共查询到20条相似文献,搜索用时 46 毫秒
1.
Oleg Volkov Krzystof Radacki Nigam P. Rath 《Journal of organometallic chemistry》2005,690(11):2736-2744
The structure of the nido-undecaborate anion, [B11H14]−, has been re-examined because of what appear to be discrepancies that were observed between our determination of the structure of the anion in [(Cp2Zr)2B5H8][B11H14] (1) and previously published structures. The structure of 1 indicated the presence of two bridging H atoms and another pseudo-bridging one whereas those of a series of published structures indicate the presence of a plane of symmetry with two bridging H atoms and one endo-H atom. Thus, we undertook a series of structural determinations and also a computational study at the B3LYP/6-31++G(d,p) level. In addition to 1, the species studied included [NBnEt3][B11H14] (2), [NBnEt3][7-Br-nido-B11H13] (3) and [NBnEt3][7-(η1-dppm)-nido-B11H12] (4). Our structure of 2 indicated the presence of two bridging H atoms and an endo-hydrogen atom with some bridging character but that of 3 contained three bridging atoms. As expected the structure of 4 contains two bridging H atoms. Calculations of bond parameters fit well with the experimental data as do the 11B NMR chemical shifts. The latter were calculated for the average of the two open face configurations, one with two bridging and one endo-hydrogen and the other with three bridging hydrogen atoms. The difference in energies for these two open face configurations is calculated to be 0.36 kJ/mol, which effectively suggests that the two structures are equally favored. 相似文献
2.
《Polyhedron》1987,6(10):1849-1858
The structure of gaseous arachno-B5H11 has been redetermined by electron diffraction and shown to be similar to that found in the solid state at low temperature (93 K) except that the inner basal interatomic distance B(3)B(4) appears to be somewhat shorter in the gas phase. The data are consistent with the presence of asymmetric B(2)H(2,3)B(3) and B(5)H(4,5)B(4) bridges with the two halves of each bridge differing in length by ca. 12 pm. The unique endo/face-capping H atom attached to the apical B(1) atom has not been located with high precision, but the best fit to the data is obtained for an asymmetric structure with the distances B(2) … H(1)endo and B(5) … H(1)endo differing by 31 pm. For comparison, the structure of nido-B5H9 has also been redetermined by electron diffraction. The interatomic distances are in excellent agreement with those previously obtained from microwave data. The directly-bonded BH(bridge) distances reveal an unusually large amplitude of vibration of the bridging H atoms but it was not possible to establish whether this was a real effect or whether the structure has a lower symmetry than that expected. 相似文献
3.
《Journal of organometallic chemistry》1987,334(3):295-305
Dimethylbis(2-pyridinethiolato-N-oxide)tin(IV), Me2Sn(2-SPyO)2, crystallizes in space group P21/c with a 9.877(3), b 11.980(4), c 13.577(3) Å, β 109.1(2)° and Z = 4. The structure was refined to RF = 0.036 for 2263 Mo-Kα observed reflections. The coordination geometry at tin is a skew-trapezoidal bipyramid, with the oxygen [SnO 2.356(3), 2.410(4) Å] and sulfur [SnS 2.536(1), 2.566(1) Å] atoms of the chelating groups occupying the trapezoidal plane and the methyl groups [SnC 2.106(6), 2.128(7) Å] occupying the apical positions. The methyl-tin-methyl skeleton is bent [CSnC 138.9(2)°]. The SSnS angle is 77.8(1)°, but the OSnO angle is opened to 136.7(1)° to accommodate the intruding methyl groups. The carbontincarbon angles predicted from quadrupole splitting (119mSn Mössbauer) and one-bond 119Sn13C coupling constant (solution 13C NMR) data agree closely with the experimental value. 相似文献
4.
《Journal of organometallic chemistry》1988,339(3):339-343
The 13C {1H} NMR spectra of a series of complexes [(η5-C5H4Me)Fe(CO)(L)I] (L t-BuNC, P(OMe)3, PMe3, PMe2Ph, PMePh3, PPh3 and P(C6H11)3) have been recorded and the five cyclopentadienyl resonances assigned to ring carbon atoms by means of CH correlated spectra. It has been observed that the C atoms ortho to the ring methyl group (C(2) and C(5)) as well as the quaternary C atom are always coupled to the ligand P atom. A correlation between the chemical shift difference Δ(C(2) – C(5)) and the Tolman cone angle, θ, has also been established. 相似文献
5.
