIPY, initially generating a dipyrromethene-centred radical compound that dimerises C-C bond formation. In contrast, reduction with magnesium anthracene leads to the formal two-electron reduction of the BODIPY, resulting in the formation of the corresponding anion.

Ketyl Radicals Generated from Magnesium(I) Compounds: Useful Reagents for C-C Bond Forming Reactions.

The aryl ketones, 9-fluorenone (fluor), 9-xanthenone (xanth) and 9,10-anthraquinone (anth), were reacted with β-diketiminato dimagnesium(I) compounds, [{( Nacnac)Mg} ] ( Nacnac=[HC(MeCNAr) ] , Ar=mesityl (Mes) or 2,6-diisopropylphenyl (Dip)). This gave stable magnesium ketyl complexes which are monomeric, [( Nacnac)(DMAP)Mg(fluor⋅)] (Ar=Mes or Dip, DMAP=4-dimethylaminopyridine) and [( Nacnac)Mg(xanth⋅)(xanth)]; dimeric, [{( Nacnac)Mg(μ-fluor⋅)} ], or tetrameric, [{( Nacnac)Mg(μ-anth⋅)} ]. In contrast, di-2-pyridylketone (OCPy ) is doubly reduced with [{( Nacnac)Mg} ] (Xyl=xylyl) to give a diamagnetic alkoxy/amido complex, [{( Nacnac)Mg} (μ-OCPy )].

Crystalline Germanium(I) and Tin(I) Centered Radical Anions.

An isostructural series of heavy Group 14 E(I) radical anions (Ge, Sn, Pb), stabilized by a bulky xanthene-based diamido ligand are reported. The radical anions were synthesised by the one-electron reduction of their corresponding E(II) precursor complexes with sodium naphthalenide in THF, yielding the radical anions as charge-separated sodium salts. The series of main group radicals have been comprehensively characterized by EPR spectroscopy, X-ray crystallography and DFT analysis, which reveal that in all cases, the spin density of the unpaired electron almost exclusively resides in a p-orbital of π symmetry located on the Group 14 center.