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A series of Co β-iminoketonate derivatives with the general formula Co(L1)2, (L1 = i-acac (R = H, R1 = R2 = Me) – (1), Mei-acac (R = R1 = R2 = Me) – (2), i-thd (R = H, R1 = R2 = tBu) – (3), Mei-thd (R = Me, R1 = R2 = tBu) – (4)) and Co(L2) (L2= dmpda(acac)2 – (5) are obtained by the reaction of CoCl2 with the sodium salt of the corresponding β-iminoketonate ligand (L1 = R1C(O)CHC(NR)CR2 or L2 = MeC(O)CHC(Me)(NCH2C(Me)2CH2N)C(Me)CHC(O)Me) in methanol. Complexes 1-5 are characterized by the methods of elemental analysis, X-ray diffraction, and IR spectroscopy. The crystal cell parameters at 293 K are as follows: space group Сс, a = 13.7304(9) A, b = 5.5516(4) A, с = 18.4034(12) A, β = 101.964(2)°, V = 1372.34(16) A3, Z = 4 (2); space group P21/n, a = 9.953(2) A, b = 12.074(3) A, с = 11.161(2) A, β = 109.924(8)°, V = 1260.9(5) A3, Z = 2 (3); space group P1, a = 11.7982(7) A, b = 13.1673(9) A, с = 17.6159(10) A, α = 71.493(2)°, β = 83.478(2)°, γ = 72.829(2)°, V = 2478.7(3) A3, Z = 4 (4); space group Pbca, a = 7.8635(2) A, b = 14.0521(4) A, с = 29.8715(9) A, V = 3300.76(16) A3, Z = 8 (5). Two pairs of shortened contacts are revealed in molecules 2 and 5 when studying their Hirshfeld surfaces. It is shown with the thermogravimetry method that complexes 1 and 2 are the most volatile in the studied series.

Two isomers of Tröger's base-linked cryptands 5a and 5b were synthesized, and both of them have two chiral N-centers, exhibiting rare diamond-like scaffolds. Particularly, when growing from the solution of rac-5a, a single enantiomer RNRN-5a was found in the crystal cell, revealing chiral self-sorting behaviour. However, when adding CF3COOH to protonate Tröger's base in the solution of rac-5a, two enantiomers were both formed in pairs in the crystal cell, exhibiting chiral self-discriminating behaviour.

The first-order phase transition is accompanied by an increase in disordering. Defects and dislocations of the crystal cell decrease the temperature of the phase transition. Atoms located on the crystal surface get higher internal free energy first. Atoms located in different areas of the crystal have different numbers of saturated bonds. The lower the number of such bonds, the lower the temperature of the atom transition into the melt. The process of melting of two fractions (with sizes of 2 nm–0.1 mm and 1.5–2 mm) plagioclase, alkali feldspar, and quartz was studied at temperatures of 950, 1000, 1100, and 1200°C. Surface melting of all mineral fragments occurred at a temperature of 950°C.

a lot of modern research devoted to the creation and study of compounds present in the condensed state. In this regard, development and improvement of methods of description of crystalline structures are actual. To describe the crystal structure and the calculation of its key parameters is developed and continue to develop special techniques. Among them is the method of compact description of the crystal lattice proposed in Ph. D. Sychev M. S. The article seeks to study the applicability of these methods to crystals of hexagonal crystal structure and a method of solving this problem.

множество современных исследований посвящены созданию и изучению соединений, находящихся в конденсированном состоянии. В связи с этим актуальны разработка и совершенствование методов описания кристаллических структур. Для описания кристаллической структуры и расчёта её ключевых параметров разработаны и продолжают разрабатываться специальные методы. Среди них выделяется метод компактного описания кристаллической решётки предложенный в работах к.т.н. Сычёва М.С. В статье ставится задача исследования применимости этих методов к кристаллам гексагональной сингонии и предлагается способ решения поставленной задачи., a lot of modern research devoted to the creation and study of compounds present in the condensed state. In this regard, development and improvement of methods of description of crystalline structures are actual. To describe the crystal structure and the calculation of its key parameters is developed and continue to develop special techniques. Among them is the method of compact description of the crystal lattice proposed in Ph. D. Sychev M. S. The article seeks to study the applicability of these methods to crystals of hexagonal crystal structure and a method of solving this problem.

