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1.
Structures of the following compounds have been obtained: N-(2-pyridyl)-N′-2-thiomethoxyphenylthiourea, PyTu2SMe, monoclinic, P21/c, a=11.905(3), b=4.7660(8), c=23,532(6) Å, β=95.993(8)°, V=1327.9(5) Å3 and Z=4; N-2-(3-picolyl)-N′-2-thiomethoxyphenyl-thiourea, 3PicTu2SeMe, monoclinic, C2/c, a=22.870(5), b=7.564(1), c=16.941(4) Å, β=98.300(6)°, V=2899.9(9) Å3 and Z=8; N-2-(4-picolyl)-N′-2-thiomethoxyphenylthiourea, 4PicTu2SMe, monoclinic P21/a, a=9.44(5), b=18.18(7), c=8.376(12) Å, β=91.62(5)°, V=1437(1) Å3 and Z=4; N-2-(5-picolyl)-N′-2-thiomethoxyphenylthiourea, 5PicTu2SMe, monoclinic, C2/c, a=21.807(2), b=7.5940(9), c=17.500(2) Å, β=93.267(6)°, V=2893.3(5) Å3 and Z=8; N-2-(6-picolyl)-N′-2-thiomethoxyphenylthiourea, 6PicTu2SMe, monoclinic, P21/c, a=8.499(4), b=7.819(2), c=22.291(8) Å, β=90.73(3)°, V=1481.2(9) Å3 and Z=4 and N-2-(4,6-lutidyl)-N′-2-thiomethoxyphenyl-thiourea, 4,6LutTu2SMe, monoclinic, P21/c, a=11.621(1), b=9.324(1), c=14.604(1) Å, β=96.378(4)°, V=1572.4(2) Å3 and Z=4. Comparisons with other N-2-pyridyl-N′-arylthioureas having substituents in the 2-position of the aryl ring are included.  相似文献   

2.
The molecular structure and conformational properties of O=C(N=S(O)F2)2 (carbonylbisimidosulfuryl fluoride) were determined by gas electron diffraction (GED) and quantumchemical calculations (HF/3-21G* and B3LYP/6-31G*). The analysis of the GED intensities resulted in a mixture of 76(12)% synsyn and 24(12)% synanti conformer (ΔH0=H0(synanti)−H0(synsyn)=1.11(32) kcal mol−1) which is in agreement with the interpretation of the IR spectra (68(5)% synsyn and 32(5)% synanti, ΔH0=0.87(11) kcal mol−1). syn and anti describe the orientation of the S=N bonds relative to the C=O bond. In both conformers the S=O bonds of the two N=S(O)F2 groups are trans to the C–N bonds. According to the theoretical calculations, structures with cis orientation of an S=O bond with respect to a C–N bond do not correspond to minima on the energy hyperface. The HF/3-21G* approximation predicts preference of the synanti structure (ΔE=−0.11 kcal mol−1) and the B3LYP/6-31G* method results in an energy difference (ΔE=1.85 kcal mol−1) which is slightly larger than the experimental values. The following geometric parameters for the O=C(N=S)2 skeleton were derived (ra values with 3σ uncertainties): C=O 1.193 (9) Å, C–N 1.365 (9) Å, S=N 1.466 (5) Å, O=C–N 125.1 (6)° and C–N=S 125.3 (10)°. The geometric parameters are reproduced satisfactorily by the HF/3-21G* approximation, except for the C–N=S angle which is too large by ca. 6°. The B3LYP method predicts all bonds to be too long by 0.02–0.05 Å and the C–N=S angle to be too small by ca. 4°.  相似文献   

