Luminescent imidazolium carboxylate supported aggregate and infinite coordination networks of copper and zinc

Suresh, P and Radhakrishnan, S and Naga Babu, C and Sathyanarayana, A and Sampath, N and Prabusankar, G (2013) Luminescent imidazolium carboxylate supported aggregate and infinite coordination networks of copper and zinc. Dalton Transactions, 42 (30). pp. 10838-10846. ISSN 1477-9226

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Abstract

The new copper dimer [LCu(DMF)]2(NO3) 4(H2O)(DMF)2 (4), where L = [{1,1′-(CH2)2-C14H8)-3, 3′-(CH2CO2)2}{(HCN)2CH}], and porous coordination polymers [{L2Cu(OH2)2} 2Br2]x (5) and [{L2Zn(OH 2)2}2Br2]x (6) have been isolated from reactions of luminescent imidazolium carboxylate ligand, LH 2Br2 (3) and the corresponding metal precursors. The reaction between Cu(NO3)2·3H2O and LH2Br2 (3) in DMF at 100 °C yielded bluish green crystals of tetracationic discrete copper dimer 4, the structure of which contains a rare tetracationic [(DMF)Cu(ii)]2 dimer unit that is bridged by four carboxylates of two L in a "paddle-wheel" structure. When the reaction was carried out in the presence of a water-ethanol-methanol mixture, light green crystals of 5 were obtained. Molecule 5 comprises two-dimensional (2D) porous coordination polymeric sheets consisting of unique symmetrical dinuclear [(C(O)O)Cu(OH2)2(O(O)C) 2]2 building blocks, which are connected by imidazolium anthracene spacers. The infinite 2D porous coordination polymeric sheets are further linked by significant intermolecular hydrogen-bonding interactions by bromide anions to form a three-dimensional supramolecular framework. Interestingly, the reaction between zinc dust and LH2Br2 (3) in H2O at room temperature gave similar structural features to those in 5, though they differ in terms of C-O bond distances and M-O-C angles. The solution-state UV-visible absorption spectra of 2-6 in water exhibits the comparable absorption pattern with decrease in the intensity of absorption from 5, 4, 3, 6 and 2, while the solid-state UV-visible absorption spectra of 2-6 are significantly different from the solution-state UV-visible absorption spectra. The considerable change in the fluorescent emission was observed upon complexation of 3 with corresponding metal precursors and the fluorescent emission was shifted towards the red region in the order of 2, 3, 6, 4 and 5 in water

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IITH Creators:

IITH Creators	ORCiD

Item Type:

Article

Uncontrolled Keywords:

Carboxylate ligands; Coordination networks; Fluorescent emission; Hydrogen bonding interactions; Porous coordination polymer; Structural feature; Supramolecular framework; UV visible absorption spectrum

Subjects:

?? sub5.8 ??

Divisions:

Department of Chemistry

Depositing User:

Team Library

Date Deposited:

27 Nov 2014 05:15

Last Modified:

27 Nov 2014 05:15

URI:

http://raiithold.iith.ac.in/id/eprint/999