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1.
The results of structural studies of the synthetic analog of the radtkeite mineral Hg3S2Cl1.00I1.00 are analyzed. The crystal structure of the compound has been refined; the unit cell parameters are a m = 16.827(4) , b m = 9.117(1) , c m = 13.165(5) , = 130.17(2)°, V = 1543.3(8) 3, space group C2/m, Z = 8, R = 0.0527. A possible transition a 0 = a m; b 0 = a m + 2c m; c 0 = –b m to the pseudo-orthorhombic F cell previously determined for radtkeite, where one of the angles ( 0 ) is slightly different from 90° (89.55°), has been found. Each sulfur atom in the structure is bonded to three mercury atoms, forming SHg3 umbrellas with distances 2.240(6) –2.474(8) and angles HgSHg 94.7(2)°–102.9(2)°. The SHg3 fragments are linked through Hg vertices to form corrugated [Hg12S8] layers. The halogen atoms lie inside and between the [Hg12S8] layers; the distances are Hg-Cl and Hg-I 2.783(7) , 2.961(7) , and 3.083(4) –3.311(3) , respectively.Original Russian Text Copyright © 2004 by N. V. Pervukhina, S. V. Borisov, S. A. Magarill, D. Yu. Naumov, V. I. Vasiliev, and B. G. NenashevTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 755–758, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.  相似文献   

2.
The stable and transition structures of N4X (X = O, S, Se, Te) series with singlet state are optimized with the ab initio (MP2) and density functional theory (B3LYP) methods using the 6‐311+G(d) basis set. The ring isomers are found to be the global minima for N4O, N4S, N4Se, and the chain isomer is the minimum for N4Te. The stabilities are studied by evaluating the dissociation barriers with respect to dissociation. The reactants and products connected by transition structures are determined by applying the intrinsic reaction coordinate (IRC) calculations. The C2v, C3v and ring isomers decompose into linear NNX and N2 molecules, however, the chain isomers decompose into cyclic N2X and N2 firstly. A new possible isomerization mechanism between the cyclic and linear structures of N2X series is studied. The cyclic structures of N2X convert into linear structures easily with the very low barriers. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009  相似文献   

3.
An attempt is made to correlate the crystal structures of ternary chalcogenides of composition AB2X4 with the cationic radius ratio and a pseudo force-constant involving their electronegativities. The resultant diagram adequately resolves structures based on the types K2SO4, monoclinic, olivine, MnY2S4, Th3P4, and CaFe2O4 but structure types based on spinel, Cr3Se4, and Ag2HgI4 are not resolved. Crystal chemical arguments are used to explain these observations and to advance reasons for the successes and failures of this method for predicting structure types.  相似文献   

4.
Two modifications of a new mercury sulfohalide of Hg3S2Br2−x Clx (x = 0.5) composition have been grown from the gas phase and explored by X-ray structural analysis. The compounds were obtained at an attempt to synthesize an analogue of the rare mineral arzakite Hg3S2(Br, Cl)2 (Br > Cl). The refinement of the crystalline structures of monoclinic (I) and cubic (II) phases (I: a = 17.824(4) Å, b = 9.238(2) Å, c = 10.269(2) Å, β = 115.69(1)°, V = 1523.8(5) Å3, space group C2/m, Z = 8, R = 0.0513; II: a = 18.248(2) Å, V = 6076.4(12) Å3, space group Pmn, Z = 32, R = 0.038) has shown that they are polymorphous modifications of the compound of Hg3S2Br1.5Cl0.5 formula. The monoclinic modification I is isostractural to the synthetic compound α-Hg3S2Br2. Modification II is isostructural to synthetic β-Hg3S2Cl2. In both structures, each atom S has in its surrounding three atoms of Hg forming umbrella-type groups SHg3 with spaces Hg—S 2.366–2.430 Å and angles HgSHg 95.66–97.60°. SHg3-fragments are bound by Hg-apices with the formation of isolated cubic groups [Hg12S8]. Like that in other structures of mercury chalcohalides, the main role in structure-forming of the investigated compounds is played by atoms of halogens creating a cubic sublattice in which radicals Hg—S are arranged. Original Russian Text Copyright ? 2006 by N. V. Pervukhina, S. A. Magarill, D. Yu. Naumov, S. V. Borisov, V. I. Vasil’yev, and B. G. Nenashev __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 2, pp. 318–323, March–April, 2006.  相似文献   

