Reference

Supramolecular hydrogen-bond structures and magnetic interactions in basal-apical, dinuclear, azide-bridged copper(II) complexes

Supramolecular hydrogen-bond structures and magnetic interactions in basal-apical, dinuclear, azide-bridged copper(II) complexes. Ray, Mau Sinha; Ghosh, Ashutosh; Chaudhuri, Siddhartha; Drew, Michael G. B.; Ribas, Joan (Department of Chemistry, University College of Science, University of Calcutta, Kolkata 700 009, India). European Journal of Inorganic Chemistry, (15), 3110-3117 (English) 2004 Wiley-VCH Verlag GmbH & Co. KGaA. CODEN: EJICFO. ISSN: 1434-1948. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Section cross-reference(s): 75, 77 The synthesis, characterization, x-ray single crystal structures and magnetic properties of three new basal-apical m2-1,1-azide-bridged complexes [CuL1N3]2 (1), [CuL2N3]2 (2) and [CuL3N3]2 (3) with very similar tridentate Schiff-base blocking ligands {HL1 = N-[2-(ethylamino)ethyl]salicylaldimine; HL2 = 7-(ethylamino)-4-methyl-5-azahept-3-en-2-one; HL3 = 7-amino-4-methyl-5-azaoct-3-en-2-one} are reported [complex 1: monoclinic, P21/c, a 8.390(2), b 7.512(2), c 19.822(6) ?, b 91.45(5)°; complex 2: monoclinic, P21/c, a 8.070(9), b 9.787(12), c 15.743(17) ?, b 98.467(10)°; complex 3: monoclinic, P21/n, a 5.884(7), b 16.147(18), c 11.901(12) ?, b 90.050(10)°]. 110-72-5 and 824950-35-8 are also in the experiment. The structures consist of neutral dinuclear entities resulting from the pairing of two mononuclear units through end-on azide bridges connecting an equatorial position of one Cu center to an axial position of the other. The Cu ions adopt a (4+1) square-based geometry in all the complexes. In complex 2, there is no inter-dimer H-bonding. However, complexes 1 and 3 form two different supramol. structures in which the dinuclear entities are linked by H-bonds giving 1-dimensional systems. Variable temp. (300-2 K) magnetic-susceptibility measurements and magnetization measurements at 2 K reveal that all three complexes have antiferromagnetic coupling. Magneto-structural correlations were made taking into consideration both the azido bridging ligands and the existence of intermol. H bonds. .