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1.
The structure of cyclopentadienyl(duroquinone)cobalt dihydrate, (C 5H 5)Co-[(CH 3) 4C 6O 2]·2H 2O, has been determined by three-dimensional X-ray analysis. The crystal structure consists of discrete cyclopentadienyl(duroquinone)cobalt molecules linked together by a complex network of hydrogen bonds between water molecules and duroquinone oxygen atoms. Each (C 5H 5)Co[(CH 3) 4C 6O 2] molecule consists of a cobalt atom sandwiched between a cyclopentadienyl ring and a duroquinone ring. A detailed comparison of the molecular parameters of this complex with those of closely related complexes is given. Crystallographic evidence that the metal---duroquinone interaction in cyclopentadienyl(duroquinone)cobalt dihydrate is considerably stronger than that in the electronically-equivalent 1,5-cyclooctadiene(duroquinone)nickel complex is given not only by the metal---C(olefin) distances being 0.12 Å (av) shorter in the duroquinone---cobalt complex [ viz., 2.104(8) Å vs. 2.222(7) Å] but also by the much greater C2v-type distortion of the duroquinone ring from the planar D2h configuration in free duroquinone. The compound crystallizes with two formula species in a triclinic unit cell of symmetry P
and reduced cell dimensions á = 8.60 Å, b = 9.00 Å, c = 10.15 Å, = 87° 34′, β = 84° 10′, γ = 73° 44′. Least-squares refinement yielded final unweighted and weighted discrepancy factors of R1 = 10.8% and R2 = 12.0%, respectively, for 2481 independent diffraction maxima collected photographically. 相似文献
2.
The complex Fe(η 6-C 5H 5CMe 3) 2 crystallizes in the centrosymmetric triclinic space group P
( Ci1; No. 2) with unit cell dimensions of a 8.770(1) Å, b 8.878(1) Å, c 11.991(1) Å, 107.56(1)°, β 90.85(1)°, γ 90.13(1)°, V 890.0(2) Å 3 and Z = 2. A full sphere of data was collected on a four-circle diffractometer. The structure was solved and refined to R 7.93% for all 3155 independent reflections and R 4.98% for those 2002 data with | F0 | > 6σ. | F0 |. The molecules lie on crystallographic inversion centers at 0, 0, 0 and 1/2, 0, 1/2; the crystallographic asymmetric unit therefore consists of two independent half molecules. The molecule centered at 0, 0, 0 (molecule “A”) is ordered and well-defined; that centered on 1/2, 0, 1/2 (molecule “B”)is probably disordered, as indicated by larger “thermal parameters” and a greater range of apparent interatomic distances. Discussion em phasizes the geometry of molecule A, which has precise Ci symmetry with Fe(1A)-B(1A) 2.297(4) Å and Fe(1A)-C(ring) distances ranging from 2.057(6) Å to 2.138(4) Å. 相似文献
3.
The structures to two 1,3-thiazine derivatives differing only in the number of CH 2 groups in their trans fused hydrocarbon ring ( n = 3 for I and n = 4 for II) have been established by X-ray crystallography from diffractometer data. Crystals of I ( trans-5,6- trimethylene-5,6-dihydro-2-phenyl-[4 H] - 1,3-thiazine) are triclinic, space group P
with a = 7.661(1), b = 8.282(1), c = 9.566(2) Å, = 91.75(1), β = 100.72(1), γ = 105.45(1)° Z = 2, Dc = 1.260 g cm -3. Crystals of II ( trans-5,6-tetramethylene-5,6-dihydro-2-phenyl [4 H]-1,3-thiazine) are monoclinic, space group P2 1/ c with a = 7.914(2), b = 19.362(13), c = 8.440(1) Å, β = 109.16(2)°C Z = 4, Dc = 1.258 g cm -3. The structures determined by Patterson (I) and direct (II) methods were refined to R = 0.050 for 1330 reflections of I and R = 0.082 for 1012 reflections of II. The proper treatment of the positional disorder of the carbon atoms (C(5) and C(6)) forming the trans ring junction in I discovered two discrete conformations with a ratio of 1:2. The opposite chirality of atoms C(51) and C(52), and C(61) and C(62), indicates a simultaneous configurational disorder with a pattern of total disorder: A
A
. The puckering parameters of the hetero rings in the same enantiomers of molecules IA, IB and II indicate a connection between the conformers: 5E(II)→ 5H6(IB)→ E6IA) via pseudorotation. Their relationship is discussed and compared with the conformational freedom of the analogous 1,3-oxazine derivatives. 相似文献
4.
