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1.
The crystal and molecular structures of c-Hex-DAB (c-hexyl-NC(H)C(H)N-c-hexyl; DAB = 1,4-diaza-1,3-butadiene) and of trans-[PdCl2(PPh3)(t-Bu-DAB)] are reported. Crystals of c-Hex-DAB are monoclinic with space group C2/c and cell constants: a = 24.70(1), b = 4.660(2), c = 12.268(3)Å, β = 107.66(4)°, Z = 4. The molecule has a flat E-s-trans-E structure with bond lengths of 1.258(3)Å for the CN double bond and 1.457(3)Å for the central CC′ bond. These bond lengths and the NC-C′ angle of 120.8(2)° indicate that the C- and N-atoms are purely sp2-hybridized and that there is little or no conjugation within the central DAB skeleton. Crystals of trans-[PdCl2(PPh3)(t-Bu-DAB)] are triclinic with space group P-1 and cell constants: a = 17.122(3), b = 18.279(3), c = 10.008(5)Å, α = 96.77(2), β = 95.29(3), γ = 109.79(2). Z = 4. The t-Bu-DAB ligand is coordinated to the metal via one lone pair only. In this 2e; σ-N coordination mode the E-s-trans-E conformation of the free DAB-ligand is still present and the bonding distances within the DAB-ligand are hardly affected. [CN: 1.261(10)Å; CC′: 1.479(10)Å (mean).] The PdN-, NC- and central CC′-bond lengths are compared with those found in other metal -R-DAB complexes.  相似文献   

2.
The molecular structure of vinyldimethylchlorosilane has been determined by gas phase electron diffraction at room temperature. The least squares values of the bond lengths (rg) and bond angles (∠α) are : r(CH) = 1.086(6) Å, r(CC) = 1.347(5) Å, r(SiC=) = 1.838(6) Å, r(SiC) = 1.876(3) Å, r(SiCl) = 2.078(2) Å, ∠CCSi = 127.8° (1.2) and ∠=CSiCl = 107° (1). Models with pure syn form and a mixture of syn and gauche gave equally good agreement with the diffraction data.  相似文献   

3.
The molecular structure of gaseous dichloromaleic anhydride has been investigated by electron diffraction at a nozzle-tip temperature of 164–170°C. The molecule is planar to within experimental error, but small deviations from planarity corresponding to torsion up to about 10° around the carbon-carbon single bonds cannot be ruled out. Values of the more important rα distances and angles with estimated 2σ uncertainties are r(CO) = 1.188(2) Å, r(CC) = 1.332(5) Å, r(C-O) = 1.389(3) Å, r(C—C) = 1.495(3) Å, r(C—Cl) = 1.685(2) Å, ∠CC-Cl = 129.4(2)°, ∠C-CO = 128.5(4)° and ∠CC—C = 107.9(2)°. The shortening of the carbonyl bond relative to that in maleic anhydride itself is discussed in terms of a possible general effect of vicinal substitution.  相似文献   

4.
The crystalline complex ImH[CuCl2(HOCH2C≡CCH2OH)] has been synthesized by the direct interaction of 2-butyne-1,4-diol with CuCl in concentrated aqueous solution of (ImH)Cl (ImH+ is imidazolium cation) and studied by X-ray crystallography. The crystals are triclinic, space group P $\overline 1 $ , a = 7.08(2) Å, b = 7.49(1) Å, c = 10.962(8) Å, α = 101.76(8)°, β = 95.85(8)°, γ = 99.57(8)°, Z = 2. The structure consists of stacks of discrete anions [CuCl2(HOCH2C≡CCH2OH)]? arranged along the [100] axis and [ImH]+ cations occupying the free space. The environment of π-coordinated Cu(I) atoms is trigonal and consists of two chlorine atoms and the C≡C bond of 2-butyne-1,4-diol molecule. The alcohol groups do not participate in the coordination, but they form strong hydrogen bonds N-H···O (H···O, 1.76(6) Å) and O-H···Cl(H···Cl, 2.29(5) Å).  相似文献   

5.
The phase diagram of the system Ag4SSe–As2Se3 is studied by means of X-ray diffraction, differential thermal analyses and measurements of the microhardness and the density of the materials. The unit-cell parameters of the intermediate phases 3Ag4SSe·As2Se3 (phase A) and Ag4SSe·2As2Se3 (phase B) are determined as follows for phase A: a=4.495 Å, b=3.990 Å, c=4.042 Å, α=89.05°, β=108.98°, γ=92.93°; for phase B: a=4.463 Å, b=4.136 Å, c=3.752 Å, α=118.60°, β=104.46°, γ=83.14°. The phase 3Ag4SSe·As2Se3 and Ag4SSe·2As2Se3 have a polymorphic transition α?β consequently at 105 and 120°C. The phase A melts incongruently at 390°C and phase B congruently at the same temperature.  相似文献   

