In the structure of the title compound, C(10)H(10)N(2) (2+)·2ClO(4) (-)·4C(7)H(7)NO(2)·2C(10)H(8)N(2)·2H(2)O, the 4,4'-bipyridinium cation has a crystallographically imposed centre of symmetry. The cation is linked by N-H⋯N hydrogen bonds to adjacent 4,4'-bipyridine mol-ecules, which in turn inter-act via O-H⋯N hydrogen bonds with 4-amino-benzoic acid mol-ecules, forming chains running parallel...

A series of pyridinium and bipyridinium salts were prepared their catalytic properties evaluated in the aza-Diels-Alder reaction between imines Danishefsky diene. Depending on substituents pyridinium/bipyridinium rings nature counterion, two mechanisms activation demonstrated. In case non-substituted rings, substrate is activated through charge transfer involving aryl ring C-side imine. When ha...

Z. Naturforsch. 43b, 475-482 (1988); received February 13/October 22, 1987 Electron Transfer Relays, Viologen Derivatives, Bipyridinium Compounds, Stable Cation Radicals, Photoinduced Water Splitting The synthesis of some new bipyridinium salts is described. Their behavior upon reduction is studied by cyclovoltammetry, coulometry and spectroscopically. Halfwave potentials range from —0.28 V to ...

A series of cationic, ditopic N-donor ligands based on 4,4'-bipyridine (4,4'-bipy), 3-aminopyrazine (apyz) and 2-aminopyrimidine (apym), each incorporating two positively-charged N-heterocycles linked by a conformationally-flexible spacer unit, have been synthesised and treated with palladium(II) or platinum(II) precursors [M(2,2'-bipy)(NO(3))(2)] (M = Pd(II) or Pt(II)) to form highly cationic ...

In this paper, 4,4ʹ-bipyridinium dichloride  supported SBA-15 (SBA@BiPy2+ 2Cl-) was used for the synthesis of dihydropyrimidinones. The synthesized catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Thermogravimetric analysis (TGA). This nanocomposite was shown to be an efficient heterogeneous ca...

Let e be an edge of a G connecting the vertices u and v. Define two sets N1 (e | G) and N2(e |G) as N1(e | G)= {xV(G) d(x,u) d(x,v)} and N2(e | G)= {xV(G) d(x,v) d(x,u) }.The number of elements of N1(e | G) and N2(e | G) are denoted by n1(e | G) and n2(e | G) , respectively. The Szeged index of the graph G is defined as Sz(G) ( ) ( ) 1 2 n e G n e G e E    . In this paper we compute th...

So-called bottom-up fabrication methods aim to assemble and integrate molecular components exhibiting specific functions into electronic devices that are orders of magnitude smaller than can be fabricated by lithographic techniques. Fundamental to the success of the bottom-up approach is the ability to control electron transport across molecular components. Organic molecules containing redox ce...

The conformational properties of conjugated heteroaromatic bipyridines, pyridyl-pyridiniums and bipyridinium have been investigated using density functional theory (DFT). The molecules studied were neutral 2,20-bipyridine (2,20-bpy), 2,30bipyridine (2,30-bpy) and 3,30-bipyridine (3,30-bpy) and the singly protonated 3-pyridyl-20-pyridinium (3-py-20-pyH) and 2pyridyl-20-pyridinium (2-py-20-pyH) a...