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Electrical Conductivity and Strong Luminescence in Copper Iodide Double Chains with Isonicotinato Derivatives
Author(s) -
Hassanein Khaled,
ConesaEgea Javier,
Delgado Salome,
Castillo Oscar,
Benmansour Samia,
Martínez José I.,
Abellán Gonzalo,
GómezGarcía Carlos J.,
Zamora Félix,
AmoOchoa Pilar
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201502131
Subject(s) - isonicotinic acid , thermogravimetric analysis , conductivity , luminescence , copper , photoluminescence , carboxylate , supramolecular chemistry , materials science , crystallography , chemistry , stereochemistry , crystal structure , organic chemistry , hydrazide , optoelectronics
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.