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For almost 30 years since the end of the civil war in Lebanon, signing of the Taif agreements in 1989 and the dissolution of the USSR in 1991 with the emergence of new Russia, the bilateral Russian-Lebanese relations remained partnership and friendly. They have reflected the trend of strengthening mutually beneficial cooperation. Nevertheless, Russian-Lebanese relations at the present stage (21st century) have remained partially unexplored. The article is devoted to a comprehensive study of Russian-Lebanese relations in the political, diplomatic, economic and cultural spheres; the focus is made on the 2000s. The research contains a quantitative analysis of Russian-Lebanese official contacts (2006-2020), as well as a review of the commodity structure of the countries turnover.

The geometrical and electronic structures of iron and cobalt metal complexes of porphyrazine and tetra(1,2,5-thiadiazole)porphyrazine in ground and low-lying excited electronic states were determined by DFT calculations and the complete active space (CASSCF) method with following accounting dynamic correlation by multiconfigurational quasidegenerate second-order perturbation theory (MCQDPT2). A geometrical structure of D[Formula: see text] symmetry has been obtained for all four complexes. According to data obtained by the MCQDPT2 method, the complexes of cobalt and iron possess the ground states 2A[Formula: see text] and 3A[Formula: see text], respectively, and wave functions of the ground states have the form of a single determinant. It is shown that the crystal field theory (CFT) can be used to describe the sequence of electronic states of the investigated complexes. The nature of the bonds between metal atoms and nitrogen atoms has been described using the analysis of the electron density distribution in the frame of Bader’s quantum theory of atoms in molecule (QTAIM).

Electronic and geometric structures of metal-free, Al, Ga and In complexes with tetrapyrazinoporphyrazine (TPyzPA) and octachlorotetrapyrazinoporphyrazine (TPyzPACl8) were investigated by density functional theory (DFT) calculations and compared in order to study the effect of chlorination on the structure and properties of these macrocycles. The nature of the bonds between metal atoms and nitrogen atoms was described using the NBO-analysis. Simulation and interpretation of electronic spectra were performed with the use of time-dependent density functional theory (TDDFT). A description of calculated IR spectra was carried out based on the analysis of the distribution of the potential energy of normal vibrational coordinates.

The paper reviews the issue of the creation of a fundamentally new innovative model of negotiation process focused on settling the Israeli-Palestinian conflict. In the author’s opinion, political leadership factor that is typical for the Arab-Israeli world is instrumental in providing a conceptual framework for peace talks between Israel and Palestine in the context of globalization. The article focuses on the peculiarities of the Islamic model of political or, to be more precise, religious and political leadership and how it can be implemented to give a new impetus to the currently bogged down Israeli-Palestinian peace talks. The author argues that is impossible to achieve any tangible regional treaty because not all the arrangements concerning Palestine have a legitimate character from the point of view of both the Palestinians and the people of other Muslim countries in the world. Therefore, in the author’s opinion, without using such an innovative model of the negotiation process it will be principally impossible to achieve a final settlement of the Israeli-Palestinian conflict.

The Knudsen effusion method with mass spectrometric control of the vapor composition was used to study the possibility of a congruent transition to the gas phase and to estimate the enthalpy of sublimation of metal-free tetrakis(1,2,5-thiadiazolo)porphyrazine and its nickel complex (H2TTDPz and NiTTDPz, respectively). The geometrical and electronic structure of H2TTDPz and NiTTDPz in ground and low-lying excited electronic states were determined by DFT calculations. The electronic structure of NiTTDPz was studied by the complete active space (CASSCF) method, following accounting dynamic correlation by multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2). A geometrical structure of D2h and D4h symmetry was obtained for H2TTDPz and NiTTDPz, respectively. According to data obtained by the MCQDPT2 method, the nickel complex possesses the ground state 1A1g, and the wave function of the ground state has the form of a single determinant. Electronic absorption and vibrational (IR and resonance Raman) spectra of H2TTDPz and NiTTDPz were studied experimentally and simulated theoretically.

First complexes of tetra(1,2,5-thiadiazolo)porphyrazine with representatives of rare earth elements [TSDPzM(acac)] (M = Y and Lu) were prepared by complexation of the metal free macrocycle [TSDPzH2] with YIII and LuIII acetylacetonates in o-dichlorobenzene in the presence of DBU. The obtained complexes were characterized by MALDI-TOF mass-spectrometry, IR spectroscopy and by electronic absorption and fluorescence emission spectra. The DFT calculations performed for the model complexes [TSDPzM(Cl)] evidence that coordination of Y and Lu leads to considerable doming deformation of the TSDPz macrocycle and were used for the assignment of the characteristic bands observed in the experimental IR spectra.

Electronic and geometric structures of Ca(II) and Zn(II) complexes with porphyrazine (Pz) and tetrakis(1,2,5-thiadiazole)porphyrazine (TTDPz) were investigated by density functional theory (DFT) calculations and compared. The perimeter of the coordination cavity was found to be practically independent on the nature of a metal and a ligand. According to the results of the natural bond orbital (NBO) analysis and quantum theory of atoms in molecules (QTAIM) calculations, Ca&ndash, N bonds possess larger ionic contributions as compared to Zn&ndash, N. The model electronic absorption spectra obtained with the use of time-dependent density functional theory (TDDFT) calculations indicate a strong bathochromic shift (~70 nm) of the Q-band with a change of Pz ligand by TTDPz for both Ca and Zn complexes. Additionally, CaTTDPz was synthesized and its electronic absorption spectrum was recorded in pyridine and acetone.