title: Electrical Conductivity and Strong Luminescence in Copper Iodide Double Chains with Isonicotinato Derivatives.
abstract: Direct reactions between CuI and isonicotinic acid (HIN) or the corresponding esters, ethyl isonicotinate (EtIN) or methyl isonicotinate (MeIN), give rise to the formation of the coordination polymers [CuI(L)]n with L=EtIN (1), MeIN (2) and HIN (3). Polymers 1-3 show similar structures based on a CuI double chain in which ethyl-, methyl isonicotinate or isonicotinic acid are coordinated as terminal ligands. Albeit, their supramolecular architecture differs considerably, affecting the distances and angles of the central CuI double chains and thereby their physical properties. Hence, the photoluminescence shows remarkable differences; 1 and 2 show a strong yellow emission, whereas 3 displays a weak emission; and 1 and 2 are semiconductors with moderate room temperature conductivities, whereas 3 has increased electrical conductivity up to 3×10(-3)  S cm(-1) . Additionally, 1 and 2 present an irreversible transition to a highly conducting phase with a conductivity almost 4 orders of magnitude higher and a quasi-metallic behaviour. Thermogravimetric analysis (TGA) coupled to a mass spectrometer and magnetic measurements point to a partial thermally induced oxidation of the carboxylate groups of the ligands with Cu(I) to Cu(0) reduction. DFT calculations have been carried out to rationalise these observations.
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid (Spain).
authors.forename: Khaled
authors.initials: K
authors.lastname: Hassanein
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid (Spain).|Instituto Madrileño de Estudios Avanzados en Nanociencia, 28049 Madrid (Spain).
authors.forename: Javier
authors.initials: J
authors.lastname: Conesa-Egea
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid (Spain).
authors.forename: Salome
authors.initials: S
authors.lastname: Delgado
authors.affiliation: Universidad del País Vasco, Departamento de Química Inorgánica, Apartado 644, e-48080 Bilbao (Spain).
authors.forename: Oscar
authors.initials: O
authors.lastname: Castillo
authors.affiliation: Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, IC/Catedrático José Beltrán 2, 46980 Paterna, Valencia (Spain).
authors.forename: Samia
authors.initials: S
authors.lastname: Benmansour
authors.affiliation: Instituto de Ciencia de Materiales CSIC, 28049 Madrid (Spain).
authors.forename: José I
authors.initials: JI
authors.lastname: Martínez
authors.affiliation: University Erlangen-Nürnberg, Department of Chemistry and Pharmacy and, Institute of Advanced Materials and Processes (ZMP), Henkestr. 42, 91054 Erlangen and, Dr.-Mack Str. 81, 90762 Fürth (Germany).
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Abellán
authors.affiliation: Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, IC/Catedrático José Beltrán 2, 46980 Paterna, Valencia (Spain).
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Gómez-García
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid (Spain). felix.zamora@uam.es.|Instituto Madrileño de Estudios Avanzados en Nanociencia, 28049 Madrid (Spain). felix.zamora@uam.es.
authors.forename: Félix
authors.initials: F
authors.lastname: Zamora
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, 28049 Madrid (Spain). pilar.amo@uam.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: Amo-Ochoa
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004553:Electric Conductivity; D007454:Iodides / Q000737:chemistry*; D008024:Ligands; D049449:Luminescence; D008958:Models, Molecular; D015394:Molecular Structure; D009525:Niacin / Q000031:analogs & derivatives* / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D007454:Iodides; D008024:Ligands; D011108:Polymers; D009525:Niacin; D003300:Copper; C073870:cuprous iodide
keywords: coordination polymers; copper iodide; electrical conductivity; luminescence; structure elucidation