The Hg(II) complex [Hg(TFP) 2(OTFP) 3][ClO 4] 2 with TFP=tri-2-furyl-phosphine and OTFP=tri-2-furylphosphinoxide has been prepared and characterised. It crystallises in the hexagonal P6 3/ m space group with Z=2, a=13.308(3), c=21.092 (4) Å, V=3235(1) Å 3. The structure of the complex cation consists of independent molecules with Hg pentacoordinated in exact trigonal bipyramidal geometry. 相似文献
5.
meso-Tetraphenylporphyrinatothallium(III) cyanide, Tl(tpp)(CN), was previously assumed to be monomeric and has been confirmed by X-ray analysis to exist as two independent molecules in one asymmetric unit. This unit displays two square-pyramidal coordination geometries for the thallium atoms with the cyano ligand coordinated to both Tl atoms. It crystallizes in the triclinic space group P
, with a 10.003(3), b 16.231(7), c 21.277(8) Å, 89.98(3), β 90.57(3), γ 90.31(3)°' and z = 4. The structure was solved by direct methods. A total of 7995 unique reflections having I > 3σ( I) was measured with an automated diffractometer and used to refine the crystal structure to a conventional R factor of 6.05 %. The thallium-cyanide distances are 2.140(14) Å (for thallium(I)) and 2.277(14) Å (for thallium(2)) respectively, with thallium(1) situated 0.908 Å above the porphyrin ring and thallium(2) located 1.027 Å below the ring. IR and NMR spectroscopy p rovide complementary methods for investigation of the CN ligand. The characteristic band observed at 2160 cm −1 in the FTIR spectrum is assigned to the CN stretching in the Tl(tpp)(CN) complex. The 13C resonance of axial cyano ligand is observed with a pulse delay of 3.5 s at 24°C at 139.2 ppm (with 1J( 205Tl- 13C) 5394 and 1J( 203Tl- 13C) 5344 Hz). This observation disagrees with the conclusion, drawn from previous work, in that an exchange process involving the apical ligand explains the invisibility due to line broadening at 35°C of the 13C signal. 相似文献
6.
In the system PbF 2/AsF 5/anhydrous hydrogen fluoride (aHF) two new lead(II) hexafluoroarsenates(V) Pb(HF)(AsF 6) 2 and PbFAsF 6 were isolated. Pb(HF)(AsF 6) 2 is formed when the molar ratio AsF 5:PbF 2 is 2 or higher. It crystallizes in the space group Pbcn with a=1058.3(3) pm, b=1520.9(6) pm, c=1079.4(3) pm, V=1.7374(10) nm 3 and Z=8. The HF molecule is directly connected to the Pb center, eight fluorine atoms from three different AsF 6− ions (Pb–F distances ranging from 248(4) to 276(2) pm) and one further fluorine at 306(3) pm complete the coordination sphere. PbFAsF 6 is obtained when equimolar amounts of PbF 2 and AsF 5 react in aHF. PbFAsF 6 crystallizes in the space group P
with: a=466.10(10) pm, b=723.70(10) pm, c=747.40(10) pm, =105.930(10)°, β=101.49(2)°, γ=90.660(10)°, V=0.23698(7) nm 3 and Z=2. The basic unit in the structure of PbF(AsF 6) consists of a four-membered ring of two Pb and two F atoms. The Pb atoms in the ring are further connected by two AsF 6− units via cis-fluorine bridges, thus forming a [PbF(AsF 6)] 2 cluster, which interacts by additional Pb–F bonds thus forming a ribbon-like polymer. 相似文献
7.
