03186nas a2200229   4500008004100000022001400041245025900055210006900314260007100383300001400454490000700468520220000475100001502675700001302690700001202703700002202715700001902737700002602756700001602782700002602798856013202824       2005                        eng d  a0020-166900aEffect of 2-(2-pyridyl)azole-based ancillary ligands (L1-4) on the electrophilicity of the nitrosyl function in [Ru-II(trpy)(L1-4)(NO)](3+) [trpy=2,2 `: 6 `,2 `'-terpyridine]. synthesis, structures, and spectroscopic, electrochemical, and kinetic aspects0 aEffect of 22pyridylazolebased ancillary ligands L14 on the elect  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a3499-35110 v443 a<p>Ruthenium nitrosyl complexes [Ru(trpy)(L1-4)(NO)](3+) (13-16) [trpy = 2,2':6',2"-terpyridine, L-1 = 2-(2-pyridyl)-benzoxazole, L-2 = 2-(2-pyridyl)benzthiazole, L-3 = 2-(2-pyridyl)benzimidazole, L-4 = 1-methyl-2-(2-pyridyl)-1H-benzimidazole] were obtained in a stepwise manner starting from [Ru-II(trpy)(L1-4) (Cl)]ClO4 (1-4) &amp;RARR; [Ru-II(trpy)(L1-4) (H2O)](ClO4)(2) (5-8) &amp;RARR; [Ru-II(trpy)(L1-4) (NO2)ClO4 (9-12) &amp;RARR; [Ru-II(trpy)(L-1,L-2,L-4) (NO)](ClO4)(3) (13, 14, 16)/[Ru-II(trpy)(L-3) (NO)](Cl)(4))(2)(NO3) (15). Crystal structures of 1, 2, 4, 9, 12, 13, 15, and 16 established the stereoretentive nature of the transformation processes. Though the complexes of L1, L3, and L 4 were isolated in the isomeric form A (π-acceptor trpy and azole ring in the equatorial plane and the pyridine and chloride donors in the axial positions), complexes of L 2 preferentially stabilized in form B (trpy and pyridine in the equatorial plane and the azole ring and chloride donors in the axial positions). The v(NO) stretching frequency varied in the range of 1957-1932 cm(-1), 13 &amp;MGT; 14 &amp;MGT; 15 &gt; 16, primarily depending on the electronic aspects of L as well as the isomeric structural forms. The coordinated nitrosyl function underwent successive reductions of [Ru-II-NO+](3+) &amp;RARR; [Ru-II-NO&amp;BULL;](2+) and [Ru-II-NO&amp;BULL;](2+) - [Ru-II-NO-](+), and the first reduction potential follows the order 14 &gt; 13 &amp;MGT; 15 &amp;AP; 16. The nearly axial EPR spectra having nitrogen hyperfine splittings (A &amp;AP; 26 G) at 77 K of 13(-)-16(-) with (g) &amp;AP; 2.0 established that the reduction process is largely centered around the nitrosyl function. Despite an appreciably high v(NO), the complexes were found to be unusually stable even in the aqueous medium. They transformed slowly and only partially into the corresponding nitro derivatives in H2O (k &amp;AP; 10(-4) s(-1) and K = 0.4-3.8). The chloro (1-4), aqua (5-8), and nitro (9-12) derivatives displayed reasonably strong emissions near 700 nm at 77 K (φ = 10(-1)-10(-2)). The aqua derivative 7 was found to interact with the calf thymus and the circular form of p-Bluescript SK DNA.</p>1 aChanda, N.1 aPaul, D.1 aKar, S.1 aMobin, Shaikh, M.1 aDatta, Anindya1 aPuranik, Vedavati, G.1 aRao, K., K.1 aLahiri, Goutam, Kumar  uhttps://library.ncl.res.in/content/effect-2-2-pyridylazole-based-ancillary-ligands-l1-4-electrophilicity-nitrosyl-function-ru-101995nas a2200229   4500008004100000022001400041245026000055210006900315260007100384300001400455490000700469520099600476100001201472700001501484700002201499700002001521700001701541700002601558700002801584700002601612856012701638       2005                        eng d  a0020-166900aUnusual monodentate binding mode of 2,2 `-dipyridylamine (L) in isomeric trans(acac)(2)Ru-II(L)2, trans-[(acac)(2)Ru-III(L)(2)]ClO4, and cis-(acac)(2)Ru-II(L)(2) (acac = acetylacetonate). Synthesis, structures, and spectroscopic, electrochemical, and magn0 aUnusual monodentate binding mode of 22 dipyridylamine L in isome  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a1571-15790 v443 a<p>{The reaction of cis-Ru(acac)(2)(CH3CN)(2) (acac = acetylacetonate) with 2,2'-dipyridylamine (L) in ethanolic medium resulted in facile one-pot synthesis of stable [(acac)(2)Ru-III(L)]ClO4 ([1]ClO4), trans-[(acac)(2)Ru-II(L)2] (2), trans[(acac)(2)Ru-III(L)(2)[ClO4 ([2]ClO4), and cis-[(acac)(2)Ru-II(L)(2)] (3). The bivalent congener 1 was generated via electrochemical reduction Of [1]ClO4. Although in [1](+) the dipyridylamine ligand (L) is bonded to the metal ion in usual bidentate fashion, in 2/[2](+) and 3, the unusual monodentate binding mode of L has been preferentially stabilized. Moreover, in 2/[2](+) and 3, two such monodentate L's have been oriented in the trans- and cis-configurations, respectively. The binding mode of L and the isomeric geometries of the complexes were established by their single-crystal X-ray structures. The redox stability of the Ru(II) state follows the order 1 &lt; 2 much less than 3. In contrast to the magnetic moment obtained for [1]ClO4</p>1 aKar, S.1 aChanda, N.1 aMobin, Shaikh, M.1 aUrbanos, F., A.1 aNiemeyer, M.1 aPuranik, Vedavati, G.1 aJimenez-Aparicio, Reyes1 aLahiri, Goutam, Kumar  uhttps://library.ncl.res.in/content/unusual-monodentate-binding-mode-22-dipyridylamine-l-isomeric-transacac2ru-iil2-trans-1