title: Thermal transformations and stability of organometallic materials with electrical and optical properties: the case of polycrystalline cis-[Ir(CO)2Cl(C5H5N)].
abstract: In this paper the solid-state transformations under heating of cis-[Ir(CO)2Cl(C5H5N)] are discussed. The complexity of the transformations was revealed by integrating infrared spectroscopy, conventional and bidimensional X-ray diffraction, thermal analysis, and hot stage optical microscopy. During heating anisotropic expansion of the lattice along the Ir-Ir stacking takes place. Then cis-[Ir(CO)2Cl(C5H5N)] undergoes an irreversible solid-solid phase transition to a lattice of higher symmetry followed by a reversible transition into the amorphous phase. Under proper cooling a partial recrystallization takes place. Experiments in the presence of oxygen must be carried out in short time periods to avoid oxidation from Ir(I) to Ir(III).
authors.affiliation: Laboratorio di Strutturistica Chimica, Università di Brescia and INSTM UdR di Brescia, via Branze 38, 25123 Brescia, Italy. paolo.bergese@ing.unibs.it
authors.forename: P
authors.initials: P
authors.lastname: Bergese
authors.forename: E
authors.initials: E
authors.lastname: Bontempi
authors.forename: C
authors.initials: C
authors.lastname: Dragonetti
authors.forename: D
authors.initials: D
authors.lastname: Roberto
authors.forename: R
authors.initials: R
authors.lastname: Ugo
authors.forename: I
authors.initials: I
authors.lastname: Colombo
authors.forename: L E
authors.initials: LE
authors.lastname: Depero
mesh_terms: D003460:Crystallization; D004583:Electrons; D007495:Iridium / Q000737:chemistry*; D055095:Optics and Photonics; D009942:Organometallic Compounds / Q000737:chemistry*; D013696:Temperature
chemical_list: D009942:Organometallic Compounds; C521421:dicarbonylchloro(pyridine)iridium(I); D007495:Iridium