Dimethylamine reacts with Ru3(CO)12 to produce the η2-hydrido-η-formamido cluster complex HRu(OCN(CH3)2)(CO)10 (I). This formulation is consistent with spectroscopic features such as the absence of v(NH) in the infrared, the presence in the Raman of v(RuHRu) at 1400 cm?1 (v(RuDRu) at 990 cm?1) and indication in the 1H NMR of diastereotopic methyl groups bonded to the nitrogen atom. Since these data could not lead to an unequivocal structure assignment a single crystal X-ray study at 115 K was undertaken. The complex crystallizes in the triclinic space group, P with cell dimensions; a 7.299(33) », b 9.5037(40) », c 13.7454(57) », α 91.876(34)°, β 96.387(34)°, γ 95.341(34)° and Z = 2. The structure was solved by a combination of Patterson and Fourier techniques and refined by full matrix least squares to a final R = 0.054 and Rω = 0.074 for 3074 unique reflections. The three ruthenium atoms define a triangle of unequal sides with both the hydride and formamido groups bridging the longest edge; the formamido group is coordinated through the carbon and oxygen atoms. The edge of the ruthenium triangle bridged both by the hydrogen atom and the formamido group is 2.8755(15) »; the other two edges of the ruthenium triangle are observed to be 2.8319(15) and 2.8577(14) », respectively. In the formamido group the distance CO 1.287(9) » and CN 1.340(10) » reflect partial double bond charater in each bond consistent with observation of two chemically distinct methyl groups on the dinitrogen atom. The hydrogen atom bridging one edge of the ruthenium triangle is asymmetrically positioned at 1.73(9) » from the ruthenium atom bonded to the oxygen atom and 1.91(9) » from the ruthenium atom bonded to the carbon atom of the carboxamido group. 相似文献
6.
Galina L. Levit Alexander M. Demin Marina A. Ezhikova Valentina A. Ol’shevskaya Victor P. Krasnov 《Journal of organometallic chemistry》2005,690(11):2783-2786
Acidic hydrolysis of N-acyl 1-methyl- and 1-phenyl-3-amino-1,2-dicarba-closo-dodecaboranes has been studied. It has been shown that acidic hydrolysis of diastereomeric amides of 1-methyl-3-amino-1,2-dicarba-closo-dodecaborane results in the partial racemization of the target 3-amino-1-methylcarborane. Under the similar conditions, the hydrolysis of N-acyl-3-amino-1-phenyl-1,2-dicarba-closo-dodecaboranes resulted in amide bond cleavage accompanied by simultaneous deboronation with the removal of boron atom at position 6 of carborane cage and formation of 7,8-dicarba-nido-undecaborane derivative according to 11B and 1H NMR spectroscopy. 相似文献
7.
Jianmin Dou Libin Wu Qingliang Guo Dacheng Li Daqi Wang Chunhua Hu Peiju Zheng 《应用有机金属化学》2005,19(11):1168-1175
The reaction of [PtCl2(PPh3)2] with closo‐B10H102? in ethanol under reflux conditions gave two nido 11‐vertex platinaundecaborane clusters: [(PPh3)2PtB10H10‐8,10‐(OEt)2]·CH2Cl2 (1) and [(PPh3)2PtB10H11‐11‐OEt]·CH2Cl2 (2) . A novel B10H102? deboronated nido 11‐vertex diplatinaundecaborane [(µ‐PPh2)(PPh3)2Pt2B9H6‐3,9,11‐(OEt)3]·CH2Cl2 (3) was obtained when the same reaction was carried out under solvothermal conditions. All of these compounds were characterized by infrared spectroscopy, NMR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. Both clusters 1 and 2 have a nido 11‐vertex {PtB10} polyhedral skeleton in which the Pt atom lies in the open PtB4 face. Each Pt atom connects with four B atoms and two P atoms of the PPh3 ligands. Cluster 3 has a nido 11‐vertex {Pt2B9} polyhedral skeleton in which two Pt atoms sit in neighbouring positions of the open Pt2B3 face, bridged by a PPh2 group. Each Pt atom connects three B atoms and a P atom of the PPh3 ligand. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
8.
