2,5-bis- pyridine

Amino-2.6-bis(pyridin-2-yl)-1,3,5-triazine 2,4,6-Tri(pyridin-2-yl)-1,3,5-triazine N,N.N, N -Tetrakis(2-pyridylmethyl)-ethylenediamine ADPTZ TPTZ TPEN... 

Terdentate 4-amino-2,6-bis(pyridin-2-yl)-l,3,5-triazine (ADPTZ) can coordinate to Am and Ln with the formation of the 1 1 complexes. In the work [33] the thermodynamic characteristics for the complex formation of Am with ADPTZ were calculated AG=-32.9 0.6 kJ/mole, A//=-28.9 3.0 kJ/mole, A5 =14.0 10.0 J/Kmole. The stability constant equal to logy0 =5.8 O.l for [Am(ADPTZ)] complex was defined using spectrophotometry. The thermodynamic data show that the observed selectivity of the ligand arises from a difference in the enthalpies of complexation for Am and lanthanides. The geometry and electronic structure of the [M(ADPTZ)(H20)6] complexes (for M = Am, Cm, Pu) were calculated using DFT theory with no symmetry constraint. Selected distances are presented in Table 4. 

The facile reaction of 2,6-bis(pyridin-3-yl)pyridine with various Cu(II) salts led to the molecular self-assembly of a series of complexes that are polymeric or of two- (25) and three- (26) dimensional composition depending on the Cu(II) salt utilized and reaction conditions (13AJC1447). Similarly, when [Pd(MeCN)4](BF4)2 was utilized with substimted 2,6-bis(pyridin-3-yl)pyridine, a quantitative yield of the derivatized 3D complex was generated (13CC3398).A series of late first-row transition-metal complexes using an N,N -di-tert-butyl-2,ll-diaza[3.3](2,6)pyridino-phane has been reported (13IC3920). 

This chemoselectivity stands in contrast to that of 2,6-disubstituted pyridines. For example, 2,6-dimethylpyridine 35 was reacted with hydrogen peroxide and acetic anhydride to produce the expected acetoxy derivative 36. A second iteration of the previous reaction conditions did not afford an aldehyde, as in the previous example, but 2,6-bis-acetoxy derivative 37. 

Methoxyquinoxaline (10, R = H) gave 6-methoxy-5-nitroquinoxaline (10, R = N02) (95% H2SO4, KN03i slowly, 20°C, 2 h 79%) ° a similar procedure was used to make 6-methoxy-3-morpholino-5-nitroquinoxalme (11) (90%) but more vigorous conditions were used to afford 6-meth-oxy-5-nitro-2,3-bis(pyridin-2-yl)quinoxalme (12) (95% H2SO4, KNO3I slowly, 20°C 70°C, 3 h 96%). ... 

Methyl-5-nitro-2,3-bis(pyridin-2-yl)quinoxaline (32, R = N02) gave 6-methyl-... 

Pyridine, 2,6-di-tert-butyl-4-methyl- (8) Pyridine, 2,6-bis(l,l-dimethylethyl)-4-methyl- (9) (38222-83-2)... 

Lewis TA, A Paszczynski, SW Gordon-Wylie, S Jeedigunta, C-H Lee, RL Crawford (2001) Carbon tetrachloride dechlorination by the bacterial transition metal chelator pyridine,2,6-bis(thiocarboxylic acid). Environ Sci Technol 35 552-559. 

Shieh, S.-J., Hong, X., Peng, S.-M. and Che, C.-M. (1994) Synthesis and crystal structure of a luminescent onedimensional phenylacetylide-gold(I) polymer with 2,6-bis(diphenylphosphino) pyridine as ligand. Journal of the Chemical Society, Dalton Transactions, 3067-3068. 

Ligand abbreviations bi = 2,2 -bi-2-imidazoline bt = 2,2 -bi-2-thiazoline bpy = 2,2 -bipyridine phen = 1,10-phenanthroline phy = l,10-phenanthroline-2-carbaldehyde phenylhydrazone bpp = 2,6-bis(pyrazol-3-yl)pyridine paptH = 2-(2-pyridylamino)-4-(2-pyridyl)thiazole 2-pic = 2-picolylamine L = macrocyclic ligand derived from condensation of 2,6-diacetylpyridine with 3,6-dioxaoctane-1,8-diamine Hjthpu = pyruvic acid thiosemicarbazone Hjthpx = pyridoxal thiosemicarbazone salen = dianion of W,iV -ethylenebis(salicylideneimine) H2fsa2en = dianion of fV,JV -ethylenebis(3-carboxysalicylaldimine). 

In 2004, ruthenium-catalysed asymmetric cyclopropanations of styrene derivatives with diazoesters were also performed by Masson et al., using chiral 2,6-bis(thiazolines)pyridines. These ligands were prepared from dithioesters and commercially available enantiopure 2-aminoalcohols. When the cyclopropanation of styrene with diazoethylacetate was performed with these ligands in the presence of ruthenium, enantioselectivities of up to 85% ee were obtained (Scheme 6.6). The scope of this methodology was extended to various styrene derivatives and to isopropyl diazomethylphosphonate with good yields and enantioselectivities. The comparative evaluation of enantiocontrol for cyclopropanation of styrene with chiral ruthenium-bis(oxazolines), Ru-Pybox, and chiral ruthenium-bis(thiazolines), Ru-thia-Pybox, have shown many similarities with, in some cases, good enantiomeric excesses. The modification... 

Further optical oxygen sensors which have been developed are those of [Ir(LI I)(L)](PF6)2 and [Ir(L)2]PF6, LH = 2,6-bis(7 -methyl-4 -phenyl-2 -quinolyl)pyridine, immobilized in a polymeric matrix321, and [Ir( ppy)3]31 immobilized in fluoropolymer film.322... 

The terdentate cyclometalated complexes [Ir(L)(L )]2+ and [Ir(L )2]1, L = 2,6-bis(7 -methyl-4 -phenyl-2 -quinoyl)pyridine (233), L = monoanion of L (234), luminesce at 77 K in MeOH/EtOH (lmax = 592 nm, r =20 ps) and at room temperature in deoxygenated acetonitrile (imax 620 nm, r = 325 ns).405 Both compounds undergo four reversible, ligand-centered, one-electron reduction processes. 

Tridentate 2,6-bis(thiomorpholinomethyl)pyridine (173) forms only the 1 1 complex [Ni(173)(N03)2] with Ni11. However, the geometry around the metal center is octahedral due to coordination of two nitrates, one as a monodenate and the other as a bidentate ligand.578... 

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