The crystal structure of the title compound, C 20H 34O 2, has been determined by single crystal X-ray diffraction methods at 295 K from diffractometer data using direct methods and refined by least squares to a residual of 0.06 for 2152 “observed” reflections. Crystals are orthorhombic, P2 12 12 1, a = 32.770(8), b = 10.960(3), c = 10.850(3) Å, Z=8. The asymmetric unit comprises two independent molecules, both of which confirm the structure proposed in the preceding paper. 相似文献
8.
The X-ray crystal structure and absolute configuration of (−) 436-(η 5-C 5H 5)Fe(CO)(CH 3CO)[Ph 2PNHCH(Me)(Ph)] have been determined from single crystal diffraction data. The compound crystallizes in the monoclinic space group P2 1 with two molecules in a unit cell of dimensions a = 10.676(4), b = 8.913(7), c = 13.275(9) Å, and β = 91.36°. The structure was solved by the Patterson method and refined to a final R value of 4.7% using 2299 independent data. The iron atom has distorted octahedral coordination, and the configuration at the iron is found to be ( S) for the (−) 436 diastereoisomer. The Fe---Cp distances average 2.131 Å, with an Fe-(ring centroid)distance of 1.76 Å. The Fe-acetyl distance is virtually identical to that found in another iron/acetyl complex, but shows substantial variation from other compounds where the nature of the C(=O)R group is changed. Comparison to the Mo-alkyl/Mo-acetyl series is made, and the argument for back-donation in transition metal acyls is strengthened. The orientation of the acetyl group is determined by a strong NHO intra-molecular hydrogen bond having an NO separation of only 2.86 ». The phosphine ligand has a very short Fe---P bond which could be in part caused by the role of the adjacent nitrogen in hydrogen bonding. The remaining ligand geometry is the same as that found in a recently reported ruthenium structure, although the absolute configurations at the chiral carbons are reversed, with the current compound being designated (S) at this site. 相似文献
9.
N-(ω-carboxyalkyl)morpholine hydrochlorides, OC 4H 8N(CH 2) nCOOH·HCl, n=1–5, were obtained and analyzed by 13C cross polarization (CP) magic angle spinning (MAS) NMR, FTIR and PM3 calculations. The structure of N-(3-carboxypropyl)morpholine hydrochloride ( n=3) has been solved by X-ray diffraction method at 100 K and refined to the R=0.031. The crystals are monoclinic, space group P2 1/ c, a=14.307(3), b=9.879(2), c=7.166(1) Å, β=93.20(3)°, V=1011.3(3) Å 3, Z=4. In this compound the nitrogen atom is protonated and two molecules form a centrosymmetric dimer, connected by two N +–HCl − (3.095(1) Å) and two O–HCl − (3.003(1) Å) hydrogen bonds. 13C CP MAS NMR spectra, contrary to the solution, showed non-equivalence of the ring carbon atoms. The PM3 calculations predict a molecular dimer without proton transfer for an HCl complex, while for an HBr complex an ion pairs with proton transfer, and reproduces correctly the conformation of both dimers but overestimates H-bond distances. Shielding constants calculated from the PM3 geometry of ion pairs gave a linear correlation with the 13C chemical shifts in solids. 相似文献
10.
