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Simulation of the atmospheric transmission, using spectral line parameters from HITRAN-2008 database and CDSD databank, and the approximation of CO₂ absorption line profile, taking the line-mixing effect of closely spaced lines into account, are carried out. For CO₂ it is shown the characteristic examples of the spectral regions, where contribution of the effect is recommended to be taken into account in calculation of transmission in the atmospheric conditions.

The results of numerical simulation of the nonlinear propagation of high-power pulsed laser radiation at a wavelength of 10.6 microns in air upon Kerr self-focusing and filamentation are presented. The optical model of air involves cubic and higher optical nonlinearity, plasma nonlinear absorption and refraction, and air linear absorption. The single-filamentation regime of the laser pulse with peak power of up to few terawatts and pulse duration of one picosecond is studied. For the first time we show that in contrast to the filamentation in the near-infrared wavelength range, the specific feature of long wavelength radiation self-action in air is the formation of abnormally elongated and wide intense light channel followed by nearly continuous along the propagation direction plasma column. The peak electron density of the formed plasma column is comparable to that created by a femtosecond radiation in the near-infrared spectral range. The physical cause for these peculiarities is the change of air ionization regime by picosecond CO₂-laser pulses in favor of bound electrons tunneling through the atomic potential barrier and the progressive development of the electron avalanche.

The results of laboratory experiments on nonlinear propagation of intense pulse-periodic and continuous wave CO₂ laser radiation in a gas medium are presented. Experiments were carried out in a cell containing a mixture of air and carbon dioxide at different partial concentrations (~ 1–10%), in the conditions of strong absorption and thermal blooming of laser radiation. The experimental conditions simulated the atmospheric propagation of intense laser radiation at a kilometer-length path. Sharply focused laser beams were used, and the areas of heat release along the beam channel were registered by the shadow imaging method. We found that the focal waist of the laser beam is characterized by the reduced heat release as compared with that in the pre- and post-focal beam regions. The most probable cause of this circumstance is considered to be the resonance absorption saturation of CO₂ molecules, which becomes apparent at high intensities in a laser pulse (a “path cleaning” effect). For continuous wave radiation, this effect appears in a lesser extent.

Bis(iso-maleonitriledithiolate)nickel(II) benzylpiperidinium, [BzPid]₂[Ni(i-mnt)₂] (1) is prepared and characterized by elemental analyses, UV, IR, molar conductivity, and single crystal X-ray diffraction. It is found that 1 crystallizes in the monoclinic space group P2₁/n with a = 9.551(1) Å, b = 16.520(2) Å, c = 11.004(1) Å, β = 96.60(1)°, V = 1724.6(3) ų, Z = 2. consolidate the stacking of the molecules The electrostatic interaction between [Ni(i-mnt)₂]^2– anions and [BzPid]⁺ cations consolidates the stacking of the molecules.

A new tetranuclear zinc(II) complex [Zn₄(tmphen)₄(tbip)₄(H₂O)₄] (1, tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, H₂tbip = 5- tert-butyl isophthalic acid) is hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, and IR spectroscopy. In complex 1, four tbip^2– ligands act as bridges between four neighboring Zn atoms to form an unusual tetranuclear zinc cluster. The clusters are further connected by two types of O—H⋯O and C—H⋯O hydrogen bonds, generating a three-dimensional supramolecular structure. Meanwhile, π—π stacking interactions and C—H⋯p interactions further consolidate the three-dimensional supramolecular framework of 1. In addition, the luminescence measurements reveal that complex 1 exhibits strong fluorescent emissions in the solid state at room temperature.

A cadmium(II) complex dicyanidobis(N,N'-dimethylthiourea- S) cadmium(II) [Cd(Dmtu)₂(CN)₂] (1) is prepared and its structure in the solid state is determined by single crystal X-ray structural analysis. The cadmium(II) ion is four-coordinate having a distorted tetrahedral geometry composed of two cyanide C atoms and two thione S atoms of N,N'-dimethylthiourea (dmtu). The molecular structure is stabilized by intermolecular N—H⋯N(CN) hydrogen bonding interactions that lead to a 3D network structure. The complex was also characterized by IR and NMR spectroscopy.

Single-crystal X-ray diffraction is used to determine the structure of a new compound based on an octahedral cyanide anionic cluster complex of rhenium and a trimethyltin(IV) cation: {(SnMe₃)₃[Re₆Se₈(CN)₆]} (1). The crystallographic characteristics: space group С2/с, a = 13.9898(14) Å, b =15.334(2) Å, c = 20.761(2) Å, β = 97.75(0)°, V = 4412.91(90) ų, Z = 4, d_x = 3.607 g/cm³, and R = 0.0526. The compound has a framework structure; two porous frameworks with pcu topology interpenetrate each other.

An X-ray crystallographic study is conducted of single crystals with the composition [Ba₂(Aet^–)₂×10(H₂O)]²⁺×2(Aet^–)×4H₂O, where Aet^– = (C₁₀H₁₁N₄O₂S₂)^– is the ethazole (2-( para-aminobenzenesulfamido)-5-ethyl-1,3,4-tiadiazole) anion. The crystals are monoclinic; the space group is P2₁/c, Z = 2; а = 9.793(2) Å, b = 15.408(4) Å, and c = 22.553(6) Å; β = 94.98(2)°; and R = 0.047. The independent part of the compound’s structural formula, [Ba(Aet)(OH₂)₅](Aet)×2H₂O, is isostructural with the analogous compound with the Sr atom. The ethazole anion is coordinated to the complexing metal atom by oxygen and nitrogen atoms to form a four-membered ring.

The crystal structure of [2-(2-hydroxybenzilydene)hydrazinecarboxoamidato(1-)][2-(2-hydroxy-benzilydene)hydrazinecarboxoamidato(2-)]chromium monohydrate [Cr(HL)(L)]×H₂O (I), where H₂L is salicylaldehyde semicarbazone, is determined. In I the central chromium atom is octahedrally surrounded by two ligand anions in the mer position and coordinated azomethine nitrogen atoms, phenol and carbamide oxygen atoms. In both ligands phenol groups are deprotonated; in one of them the imine group is also deprotonated. In the crystal, complexes of the compound studied are hydrogen bonded into layers along the [100] direction, with π–π stacking being observed between the phenyl rings inside the layer along with the X–Н⋯Cg (π ring) interaction.

Two hydrazone compounds N'-(2,4-dichlorobenzylidene)-4-methylbenzohydrazide monohydrate (1) and 2-chloro-5-nitro- N'-(4-methylbenzylidene)benzohydrazide (2) derived from 4-methylbenzohydrazide with different benzaldehydes are synthesized and characterized by physicochemical methods and single crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic space group P2₁2₁2₁ with unit cell parameters a = 4.714(2) Å, b = 13.093(3) Å, c = 24.754(3) Å, V = 1527.9(8) ų, Z = 4, R ₁ = 0.0812, and wR ₂ = 0.1623. Compound 2 crystallizes in the monoclinic space group Cc with unit cell parameters a = 11.564(2) Å, b = 13.271(2) Å, c = 9.462(2) Å, β = 96.860(2)°, V = 1441.7(4) ų, Z = 4, R₁ = 0.0461, and wR₂ = 0.0896. The crystals of the compounds are stabilized by intermolecular hydrogen bonds as well as π⋯π stacking interactions.