Luminescence properties of [Ir(C^N)(N^N)] complexes: relations between DFT computation results and emission band-shape analysis data.

Luminescence properties of two series of [Ir(C^N)(N^N)] complexes bearing deprotonated 1-phenyl-1-pyrazole or 1-(2,4-difluorophenyl)-1-pyrazole as cyclometalating C^N ligands and different α-diimines (2,2'-bipyridine, 1,10-phenanthroline and their derivatives) as ancillary N^N ligands have been studied in acetonitrile solutions at room temperature and in 77 K methanol/ethanol (1 : 1) matrices. Ligand and temperature induced changes in the nature of the emissive *[Ir(C^N)(N^N)] species result in well-pronounced changes in their emission properties like emission wavelength, emission quantum yields and emission lifetimes. Depending on the nature of the coordinated C^N and N^N ligands and/or the measurement temperature, the investigated luminophores exhibit emissions arising from the intraligand transitions localized within the N^N ligand or from the metal-to-ligand charge-transfer transitions involving the Ir(C^N) and N^N moieties as confirmed by means of the DFT computations.

Heteroleptic Re(CO) and Re(CO) complexes with α-diimines: similarities and differences in their luminescence properties.

The photophysical properties of two series of phosphorescent rhenium(i) complexes, [Re(CO)(N^N)(tpp)] and [Re(CO)(N^N)(tpp)] with carbon monoxide (CO), triphenylphosphine (tpp) and α-diimine (N^N) ligands have been investigated in deoxygenated acetonitrile solution at room temperature and in solid methanol/ethanol 1 : 1 matrices at 77 K. The complexes display moderate to strong phosphorescence which is related to the N^N ligand modulated metal-to-ligand charge-transfer S ← *MLCT or intraligand S ← *LC transitions. Luminescence properties of the investigated series have been found to be very similar but some intrinsic differences between them are clearly seen.

Heteroleptic [Os(Cl)(CO)(P^P)(pbi)] complexes bearing bidentate phosphine and 2-(2-pyridyl)benzimidazolate ligands: impact of isomerism on their luminescence properties.

A series of six [Os(Cl)(CO)(P^P)(pbi)] complexes have been synthesized and characterized using FT-IR, 1H NMR, and 31P NMR spectroscopy. Their molecular structures have been confirmed by means of X-ray diffraction studies. For each of the studied bidentate phosphines (P^P = cis-1,2-bis(diphenylphosphino)ethene - dppv, 1,2-bis(diphenylphosphino)ethane - dppe, 1,2-bis(diphenylphosphino)benzene - dppb) the applied synthesis procedure has afforded preparation of two isomers with pseudo-octahedral coordination of the osmium(ii) ion.

Heteroleptic [Os(H)(CO)(NN)(tpp)] and [Os(Cl)(CO)(NN)(tpp)] complexes - comparative studies of their luminescence properties.

Two series of cationic heteroleptic osmium(ii) complexes with a coordinated CO molecule, a chloride Cl or hydride H anion, two monodentate triphenylphosphine (tpp) ligands and one bidentate α-dimine (NN) ligand were prepared from an OsCl(CO)(tpp) precursor. The investigated complexes, available in the form of PF salts, have been identified by means of FT-IR, H and P NMR spectroscopy and X-ray diffraction studies. Their photophysical properties have been investigated in dichloromethane solutions at room temperature and 1 : 1 ethanol-methanol matrices at 77 K.

Cyclometalated iridium(III) chelates-a new exceptional class of the electrochemiluminescent luminophores.

Recent development of the phosphorescent cyclometalated iridium(III) chelates has enabled, due to their advantageous electrochemical and photo-physical properties, important breakthroughs in many photonic applications. This particular class of 5d(6) ion complexes has attracted increasing interest because of their potential application in electroluminescence devices with a nearly 100 % internal quantum efficiency for the conversion of electric energy to photons. Similar to electroluminescence, the cyclometalated iridium(III) chelates have been successfully applied in the electricity-to-light conversion by means of the electrochemiluminescence (ECL) processes.

The luminescence properties of the heteroleptic [Re(CO)3(N∩N)Cl] and [Re(CO)3(N∩N)(CH3CN)](+) complexes in view of the combined Marcus-Jortner and Mulliken-Hush formalism.

The luminescence properties of the heteroleptic fac-Re(CO)3(+) complexes with α-diimine N∩N ligands, neutral [Re(CO)3(N∩N)Cl] and cationic [Re(CO)3(N∩N)(CH3CN)](+) species, have been studied in acetonitrile solutions at room temperature. The investigated complexes exhibit the metal to ligand charge-transfer (MLCT) phosphorescence with the emission characteristics strongly affected by the nature of coordinated α-diimine N∩N ligands. The observed trends can be quantitatively described by invoking the electronic interactions between (3)*LC and (3)*MLCT states as well as the spin-orbit interactions between (3)*MLCT and (1)*MLCT states, respectively.

The luminescence properties of heteroleptic [OsCl(CO)(N∩N)(P∩P)](+) complexes - radiative and non-radiative deactivation of the excited (3)*MLCT state.

The luminescence properties of the heteroleptic [OsCl(CO)(N∩N)(P∩P)](+) complexes with bidentate phosphine P∩P and diimine N∩N ligands have been studied in acetonitrile solutions at room temperature and in methanol/ethanol (1 : 1) glasses at 77 K. At room temperature the investigated complexes feature strong (with the quantum yields ϕem from 0.17 up to 0.