The reactions of 2- trans-6-N 4P 4(NHPr n) 2Cl 6 (2), which was obtained from N 4P 4Cl 8 (1) and n-propylamine, with pyrrolidine and t-butylamine in different solvents have been studied. Compound (2) gave two different products, namely monocyclic (3 and 5) and bicyclic (4 and 6) phosphazenes. Compounds (2–6) have been characterized by elemental analysis, IR, 1H-, 13C-, 31P NMR, HETCOR and MS and the structure of compound (5) has been examined crystallographically. The bicyclic phosphazene (6) is the first exciting example of bicyclic phosphazenes containing chlorine atoms, in the literature. The formation mechanisms of bicyclic phosphazenes are re-considered by taking into account the synthesis of compound (6), which contains three stereogenic phosphorus atoms. Compound (5) crystallizes in the monocyclic space group P2 1/ n with a=13.974(2), b=17.836(5), and c=18.683(4) Å, β=98.50(1)°, V=4605.4(2) Å 3, Z=4 and Dx=1.051 g cm −3. It consists of a non-centrosymmetric, non-planar phosphazene ring in a saddle conformation, with two n-propylamino (in 2- trans-6 positions) and six bulky t-butylamino side groups. The bulky substituents are instrumental in determining the molecular geometry. 相似文献
11.
The crystal structure of dicesium trans-tetraaquadichlorochromium(III) chloride Cs 2Cr IIICl 5·4H 2O with trans-[M IIIX 2(H 2O) 4] + complex ions (space group C2/c, Z=4, a=1915.3(4) pm, b=614.1(1) pm, c=1392.0(3) pm, and β=118.24(3)°, final R1=0.0246 for 2100 unique reflections) was redetermined by single-crystal X-ray diffraction studies. It was found to crystallize in a 2c super structure of the structure reported previously (Inorg. Chem. 20 (1981) 1566; Inorg. Chem. 36 (1997) 2248). The obtained structure data now agree with the results of infrared spectroscopic studies, which has been confirmed in this work, namely that there are two different hydrate H 2O molecules in the structure. Phase transitions, static or dynamic disorder of the hydrate H 2O molecules, and space group C2/m proposed in the literature were ruled out. The coordinates of the four hydrogen positions derived from the X-ray data have been improved via the O–H distances derived from the wave numbers of the OD stretching modes of matrix isolated HDO molecules (2426, 2323, and 2306 cm −1, 263 K) by using the νOD versus rO–H correlation curve reported in the literature (J. Mol. Struct. 404 (1997) 63). The νOD versus rHCl correlation curve reported by Mikenda (J. Mol. Struct. 147 (1986) 1) should be improved, especially for strong hydrogen bonds. The two hydrate H 2O molecules of the title compound are strongly distorted with a weak and a relatively strong O–HCl hydrogen bond each thus intramolecular coupling of the two OH stretching vibrations to coupled ones is largely reduced and, hence, the wavenumbers of the OH and OD stretching modes of the HDO molecules mainly resemble those of the H 2O and D 2O molecules. The strength of the hydrogen bonds is in accordance with the predictions of the competitive and synergetic effects. Chloro ligands are weaker hydrogen bond acceptor groups than chloride ions. 相似文献
12.
The reaction of N-benzoylphosphoramidic dichloride with piperidine and 4-methylpiperidine lead to PhC(O)N(H)P(O)R 2 with R=piperidine (1) and R=4-methylpiperidine (2) as N-benzoyl- N′, N″-bis(piperidine) phosphoric triamide and N-benzoyl- N′, N″-bis(4-methylpiperidine) phosphoric triamide, respectively. The products have been characterized by 1H, 13C, 31P NMR spectra, and by elemental analysis. The crystalline solid for (1) and (2) consists surprisingly of four and two independent molecules, respectively. There is a disorder in one amine group due to ring inversion in each conformer in compound 1. In the solid state, comparable magnitudes for the stabilization of the stable conformers for the more or less discrete molecules, the polarization effects, hydrogen bonding and the packing effects could be anticipated. The geometry of compound (1) optimized by density functional calculations at the B3LYP/6-31++G* (d,p) level, is in good agreement with data obtained from X-ray crystallography. 相似文献
13.