3.
Nickel(II) chromate complex with imidazole (HIm) was isolated from the [Ni2+–HIm–CrO42−] system in various experimental conditions, i.e. reagent molar ratios and nickel(II) salts. The catena(μ-CrO4-O,O′)[Ni(HIm)3H2O] (1) crystallizes in monoclinic crystal system—space group P21/n with cell parameters: a=11.784(2), b=8.899(2), c=13.934(3) (Å), β=95.19(3) (°). The unit cell contains two independent helixes, left- and right-handed, stabilized by intrahelical and interhelical hydrogen bonds (HB) and π–π interactions. The cis coordination of the CrO42− anions and the HB systems appeared to be the main determinants of the helical architecture. To the best of our knowledge the cis-chromate coordination was observed for the first time. The cis coordination causes the distortion of the nickel octahedron, which was analysed by 4 K single crystal electronic spectra with D4h symmetry approximation (gaussian resolution and crystal field parameters). This symmetry was also confirmed with the polarised electronic spectra. The magnetic properties of the complex suggest the occurrence of weak intrachain antiferromagnetic interactions between the magnetic NiII center. The computational DFT studies of complex 1 assuming three possible isomers mer[(HIm)3]–cis[(CrO42−)2], mertrans and faccis suggested that the main contribution to the stability of 1 might have interhelical and intrahelical hydrogen bonds.  相似文献   

4.
A pulsed, tunable dye laser has been used to excite the 0---0 band of cis-glyoxal near 4875 Å, at pressures from 30 to 150 mtorr. Fluorescence was resolved through a spectrometer and lifetines measured. Rate constants for the quenching of the vibrationless levels of the first excited singlet states of cis- and trans-glyoxal by argon, cyclohexane and glyoxal are presented. Quenching rates of cis-glyoxal are generally two to three times faster than the corresponding trans rates. A zero-pressure extrapolated lifetime of 0.96 ± 0.02 μsec is obtained for cis-glyoxal.  相似文献   

5.
N-(p-anisoyl)pyrrolidin-2-one in the crystalline state exhibites a cisrans conrotatory conformation with N---CO and CO---Car rotational angles of 33.5° and 38.5° respectively, and the p-methoxy group situated cis to the central carbonyl bond, as shown by X-ray structure analysis. As suggested by dipole moment analysis and MMP2 molecular mechanics calculations, in solution similar conrotatory models hold for both c- and t-subconformers having the p-methoxy group cis or trans to the central carbonyl bond. INDO calculations were also carried out, indicating that both subconformers are equally stable.  相似文献   

6.
N-2-(4-picolyl)-N′-2-chlorophenylthiourea, 4PicTu2Cl, monoclinic, P21/c, a=10.068(5), b=11.715(2), β=96.88(4)°, and Z=4; N-2-(6-picolyl)-N′-2-chlorophenylthiourea, 6PicTu2Cl, triclinic, P-1, a=7.4250(8), b=7.5690(16), c=12.664(3) Å, =105.706(17), β=103.181(13), γ=90.063(13)°, V=665.6(2) Å3 and Z=2 and N-2-(6-picolyl)-N′-2-bromophenylthiourea, 6PicTu2Br, triclinic, P-1, a=7.512(4), b=7.535(6), c=12.575(4) Å, a=103.14(3), β=105.67(3), γ=90.28(4)°, V=665.7(2) Å3 and Z=2. The intramolecular hydrogen bonding between N′H and the pyridine nitrogen and intermolecular hydrogen bonding involving the thione sulfur and the NH hydrogen, as well as the planarity of the molecules, are affected by the position of the methyl substituent on the pyridine ring. The enthalpies of fusion and melting points of these thioureas are also affected. 1H NMR studies in CDCl3 show the NH′ hydrogen resonance considerably downfield from other resonances in their spectra.  相似文献   

7.
X-Ray diffraction, IR and 1H NMR studies were performed on the 1:1 adduct of 1,8-bis(dimethylamino)naphthalene (DMAN) with 1,8-dihydroxy-2,4-dinitronaphthalene (DHDNN). The adduct crystallizes in the triclinic system, space group , a = 9.911(2) Å, b = 11.212(2) Å, c = 11.194(2) Å, = 68.95(2)°, β = 79.72(2)°, γ = 73.78(2)°, Z = 2. Both [NHN]+ and [OHO] hydrogen bonds formed in the ion pairs are asymmetrical with lengths equal to 2.574(2) Å and 2.466(4) Å respectively. The [NHN]+ bridge shows a typical behaviour in the IR spectrum, i.e. a low-frequency absorption between 300 and 700 cm−1. The coupling of [OHO] hydrogen bonds with the naphthalene π-electron system is so strong that no absorption related to the proton stretching vibrations can be detected in the high- and low-frequency regions. The 1H NMR chemical shifts for the [NHN]+ and [OHO] bridge protons of 18.63 and 15.81 ppm respectively confirm the strong hydrogen bonds.  相似文献   

