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Shiv Nadar University

(SoNS) School of Natural Sciences

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Chemistry

Fulltext

Journal of Physical Chemistry A

Erratum: Computational Prediction of Antibody Binding Sites on Tetracycline Antibiotics: Electrostatic Potentials and Average Local Ionization Energies on Molecular Surfaces

Two new chromophores in the format, donor-acceptor-donor, have been synthesized in high yields from easily available starting materials. These compounds do not show any two-photon absorption (TPA) cross-section in the wavelength range, 780-900 nm when probed by the Z-scan technique with a femtosecond laser. However, in presence of Zn(II), Ca(II) or Mg(II) ion, each compound gives exceptionally large TPA cross-section in the same wavelength range. © 2008 Elsevier B.V. All rights reserved.

Journal of Luminescence

Acyclic donor-acceptor-donor chromophores for large enhancement of two-photon absorption cross-section in the presence of Mg(II), Ca(II) or Zn(II) ions

The first BODIPY library (BD) was synthesized, and a highly selective glucagon sensor, Glucagon Yellow (BD-105), was discovered by fluorescence image-based screening method. BD library was synthesized via a Knoevenagel-type condensation reaction with 160 benzaldehydes and the 1,3 dimethyl-BODIPY scaffold. Using BD compounds, a fluorescence image-based screening was performed against three cell lines including AlphaTC1 and BetaTC6 cells which secret glucagon and insulin, respectively, and HeLa as control cells. Out of the 160 candidate probes, one compound, Glucagon Yellow, exhibited selective staining only in AlphaTC1 cells. The selectivity of Glucagon Yellow toward glucagon was confirmed in vitro by comparison of its fluorescence intensity change against 19 biologically relevant analytes. Subsequent immunostaining experiments revealed that Glucagon Yellow and the glucagon antibody colocalized in pancreas tissue, showing a high quantitative correlation analysis by the Pearson's coefficient constant (Rr ) 0.950). These results demonstrated the potential application of Glucagon Yellow as a glucagon imaging agent in live cells and tissues. © 2009 American Chemical Society.

Journal of the American Chemical Society

Synthesis of a BODIPY library and its application to the development of live cell glucagon imaging probe

The design and two-component [2 + 3] self-assembly of a series of new organometallic molecular prisms (3a-d) are described. Assemblies 3a,b incorporate 4,4',4'-tris[ethynyl-trans-Pt(PEt2)2(N0 3)]triphenylamine (la) containing a Pt-ethynyl functionality as tritopic planar acceptor and organic "clips" 2a and 2b, respectively [where 2a = l,3-bis(3-pyridyl)isophthalic amide; 2b = l,3-bis(ethynyl3-pyridyl) benzene]. In a complementary approach an organic tritopic planar donor ligand 2c [2c = 4,4',4'-tris(4-pyridylethynyl)triphenylamine] was assembled with an organometallic "clip", 1,8-bis[{trans-Pt(PEt3) 2(N03)}ethynyl]anthracene (lb), to obtain prism 3c. A new organometallic carboncentered acceptor, l,l,l-tris[4-{trans-Pt(PEt 3)2(N03)}ethynylphenyl]ethane (1c), has been prepared and its prism derivative (3d) using an organic "clip" is prepared. Assemblies (3a-d) were characterized by multinuclear NMR spectroscopy, electrospray ionization mass spectroscopy and elemental analysis. 3a-d showed fluorescence behavior in solution and quenching of fluorescence intensity (3a, 3c-d) was noticed upon addition of TNT (2,4,6-trinitrotoluene), a common constituent of many commercial explosives. A thin film of the assembly 3d made by spin coating of a solution of 3x 10-5 M in DMF on a 1 cm 2 quartz plate showed fluorescence response to the vapor of TNT. Copy; 2009 American Chemical Society.

Organometallics

Self-Assembly of molecular prisms via Pt3 organometallic acceptors and a Pt2 organometallic clip

Two new neutral copper-azido polymers [Cu3(N3) 6(tmen)2]n (1) and [Cu6(N 3)12(deen)2]n (2) [tmen = N,N,N,N -tetramethylethylenediamine and deen = N,N-diethylethylenediamine] have been synthesized by using lower molar equivalents of the chelating diamine ligands with Cu(NO3)2 {\textperiodcentered} 3H2O and an excess of NaN3. The single crystal X-ray structure shows that in the basic unit of the 1D complex 1, the three Cu" ions are linked by double end-on azido bridges with CU-NEO-CU angles on both sides of the magnetic exchange critical angle of 108°. Complex 2 is a 3D framework of a basic Cu6 cluster. Cryomagnetic susceptibility measurements over a wide range of temperature exhibit dominant ferromagnetic behavior in both the complexes. Density functional theory calculations (B3LYP functional) have been performed on the trinuclear unit to provide a qualitative theoretical interpretation of the overall ferromagnetic behavior shown by the complex 1. {\textcopyright}2009 American Chemical Society.