A new tellurium-containing heterocyclic compound, 2,2,6,6-tetramethyl-1-oxa-4-tellura-2,6-disilacyclohexane (C 6H 16OSi 2Te) (1), has been prepared by treatment of 1,3-bis(chloromethyl)-1,1,3,3-tetramethyldisiloxane with sodium telluride. Mononuclear and dinuclear palladium complexes of this telluride have been prepared by the reaction of 1 with PdCl 2(PhCN) 2 and Na 2PdCl 4, respectively. The following new derivatives of 1 have also been produced: C 6H 16OSi 2TeI 2 (2), C 6H 16OSi 2TeBr 2, C 6H 16OSi 2TeCl 2, C 6H 16OSi 2Te(CH 3)I, and C 6H 16OSi 2Te(CH 2Ph)Br. IR, 1H and 13C NMR and mass spectral data of these new compounds are reported and discussed. 1H NMR studies revealed that in CDCl 3 solution both telluronium salts reductively eliminate alkyl halide. The crystal structure of compound 2 has been determined by X-ray diffraction. The compound crystallizes in the monoclinic space group, P2 1/ c, with four molecules in a unit cell of dimension a 12.960(3), b 8.846(2), c 13.754(4) Å, β 92.44(2)°, R = 0.049, and Rw = 0.067 for 3599 unique reflections with | F0| > 3σ( F0). The compound forms a six-membered ring of a slightly displaced boat type. The geometry about the Te atom is pseudo-octahedral, with two carbon atoms (Te-C = 2.156(7) and 2.137(6) Å) and two iodine atoms of the neighbouring molecules (weak intermolecular bonds, Te · I = 3.769 and 3.806 Å) in the equatorial positions and two iodine atoms (Te-I = 2.909(1) and 2.913(1) Å) in the axial positions. 相似文献
14.
The crystal structure of NdCl 3·C 6H 12O 6·9H 2O has been determined. It crystallizes in the monoclinic system, p2(1)/ n space group with cell dimensions: a=15.824(3) Å, b=8.633(2) Å, c=16.219(3) Å, β=107.24°, V=2116.1(7) Å 3 and Z=4. Each Nd ion is coordinated to nine oxygen atoms, two from inositol and seven from water molecules, with an Nd–O distance of 2.449–2.683 Å, the other two water molecules are hydrogen bonded. No direct contacts exist between Nd and Cl. There is an extensive network of hydrogen bonds in hydroxyl groups, water molecules and chloride ions in the crystal structure of the lanthanide complex. The Raman spectra of Pr–, Nd– and Sm–inositol are similar, which show that the three metal ions have the same coordination mode. The Raman spectra are consistent with their structures. 相似文献
15.
1-Aza-5-stanna-5-chlorotricyclo[3.3.3.0]undecane crystallizes in the space group P6 3. The unit cell, with a 8.435(3), c 9.243(2) Å, V 569.5(3) Å 3, contains two molecules. The structure was refined to a final R value of 0.057. The molecules CISn(CH 2CH 2CH 2) 3N belong to the point group 3, and the Sn, Cl and N atoms lie on the crystallographic 3-axis. The tin atom has a trigonal bipyramidal environment with the nitrogen and chlorine atoms in apical positions. The tin-nitrogen intramolecular interaction is 2.372(29) Å. 相似文献
16.
The crystal structure of bis(betaine)-selenic acid has been determined by X-ray diffraction as orthorhombic, space group Pbca, with a = 11.591(2), b = 22.930(5), c = 12.045(2) Å and Z = 8. The crystal comprises hydrogen selenate ions, HSeO −4, and two distinct betaine molecules, which are held together into a complex by short hydrogen bonds. One of the betaine molecules is present as the zwitterion form (CH 3) 3N +---CH 2---COO − and the second occurs as the protonated form (CH 3) 3N +---CH 2---COOH. Powder FTIR and Raman spectra were measured. An assignment of the observed bands to vibrations of the hydrogen bonds and internal vibrations of the hydrogen selenate ion and the betaine molecules is proposed. 相似文献
17.