5.
Using the XRD method, the crystalline and molecular structures of two halogenated propionamides, CF2XCF2CONH2, X = H (I) and Cl (II), have been studied. Crystals I and II are monoclinic: space group P21/c, Z = 4; (I) a = 10.967 Å, b = 5.406 Å, c = 10.063 Å, β = 107.86°; (II) a = 11.979 Å, b = 5.608 Å, c = 10.042 Å, β = 99.31°. Structures I and II were solved by the direct method and refined by the full-matrix least-square method to R = 0.112 (I) and 0.139 (II) over all 1299 (I) and 1175 (II) independent measured reflections (a CAD-4 autodiffractometer, λMoK α).  相似文献   

6.
Crystal-chemical analysis of 312 compounds containing complexes [Ru a X b ] z (X = O, S, Se, Te) is performed using Voronoi–Dirichlet polyhedra (VDP) and the method of intersecting spheres. In most of these complexes, Ru atoms have coordination number (CN) 6 and form RuX6 octahedra. However, only with respect to oxygen do the Ru(V)–Ru(VII) atoms exhibit CN 5 or 4 with trigonal-bipyramidal and tetrahedral coordination, respectively.The effect of the valence state of the Ru atoms on their stereochemistry is considered. The important role of the Ru–Ru interactions in the structure of the Ru(II)–Ru(V) compounds is established. As a result of the Ru–Ru interactions, the RuX6 octahedra are linked through a face or common edge or give O5Ru–RuO- dimers in which every metal atom occupies one of the vertices of an octahedron formed by the neighboring Ru atom.The dependence of the Ru–Ru and Ru–O bond orders on their lengths is established on the basis of a crystal-structure analysis and the 18-electron rule.  相似文献   

7.
By the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6‐dimethyl‐2‐pyrimido(thio)nium salts, which were characterized by single‐crystal X‐ray diffraction, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bifluoride, C6H9N2O+·HF2? or (dmpH)F2H, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bromide, C6H9N2O+·Br? or (dmpH)Br, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide, C6H9N2O+·I? or (dmpH)I, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide–urea (1/1), C6H9N2O+·I?·CH4N2O or (dmpH)I·ur, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bifluoride–thiourea (1/1), C6H9N2S+·HF2?·CH4N2S or (dmptH)F2H·tu, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bromide, C6H9N2S+·Br? or (dmptH)Br, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium iodide, C6H9N2S+·I? or (dmptH)I. Three HCl derivatives were described previously in the literature, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium chloride, (dmpH)Cl, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride monohydrate, (dmptH)Cl·H2O, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride–thiourea (1/1), (dmptH)Cl·tu. Structural analysis shows that in 9 out of 10 of these compounds, the ions form one‐dimensional chains or ribbons stabilized by hydrogen bonds. Only in one compound are parallel planes present. In all the structures, there are charge‐assisted N+—H…X? hydrogen bonds, as well as weaker CAr+—H…X? and π+X? interactions. The structures can be divided into five types according to their hydrogen‐bond patterns. All the compounds undergo thermal decomposition at relatively high temperatures (150–300 °C) without melting. Four oxopyrimidinium salts containing a π+X?…π+ sandwich‐like structural motif exhibit luminescent properties.  相似文献   

8.
The title compounds (S)-methyl-2-(4-R-phenylsulfonamido)-3-(1H-indol-3- yl)propanoate (R = H (1), Cl (2)) have been synthesized and their crystal structures also have been determined by X-ray single-crystal diffraction. Compound 1 (C18H18N2O4S) belongs to orthorhombic, space group P212121 with a = 9.6348(14), b = 11.1517(17), c = 16.412(3) A, V = 1763.4(5) A^3, Mr = 358.40, Z = 4, De = 1.350 g/cm^3,/t = 0.209 mm^-1, F(000) = 752, R = 0.0348 and wR = 0.0714. Compound 2 (CI8H17ClN2O4S) crystallizes in orthorhombic, space group P212121 with a = 9.3128(14), b = 10.9655(16), c = 17.783(3) A, V = 1815.9(5) A^3, Mr = 392.85, Z = 4, De = 1.437 g/cm^3, p = 0.352 mm^-1, F(000) = 816, R = 0.0389 and wR = 0.0845. The absolute structure Flack parameters X of compounds 1 and 2 are -0.03(8) and -0.06(7), respectively. X-ray analysis reveals that the crystal structures of these two compounds both involve two intermolecular N-H…O hydrogen bond's.  相似文献   