8.
Crystallization fields for the formation of V-MFI were determined from gels of composition: xNa2O–yVO2–7NaF–ySO3zSiO2–2TPABr–260H2O at 190 °C with 3.6≤x≤14.4 and 2.1≤y≤7.1 for z=12.0 and with 0.3≤y≤4.2 and 4.0≤z≤12.0 for x=3.6; TPA=tetrapropylammonium ions. The crystallization curves were analysed together with the various intermediate phases using XRD, pH of mother liquors, thermal analysis and SEM. The final samples were analysed, in addition, by multinuclear NMR. It is concluded, that V can be introduced into the MFI framework as V(IV) ions, accompanied by the presence of two SiOH defect groups per V atom introduced. The 51V-NMR signal due to V(V) can only be detected when additional vanadium-containing siliceous phases are formed.  相似文献   

9.
Treatment of [Pd{CH2C(CH3)CH2}(Ph2PPy)Cl] (Ph2PPy = 2-(diphenylphosphino)pyridine) with cis-[Pd(tBuNC)2Cl2] in dichloromethane affords the mixed isocyanide-tertiary phosphine complex cis-[Pd(tBuNC)Ph2PPy)Cl2], in which the Ph2PPy is a monodentate P-donor, and [{Pd[CH2C(CH3)CH2]Cl}2]. The steric effects of the Ph2PPy bridging ligand in determining the reaction course is discussed. The complex cis-[Pd(tBuNC)(Ph2PPy)Cl2] was crystallographically characterized: P21/n, a = 15.143(2), b = 9.527(1), c = 17.517(4) Å, β = 113.96(1)°, V= 2309.4(7) Å3, Z = 4. The final R value was 0.044, Rw= 0.046 for the 3078 reflections with I > 3σ(I).  相似文献   

10.
Using gas-phase electron diffraction it has been demonstrated that a composition of known isomer mixtures can be determined with error limits of about 5%, all relevant structural parameters being refined simultaneously by the least-squares method. If, however, corresponding bond distances and valence angles have erroneously been assigned equal values in the two isomers, a large increase in the least-squares error limits from 5% to 12% is noticed. Apparently innocent assumptions about some of the parameters can lead to incorrect isomer composition and to too small error limits as estimated by the least-squares formulae.

From the reinvestigation of pure cis-1,2-dichloroethene the following bond distances (ra) and valence angles () were determined: r(C---H) = 1.090(29) Å, r(C=C) = 1.345(6) Å, r(C---Cl) = 1.716(4) Å, C=C---Cl = 123.8(2)°, C=C---H = 119.4(26)°. Error limits are 2σ.  相似文献   


11.
The geometric structure of c-C4F8SF4 has been determined by gas-phase electron diffraction. The five-membered ring has the twist form (C2 symmetry) with a puckering amplitude q = 0.42 (2) Å. The following principle geometric parameters (ra values) with estimated uncertainties have been derived: (C---C)av = 1.541(10), S---C = 1.896(7), S---Fe = 1.558(6), S---Fa = 1.594(6) Å, CSC = 90.0(9)°, SCC = 109.1(8)°, CCC = 106.5(12)°, FaSFe = 90.5(15)° and FeSFe = 87.7(29)°. Vibrational amplitudes for long non-bonded CF and FF distances indicate a high barrier to pseudorotation of the ring.  相似文献   

12.
Bis[bis{(diphenylphosphinyl)methyl}ethyl phoshinate]bis(ethanol) metal(II) perchlorate complexes, where METAL = Co, Ni or Cu, have been prepared by the reaction of metal perchlorates and bis[(diphenylphosphinyl)methyl]ethyl phosphinate, (RPOEt), in absolute ethanol. The crystal structure of the copper complex is triclinic, space group P , a = 13.688(7) Å, b = 14.424(10) Å, c = 9.865(2) Å, = 110.43(4)°, β = 90.13(2)°, γ = 115.54(4)°, V = 1619.8 Å3, Z = 1 and refined to R = 0.048 (Rw = 0.057). The structure consists of complex cations surrounded by perchlorate anions. Two RPOEt ligands and two ethanols are coordinated to the copper atom situated at the centre of symmetry 0, 0, 0. The RPOEt ligand is bidentate [Cu---O distances 1.969(4) Å, 2.312(4) Å], but the third oxygen atom from phosphoryl bonds is hydrogen bonded [2.669(6) Å], to the oxygen atom of ethanol molecule coordinated to the copper at 1.988(4) Å. The conformations of the ligand and chelate rings, magnetic data, molar conductance values, infrared and electronic spectra are given.  相似文献   

