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-101764nas a2200205   4500008004100000022001400041245017100055210006900226260007300295300001000368490000800378520092200386653000801308653003701316653002601353653002401379100001901403700001201422856012401434       2005                        eng d  a0166-128000aEffects of conjugation length and donor-acceptor functionalization on the non-linear optical properties of organic push-pull molecules using density functional theory0 aEffects of conjugation length and donoracceptor functionalizatio  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a59-640 v7153 a<p>We consider a series of dipolar organic molecules where the donor groups and the acceptor groups are separated by pi-conjugation like phenyl ring or alkene chains. We have performed extensive quantum chemical calculations based on density functional theory (DFT) to calculate their linear and non-linear optical coefficients. We show that though DFT is known to overestimate the polarizabilities of quasilinear systems,the results with proper inclusion of exchange correlation compare well with the experimental studies. On increasing the pi-conjugation length, the coefficients increase non-linearly. We also vary the donor and the acceptor groups and study the role of chemical modifications on the response properties. Herein we suggest experimental methods by which the molecules may be arranged in non-centrosymmetric fashion in the bulk for device integration. (c) 2004 Elsevier B.V. All rights reserved.</p>10aDFr10adonor-acceptor functionalization10anon-linear properties10apush-pull molecules1 aDatta, Anindya1 aPal, S.  uhttps://library.ncl.res.in/content/effects-conjugation-length-and-donor-acceptor-functionalization-non-linear-optical-0