Inorganic Chemistry

CuII-azide polymers of Cu3 and Cu6 building units: Synthesis, structures and magnetic exchange mechanism

In the present work the desired quinazolinone derivatives (DK-1, DK-2, DK-3, DK-4, DK-5, DK-6 &amp; DK-7) were synthesized by treating 2-Chloro-N-(4-oxo-2-phenylquinazolin-3(4H)-yl) acetamide (I-1) with the different substituted phenols in presence of anhydrous potassium carbonate &amp; catalytic amount of potassium iodide in dry acetone. The structures of the newly synthesized compounds have been established on the basis of their m.p., TLC, IR and 1HNMR data. All the newly synthesized quinazolinone derivatives were evaluated for their antibacterial activity by cup plate method by measuring inhibition zone. Ampicillin was used as standard drug. The compound DK-2 showed more potent antibacterial activity than the standard drug ampicillin.

Life Sciences

International Journal of Pharmacy and Pharmaceutical Sciences

Synthesis and antibacterial activity of quinazolinone derivatives

We describe and discuss the unique electrical characteristics of an organic field-effect transistor in which the active layer consists of a type II lateral heterojunction located approximately midway between the source and drain. The two active semiconductors on either side of the junction transport only one carrier type each, with the other becoming trapped, which leads to devices that operate in only the steady state when there is balanced electron and hole injections from the drain and source. We describe the unique transfer characteristics of such devices in two material systems. © 2009 American Institute of Physics.

Physics

Applied Physics Letters

Electrical characteristics of lateral heterostructure organic field-effect bipolar transistors

The synthesis and characterization of solution processable donor-acceptor-donor (D-A-D) based conjugated molecules with varying ratios of thiophene as donor (D) and benzothiadiazole as acceptor (A) are reported. Optical, electrochemical, thermal, morphological and organic thin film transistor (OTFT) device properties of these materials were investigated. The thermal and polarized optical microscope analysis indicates that the materials having higher D/A ratios exhibit both liquid crystalline (LC) and OTFT behavior. AFM analysis of the materials having D/A ratios of 3 and 4 (3T1B and 4T1B) show well ordered structures, resulting from strong π-π interchain interactions compared to the other molecules in this study. A XRD patterns for 3T1B and 4T1B thin films also shows high crystalline ordering. Solution processed OTFTs of 3T1B and 4T1B have shown un-optimized charge carrier mobilities of 2 × 10-2 cm2 V-1 s -1 and 4 × 10-3 cm2 V-1 s -1, respectively on bare Si/SiO2 substrate. © The Royal Society of Chemistry 2009.

Journal of Materials Chemistry

Synthesis, characterization and comparative study of thiophene- benzothiadiazole based donor-acceptor-donor (D-A-D) materials

Two azine molecules, [3-{4-(dimethylamino)phenyl}prop-2-en-1-ylidene] hydrazone (HL) and [4-(dimethylamino)benzylidene]hydrazone (LL) synthesized via Schiff base condensation, show an absorption band due to intra-ligand charge transfer (ILCT). Both ligands show weak emission in the absence of a metal ion as input. When Ag+ ions are added to either compound in THF, the metal ion gets bonded to the azine moiety resulting in a high intensity emission (∼400 fold). While Cu+ shows a slight enhancement of emission, other first-row transition, alkali or alkaline-earth metal ions do not show any emission allowing Ag+ ions to be detected in the presence of these metal ions. Both the Ag+ complexes were characterised by X-ray crystallography and show solid-state spectra similar to their solution spectra. Time-resolved fluorescence measurements done on the complexes show two excited-state lifetimes. © The Royal Society of Chemistry 2009.

Dalton Transactions

Ag(i) induced emission with azines having donor-acceptor-donor chromophore

To expand the diversity of 1,3,5-triazine libraries to aryl and alkyl functionalities through the CC bond, we employed a novel orthogonal synthesis via Grignard monoalkylation or monoarylation of cyanuric chloride in solution to prepare aryl- or alkyl-substituted triazine building blocks. These aryl- or alkyl-substituted triazine building blocks were captured by a resin-bound amine, followed by amination and acidic cleavage with high purity. Herein, we demonstrate a novel orthogonal synthesis of a tagged aryl- and alkyl-triazine library on solid support, utilizing building blocks prepared via Grignard reaction in solution. Through incorporation of a triethylene glycol linker at one of the alternate sites on the triazine scaffold we explored an intrinsic tagged library approach. © CSIRO 2009.