Manipulating MLCT transition character with ppy-type four-coordinate organoboron skeleton for highly efficient long-wavelength Ir-based phosphors in organic light-emitting diodes

Inspired by the intriguing optoelectronic characteristics of 2-phenylpyridine-type (ppy-type) four-coordinate organoboron skeleton, we envisage a molecular design strategy through manipulating MLCT transition character to develop high-performance long-wavelength Ir-based phosphors with...

A Varied Alkyl Chains of Ruthenium(II) Complexes for Dye Sensitized Solar Cells (DSSCs)

Ruthenium(II) complexes were synthesized and characterized for dye-sensitized solar cells (DSSCs) with varied alkyl chains specifically methyl (PC01), hexyl (PC02) and octyl (PC03). The photophysical property was studied by UV-Visible absorption. The results showed that the main absorption peaks were asigned to the metal to ligand charge transfer (MLCT) transition (350-600 nm). The incident photon to current conversion efficiency (IPCE) covered the entire visible spectrum reaching to 18-20% at 520 nm. The DSSC performances were investigated with liquid iodide/tri-iodide electrolyte under standard AM 1.5. PC01-PC03 showed that the power conversion efficiency (h) were obtained at 3.08%, 3.18% and 3.14%, respectively, compared with N719 (7.80%). Interestingly, PC02 and PC03 showed the long term stability with %hlossbetter than the standard up to 1000 h.

Surprisingly high quantum yield of emission in a fluorescent coordination polymer with paramagnetic Mn(ii) ions

A layered CP built from multi-carboxylate ligands and paramagnetic Mn2+ ions exhibits dual emissions with the highest quantum yield of MLCT transition of 12.3% in Mn-based MOFs/CPs.

Ultrafast excited state dynamics of [Cr(CO)4(bpy)]: revealing the relaxation between triplet charge-transfer states

Ultrafast excited state dynamics of [Cr(CO)4(bpy)] upon metal-to-ligand charge-transfer (1MLCT) transition have been studied by pump-probe absorption spectroscopy and DFT calculation.

A perfluorocyclopentene based diarylethene bearing two terpyridine moieties – synthesis, photochemical properties and influence of transition metal ions

The synthesis of a perfluorocyclopentene based diarylethene bearing two terpyridine units is reported. Furthermore studies of the free ligand’s photochromism and investigations regarding the influence of various transition metal ions on the photochromic reaction are presented. The photochromism of the central diarylethene unit is strongly dependent on the transition metal present, vice versa the photochromic reaction seems to influence the MLCT transition of a binuclear Ru(II) complex.

Synthesis, structures, and spectroscopic properties of copper(I) complexes bearing 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine and 1,2-bis(diphenylphosphino)ethane ligands

A new ligand napaa (napaa = 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine) and its two dinuclear copper(I) complexes, Cu2(napaa)(dppe)2(ClO4)2 (1) and Cu2(napaa)(PPh3)4(BF4)2 (2) (dppe = 1,2-bis(diphenylphosphino)ethane) and PPh3 = triphenylphosphine) were synthesized and characterized, and the structure of 1 was determined by X-ray crystal analysis. Each copper atom in 1 has a distorted tetrahedral geometry in which the metal center is associated to napaa and dppe ligands displaying chelating coordination modes and the naphthyridine rings of napaa are almost coplanar. The two complexes exhibit similar electronic absorption spectra with λmax at about 366 nm, which can be tentatively assigned to metal-to-ligand charge-transfer (MLCT) transition. The assignment was further supported by density functional theory (DFT) calculations.