13.
The thermodynamic functions, Cp, S√,—FoH√)/T and (H√—Ho)/T have been calculated in the ideal gas state at one atmosphere for the following halogenated propenes: cis-1-chloropropene; trans-1-chloropropene; cis-1-bromopropene; trans-1-bromopropene; 2-fluoropropene; 2-chloropropene; 2-bromopropene; 2-iodopropene; cis-3-fluoropropene; gauche-3-fluoropropene; isomeric-3-fluoropropene; mixture; cis-3-chloropropene; gauche-3-chloropropene; isomeric-2-chloropropene mixture; cis-3-bromopropene; gauche-3-bromopropene; isomeric-3-bromopropene; mixture; cis-3-iodopropene; gauche-3-iodopropene and isomeric-3-iodopropene mixture. The agreement with other results, whenever available, is very good.  相似文献   

14.
Pt(II) and Pd(II) dichloride complexes with 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp) have been synthesized and characterized by infrared and 1H, 13C NMR, 13C CPMAS spectroscopy. The structures of the cis-PtCl2(dbtp)2 · EtOH (1) and cis-PdCl2(dbtp)(dmso) (2) has been determined by signal-crystal X-ray diffraction. In both complexes the X-ray crystal structures shows that heterocycle ligand (dbtp) binds the central atom monodentate via nitrogen atom N(3). In addition, compound (2) is interesting for its structural features, because it is the first report of mixed dichloride Pd(II) complexes with N-donor (triazolopyrimidine) and S-donor (dimethylsulfoxide) ligands. In this structure the Pd–Cl distances are: 2.302(1) and 2.281(1) Å, Pd–N 2.041(3) Å and Pd–S 2.245(1) Å. The 1H, 13C NMR studies show clearly that these structures are retained in solution.  相似文献   

15.
The adducts of O2 and SO2 with trans-MeOIr(CO)(PPh3)2 are formed in equilibria and have been characterized. Reaction of the SO2 adduct, Ir(OMe)(SO2)(CO)(PPh3)2 with dioxygen leads to the sulfato complex, Ir(Ome)(CO)(PPh3)2(SO4), the structure of which has been determined. Ir(Ome)(CO)(PPh3)2(SO4) crystallizes in the monoclinic system with a 11.958(2), b 14.163(3), c 12.231(2) Å, β 118.365(12)°, V 1822.7(6) Å3 and Z = 2. Diffraction data for 2θ = 4.5–45.0° (Mo-K) were collected with a Syntex P21 diffractometer and the structure was solved (assuming space group P21/m and an unpleasant 2-fold disordered model) and refined to R = 4.8% for all 2512 independent data (R = 3.5% for those 2042 data with ¦FO¦ > 6σ(¦F¦)). The iridium(III) atom has a distorted octahedral coordination sphere with trans PPh3 ligands and a cis-chelating bidentate O,O′-SO4 group; the structure is completed by mutually cis OMe and CO ligands.  相似文献   

16.
We have recently described the electrochemical oxidation of 5,11,17,23-tetra-tert-butyl-25, 26-bis(diphenylphosphinoylmethoxy)-27,28-dihydroxycalix[4]arene into the corresponding diquinone 1. The solid state structure of 1 has now been determined by a single crystal X-ray diffraction study. Diquinone 1 crystallizes in the monoclinic space group with a=10.3507(12), b=25.219(4), c=20.2315(14) Å, β=101.166(8)°, V=5181.1(10) Å3, Z=4, and Dx=1.273 g cm−3. The calixarene skeleton adopts a partial cone conformation in which one quinone ring is anti-oriented with respect to the other three rings of the calixarene core. A variable temperature NMR study shows that 1 is dynamic in solution, each quinone unit undergoing fast oscillation about the axis that passes through the two meta carbon atoms bonded to the adjacent methylene groups. The motion of the quinone rings was confirmed by 2D NMR experiments.  相似文献   

