The title metal-organic polymer, catena-poly[[(5,5'-dimethyl-2,2'-bipyridine-κ2N,N')iron(II)]-di-μ-azido-κ2N1:N3-[(5,5'-dimethyl-2,2'-bipyridine-κ2N,N')iron(II)]-di-μ-azido-κ2N1:N1], [Fe(N3)2... Show moreThe title metal-organic polymer, catena-poly[[(5,5'-dimethyl-2,2'-bipyridine-κ2N,N')iron(II)]-di-μ-azido-κ2N1:N3-[(5,5'-dimethyl-2,2'-bipyridine-κ2N,N')iron(II)]-di-μ-azido-κ2N1:N1], [Fe(N3)2(C12H12N2)]n, features alternating μ-1,1 (end-on mode of coordination) and μ-1,3 (end-to-end mode of coordination) double azide bridges, forming chains running in the [100] direction. The octahedral coordination geometry around the FeII centre is completed by a bidentate 5,5'-dimethyl-2,2'-bipyridine ligand. Two polymorphs for this compound were obtained from the crude reaction product, the first in the space group P-1 and the other in P21/c. The molecular and crystal structures are very similar for both forms, the main difference being that the eight-membered Fe(μ-1,3-N3)2Fe metallacycle formed with end-to-end azide ligands has a nearly flat conformation in the triclinic form and a chair conformation in the monoclinic form. In spite of this geometric difference, both forms have the same density, the same packing index and similar arrangements of the one-dimensional chains in the crystal. As a consequence, they also share very similar Hirshfeld surfaces and fingerprint plots. However, a density functional theory (DFT) computational study showed that the monoclinic form is more stable than the triclinic form by ca 30.5 kJ mol-1. Show less
The synthesis, characterization and 3D structure determination of Zinc and Cadmium compounds are reported, containing the non-chelating bidentate ligand 4,4'-bipyridine and the anions 1,1,3,3... Show moreThe synthesis, characterization and 3D structure determination of Zinc and Cadmium compounds are reported, containing the non-chelating bidentate ligand 4,4'-bipyridine and the anions 1,1,3,3-tetracyano-2-propoxy-propenide (tcnopr) or 1,1,3,3-tetracyano-2-ethoxy-propenide (tcnoet). The structures consist of linear chains (1D) built from metal ions and 4,4'-bipyridine, where the octahedral coordination around the metals is completed by two trans anions tcnoet (or tcnopr), and two trans-oriented water molecules. Weak interchain interactions are present, based on hydrogen bonds between the water ligands (both hydrogens are involved) and two CN groups of two nearby other chains. Metal-ligand distances appear as uneventful. For the same anion, the Zn and Cd compounds are isomorphous. Possible decomposition of the compounds has been investigated in the temperature range 30-800 degrees C in a static air atmosphere. Thermal analysis studies (TG, DTG, DTA) show that the axial water ligands for all three compounds are gradually lost upon heating above 60 degrees C to about 170 degrees C. Luminescence properties, recorded as powders, are reported as well, and these appear as strong for the Cd compound I, when irradiated at 390 nm, extremely weak for the Cd compound II, when irradiated at wavelengths from 300-400 nm, and moderately weak for the Zn compound III when irradiated at 385 nm. (C) 2019 The Author(s). Published by Elsevier Ltd. Show less
![Concomitant dimorphism in poly[di-μ-azido-(5,5′-dimethyl-2,2′-bipyridine)iron(II)]](/sites/all/modules/custom/islandora_solr_search/images/defaultimg.png?solr_nav%5Bid%5D=9f59809435b201a8d383&solr_nav%5Bpage%5D=0&solr_nav%5Boffset%5D=0)