André L. Beauchamp Stephan Latour Marc J. Olivier James D. Wuest 《Journal of organometallic chemistry》1983,254(3):283-291
The title compound, C58H52Sn3, belongs to the triclinic space group P, with a 10.165, b 13.365, c 18.670 Å, α 96.28, β 93.88, γ 103.15°, V = 2443.8 Å3, fw = 1105.1, Z = 2, Dcalc 1.501 g cm?3, m.p. 206.5–208°C, λ(Mo-K) 0.71069 Å. The structure was refined on 2684 nonzero reflections to an R factor of 0.044. The crystal contains molecules in which the (SnCH2)3CH core possesses an approximate C3 symmetry. The three SnC(H2) bonds are gauche to the C(4)-H bond. Repulsive interactions involving the bulky Ph3Sn substituents lead to large SnC(H2)C(H) angles (av. 117.3°), whereas the C(H2)C(H)C(H2) angles at the tertiary carbon average 111.3°. Little distortion of the Ph3Sn groups themselves is present, since the PhSnPh angles (av. 109.8°) are almost equal to the C(H2)SnPh angles (av. 109.9°). The molecule as a whole has no symmetry because the aromatic rings in the three Ph3Sn groups have different orientations. The phenyl groups create a pocket in the middle of the molecule which encloses and shields the tertiary hydrogen atom. The resulting inaccessibility of this hydrogen accounts in part for the low reactivity of the title compound in redox reactions. 相似文献
9.
Kunio Miki Yasushi Kai Noritake Yasuoka Nobutami Kasai 《Journal of organometallic chemistry》1979,165(1):79-91
The precise molecular structure of [PdCl(CH2SCH3)(PPh3)2] has been determined from three-dimensional X-ray diffraction data collected at ?160°C. The CH2Cl2 solvated crystal ([PdCl(CH2SCH3)(PPh3)2 · CH2Cl2]) belongs to the monoclinic system, space group P21/n, with four formula units in a cell of dimensions: a 14.973(3), b 15.333(3), c 17.377(3) Å and β 115.77(1)° at ?160°C. The structure was solved by the conventional heavy atom method and refined by the least-squares procedure to R = 0.035 for observed reflections. The geometry around the palladium atom is square-planar. The phosphorus atoms of the two triphenylphosphine ligands are mutually trans. The CH2SCH3 group is bonded to the palladium atom only through the PdC σ-bond and the sulfur atom is not bonded to the metal atom (PdC(1) 2.061(3), SC(1) 1.796(3), SC(2) 1.817(5), Pd?S 2.973(1) Å, PdC(1)S 100.64(14)° and C(1)SC(2) 101.28(18)°). The structure is in contrast to that of [PdCl(CH2SCH3)(PPh3)], in which both the carbon and sulfur atoms of the CH2SCH3 group are bonded to the palladium atom. 相似文献
10.
《Journal of organometallic chemistry》1986,317(3):267-275
The solid state structure of trimethylsilylmethyllithium has been determined by single crystal X-ray diffraction techniques. The compound crystallizes in the monoclinic system, space group P21/n. Cell dimensions were determined as follows: a 10.931(3), b 18.397(6), c 21.490(8) Å, β 96.0(2)°, V 4298(2) Å3, Z = 4, and a final Rf 5.1% based on 2203 data with σ(I) ≥ 2.5σ(I). The compound is formed by hexameric units, {LiCH2Si(CH3)3}6, with two distinct classes of LiLi distances of 2.46 and 3.18 Å. There are also two LiC distances av 2.20 and 2.27 Å. The LiH distances to the methylene H atoms have been determined and are short varying between 2.0 and 2.3 Å to the closest lithium atom. The structure, including possible LiH interactions, is discussed and compared with the other known hexameric aggregates. 相似文献
11.
Jonathan Bould Raikko Kiveks Reijo Sillanp Francesc Teixidor Clara Vias 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o271-o273
Tetraethylammonium 7‐dimethylsulfanyl‐nido‐dodecahydroundecaborate, [Et4N][7‐Me2S‐nido‐B11H12] or C8H20N+·C2H18B11S−, is a product of the deprotonation of [7‐Me2S‐nido‐B11H13] with KHBEt3 and precipitation with tetraethylammonium chloride. The effect of removing one endo‐terminal H atom is to cause a general contraction of the open‐face B—B distances. 相似文献
12.
Ulrich Schubert Klaus Ackermann Paul Rustemeyer 《Journal of organometallic chemistry》1982,231(4):323-334
Steric and electronic influences on bond lengths and angles at the carbene carbon atoms of cis-Re2(CO)9C(OR)SiPh3 (I: R = CH3, II, R = C2H5) and cis,trans-Re2(CO)8[C(OEt)SiPh3]2 (III) are discussed based on their structural analyses. I (ReRe 305.2(1) pm; ReC(carbene) 209(2) pm) and II (two independent molecules; ReRe 305.0(3) and 305.2(4) pm; ReC (carbene) 208(5) and 210(5) pm) differ by the cis and trans positions of the alkyl groups at the partial C(carbene)O double bonds. The change in configuration affects the bond angles at the carbene carbon. In III the carbene ligands are bonded to different rhenium atoms; cis to one Re atom and trans to the other Re atom (ReRe bond 309.1(2) pm). The ReC(carbene length of the trans- carbene ligand is significantly shorter (185(3) pm) than that of the cis-carbene ligand (208(3) pm). 相似文献
13.