A series of E-2-benzylideneindanones (a) -tetralones (b) and -benzosuberones (c) with OCH 3 (2–4), NO 2 (5–7) and F (8–10) substituents in ortho, meta or para position was studied by IR and mass spectrometry. The most important IR bands were assigned and stated correlations between some frequencies and the stereostructure or conjugation feature of the molecules investigated. IR spectra were also analyzed in order to find frequencies characteristic of the size of the alkanone ring. The mass spectrometric investigation aimed at determining fragmentation pathways and finding correlations between them and the ring size of the alkanone ring or the position of the substituents. 相似文献
18.
The solid state structure of the triphenylphosphine oxide (TPPO) adduct of tri-3-thienyltin bromide has been investigated by both single crystal X-ray analysis and Mössbauer spectroscopy. The crystal structure consists of discrete molecules and there is no evidence of any intermolecular tin-sulphur interactions. Each tin atom is found to be in a five-coordinate trigonal bipyramidal environment in which the three thienyl groups occupy equatorial positions. The metal atom is displaced by 0.182 Å out of the equatorial plane and towards the axial bromine. Two of the thienyl ligands exhibit rotational disorder and the lack of disorder in the remaining heteroaryl ligand is attributed to the close proximity of this group to a phenyl ligand. The Mössbauer parameters are also in accord with five-coordination for tin and are indicative of the aryl groups being equatorial. 相似文献
19.
A gas electron diffraction study of cyclobutylsilane results in a mixture of equatorial and axial conformers, with the equatorial confomer slightly more stable (Δ G = 0.8 ± 0.4 kJ mol −1). The cyclobutyl ring is distorted with the adjacent bonds longer (C 1---C 2 = 1.573 (4) Å) than the opposite bonds (C 2---C 3 = 1.557 (4) Å). The experimental values for the energy difference between the two conformers and for the geometric parameters are reproduced very well by ab initio calculations. The importance of silicon 3 d orbitals in the interpretation of ring distortion is ambiguous, but on the basis of the ab initio calculations the participation of silicon 3 d functions is negligible. 相似文献
20.
The bimetallic [Pt(NH 3) 4] 2[W(CN) 8][NO 3]·2H 2O is characterised by single-crystal X-ray diffraction [S.G. P2 1/ m(11), a=8.0418(7), b=19.122(2), c=9.0812(6) Å, Z=2]. All platinum centres have the square-plane D4h geometry with average dimensions Pt(1)–N 2.042(2) and Pt(2)–N 2.037(10) Å. The octacyanotungstate anion has the square-antiprismatic D4d configuration with average dimensions W(1)–C 2.164(13), C–N 1.140(12), W(1)–N 3.303(5) Å. The structure exhibits two different mutual orientations of Pt versus W units resulting in Pt(2)–W(1), W(1) * separations of 4.77(2), 4.55(2) * and Pt(1)–W(1) of 6.331(8) Å. A centrosymmetric structure reveals groups of two distinct columns: the first is formed by intercalated NO 3− between parallel [Pt(1)(NH 3) 4] 2+ planes and the second consists of [W(CN) 8] 3− interlayered by, parallel to square faces of W-antiprisms, [Pt(2)(NH 3) 4] 2+. The structure is stabilised through a three-dimensional hydrogen bond network via nitrogen atoms of cyanide ligands, hydrogen atoms of NH 3 ligands, water molecules and oxygen atoms of NO 3− counteranions. The vibrational pattern and the range of ν(CN) frequencies attributable to the electronic environment of W(V) and W(IV) are consistent with the ground state Pt(II)↔W(V) charge transfer. 相似文献
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