Coordination polymers of silver(I) with ditopic cross-conjugated dienone
摘要:
The reaction of the silver salts AgX (a: X = BF4 (-), b: X = ClO4 (-), c: X = OTf-) with alpha,alpha'-di(3/4-pyridylmethylene)cycloalkanones (L-1-L-3) and piperidones (L-4-L-7) results in the formation of coordination products of general composition [AgX(L (n) )(solvent)] and [AgX(L (n) )] (L (n) = L-1-L-7). All complexes were characterized by elemental analysis and IR-spectroscopy. The structures of [Ag(ClO4)(L-1)(MeCae N)](a) (1b center dot MeCae N) and [Ag(ClO4)(L-1)](a) (1b) in the solid state are reported. In both structures {Ag(L-1)}(+) building units are linked to each other via Ag-N-pyridine primary bonds resulting in the formation of infinite chains. In both structures the ligands L-1 are fixed in transoid conformations, thus forming zig-zag polar chains. The structure of 1b center dot MeCae N consists of pairs of tightly and loosely stacked chains. The tightly packed chains are weakly coupled by perchlorate anions acting as mu-bridges in between Ag(I) centers as well as by pi-pi-stacking interactions of unsaturated fragments of the respective ligands. In contrast, polar 2D layers composed of {Ag(L-1)} (m) (m+) chains, which interdigitate via multiple weak interactions by Ag-O contacts, are found in the solid structure of 1b. The dissolution of coordination products in coordinating solvents like MeCN or DMSO leads to the decomposition of complexes due to formation of silver-solvent coordination compounds. The coordination products 1-5 are stable in solid state against exposure to the ambient light, whereas solutions of the compounds, especially in DMSO-d (6), appeared to be photochemically labile. As revealed by NMR spectroscopic studies, the organic components undergo trans-cis isomerization.
[EN] SMALL MOLECULE STIMULATORS OF STEROID RECEPTOR COACTIVATOR PROTEINS AND THEIR USE IN THE TREATMENT OF CANCER [FR] STIMULATEURS À PETITES MOLÉCULES DES PROTÉINES CO-ACTIVATRICES DES RÉCEPTEURS DE STÉROÏDES ET MÉTHODES POUR LES UTILISER
Metal–organic frameworks constructed using acid–base mixed ligands, carboxylic acids and N-containing chalcone, and their catalytic performance for Knoevenagel condensation
layered structures and serve as an efficient and economical porous heterogeneouscatalyst for Knoevenagelcondensation under mild conditions. The yields of Knoevenagelcondensation can be reached between 96% and 99% in the presence of catalysts 1–3. Notably, the catalytic performance of 1 through reusability was explored, and it was observed that 1 could be reused up to six cycles with almost consistent
Design, Synthesis, and Photoluminescence Properties of One-, Two-, and Three-Dimensional Coordination Polymers: Anion-Assisted Argentophillic Interactions as Building Blocks
作者:Kaustuv Banerjee、Sandipan Roy、Kumar Biradha
DOI:10.1021/cg500898c
日期:2014.10.1
Five new Ag(I) complexes of the formulae [Ag-2(L-1)(2)(NDS)](3)H2O}(n) (1), [Ag-2(L-2)(2)(NDS)]center dot 2H2O}(n) (2), [Ag-3(L-2)(2)(IQS)(2)]center dot(NO3)center dot 4H(2)O center dot 2MeOH}(n) (3), [Ag-2(L-3)(2)(NDS)]center dot 4H(2)O}(n) (4), and [Ag-2(L-3)(2)(IQS)]center dot(NO3)center dot H2O}(n) (5) (L-1 = 2,5-bis-pyridine-3-ylmethylene-cyclopentanone, L-2 = 2,5-bis-pyridine-3-ylmethylene-cyclohexanone, L-3 = 2,5-bis-pyridine-4-ylmethylene-cyclopentanone, NDS = naphthalene disulfonate, and IQS = isoquinoline-5-sulfonate) have been synthesized and characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. Complexes 13 were found to have sulfonate supported Ag center dot center dot center dot Ag interaction, and the sulfonate ions act as linkers to form higher dimensional networks (ladder, two- and three-dimensional networks). The complexes 4 and 5, which contain 4-pyridyl substitution, do not form such Ag center dot center dot center dot Ag interactions, indicating a clear tendency of 3-pyridyl derivatives to promote such interactions over 4-pyridyl derivatives. This observation was also evidenced by the analysis of Ag(I) complexes in Cambridge Structural Database. Further, complexes 15 were found to exhibit solid-state photoluminescence in the green region at room temperature.
A temperature study on a stereoselective organocatalyzed aldol reaction in water
作者:Enrico Emer、Paola Galletti、Daria Giacomini
DOI:10.1016/j.tet.2008.09.059
日期:2008.12
We report the first temperature Study on the stereoselectivity of the 'in-water' aldol reaction between nicotinaldehyde (3-pyridinecarbaldehyde) and cyclohexanone catalyzed by morpholine and trans-4-tert-butyldimethylsilyloxy-L-proline. Eyring plots of diastereomeric ratio anti/syn gave a constant diastereoselectivity with respect to reaction temperature using morpholine as catalyst. With O(TBS)-L-proline we observed a non-linear behaviour of the Eyring plot with the presence of an inversion temperature (T-inv), which disclosed dynamic solvation effects in water. (C) 2008 Elsevier Ltd. All rights reserved.