9.
Using the Voronoi–Dirichlet partition procedure and the method of intersecting spheres, it is demonstrated that in the crystal structures of chalcogen-containing compounds, Pt(IV) atoms form only PtX6 octahedra (X = S, Se, Te), whereas in the case of Pt(III) and Pt(II), square coordination by X atoms is typical. The Pt(II) atoms can also form PtX5 square pyramids (X = S, Se), PtS6 octahedra, and PtTe3Pt3 quasi-octahedra in which a platinum atom is located in the trans-position to each coordinated tellurium atom. It was found that Pt(II) atoms in the PtX4 squares (X = S, Se), unlike square-coordinated Pt(III) atoms, can form one or two Pt–M bonds (M is a d metal) and 1 to 4 secondary Pt–Q bonds, where Q is an s metal or hydrogen. The main features of platinum stereochemistry depending on the metal valence state and coordination number (CN) and on the nature of the chalcogen atom were quantitatively characterized in terms of the Voronoi–Dirichlet polyhedra.  相似文献   

10.
The Voronoi–Dirichlet polyhedra (VDP) and the method of intersecting spheres were applied to crystal-chemical analysis of all known compounds whose structures contain rhodium atoms surrounded by chalcogen atoms. The influence of the rhodium valence state and the nature of the chalcogen on the main features of Rh stereochemistry are discussed. Rhodium atoms exhibit coordination numbers of 6, 5, or 4 with respect to S, Se, or Te atoms; in addition to the bonds with chalcogens, rhodium can form 1 to 4 bonds with metal atoms. The VDP volume for Rh(III), Rh(2.67), and Rh(II) atoms in selenides and tellurides very weakly depends on the valence state, whereas in the case of sulfides, the volume increases rather regularly with a decrease in the metal oxidation number from Rh(III) to Rh(I).  相似文献   

11.
The reactions of Te2Br with MoOBr3, TeCl4 with MoNCl2/MoOCl3, and Te with WBr5/WOBr3 yield black, needle-like crystals of [Te15X4][MOX4]2 (M = Mo, W; X = Cl, Br). The crystal structure determinations [Te15Br4][MoOBr4]2: monoclinic, Z = 1, C2/m, a = 1595.9(4) pm, b = 403.6(1) pm, c = 1600.4(4) pm, β = 112.02(2)°; [Te15Cl4][MoOCl4]2: C2/m, a = 1535.3(5) pm, b = 402.8(2) pm, c = 1569.6(5) pm, β = 112.02(2)°; [Te15Br4][WOBr4]2: C2, a = 1592.4(4) pm, b = 397.5(1) pm, c = 1593.4(5) pm, β = 111.76(2)° show that all three compounds are isotypic and consist of one-dimensional ([Te15X4]2+)n and ([MOX4]?)n strands. The structures of the cationic strands are closely related to the tellurium subhalides Te2X (X = Br, I). One of the two rows of halogen atoms that bridges the band of condensed Te6 rings is stripped off, and additionally one Te position has only 75% occupancy which leads to the formula ([Te15X4]2+)n (X = Cl, Br) for the cation. The anionic substructures consist of tetrahalogenooxometalate ions [MOX4]? that are linked by linear oxygen bridges to polymeric strands. The compounds are paramagnetic with one unpaired electron per metal atom indicating oxidation state Mv, and are weak semiconductors.  相似文献   

12.
The Voronoi–Dirichlet polyhedra (VDP) and the method of intersecting spheres were used to perform a crystal-chemical analysis of compounds whose structures contain Os atoms surrounded by chalcogen atoms. Depending on the valence state, Os atoms bind four to seven X atoms (X = O, S, Se, Te) forming OsX n coordination polyhedra which can be tetrahedra (n = 4), trigonal bipyramids or square pyramids (n = 5), octahedra (n = 6), or pentagonal bipyramids (n = 7). In some compounds, pairs of OsO6 octahedra share edges to form Os–Os bonds. The influence of the Os valence state and the nature of the chalcogen atom on the composition and structure of the [Os a X b ] groups is discussed. On the basis of analysis of the crystal-structural data from the standpoint of the 18-electron rule, dependences of the Os–O and Os–Os bond orders on the bond lengths are proposed.  相似文献   