6.
The structures of isobutene and 2,3-dimethyl-2-butene have been studied by gas electron diffraction. For isobutene the rotational constants obtained by Laurie by microwave spectroscopy have also been taken into account. Leastsquares analyses have given the following rg bond distances and valence angles (rav for isobutene and rα for dimethylbutene): for isobutene, r(CC) = 1.342±0.003 Å, r(C-C)= 1.508±0.002Å, r(C-H, methyl) = 1.119±0.007 Å, r(C-H, methylene) = 1.095±0.020 Å, ∠(C-CC) = 122.2±0.2°, ∠(H-C-H) = 107.9±0.8°, and ∠(C-C-H) 121.3±1.5°; for dimethylbutene, r(CC)= 1.353 ±0.004 Å, r(C-C) = 1.511±0.002 Å, r(C-H) = 1.118± 0.004 Å, ∠(C-CC)= 123.9±0.5°, and ∠(H-C-H)= 107.0±1.0°, where the uncertainties represent estimated limits of experimental error. The bond distances and valence angles in these molecules and in related molecules are compared with one another. The CC and C-C bond distances increase almost regularly with the number of methyl groups, and the C-C bonds in isobutene and dimethylbutene are shorter than those in acetaldehyde and acetone by about 0.01 Å. Systematic variations in the C-CC angles suggest the steric influence of methyl groups.  相似文献   

7.
The structure of (Ph3SiN)2C has been determined by single crystal X-ray diffraction. The structure was solved by direct methods and refined to R = 0.071 for 593 independent diffractometer data. The crystals are rhombohedral, R3 with a = b = c 18.201(20) Å, α = β = γ = 48.82(2)°, and Z = 4. The three crystallographically independent molecules each have linear SiNCNSi chains lying along the crystallographic threefold axes; in two of the molecules the central carbon atom lies on a centre of symmetry. Principal mean bond lengths and angles are: Si, 1.696(25); SiC, 1.846(20); NC, 1.164(30); CC, 1.387(14) Å; CSi, 108.2(6); and CSiC, 110.8(6)°.  相似文献   

8.
Vibrational data of vapour, liquid and matrix-isolated fluorocarbonyl isocyanate, FC(O)NCO, were investigated. A subsequent normal coordinate analysis was performed for the A′ species of the predominant planar cis conformer (CO double bond cis with respect to the vicinal NC double bond). The following internal force constants were derived: fCO= 12.88 mdyn Å−1, fCF=6.20 mdyn Å−1 and FCN= 4.42 mdyn Å−1.  相似文献   

9.
The structures of propene and 3,3,3-trifluoropropene have been studied by electron diffraction intensities measured in the present study and rotational constants reported in the literature. The following average structures have been determined: For propene, rg(CC) = 1.342 ± 0.002 Å, rg(C-C) = 1.506 ± 0.003 Å, rg(C-H)vinyl = 1.104 ± 0.010 Å, rg(C-H)methyl = 1.117 ± 0.008 Å, ∠(C-CC) = 124.3 ± 0.4°, ∠(CC-H) = 121.3 ± 1.4°, and ∠(C-C-H) = 110.7 ± 0.9°; for trifluoropropene, rg(CC) = 1.318 ± 0.008 Å, rg(C-C) = 1.495 ± 0.006 Å, rg(C-H)= 1.100 ± 0.018 Å, rg(C-F) = 1.347 ± 0.003 Å, ∠(C-CC) = 125.8 + 1.1°, ∠(C-C-F) = 112.0 ± 0.2°, where the valence angles refer to the rav structure, and the uncertainties represent estimated limits of experimental error. A simple set of quadratic force constants for each molecule has been estimated. Regular trends have been observed in the CC and C-C bond distances and the C-CC angles in these and related molecules. Significant differences between the CC, C-C and C-F distances and the C-C-F angle in trifluoropropene and in hexafluoroisobutene reported by Hilderbrandt et al. have been indicated.  相似文献   

