Metal ion complexes of 2-picolinamineN-oxide

Summary A series of cobalt(II), nickel(II) and copper(II) complexes of 2-picolinamineN-oxide, HA, has been prepared. Solids of formula [M(HA)₃](BF₄)₂ (M=cobalt(II) or nickel(II); [Cu(HA)₂]X₂ (X=BF ₄ ^– , NO ₃ ^– ); [Co(HA)₂X₂] (X=Cl^– or Br^–); [Ni(HA)₂Cl₂] and [Cu(HA)X₂] (X=Cl^– or Br^–] have been isolated and characterized by partial elemental analyses, molar conductivities, magnetic susceptibilities, DSC-TGA, and spectral methods. All complexes were found to be monomeric, and their spectral parameters are compared with those of the metal ion complexes ofN-alkyl-2-picolinamineN-oxides, 2-dialkylaminopyridineN-oxides and 2-picolinamine. The cobalt(II) and nickel(II) halide complexes spectrally show a mixture of octahedral and tetrahedral centres.     

Chemistry of condensed thiophenes. IV. Acetylation of phenanthro[4,5-bcd]thiophene

Treatment of phenanthro[4,5-bcd]thiophene ( 2 ) with acetyl chloride and aluminum chloride in nitrobenzene gives acetylation of positions ortho and para to the heteroatomic sulfur atom. In separate experiments, mixtures of 1- and 3-acetyl (50% yield, ratio 1.9:1) or of 1,5-, 1,7-, and 3,5-diacetyl (79% yield, ratio 3:1:1) derivatives were obtained. Isolated as isomerically pure products were the 1-acetyl and the 1,5-diacetyl compounds, as well as the oximes of the 1- and 3-acetyl derivatives. Comparison of these results is made with those reported for nitration of 2 , which also occurs ortho and para to the sulfur atom, and with nitration and acetylation of pyrene (the benzolog of 2 ) which substitutes in the corresponding positions.     

Cobalt(II) complexes of the 2-aminopicolineN-oxides and 2-amino-4, 6-lutidineN-oxide

Summary Cobalt(II) complexes of the four 2-aminopicolineN-oxides and 2-amino-4, 6-lutidineN-oxide were prepared from Co(BF₄)₂ and CoCl₂, and characterized by partial elemental analyses, magnetic moments, molar conductivities, thermal analyses, and by plasma desorption mass, i.r., electronic, and e.s.r. spectroscopy. The compounds derived from CoCl₂ are 4-coordinate, tetrahedral, molecular solids with CoO₂Cl₂ chromophores. Dq values range from 332 to 382 cm^–1 and those of B from 758 to 813 cm^–1 for the five solids. Three of the compounds prepared from Co(BF₄)₂ are octahedral with the following stoichiometry: [CoL₆](BF₄)₂ where L=2-amino-4-picolineN-oxide and [CoL₅(H₂O)] (BF₄)₂ where L is either 2-amino-3-or 2-amino-5-picolineN-oxide. Both 2-amino-6-picolineN-oxide and 2-amino-4, 6-lutidineN-oxide gave square planar [CoL ₄ ²⁺ ] complex ions. While numerous square planar cobalt(II) centers are known, those described here are probably the first examples with monodentate ligands and a CoO₄ center. They have weak e.s.r. spectra, magnetic moments between 2 and 3 BM and characteristic d-d spectra.     

Chemistry of thienopyridines. XXXIX. Synthesis of benzothieno[2,3-h]isoquinoline and related studies

Benzo[b]thiophene-2-carboxaldehyde undergoes condensation with 4-methylpyridine and with 2-methylquinoline to produce trans-diarylethenes (52% and 76%, respectively). The former alkene photocyclizes in cyclohexane to yield [1]benzo[2,3-h]isoquinoline (35%), while the latter alkene does not give successful, analogous cyclization.     

2-amino-4,6-lutidineN-oxide complexes formed from various copper(II) salts

Summary Copper(II) complexes of 2-amino-4,6-lutidineN-oxide (4,6DMAH) have been isolated as tetrafluoroborate, nitrate, chloride and bromide salts, and characterized by spectral methods (i.e., i.r., u.v.-vis. and e.s.r.). Variation of the ligand-to-copper(II) ratio yielded solids having the following empirical formulae: [Cu(4,6DMAH)₄]X₂ (X=BF₄), [Cu(4,6DMAH)₂X₂] (X=NO₃, Cl) and [Cu(4,6DMAH)X₂] (X=Br). In addition, a deprotonated ligand complex, Cu(4,6DMA)₂, was prepared using copper(II) acetate. The Sigand usually binds to the copper(II) centresvia theN-oxide oxygen and only the deprotonated ligand coordinatesvia the exocyclic nitrogen as well as the TV-oxide oxygen. The complexes involving coordinated anions and at least two ligands are monomeric while Cu(4,6DMAH)Br₂ is polymeric. The ring substituents affect either the stoichiometry or the stereochemistry of these solids when compared to less sterically demanding 2-aminopyridineN-oxides.