http://nopr.niscair.res.in/handle/123456789/790 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/2235 Title: Physicochemical behaviour of copper(II) complexes of chelated dianune ligands: Catalytic role of diaquabis(ethylenediamine)copper(II) perchlorate in acylal formation <br/> <br/>Authors: Sarmah, Purabi; Singha, Sunita; Chakrabarty, Rajesh; Bora, Sanchay J; Das, Birinchi K <br/> <br/>Abstract: Preparation and propertics of a few chelated diarnine complexes of copper(II) are reported. Thc compounds, [Cu(en)₂(H₂O)₂](C lO₄)₂ (1), [Cu(tmen)₂(H₂O)₂](C lO₄)₂ (2), [Cu(en)₂Cl₄]ո (3) and [Cu(en)₂(SO₄)₂(H₂O)₄].2H₂O (4) have been prepared in moderate to excellent yields and characterized by various physicochemical techniques. The structure of [Cu₂(en)₂Cl₄]n (3) has been determined by single crystal X-ray diffraction. Complex 3 crystallizes in monoclinic space group P2l/m, with unit cell parameters a = 6.7850 (14) Aº, b = 5.7600(12)Aº, c = 8.2240(l6)Aº, β = 93.75(3)º, V = 320.7(1)Aº³. The structurc has been solved by direct method and refined by full-matrix least squares to final R₁ = 0.0460, wR₂ = 0.1249 and GooF = 1.135 for all 8 I 8 reflections. Each copper atom in complex 3 is present in a distorted octahedral environment creatcd by a chelating ethylenediamine ligand and four chlorine atoms. Two adjacent parallel -Cu-Cl-Cu- chains joined by short Cu-C1 bonds give rise to a zigzag ribbon-like polymer. Complex 1has been studied as a catalyst 1'01' thc conversion of aromatic aldehydes to acylals under solvent-free conditions at room temperature. <br/> <br/>Page(s): 1929-1937 http://nopr.niscair.res.in/handle/123456789/2234 Title: Viscosities of binary liquid mixtures of some n-alkoxypropanols with n-alkanols at 298.15 K <br/> <br/>Authors: Pal, Amalendu; Gaba, Rekha <br/> <br/>Abstract: The viscosities (η) in binary liquid mixtures of (n-alkoxypropanols + methanol, ethanol, or I-propanol) have been measured as a function of composition using an Ubbelohde viscometer at 298.15 K and atmospheric pressure over the full range of composition. The n-alkoxypropanols are propylene glycol monomethyl ether (l-methoxy-2-propanol). CH₃OCH₂CH₂CH₂OH, propylene glycol monoethyl ether (l-ethoxy-2-propanol), C₂H₅OCH₂CH₂CH₂OH, propylene glycol monopropyl ether (l-propoxy-2-propanol), C₃H₇OCH₂CH₂CH₂OH, propylene glycol monobutyl ether (l-butoxy-2- propanol), C₄H₉OCH₂CH₂CH₂OH propylene glycol rert-butyl ether (l-rert-butoxy-2-propanol), CH₃CHOHCH₃0C(C₄H₉)₃. The η values for each of the mixture studied are positive over the whole mole fraction range. For all the cases, except propylene glycol rert-butyl ether, η increases in a positive direction with increase in chain length of n-alkoxypropanols. The values of Δη, which refers to the deviation of the experimental values of the dynamic viscosities of the mixtures from the mole fraction mixture law values, are found to be positive for all the mixtures. Further, the excess free energies of activation (ΔG*E) for viscous flow have been calculated from the experimental data. The results for η, Δη, and ΔG*E are discussed in terms of interactions between the components of the mixtures. Equations such as Heric's, Auslaender's, and MeAllister's four-body interaction model have been used to correlate the kinematic viscosities, <br/> <br/>Page(s): 1763-1771 http://nopr.niscair.res.in/handle/123456789/2233 Title: Simple anion receptor with imidazole and phenol groups: Forming hydrogen-bond complex with Cl⁻ <br/> <br/>Authors: Chen, Huamei; Lin, Hai; Cai, Zunsheng; Lin, Huakuan <br/> <br/>Abstract: A simple anion receptor 2'-(2"-hydroxy-3"-methoxyphenyl)imidazo[4',5'-f]-1, 10-phenanthroline[5,6-f] (1) with imidazole and phenol groups has been synthesized and its interaction investigated with anions (F⁻, Cr⁻, Br⁻, I⁻, AcO⁻ and H₂PO₄⁻) by UV -vis and ¹H NMR titrations. Added with Cl⁻, the change of UV -vis spectra of 1 is different from that of added AcO⁻,F⁻ and H₂PO₄⁻. Also, the change of ¹H NMR titration spectra of 1 with Cl⁻ is different from that of added AcO⁻, F⁻ and H₂PO₄⁻, 1 forms supramolecular complex with Cl⁻ as a receptor and is deprotonated with AcO⁻, F⁻ and H₂PO₄⁻ as a colormetric sensor. The receptor forms H-bond complex with Cl⁻ by NH of imidazole, Hc' of phenanthroline and H₁ of phenyl. As an acid proton donor, the protons of NH of imidazole and OH of phenol are too acidic to form hydrogen-bond complex with AcO⁻, F⁻ and H₂PO₄⁻. So, the interaction of 1 with AcO⁻, H₂PO₄⁻ and F⁻ is acid-basic reaction. The affinity to anions of NH is dramatically more powerful than that of OH. <br/> <br/>Page(s): 748-754 http://nopr.niscair.res.in/handle/123456789/2232 Title: Spectral and thermal characterization of newly synthesized arylazo benzimidazole mercury(II) complexes <br/> <br/>Authors: Haggag, Sawsan S <br/> <br/>Abstract: Mercury(ll) complexes of benzimidazole and its derivatives, (viz., benzimidazole (Benz.) (I); lH-2(naphthyl ⍺-azo) benzimidazole (⍺-NaBenz.) (II); and 1 H-2-(arylazo)benzimidazole (III)) of the type HaaBZR, where R=H (a), CH3 (b), -NO₂ (c) and-OH (d) have been synthesized and characterized by elemental analysis, infrared. mass and ¹H NMR spectra. The stoichiometric ratios for the Hg(II) complexes have been identified as (1:1), (1:2) or (2: 1) with the contribution of coordinated water and chloride in complex formation. The probable structures for the mercury(II) complexes are also proposed. The results from mass spectral studies are in agreement with the TGA of the fragmentation and mass losses. <br/> <br/>Page(s): 582-588