The crystal C18H12O10Pb3 is synthesized by Pb and phenyl propylene acid. The crystal is characterized by IR and single-crystal X-ray diffraction. The crystal belongs to monoclinic system, space group P21/c with the crystal cell parameters of a = 15.3263(14) A, b = 16.3479(14) A, c = 8.1006(7) A, β = 92.3060(10)°, V = 2028.0(3) A3, and Z = 4. Through the molecular structure of complex, we can see that Pb has three kinds of coordination modes (5, 6, 7). The compound has formed a 1D surface shape structure through these coordinate modes with the ligand, and this 2D layer piles through C-H…π forms the 3D compound.

The energy, electronic structure, and magnetic and mechanical properties of LaNi5 compound have been studied by the first-principles method based on the density functional theory. The results show that the calculated lattice parameters of LaNi5 compound are almost the same with the experimental ones, and the compound is easy to form and very stable. The bond between La and Ni1 atoms is an ionic bond, and electrostatic attraction effect exists between Ni atoms. The farther the distance between Ni atoms in the LaNi5 crystal cell is, the stronger the electrostatic attraction effect is. LaNi5 intermetallic compound is ductile and ferromagnetic. The calculated hardness value of LaNi5 compound is 7.04 GPa, and the calculated elastic properties are close to the experimental results.

The relationship between the solid/liquid interface and the crystal orientation for pure magnesium, which grows in fashion of cellular crystal in unidirectional solidification, was investigated. The results show that the energy of the solid/liquid interface is the lowest during cellular crystal growth of pure magnesium; and the solid/liquid interface is covered by the basal face {0001} and by the crystal face made up of three atoms located at the orientation {0001} and two atoms located at the inner of magnesium crystal cell. The strongest bond is formed in the direction of 61.9° deviating from the growth direction, and the second strong bond is formed in the directions of 8.5° and 47.7°, respectively, deviating from the growth direction. The angle between the basal face {0001} and the growth direction is 61.9°. The theoretical analysis results are basically consistent with the experimental results from SUSUMU et al.

A copper(II) complex of type {[Cu(phen)(py)(H2O)2]·2H2O}n (where phen=1,10-phenanthroline, py=pyridine-3,4-dicarboxylate) has been synthesized by a normal temperature volatilization method and structurally determined by single-crystal X-ray crystallography. The crystal belongs to monoclinic system, space group P2(1)/c with the crystal cell parameters of a=7.5258(4) A, b=12.3184(7) A, c=21.0000(12) A, α=90.00°, β=98.0720(10) °, γ=90.00°, V=1927.53(19) A3 and Z=4. The final reliability factors are R=0.0398 and wR=0.1138 for 3771 reflections with I>2δ(I0). Its mode of interaction with DNA and the binding constants have been determined by fluorescence, ultraviolet spectra and viscometry.

The new ligand 2,4-N,N′-bis(napthylamino)-pent-2-ene (Lnapth) (1) has been synthesized and crystallizes in space group P212121 with crystal cell parameters a = 8.196(3) A, b = 9.119(3) A, c = 25.746(10) A, V = 1924.3(12) A3 and Z = 4. The complexes bis[2,4-pentane-N,N′-bis(napthyl)ketiminato] chromium(II) (2), bis[2,4-pentane-N,N′-bis(isopropylphenyl)ketiminato] chromium(II) (3), and bis[2,4-pentane-N,N′-bis(tertbutylphenyl)ketiminato] chromium(II) (4) were synthesized and structurally characterized. Complex 2, the first complex reported with a bis(napthyl) β-diketiminate ligand, crystallizes in space group P − 1 with crystal cell parameters a = 12.0824(15) A, b = 12.2462(16) A, c = 14.8975(19) A, α = 87.035(2)°, β = 80.615(2)°, γ = 62.756(2)°, V = 1932.9(4) A3 and Z = 2. Complex 3 crystallizes in space group P21/n with crystal cell parameters a = 13.088(3) A, b = 22.222(5) A, c = 14.206(3) A, β = 102.310(4)°, V = 4036.6(17) A3 and Z = 4. Complex 4 crystallizes in space group P21/n with crystal cell parameters a = 20.831(6) A, b = 11.575(4) A, c = 21.373(7) A, β = 107.241(5)°, V = 4922(3) A3 and Z = 4. The degree of twist between the ligand planes is dependent on the steric bulk of the ligand. Three bis(β-diketiminate) chromium(II) complexes have been synthesized and structurally characterized. The degree of twist between the ligands was observed to be dependent on the steric bulk of the ligand.