10.
A novel 1-benzhydryl piperazine derivative 1-benzhydryl-4-(2-nitro-benzenesulfonyl)-piperazine was synthesized by the nucleophilic substitution of 1-benzhydryl piperazine with 2-nitro-benzenesulfonyl chloride. The product obtained was characterized spectroscopically and finally confirmed by X-ray diffraction study. The title compound, C23H23N3O4S crystallizes in the monoclinic space group C2/c with cell parameters a = 13.1120(9) Å, b = 21.4990(9) Å, c = 16.655(1) Å, β = 111.352(2)°, Z = 8, and V = 4372.7(4) Å. The structure reveals that the piperazine ring is in a chair conformation. The geometry around the S atom is distorted tetrahedral. There is a large discrepancy in the bond angles around the piperazine N atoms. The structure is stablized by C–H···O type intermolecular hydrogen bonding interactions.  相似文献   

11.
The structures of tetrachloro-p-benzoquinone and tetrachloro-o-benzoquinone (p- and o-chloranil) have been investigated by gas electron diffraction. The ring distances are slightly larger and the carbonyl bonds slightly smaller than in the corresponding unsubstituted quinones. The molecules are planar to within experimental error, but small deviations from planarity such as those found for the para compound in the crystal are completely compatible with the data. Values for the geometrical parameters (ra distances and bond angles) and for some of the more important amplitudes (l) with parenthesized uncertainties of 2σ including estimated systematic error and correlation effects are as follows. Tetrachloro-p-benzoquinone: D2h symmetry (assumed); r(CO) = 1.216 Å(4), r(CC) = 1.353 Å(6), r(C-C) = 1.492 Å(3), r(C-Cl) = 1.701 Å(3), ∠C-C-C = 117.1° (7), ∠CC-C1 = 122.7° (2), l(CO)= 0.037 Å(5), l(CC) = l(C-C) - 0.008 Å(assumed) = 0.049 Å(7), and l(C-Cl) = 0.054 Å(3). Tetrachloro-o-benzoquinone: C2v symmetry (assumed); r(CO) = 1.205 Å(5), r(CC) = 1.354 Å(9), r(Ccl-Ccl) = 1.478 Å(28), r(Co-Ccl) = 1.483 Å(24), r(Co-Co) = 1.526 Å(2), r(C-Cl)= 1.705 Å(3), <Co-CO = 121.0° (22), ∠C-C-C = 117.2° (9), ∠Cco, ClC-Cl = 118.9° (22), ∠Cccl, ClC-Cl = 122.2°(12), l(CO) = 0.039 Å(5), and l(Ccl-Ccl) = l(Co-Ccl) = l( Co-Co) = l(CC) + 0.060 Å(equalities assumed) = 0.055 Å(9). Vibrational'shortenings (shrinkages) of a few of the long non-bond distances have also been measured.  相似文献   

12.
The title compound was obtained in crystalline form suitable for X-ray structure determination. It forms crystals in the monoclinic space group P21/c with two centrosymmetric molecules in a unit cell of dimensions, a = 10.888(1) Å, b = 10.182(2) Å, c = 17.929(4) Å, β = 104.33(1)°. The central Mo2Cl2(O2C)2P2 core has effectively C2h-symmetry with the following principal dimensions: MoMo = 2.091(1) Å, MoCl = 2.405 Å, MoP = 2.566(2) Å, MoO(av.) = 2.103[4] Å, MoMoP = 104.38(7)°, and MoMoCl = 116.23(8)°.  相似文献   

13.
The diiron ynamine complexes [Fe2(CO)7{μ-C(R)C(NEt2)}] (1) (R=Me, Ph, C3H5, SiMe3) react with theN-sulfinylaniline, PhNSO, in refluxing hexane to yield the complexes [Fe2(CO)6{μ-N(Ph)C(Me)S}] (2), [Fe2(CO)6{μ-N(Ph)C(NEt2)C(Ph)S}] · 0.5C6H12 (3), [Fe2(CO)6{μ-C(C3H5)C(NEt2)N(Ph)SO}] · 0.5CH2Cl2 (4), and [Fe2(CO)6{μ-C(SiMe3)C(NEt2)S)}] (5). Compound 5 was found to be identical to the previously reported product obtained from the reaction of 1 with sulfur. Compounds 2, 3, and 4 were characterized by single crystal X-ray diffraction analyses. Crystal data: for 2: space group = P21/n,a=9.533(1) Å,b=18.830(4) Å,c=12.705(4) Å, β=107.01(2)°,Z=4, 2687 reflections,R=0.027; for 3: space group=P21/n,a=13.660(2) Å,b=19.096(8) Å,c=10.972(2) Å, β=90.62(1)°,Z=4, 2821 reflections,R=0.036; for 4: space group=P21/a,a=18.098(5) Å,b=16.564(4) Å,c=18.548(2) Å, β=115.44(2)°,Z=4, 3569 reflections,R=0.041. Complexes 2 and 3 result from fragmentation of theN-sulfinylaniline ligand and insertion of the nitrene grouping into the Fe=C(aminocarbene) bond, whereas the sulfur atom inserts into one Fe-C bond of the bridging carbene. Compound 4 is formed by insertion of the entireN-sulfinyl aniline ligand into the Fe=C(aminocarbene) bond. All three complexes have basket-like arachno structure isolobal to the benzvalene one.  相似文献   