17.
Dichlorotetramethyldisiloxane is studied by gas-phase electron diffraction at room temperature. The least-squares values of the bond distances (rg) and bond angles () are: r(C---H)=1.084(5) Å, r(Si---O) = 1.624(2) Å, r(Si---C) = 1.852(2) Å, r(Si---Cl) = 2.067(2) Å, SiOSi = 154.0° (1.5), ClSiO = 110.2° (0.8), ClSiC = 109.6°(0.7), HCSi = 111.7°(1.5), OSiC = 110.0°(0.8), τ1 (zero corresponds to the Si---Cl bond trans to the Si---O---Si linkage) = 78°(6) and τ2 = 141°(19). A two-conformer model cannot be ruled out.  相似文献   

18.
The reaction of Ru(CO)4(C2H4) or Ru(CO)5 with 1,5-Ph4P2N4S2 in CH2Cl2/hexane at 23°C produces the dimer [Ru(CO)2(Ph4 P2N4S2)]2 (2), which was shown by X-ray crystallography to have a centrosymmetric structure in which the P2N4S2 ring is attached to one ruthenium atom through two (geminal) nitrogen atoms and the remote sulfur atom and serves as a bridge to the other ruthenium atom via the second sulfur atom. Crystals of 2 ·2(CH2Cl2) are triclinic, space group P (No. 2), a = 12.901(1) Å, b = 13.072(1) Å, c = 10.123(1) Å, = 100.88(1)°, β = 98.90(1)°, γ = 67.50(1)°, V = 1542.4(3) Å, Z = 1 with final R and Rw values of 0.040 and 0.027, respectively.  相似文献   

19.
The molecular structure of gaseous epichlorohydrin has been investigated using electron diffraction data obtained at 67°C. The conformational composition at this temperature is such that the molecules exist predominantly in a gauche-2 conformer (where the C---Cl bond is 160° away from the C---O) bond). Refinements showed that 33% (σ = 4) of the molecule exist in the gauche-1 form. The important distances (rg) and angle () with the associated uncertainties are r(C---H) = 1.095(5) Å, r(C---O) = 1.442(3) Å, r(C---C) = 1.475(8) Å, r(C---CM) = 1.523(7) Å, r(C---Cl) = 1.788(2) Å, CCO = 114° (1), CCCM = 119°(1), ClCC = 108.9° (7), and Tau(ClCCO) = −150°(10) (gauche-2) and Tau(ClCCO) = 78° (10) (gauche-1).  相似文献   

20.
The pentaamminecobalt(III) complex with the 3-cyano-2,4-pentanedionate anion coordinated through the nitrile nitrogen has been characterized by X-ray crystallography. The crystals of [(NH3)5CoNCacac](Cl)(ClO4)·2H2O are triclinic, space group P , a = 10.245(2) Å, b = 14.071(4) Å, c = 6.971(2) Å, = 90.03(3)°, β = 109.86(2)°, γ = 108.91(2)°, V= 887.1 Å3, Z = 2, Dc = 1.64 g cm−3, F(000) = 456, Mo-K radiation, λ = 0.71069 Å, μ(Mo-K) = 12.7 cm−1. The structure was determined by the heavy-atom method, and refined by block-diagonal least-squares calculations, R = 0.0537, Rw = 0.0607, for 2499 observed reflections. Principal dimensions are: Co---N(NH3) trans to NCacac 1.940(5), other Co---N(NH3) 1.967(2), Co---N(NCacac) 1.911(5) Å. The pendant acac moiety is best described in terms of a delocalized bond network with, for example, C---C distances in the range 1.44–1.52(1) Å. Several reactions involving this free acac group are also described including the preparation and characterization of the dimeric species pentaamminecobalt(III) - μ - (3 - cyano - 2,4 - pentanedionato) - bis(propylenediamine) cobalt(III) perchlorate.  相似文献   

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