Catherine J. Hurt Joseph C. Calabrese Robert West 《Journal of organometallic chemistry》1975,91(3):273-278
The crystal structure of [Si(CH3)(t-C4H9)]4 has been determined by single crystal X-ray diffraction. The crystals are tetragonal, P42/n; a = b = 13.069(4), c = 7.880(2) Å, Z = 2. The structure was determined using 745 independent data and refined with anisotropic least-squares to a final unweighted R-value of 3.5%. Each tetrameric molecule was found to be arranged about a axis, with the independent crystallographic unit comprising one silicon atom, one methyl and one tert-butyl group. The four-membered ring of silicon atoms is nonplanar with an unusually large dihedral angle of 36.8°. The principal mean bond lengths are SiSi 2.377(1), SiC(methyl) 1.893(4), SiC(tert-butyl) 1.918(3) Å, and the SiSiSi bond angle is 86.99°. The SiSi bond length is somewhat longer than in other polysilanes. 相似文献
14.
Frank Herwig Köhler Hans Jürgen Kalder Ernst Otto Fischer 《Journal of organometallic chemistry》1976,113(1):11-22
The nuclear spin coupling constants1J(183W13C) and in some cases 2J(183W13C) and 3J(183W13C) are determined for 10 tungsten carbene and 9 tungsten carbyne complexes. 1J is of analytical importance, being characteristically greater for WC than for WC bonds. This is due to different hybridisation at the carbon atom, and provides information about bond angles and polarities of WC and WCR units.Substituents R and R' in (CO)5WCRR' and X(CO)4WCR as well as the halogens X lead to minor changes in 1J. These changes are comparable to those of 1J(13C1H) in correspondingly substituted methanes. Unexpectedly 1J in_ creases with X = Cl, Br, I. 2J(183W13C) though being much smaller than 1J reflects different hydridisation at the β carbon atom. 相似文献
15.
[PtCl2(PPh3)2]与B10H102-在异丙醇中回流反应, 得到3个巢式十一顶铂十硼烷簇合物: [(PPh3)2PtB10H11-9-O-i-Pr] (1), [(PPh3)2PtB10H10-8,10-(O-i-Pr)2] (2)和[(PPh3)2PtB10H11-8-O-i-Pr] (3). 簇合物1~3都具有PtB10多面体骨架结构, 其中Pt原子位于敞开的PtB4面上, 且与4个B原子成键, 每个Pt原子还与2个PPh3基团中的P原子成键. 将溶剂热合成的方法引入到硼簇合物的合成中并进行同一反应, 得到2个B10H102-降解的巢式十一顶双铂九硼烷簇合物: [(PPh3)2(μ-PPh2)Pt2B9H6-3,9,11-(O-i-Pr)3] (4)和[(PPh3)2(μ-PPh2)Pt2B9H6-3,9-(O-i-Pr)2-11-Cl] (5). 簇合物4和5都具有Pt2B9多面体骨架结构, 2个Pt原子位于敞开的Pt2B3面上的相邻位置, 且由一个PPh2基团桥连, 每个Pt原子还与3个B原子和一个PPh3基团中的P原子成键. 通过红外光谱、元素分析、X射线单晶衍射对5个簇合物进行了结构表征. 相似文献
16.
M.N. Bochkarev G.A. Razuvaev L.P. Maiorova N.P. Makarenko V.I. Sokolov V.V. Bashilov O.A. Reutov 《Journal of organometallic chemistry》1977,131(3):399-408
A single-crystal X-ray diffraction study of tetracarbonyl-ferra-3-cyclopentene-2,5-dione has been made. Formally the compound can be derived from maleic anhydride by substitution of the bridging oxygen by Fe(CO)4. Accordingly the bonding character is similar to that of maleic anhydride. The ironcarbon distances in the ring indicate partial double bonds. The octahedrally coordinated iron atom is linked to four terminal carbon monoxide ligands, with a longer bond distance to the equatorial than to the axial ones (FeCax 1.809 Å, FeCeq 1.854 Å). The axial CO groups are strongly inclined towards the ring (CaxFeCax 164°). The latter effect is explained by electronic repulsion of the CO groups.IR, 1H NMR, and 13C NMR data are reported. Crystal data: space groupPnama:α 12.708(10),b 10.058(7),c 7.527(5) Å;Z 4. With 625 reflections [Fo > 3o(Fo)] the structure has been refined anisotropically (hydrogen isotropically) to R0.022. 相似文献
17.