14.
The crystal and molecular structure of 2-methyl-4-(4-methoxyphenylazo)phenol have been determined by X-ray single crystal diffraction technique. The compound crystallizes in the monoclinic space group P21/c with a=9.7763(8) Å, b=11.3966(8) Å, c=11.9531(8) Å and β=108.752(6)°. In addition to the molecular geometry from X-ray experiment, its optimized molecular structure has been obtained with the aid of PM3 semiempirical quantum mechanical method, and then the corresponding geometric parameters were compared with those of X-ray crystallography. To determine conformational flexibility and crystal packing effects on the molecules, molecular energy profile of the title compound was obtained with respect to two selected degrees of torsional freedom, which were varied from ?180° to +180° in steps of 10°. Crystal structure of the title compound is a fibroid structure constructed by C–H···O and O–H···N type intermolecular hydrogen bonds. The most favorable conformer of the title compound has been determined by the crystal packing effects and there is no steric hindrance during rotation around the selected torsion angles.  相似文献   

15.
The molecular structure of fumaric acid was studied by means of gas electron diffraction at 260° C. The molecular parameters and their standard deviations obtained for a C2h model are (ra distances in Å, angles in degrees): CO: 1.202(0.002), C-O: 1.341(0.006), C-C: 1.486(0.004), CC: 1.356(0.016). C-C-O: 112.1(1.0), C-CO: 124.4(1.1), C-CC: 121.8(1.2). From the available data on carboxylic acids the weighted average deformation of the structure of a carboxylic group on crystallization was determined; a significant expansion of the O-H bond (0.040 Å ), the CO bond (0.010 Å ) and the C-C-O bond angle (1.5° ) and a shrinkage of the C-O bond (0.041 Å ), the Cα-C bond (0.012 Å ) and the C-CO bond angle (2.0° ) was found. The energy for these deformations was estimated to be 1.8 kcal mol?1.  相似文献   

16.
A new iron basic salt, Fe4(OH)11NO3·2H2O, has been prepared by partially hydrolyzing a solution of Fe(NO3)3·9H2O with urea. The X-ray powder diffraction pattern has been indexed within a monoclinic cella=9.99(3) ?,b=9.48(2) ?,c=3.074(3) ? andβ=90.57(1)°. Thermal decomposition reactions in still air and nitrogen flow have been studied by DTA and TG analysis, and the intermediate and final products have been characterized by X-ray diffraction and IR spectroscopy. When this material is thermally decomposed in an X-ray high temperature diffraction chamber, pure iron is formed at 900 °C together with Fe(III) and Fe(II) oxides.
Zusammenfassung Mittels Hydrolyse einer L?sung von Fe(NO)3)3·9H2O mit Karbamid wurde das neue basische Eisensalz Fe4(OH)11NO3·2H2O dargestellt. Aus einem R?ntgenpulververfahren resultierena=9,55(3) ?,b=9,48(2) ?,c=3,074(3) ? undβ=90,57(1)° für eine monozyklische Zelle. Mittels DTA- und TG-Untersuchungen wurden die thermischen Zersetzungsreaktionen an Luft und im Stickstoffflu? untersucht und die Zwischen- und Endprodukte mit r?ntgendiffraktionsverfahren und IR-Spectroskopie charakterisiert. Bei einer thermischen Zersetzung dieses Stoffes in einer Hochtemperatur-r?ntgendiffraktionskammer wird bei 900 °C elementares Eisen zusammen mit Fe(II)- und Fe(III)-oxiden gebildet.

Резюме Частичным гидролизо м раствора соли Fe(NO3)3 · 9H2O с мочевиной получен а новая основная соль Fe4(OH)11NO3 · 2Н2О, для которой методо м порошкового рентген оструктурного анализа была установ лена моноклинная стр уктура с параметрами ячейкиа=9,55(3) А,b=9,48(2) ?,c=3,074(3) ? иβ=90,57(1)°. Термиче ское разложение соли изучено методом ДТА и ТГ в динамическо й атмосфере воздуха и азота, а образующиеся промеж уточные и конечные продукты ре акции были охарактер изованы рентгенофазовым ана лизом и ИК спектроскопией. ˉПри термическом разложе нии соли в высокотемпературно й рентгено-диффракци онной камере при 900° образует ся чистое железо вмес те с оксидами двух- и трехвалентного желе за.