The complexes (bis(2,6-diisopropylphenyl)pentane-2,4-ketiminato)(μ2-diisopropylacetamidinato) chromium(II) (1) and (bis(2,6-diisopropylphenyl)pentane-2,4-ketiminato)(μ2-dicyclohexylacetamidinato) chromium(II) (2) have been synthesized and structurally characterized. Complex 1 crystallizes in space group Pbcn with crystal cell parameters a = 10.7183(13) A, b = 16.4093(19) A, c = 20.687(2) A, V = 3,638.3(7) A3 and Z = 4. Complex 2 crystallizes in triclinic space group P-1 with crystal cell parameters a = 10.750(3) A, b = 12.174(3) A, c = 16.308(4) A, α = 75.903(4)°, β = 82.137(4)°, γ = 85.511(4), V = 2,048.4(8) A3 and Z = 2. The complexes adopt a spiro distorted square planar geometry and have similar structural parameters. Two complexes that each possesses both a β-diketiminate and an amidinate ligand were synthesized and structurally characterized.

The complexes (TMEDA)Cr(I)2(THF) (1) and [(N,N-DMEDA)2CrI] I (2) were synthesized and spectroscopically characterized (TMEDA = tetramethylethylenediamine, N,N-DMEDA = N,N dimethylethylenediamine). Complex 1 possesses square pyramidal geometry and crystallizes in spacegroup Pbca with crystal cell parameters a = 11.206(2) A, b = 12.698(3) A, c = 23.434(5) A, V = 3,334.6(12) A3 and Z = 4. Complex 2 also possesses square pyramidal geometry with a non-coordinated iodide counter anion and crystallizes in spacegroup P21/n with crystal cell parameters a = 9.4071(13) A, b = 14.628(2) A, c = 11.7516(16) A, β = 98.904(2) A°, V = 1,597.6(4) A3 and Z = 4. Complex 2 has previously been incorrectly assigned as an octahedral complex based on spectroscopy. The title compounds were synthesized and determined to have square pyramidal geometries. The second compound has been previously incorrectly assigned as an octahedral complex based on spectroscopy.

The title compound 1,3-bis(p-nitrophenoxy)propane was synthesized by nucleophilic substitution of p-nitrophenol and 1,3-dibromopropane. Single crystal X-ray diffraction analysis reveals that the molecule in the solid state packs in the monoclinic P2/n space group with crystal cell parameters a = 17.465(5) A, b = 4.8433(13) A, c = 17.610(5) A, β = 100.290(6)o, V = 1465.6(7) A3, Dcalc = 1.442 g/cm−3. Two half-molecules are located in the asymmetric unit which are each completed by twofold symmetry making Z = 4, Z′ = 1. The title compound 1, 3-bis (p-nitrophenoxy) propane was prepared from p-nitrophenol and 1, 3-dibromopropane, crystallized from an ethanolic solution, and the structure was obtained by single crystal X-ray diffraction: monoclinic, P2/n, a = 17.465(5) A, b = 4.8433(13) A, c = 17.610(5) A, β = 100.290(6)°, V = 1465.6(7) A3.

In this work, the phase transition from zincblende (B3) to rocksalt (B1) structure in bulk GaAs is investigated by using Mobius inversion potentials. A Cm transition path is proposed from the molecular static simulation results, even though it is different from previously proposed transition paths Imm 2, R 3 m and P 3 2 . The present Cm path is quite close to the previously suggested Imm 2 path according to the crystal cell geometries and activation enthalpies. By comparison, the activation enthalpies along the R 3 m and P 3 2 path are relative high. Therefore, the Imm 2 mechanism, as a simplified model of the Cm one, is suggested to describe the microscopic process of the B3–B1 phase transition of GaAs. In this way, we investigate the changes of the system features during the transition process characterized by Imm 2 mechanism and obtain a concise picture for the common B3–B1 transition. All the calculated results are compared to relevant experimental observations and other calculations.

In order to develop new alloys with high hydrogen storage capacity, commercially available VFe alloys were used to substitute partial Cr of TiCr1.8. In this paper, the effects of stoichiometry on hydrogen storage performance of pseudo-binary TiCr2X(VFe)X (X=0.3–0.9) alloys were investigated by X-ray diffraction (XRD) and pressure composition temperature (PCT) tests. XRD tests showed that body centered cubic (BCC) phase and Ti1.07Cr1.93 phase coexisted in these alloys. The crystal cell parameters of BCC phase decreased linearly with increasing ratio of (Cr+VFe)/Ti. The hydrogen storage capacity of these alloys changed nonlinearly with the increase of (Cr+VFe)/Ti. The alloys with slightly substoichiometric composition were more suitable for hydrogen storage.