13.
(1R,2S,3S,4S)-(6-O-Acetyl-1,2-O-isoproplidene-3,5-dideoxy-a-D-glucofuranoso)1,3,5-trihydro-2,3-oxathiaindene-2,2-dioxide (C_(11)H_(16)O_8S,M_r=308.30) was synthesized and structurally characterized by NMR,MS and single-crystal X-ray diffraction.It belongs to the triclinic system,space group P1 with a=7.0836(14),b=10.832(2),c=14.895(3) (A),α=96.01(3),β=98.85(3),γ=108-59(3)°,V=1055.8(4) (A)~3,Z=3,D_c=1.455 g/cm~3,F(000)=486,μ=0.264 mm~(-1),the final R=0.0360 and wR=0.0712.It is a tricyclic sultone derivative composed of three five-membered rings.  相似文献   

14.
A theoretical study of the HTeXH (X=O, S, Se and Te) monomers and homodimers was carried out by means of second‐order Møller‐Plesset perturbation theory (MP2) computational methods. In the case of monomers, the isomerization energy from HTeXH to H2Te=X and H2X=Te (X=O, S, Se, and Te) and the rotational transition‐state barriers were obtained. Due to the chiral nature of these compounds, homo and heterochiral dimers were found. The electron density of the complexes was characterized with the atoms‐in‐molecules (AIM) methodology, finding a large variety of interactions. The charge transfer within the dimers was analyzed by means of natural bond orbitals (NBO). The density functional theory‐symmetry adapted perturbation theory (DFT‐SAPT) method was used to compute the components of the interaction energies. Hydrogen bonds and chalcogen–chalcogen interactions were characterized and their influence analyzed concerning the stability and chiral discrimination of the dimers.  相似文献   

15.
With an aim to discover novel AHAS inhibitors,the title compound (S)-ethyl-2(2-methoxy-phenylsulfenamido)-3-(1H-indol-3-yl)propanoate (C 21 H 22 N 2 O 4 S,M r=398.47) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction analysis.The crystal belongs to orthorhombic,space group P2 1 2 1 2 1 with a=8.078(2),b=12.824(4),c=18.788(6),V=1946.2(10) 3,Z=4,F(000)=840,D c=1.360 mg/m 3,μ=0.197 mm-1,the final R=0.0433 and wR=0.1035 for 3075 observed reflections with I > 2σ(Ⅰ).The absolute structure Flack parameter X of this compound is 0.00(8).A total of 14375 reflections were collected,of which 3431 were independent (R int=0.0437).X-ray analysis reveals that the crystal structure involves two intermolecular N-H···O and one N-H···S intermolecular hydrogen bonds with the neighboring molecules.The crystal structure was compared with our previously reported (S)-methyl 2-(4-R-phenylsulfonamido)-3-(1H-indol-3-yl)propanoate (R=H(1) and Cl(2)),which provided some useful information of these compounds.  相似文献   

