Anna Maroń

A ruthenium(II) hydride carbonyl complex with 4-phenylpyrimidine as co-ligand

The reaction of [RuHCl(CO)(PPh3)3] with 4-phenylpyrimidine gave a new ruthenium(II) complex, namely [RuHCl(CO)(PPh3)2(pyrim-4-Ph)]. The complex has been studied by IR and UV–vis spectroscopy and by X-ray crystallography. The molecular orbitals of the complex have been calculated by density functional theory. The spin-allowed singlet–singlet electronic transitions of the complex have been calculated by time-dependent DFT, and the UV–vis spectrum of the compound has been discussed on this basis. The emission properties of the complex were also studied.

Chloride and pseudohalide hydride-carbonyl ruthenium(II) complexes with 4-pyrrolidinopyridine as co-ligand

Chloride and pseudohalide (N3−, NCS−) hydride-carbonyl ruthenium(II) complexes with 4-pyrrolidinopyridine as co-ligand were synthesized and characterized by IR, 1H, and 31P NMR, electronic absorption and emission spectroscopy and X-ray crystallography. The electronic structures of the complexes were calculated by density functional theory (DFT) on their crystal structures. The spin-allowed singlet–singlet electronic transitions of the complexes were calculated by time-dependent DFT, and the UV–Vis spectra have been discussed on these basis. The emission properties of the complexes were also studied.

Solid-state and solution photoluminescence of platinum(II) complexes with 4′-substituted terpyridine ligands – structural, spectroscopic and electrochemical studies

Platinum(II) complexes with the formula [PtCl(L)]CF3O3S (where L = 4′-(4-chlorophenyl)-2,2′:6′,2′′-terpyridine (L1), 4′-(4-bromophenyl)-2,2′:6′,2′′-terpyridine (L2), and 4′-(benzothiophene-2-yl)-2,2′:6′,2′′-terpyridine (L3)) were synthesized from precursor [Pt(PhCN)2Cl2] and characterized by FT-IR, NMR, UV-vis spectroscopy, X-ray crystallography and electrochemical studies. The emission properties of the coordination compounds were studied in solution and in the solid state at ambient temperature and in methanol : ethanol frozen glass matrices at 77 K. The quantum yields of fluorescence, lifetimes and the nature of the excited states were described on the basis of the molecular properties of the compounds. To elucidate the structural, spectroscopic and bonding properties of the obtained compounds, calculations at the DFT level were undertaken. Coordination compounds are emissive in both solution and solid states. Emission energies and the character of excited states in solution are governed by the donor–acceptor properties of the 4′ substituent of the terpyridine core. The emission properties in the solid state are attributed to the aggregation induced phenomenon. Moreover, the compounds [PtCl(L1)]CF3O3S and [PtCl(L2)]CF3O3S display a bathochromic shifted emission corresponding to J-aggregation (head-to-head Pt⋯Pt interactions), while in the case of compound [PtCl(L3)]CF3O3S a hypsochromic shifted emission compared to that in solution is characteristic of the H-aggregation process (head-to-tail Pt⋯π interaction). The coordination compounds display a strong rigidochromic effect with decay times changing from the ps/ns scale at ambient conditions to the μs domain in frozen glass matrices.

Synthesis, crystal, molecular, and electronic structures of hydride carbonyl ruthenium(II) complexes with pseudohalide ligands

Two pseudohalide hydride carbonyl ruthenium(II) complexes with formulae: [RuH(N3)(CO)(PPh3)3] (1) and [RuH(NCO)(CO)(PPh3)3] (2) have been synthesized by the reactions of [RuHCl(CO)(PPh3)3] with sodium azide or sodium cyanate, respectively, and are compared with the previously described thiocyanate analog [RuH(NCS)(CO)(PPh3)3]. The molecular structures of the new compounds were determined by X-ray crystallography and their spectroscopic properties have been studied. Based on the crystal structures, computational investigations have been carried out in order to determine the electronic structures of the complexes. The electronic spectra were calculated with the use of time-dependent DFT methods, and the electronic spectra of the transitions were correlated with the molecular orbitals of the complexes.

A copper(I) phosphine complex with 5,7-dinitro-2-methylquinolin-8-ol as co-ligand

Abstract5,7-Dinitro-2-methylquinolin-8-ol has been synthesized, and its copper(I) complex has been prepared. Both the free 2-MequinNO2 ligand and its complex were characterized by IR, NMR, and UV–Vis spectra. The structure of the [Cu(2-MequinNO2)(PPh3)2] complex has been determined by single-crystal X-ray analysis. The free 2-MequinNO2 ligand reveals luminescence in contrast to the complex. For 2-MequinNO2, the quantum yield, lifetime of the excited state, and the rate constants of both radiative and non-radiative decay have been determined. The lack of luminescence for the complex has been explained with the use of a quantum chemical study.

NCN-Coordinating Ligands based on Pyrene Structure with Potential Application in Organic Electronics

Five novel derivatives of pyrene, substituted at positions 1,3,6,8 with 4-(2,2-dimethylpropyloxy)pyridine (P1), 4-decyloxypyridine (P2), 4-pentylpyridine (P3), 1-decyl-1,2,3-triazole (P4), and 1-benzyl-1,2,3-triazole (P5), are obtained through a Suzuki-Miyaura cross-coupling reaction or CuI -catalyzed 1,3-dipolar cycloaddition reaction, respectively, and characterized thoroughly. TGA measurements reveal the high thermal stability of the compounds. Pyrene derivatives P1-P5 all show photoluminescence (PL) quantum yields (Φ) of approximately 75 % in solution. Solid-state photo- and electroluminescence characteristics of selected compounds as organic light-emitting diodes are tested. In the guest-host configuration, two matrixes, that is, poly(N-vinylcarbazole) (PVK) and a binary matrix consisting of PVK and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) (50:50 wt %), are applied. The diodes show red, green, or blue electroluminescence, depending on both the compound chemical structure and the actual device architecture. In addition, theoretical studies (DFT and TD-DFT) provide a deeper understanding of the experimental results.

Luminescent-Substituted Fluoranthenes-Synthesis, Structure, Electrochemistry, and Optical Properties

Six novel fluoranthene derivatives, namely, three terminally substituted and three bis(fluoranthene) units with fluorene, bithiophene, and carbazole spacers, were obtained through [2+2+2] cycloaddition and characterized completely. Based on the conducted studies, the obtained derivatives can be classified as donor-acceptor (D-A) and acceptor-donor-acceptor (A-D-A) systems, in which the fluoranthene unit acts as an electron-withdrawing unit. The optical results revealed that novel fluoranthene derivatives absorb light in the range λ=236-417 nm, which originates from a π→π* transition within the conjugated system. The compounds exhibit fluorescence that range from deep blue to green, which mainly arises from intramolecular charge transfer (ICT) states. High Stoke shifts and high quantum yields in solution (ϕ=0.22-0.57) and in the solid state (ϕ=0.18-0.44) have been observed for fluoranthene derivatives. All the derivatives display multistep oxidation processes at low potentials. The electronic structure of the presented compounds is additionally supported by time-dependent DFT computations.