A convenient simple method is proposed for the crystallochemical analysis of structures containing several molecules in the asymmetric unit of the crystal cell (Z′>1). The basic statistical data on the structures with Z′>1 found in the Cambridge structural database, and the role of molecular association in occurrence of pseudosymmetry in organic crystals are discussed.

A series of four 1 : 1 host–guest supramolecular complexes of [n]CPPs and C70 have been analyzed by Raman spectroscopy in the solid state and complemented with the analysis of their spectroscopic responses under mechanical and thermal stresses. By following the frequency behaviour of the G and RBM modes we have found that [10]CPP in the [10]CPP@C70 complex displays a more “ordered” structure. However, in [11]CPP@C70, the nanoring becomes oval-shaped with closer contacts with the C70 poles and less conformational restriction in the flattened region. By mechanical and thermal stresses we are able to modify the lying conformation of [10]CPP@C70 towards a standing orientation. [11]CPP@C70 resists pressure changes, although it tends to shift from the standing to the lying orientation by heating. As for the crystal cell, the [n]CPPs occupy the residual empty spaces while the main crystallographic positions are reserved for C70. These are new examples of the impressive adaptability of the [n]CPP molecules to different physico-chemical environments, a chameleon-like property which reveals the delicate equilibrium provided by cyclic conjugation and ring strain.

The substitution of Ce by Y in ${\mathrm{YMn}}_{2}$ leads to the destabilization of the Mn magnetic moment and inhibits both the transition to antiferromagnetism and the associated expansion of the crystal cell observed in pure ${\mathrm{YMn}}_{2}$. We show in this work how hydrogen uptake in the ${\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{Ce}}_{x}{\mathrm{Mn}}_{2}$ series gives rise to the recovery of long-range magnetic ordering in these systems. The analysis of magnetic and x-ray-absorption spectroscopy experiments addresses the critical role played by the modification of the Ce electronic state in the stabilization of the Mn magnetic moment through the hybridization changes.

The expected [1:2] complex between a tetraprotonated tetraazapara-cyclophane and squaric acid is not formed and the ligand undergoes drastic deformation. The peculiar features of this structure is the coexistence, in the same crystal cell, of 2 types of crystal lattice inclusions, corresponding to 2 different dissociation modes of squaric acid.

In the present work the charge states of all atoms in the cell of the ReBa 2 Cu 3 O x cuprates (Re = Yb, Er, Ho, Y, Gd, Eu, Sm, Nd, Pr; x = 0, 1) were determined. The analyses of charge states were performed on the basis of the calculation electric field gradient (EFG) in the frame of quantum chemical MO LCAO method with a glance of d-orbital. The calculated EFG tensor was compared with the experimental ones obtained from NQR experiments.

Glutathione peroxidase prepared from bovine erythrocytes yields small, but well-ordered plate-like crystals. X-ray investigation shows them to belong to monoclinic space group C 2. Unit cell dimensions are: a = 90.4 A , b = 109.5 A , c = 58.6 A , β = 99 ° ± 15 min. The crystal density is ϱ c = 1.36 ± 0.02 g . cm −3 . Consequently, the asymmetric unit of the crystal cell is occupied by one tetrameric molecule of M r 84,000. Matthew's (1968) parameter Γ M is calculated to be 1.71 A 3 /dalton.

Seven thallium(I) germanates have been identified in the binary system Tl 2 O GeO 2 . Tl 6 Ge 2 O 7 and Tl 8 Ge 5 O 14 melt congruently, Tl 4 GeO 4 , Tl 2 Ge 4 O 9 , Tl 2 Ge 6 O 13 , and Tl 2 Ge 7 O 15 melt incongruently, and Tl 2 Ge 2 O 5 is decomposed in the solid state. This compound has been characterized only with powder diagrams. Monocrystals of all the other germanates, and also of a second form of Tl 2 Ge 6 O 13 and of Tl 8 Si 5 O 14 , have been obtained to allow determinations of crystal cell parameters and indexed powder diagrams. The structural evolution of thallium(I) germanates is proposed. Ge 4+ has a mixed coordination (four and six) in Tl 2 Ge 4 O 9 and probably in Tl 2 Ge 6 O 13 and Tl 2 Ge 7 O 15 where the lone pair of Tl + is stereochemically inert. The pair is stereochemically active in Tl 4 GeO 4 , in Tl 6 Ge 2 O 7 , and in a new germanate, Tl 8 Ge 5 O 14 ; the structure of those compounds consists of isolated units (GeO 4 ) 4− , (Ge 2 O 7 ) 6− , and (Ge 5 O 14 ) 8− formed only by (GeO 4 ) 4− tetrahedra.