The authors are greateful to Dr. R. M. Rojas for his helpful suggestions.  相似文献   

17.
A series of [3]ferrocenophanes of general formula Fe(C5H4X)2YCl2 and the spiro compounds [Fe(C5H4X)2]2Ge (X = S, Se; Y = Ge, Sn) have been prepared by the reaction of ferrocene 1,1′-dithiol and ferrocene 1,1′-diselenol with tetrahalides of germanium and tin. Spectroscopic properties of the compounds are reported. In solution, the compounds are fluxional by a bridge reversal process. The crystal structure of 1,3-diselena-2,2-dichlorogermyl-[3]ferrocenophane at 163 K. has been determined by X-ray diffraction methods. At that temperature, crystals have space group P21/n with a 6.222(3), b 16.156(13), c 12.968(4) Å, β 97.53(1)° and Z = 4. Least-squares refinement gave R = 0.033 for 2834 unique significant reflections whose intensities were measured by counter diffractometry. The two SeGe bond lengths are 2.323 and 2.325(1) Å, with GeCl 2.148 and 2.161(1) Å. The SeGeSe bond angle is 118.2(1)°, ClGeCl 104.7(1)°, and SeGeCl angles range from 106.2 to 109.8(1)°. The SeC bond lengths are 1.901 and 1.904(5) Å, with CSeGe angles of 95.8 and 96.5(2)°. The cyclopentadienyl rings are in an eclipsed conformation with a mean twist angle of 2.7°, and are inclined to one another at 6.1°. The Se atoms are displaced from the ring planes by 0.17 and 0.20 Å yielding a non-bonded intramolecular Se…Se contact of 3.99 Å.  相似文献   

18.
2-Chloro-3-fluoro-1-propene has been studied by electron diffraction, and the molecule was found to exist in equilibrium between a syn and a gauche conformation, with the syn conformation as the most stable. The most important structure parameters with standard deviation are: rg(CC) = 1.338(6) Å,rg(C—C) = 1.505(5) Å, rg(C—F) = 1.378(4) Å, rg(C-Cl) = 1.743(3) Å, ∠CC—Cl = 123.0(7)°, ∠CC—C = 125.6(6)° and ∠C—C—F = 111.2(8)°.A force field was determined by a least-squares refinement to vibrational frequencies. Mean square amplitudes of vibration and perpendicular amplitude correction coefficients have been calculated. The mean square amplitudes of vibration from the electron diffraction data are in very good agreement with the values calculated from the spectroscopic data.  相似文献   

19.
The preparation and the chemical properties of the clathrate compound tetrakis[(benzonitrile)(triphenylphosphorane)nickel(0)] · 2 toluene · ~1 n-hexane · ~1 cycloocta-1,5-diene are described. The crystal and molecular structure of this compound were determined from X-ray diffractometer data. The structure was solved by direct and Fourier methods and refined by least-squares techniques to R = 0.117 for 3441 independent reflections. The crystals are monoclinic, space group P21, with Z = 2, in a unit cell of dimensions a 14.680(7), b 28.198(18), c 15.482(8) Å, β = 118.43(8)°. Eight (NiP(C6H5)3 · NCC6H5) formula units are present as two tetrameric molecules in the unit cell. Each Ni atom of the tetramer is linked by σ bonds to a P and N atom and by π bonds to the NC group of another benzonitrile molecule. The coordination of the nickel atoms is roughly trigonal. The nickel and N atoms form an eight-membered ring with a boat conformation. The NCC groups of the benzonitrile residues are bent and the NC distances indicate a high degree of double bond character for all these bonds. The triphenylphosphorane groups adopt a “propeller”-like conformation. Four solvent molecules 2 toluene, 1 n-hexane, and ~1 cycloocta-1,5-diene per asymmetric unit are present in the unit cell.  相似文献   

20.
The crystal structure of Ph3SnNCS has been determined by single crystal X-ray diffraction. The crystals are monoclinic, P21, a = 19.02(3), b = 11.67(2), c = 15.49(2)Å;, β = 95.64(10)°, Z = 8. The molecules are arranged in infinite zig-zag S…SnNCS…Sn&.sbnd; chains similar to those in Me3SnNCS, but with slightly longer SnN, shorter SnS bonds, and almost planar SnC3 units. Principal mean bond lengths and angles are: SnN, 2.22(5); NC, 1.17(8); CS, 1.58(7); SSn, 2.92(1); SnC, 2.09(3); CC, 1.38(2)Å; SnNCm 161(4); CSSn, 97(3); SSnN, 175(3) and CSnC, 119.8(1.5)°.  相似文献   

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