N- 2-(4-methoxyphenyltelluro)ethyl benzamide (L-1) and N- 2-(4-methoxyphenyl telluro)propyl phthalimide (L-2): synthesis and ligation with palladium(II), platinum(II) and ruthenium(II). Crystal structures of L-1 and L-2, the latter as a mixed crystal with (LH2)-H-2

yThe reactions of N-(2-chloroethyl)benzamide and N-[3-bromopropyl]phthalimide with ArTe- Na+ generated in situ by borohydride reduction of Ar2Te2, have resulted in N-[2-(4-methoxyphenyltelluro)ethyl]benzamide (L-1) and N-[2-(4-methoxyphenyltelluro)propyl] phthalimide (L-2) respectively. The L-1 and L-2 both exhibit characteristic H-1 and C-13 NMR spectra. The single crystal structures of L-1 and L-2, the latter as a mixed crystal with (LH2)-H-2 are determined by X-ray diffraction (XRD). The Te-C(alkyl) bond length is 2.140(8)/2.149(4) Angstrom and longer than Te-C(aryl), 2.107(8)/2.123(5) Angstrom. The complexes having stoichiometries [PdCl2(L-1)] (1), [PtCl2(L-1)](2), [(Phen)Pd(L-1)](ClO4)(2) (3), [(DPPE)Pd(L-1)](ClO4), (4) and [RuCl2(L-2)(2)] (5) were synthesized and characterized by elemental analyses, conductance and molecular weight measurements, NMR (H-1 and C-13) and FT-IR spectra. The deshielding of CH2Te ( similar to 0.2 ppm in H-1 NMR and up to 22 ppm in C-13{H-1} NMR) and NH signals (upto 0.8 ppm in H-1 NMR) of 1 -4, with respect to those of free L-1 indicates that L-1 coordinates with Pd-Pt(II) as a (Te, N) ligand. The CH2Te/CH2N signals in H-1 and C-13 NNIR spectra of 5 appear deshielded (0.8/0.14 and 20/8 ppm, respectively), when compared with those of free L2, indicating ligation of L-2 via Te and N

2-(4-ethoxyphenlytelluromethyl)tetrahydro-2H-pyran (L-1) and 2-(2-{4-ethoxyphenyl}telluroethyl)-1,3-dioxane (L-2): synthesis, reactions of L-1 with iodine and ligation of L-1 with Ru(II), Cu(I), and Hg(II) and L-2 with Ru(II). Crystal structures of RuCl2(p-cymene)center dot L-1/L-2

2-(4-Ethoxyphenlytelluromethyl)tetrahydro-2H-pyran (L-1) and 2-(2-{4-ethoxyphenyl}telluroethyl)-1,3-dioxane (L-2) have been synthesized by reacting in situ generated ArTe-Na+ with an appropriate organic halide. The reaction of L-1 with iodine results in its diiodo derivative [L-1(I)(2)] (1). The complexes of stoichiometries [CuBrL1] (2), [HgBr2L1] (3) and [RuCl2(p-cymene)-L-1/L-2] (4/5) are synthesized. The NMR (H-1 and C-13) in conjunction with elemental analyses, molecular weight and conductance measurements were used to characterize L, L 2, 1 and the complexes 2-5. The ligands coordinate in all the complexes through Te, as indicated by the deshielding of CH2Te signals (up to similar to0.8 ppm) with respect to those of free ligands, except in the case of 2 in which bonding through CH2O has also to be invoked. Complexes 4 and 5 are characterized structurally (Ru-Te bond length: 2.619(8) and 2.642(1) Angstrom, respectively). The Ru-Cl bond lengths are in the range 2.404(3)-2.420(6) Angstrom. The Te-C(aryl) bond is shorter than the Te-C(alkyl) bond in 4 but similar in 5. The two Ru(Il) complexes are the first examples with potential (Te, O) ligands of Ar(R)Te type, which have been structurally characterized

Synthesis and crystal structures of two new (Te,N,) type hybrid organotellurium ligands

The reaction of N-(2-chloroethyl)benzamide and N-[3-bromopropyl]phthalimide with ArTe- Na+ generated in situ by borohydride reduction of Ar2Te2, has resulted in N-[2-(4-methoxyphenyltelluro)ethyl] benzamide (L-1) and N-[2-(4-methoxyphenyl telluro)propyl] phthalimide (L-2) respectively, which are potentially (Te, N)-type ligands. Their NMR (H-1 and C-13) spectra are characteristic and single crystal structures are solved. The Te-C(alkyl) distance [2.140(8)/2.151(4) Angstrom] is longer than Te-C(aryl) distance [2.107(8)/2.128(5)Å]

Selective Fluorescence Sensing of Copper(II) and Water via Competing Imine Hydrolysis and Alcohol Oxidation Pathways Sensitive to Water Content in Aqueous Acetonitrile Mixtures

Addition of hydrazines to a 1,8-disubstituted anthraquinone macrocycle containing a polyether ring produces site-selective imination, where hydrazone formation produces the more sterically hindered adduct. Reduction of the remaining carbonyl group to a secondary alcohol followed by addition of copper­(II) ion causes intense yellow fluorescence to occur, which is selective for this metal cation and allows this system to be used as a fluorescence sensor. In the presence of water, a green-fluorescent intermediate appears, which slowly decomposes to produce the original starting anthraquinone. The addition of a large amount of water radically changes the reaction pathway. In this case, oxidation of the secondary alcohol is kinetically faster than hydrolysis of the hydrazone, although the same anthraquinone product is ultimately produced. Stern–Volmer data suggest that dioxygen quenches the green emission through both dynamic and static mechanisms; the static ground-state effect is most likely due to association of oxygen with the copper-bound fluorescent intermediate

The Zebrafish GenomeWiki: a crowdsourcing approach to connect the long tail for zebrafish gene annotation.

A large repertoire of gene-centric data has been generated in the field of zebrafish biology. Although the bulk of these data are available in the public domain, most of them are not readily accessible or available in nonstandard formats. One major challenge is to unify and integrate these widely scattered data sources. We tested the hypothesis that active community participation could be a viable option to address this challenge. We present here our approach to create standards for assimilation and sharing of information and a system of open standards for database intercommunication. We have attempted to address this challenge by creating a community-centric solution for zebrafish gene annotation. The Zebrafish GenomeWiki is a 'wiki'-based resource, which aims to provide an altruistic shared environment for collective annotation of the zebrafish genes. The Zebrafish GenomeWiki has features that enable users to comment, annotate, edit and rate this gene-centric information. The credits for contributions can be tracked through a transparent microattribution system. In contrast to other wikis, the Zebrafish GenomeWiki is a 'structured wiki' or rather a 'semantic wiki'. The Zebrafish GenomeWiki implements a semantically linked data structure, which in the future would be amenable to semantic search. Database URL: http://genome.igib.res.in/twiki