Aryl-substituted bis(imino)pyridine cobalt dinitrogen compounds, ((R)PDI)CoN2, are effective precatalysts for the intramolecular [2π + 2π] cycloaddition of α,ω-dienes to yield the corresponding bicyclo[3.2.0]heptane derivatives. The reactions proceed under mild thermal conditions with unactivated alkenes, tolerating both amine and ether functional groups. The overall second order rate law for t...

The title compound, [Zr2(C10H15)4(C6H6N2)2]·C6H14, was obtained by the stoichiometric reaction of adipo-nitrile with [Zr(C10H15)2(η(2)-Me3SiC2SiMe3)]. Intra-molecular nitrile-nitrile couplings and deprotonation of the substrate produced the (1-imino-2-enimino)-cyclo-pentane ligand, which functions as a five-membered bridge between the two metal atoms. The Zr(IV) atom exhibits a distorted tetra-...

A high-resolution solution structure of a stable 42-nt RNA dimeric construct has been derived based on a high number of NMR observables including nuclear overhauser effects (NOEs), J-coupling constants and residual dipolar couplings (RDCs), which were all obtained with isotopically unlabeled molecules. Two 21-nt siRNA that efficiently hybridize consist of ribose units that were alternately subs...

The geometries of various tautomers and isomers of 2-methylamino-2-imidazoline, 2-methylamino-2oxazoline, 2-methylamino-2-thiazoline, 2-phenylamino-2-imidazoline, 2-phenylamino-2-oxazoline, and 2-phenylamino-2-thiazoline have been studied using the Becke3LYP/6–31+G(d,p) DFT, ONIOM(Becke3LYP/6–31+G(d,p):HF/3–21G∗) and ONIOM(Becke3LYP/6–31+G(d,p):AM1) methods. The optimized geometries indicate th...

3-mercapto-1,2,4 benzotriazine (1) was methylated by methyl iodide in the presence of base to afford 1,2-dihydro-3-methyhercapto-1, 2,4 benzotriazine (2). the latter was reacted with hydrazine hydrate to give the corresponding 3-hydrazine derivative (3). compound (3) on condensation with phenacyl bromide gave 3- phenacyl hydrazino l,2,4-benzotriazine (4). ppa cyclization of the ketone (4) yield...

The existence of DNA triple helices in vitro has been known for some time. Recent evidence suggesting that DNA triplexes exist in vivo and showing their potential for chemotherapeutic applications has renewed interest in these triple-strand conformations. However, little structural information is currently known about these unusual nucleic acid forms. We have induced and stabilized triple-helic...

The reaction between copper(II) nitrate and (E)-N-(3-amino-2,2-dimethyl-prop-yl)-2-(hy-droxy-imino)-propanamide led to the formation of the dinuclear centrosymmetric copper(II) title complex, (C8H18N3O2)2[Cu2(C8H15N3O2)2(C8H17N3O2)2](C9H16N3O4)2·2CH3CN, in which an inversion center is located at the midpoint of the Cu2 unit in the center of the neutral [Cu2(C8H15N3O2)2(C8H17N3O2)2] complex frag...

In the title compound, [Ba(C7H5N2O5)2(H2O)6]·4H2O, the Ba(2+) cation lies on a twofold rotation axis and is ten-coordinated by two 3,5-bis-(hy-droxy-imino)-1-methyl-2,4,6-trioxo-cyclo-hexa-n-ide oxo O atoms [Ba-O = 2.8715 (17) Å], two hy-droxy-imino N atoms [Ba-N = 3.036 (2) Å], and six water mol-ecules [Ba-O = 2.847 (2), 2.848 (2), and 2.880 (2) Å]. The 3,5-bis-(hy-droxy-imino)-1-methyl-2,4,6-...