16.
Thiourea compounds are excellent agents of bioactive substance. A number of biological activities are associated with substituted thiourea derivatives. A survey of literature reveals that some work has been reported on benzoylthiourea, which has found plenty of applications as a facile and simple ligand in determination of trances of the transition metal and as an available starting material in preparation of a wide variety of metal complexes. In recent years,N-benzoyl-N'-(2-hydroxyethyl)-thiourea has attracted considerable attention as selective reagents for the liquid-liquid extraction and preconcentration of platinum group metals and its antifungle activity.As a part of our works in studying coordination behaviours of N-benzoyl-N'-(2-hydroxyethyl)-thiourea and its bioactivity, in view of these observations and in continuation of our previous works on it, the present work was reported on the crystal structure of N-benzoyl-N'-( 2-hydroxyethyl)-thiourea.The crystals structure in the monoclinic system and space group of P21/c of N-benzoyl-N'-(2-hydroxyethyl)- thiourea (C10H12N2O2S) was determined from single-crystal X-ray diffraction analysis, a = 17.083 (3) A, b = 4.5490 (10) A, c = 14.279 (3)A, a = 90.00°, a = 102.44(3)°, a = 90.00 °, Ⅴ = 1083.6 (4)A3, Z = 4, Dc = 1.375 Mg/m3, i (Mo Ka)= 0.280 mm-1, F(000) =472. The final R and u R are 0.0399 and 0.0881 for 783 observed reflections [Ⅰ>26(Ⅰ)].Fig. 1 shows the molecular crystal structure of N-benzoyl-N'-(2-hydroxyethyl)thiourea indicating that the carbonyl and thiocarbonyl moieties are pointing in approximate opposite directions. The six atoms in the ring structure hydrogen bonded are almost in one plane. The N(2)-H proton pendant arm extends to the carbonyl oxygen atom, forms hydrogen bond between them.The existence of hydrogen bond in benzoyl-thiourea molecular six-membered ring structure has significant implications on coordination properties, suggest the possibility of intramolecular hydrogen bond controlled coordination behaviors of these potentially bidentate ligands. In the coordination compound reported by Bourne et al.,cis-bis(N-benzoyl-N'-propylthiourea)dichloroplatinum(Ⅱ), the two ligand molecules bind to Pt(Ⅱ)via the sulfur atoms only, the carbonyl oxygen atom being locked into hydrogen bond similar to that in the free ligands.  相似文献   

17.
Crystal structure of (2S,3S)-tartrate of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo-[8.8.8]hexacosane, [H2(Crypt-222)]2+·(C4H4O6)2? (I) has been studied by single crystal X-ray diffraction. Triclinic structure of I (space group P1, a = 8.424 Å, b = 13.011 Å, c = 13.806 Å; α = 116.37°, β = 106.45°, γ = 91.81°; Z = 2) was solved by the direct method and refined in the full-matrix anisotropic approximation to R = 0.140 for 5850 measured independent reflections (automated diffractometer CAD-4, λMoK α). In the structure of I, two independent dications of 2.2.2-cryptand (nitrogen atoms are protonated) are linked to the approximate inversion symmetry and have a rare conformation of exo-exo type, when two atoms sitting on N atoms are protruded out of their cavity. The centroids of two crystallographically unique (2S,3S)-tartrate dianions are bound with the same approximate inversion center. An extended system of hydrogen bonds is developed in the crystal of I.  相似文献   

18.
A new carbbenzyloxymethylenetriparatolylphosphorane ylide (BTPY), {(p-tolyl)3PCHCOOCH2C6H5},was synthesized and characterized with elemental analysis as well as various spectroscopic techniques. The reactions of the title ylide with mercury(II) chloride, mercury(II) bromide and mercury(II) iodide in equimolar ratios using dry methanol as solvent have yielded [BTPY · HgCl2]2 (1), [BTPY · HgBr2]2 (2) and [BTPY · HgI2]2 (3), respectively. Single crystal X-ray analysis of 2 reveals the presence of a centrosymmeteric dimeric structure containing the ylide and HgBr2. The analytical data, IR and 1H, 13C and 31P NMR data for the latter compound are similar to those of 1 and 3, indicating similar structures. The theoretical studies indicated that, for all three compounds, the observed trans-like structure for compound 2, is more stable than the possible cis-like structure in each case.  相似文献   

19.
Cadmium phosphide chloride Cd2PCl2 was prepared by the ampule synthesis method at 770 K. Crystals were obtained from the gaseous phase by the chemical transport reaction. The crystal structure of Cd2PCl2 is built of the P2Cd6 octahedra, which are linked in layers by sharing four equatorial vertices. The layers alternate in a fashion analogous to that observed in the K2NiF4 structural type and are linked in a three-dimensional framework through the halogen atoms. The characteristic features of the crystal and electronic structures of pnictide halides M2PCl2 (M = Cd or Hg) were considered based on X-ray diffraction data and results of quantum-chemical calculations.  相似文献   

20.
《Mendeleev Communications》2023,33(2):171-173
Crystal structure of widely employed precatalyst [Pd(Ph3P)4] is reported. It crystallizes in P-3 space group [a = 19.0828(8) and c = 26.4423(18) Å] with six molecules per unit cell. It is demonstrated that the phase purity of this important compound can now be routinely controlled via powder X-ray diffraction analysis.  相似文献   

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