《Journal of organometallic chemistry》1987,326(1):93-98
13C, 1H NMR investigation of the (CH3nC5H5–nRe(CO)3 MenCpReT) n = 0–5 analogous series showed that the signals of almost all magnetic nuclei shift upfield with increase n, which also occurs in (MenCp)2M compounds (M = Fe2+, Co3+; n = 0–5). The smaller value of the C(CH3) signal (1.5 ppm.) shifts upfield when a further methyl group is introduced into the vicinal position, this shift can be attributed to the absence of the second methyl cyclopentadienyl ring. It is noteworthy that methyl cyclopentadienyl ring coordination to the transition-metal atom results in the downfield shift of the substituted carbon atom (Ckey) signal. One of the reasons for such a shift might be the reduction in screening effect of the central CpM bond π-electron current on Ckey owing to nodal properties of Cp ring e-orbitals. The δ 13C(CO), δ 17O(CO), and v(CO) values reflect successive increases of Re → CO π-back donation with increase in n. 相似文献
18.
《Polyhedron》1987,6(7):1551-1557
In ethereal solutions, WSCl4 and 4 equiv LiOR (R = But or Pri) react to form compounds of formula W(S)(OR)4. A single-crystal X-ray diffraction study of W(S)(O-But)4 showed it to have a square-based pyramidal geometry with an apical sulfide ligand. Pertinent bond distances (Å) and angles (°) are: WS = 2.1396(13), WO(av.) = 1.886(3), SWO(av.) = 105.09(10), WOC(av.) = 143.47(27). The tert-butoxide compound is stable toward sulfur atom abstraction by phosphines, and neither compound has shown any tendency to undergo comproportionations with W2(OR)6 (R = Pri or CH2But) species to form compounds of formula W3(μ3-S)(OR)10, in direct contrast to analogous molybdenum and tungsten oxo alkoxides. 相似文献
19.
Kunio Miki Yasushi Kai Noritake Yasuoka Nobutami Kasai 《Journal of organometallic chemistry》1977,135(1):53-64
The molecular structure of [PdCl(CH2SCH3)(PPh3)] has been determined from three-dimensional X-ray diffraction data collected at both ?160 and 20°C. The crystal belongs to the monoclinic system, space group P21/c, with four formula units in a cell of dimensions: a 11.398(2), b 9.788(1), c 17.267(2) Å and β 95.38(1)° at ?160°C; a 11.454(3), b 9.880(2), c 17.459(2) Å and β 95.84(1)° at 20°C. The structure was solved by the conventional heavy atom method, and refined by the least-squares procedure to R = 0.049 (?160°C) and 0.068 (20°C) for observed reflections. No essential difference is observed between molecular structures at ?160 and 20°C. The geometry around the palladium atom is square-planar. The CH2SCH3 group, bonded to the palladium atom through PdC and PdS bonds, forms a metallocyclic three-membered ring [PdC(1) 2.042(6), PdS 2.371(1), SC(1) 1.756(6) and SC(2) 1.807(7) Å, PdC(1)S 76.9(2), PdC(1)H 113(3) and 122(4)°, SC(1)H 115(3) and 112(4) and HC(1)H 113(5)° at ?160°C]. 相似文献
20.
《Polyhedron》1987,6(11):1981-1986
Electrophilic deuteration of closo-[1-CB11H12]− in the DCl/D2O system confirmed the expected order of reactivity on individual skeletal atoms, decreasing in the series B(12) > B(7–11) > B(2–6) > C(1). In contrast, electrophilic B-substitution of closo-[1-CB11H12]− with H2NOSO3H is consistent with the preference of the B(7)-substitution to suggest a different mechanism for almost exclusive formation of 7-H3N-closo-1-CB11H11. 7-Me3N-closo-1-CB11H11 was isolated along with the remaining 2- and 12-Me3N-1-CB11H11 isomers as side products of the thermal decomposition of [BH2(NMe3)2]+[nido-7-CB10H13]− at 270°C, which is inconsistent with a specific insertion of the BNMe3 fragment into the open face of nido-[7-CB10H13]−. Nevertheless, clean 10B-insertion was observed in the reactions of Et3N10BH3 with both nido-[7-CB10H13]− and 7-Me3N-nido-7-CB10H12 to give respectively closo-[1-CB11H12]− and [1-Me2N-1-CB11H11]− labelled by 10B exclusively at the B(2) site. Cage rearrangement was observed, however, in the reaction of 7-Me3N-8-PhCH2-nido-7-CB10H11 with Et3NBH3 under similar conditions to produce only the 1-Me3N-7-PhCH2-1-CB11H10 closo-isomer. 相似文献