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1.
The geometric structures and conformational properties of trifluoromethanesulfonic anhydride, (CF 3SO 2) 2O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF 3SO 2) 2CF 2 have been studied by gas electron diffraction (GED) and ab initio calculations (HF/3–21G*). The calculations predict for both systems two stable conformers with C2 symmetry and one with C1 symmetry. In both compounds structures with C2 symmetry and dihedral angles SOSC ≈ 100° ((CF 3SO 2) 2O) and SCSC ≈ 150° ((CF 3SO 2) 2CF 2) are lowest in energy. According to the GED analyses the dominant conformer of (CF 3SO 2) 2O possesses C2 symmetry with SOSC dihedral angles of 99.1(14)°. The presence of up to 30% of the two other conformers cannot be excluded; for (CF 3SO 2) 2CF 2 only one conformer with C2 symmetry and SCSC dihedral angles of 143(2)° is observed. A complete set of geometric parameters is given. 相似文献
2.
The geometric structures and conformational properties of trifluoromethanesulfonic anhydride, (CF 3SO 2) 2O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF 3SO 2) 2CF 2 have been studied by gas electron diffraction (GED) and ab initio calculations (HF/3–21G*). The calculations predict for both systems two stable conformers with C2 symmetry and one with C1 symmetry. In both compounds structures with C2 symmetry and dihedral angles SOSC ≈ 100° ((CF 3SO 2) 2O) and SCSC≈ 150° ((CF 3SO 2) 2CF 2 are lowest in energy. According to the GED analyses the dominant conformer of (CF 3SO 2) 2O 2 possesses C2 symmetry with SOSC dihedral angles of 99.1(14)°. The presence of up to 30% of the two other conformers cannot be excluded; for (CF 3SO 2) 2CF 2 only one conformer with C2 symmetry and SCSC dihedral angles of 143(2)° is observed. A complete set of geometric parameters is given. 相似文献
3.
The tail-to-tail dimerization of methyl acrylate (MA) in the presence of H 2Ru(PPh 3) 4 (1) or H 2(CO)Ru(PPh 3) 3 (2) and CF 3SO 3H to give a mixture of linear dimers is described. In neat methyl acrylate at 85°C the reaction shows turnover numbers of 300 in 20 h and 640 in 7 d. Mechanistic studies show that the initial step of the reaction is the reduction of H 2Ru(PPh 3) 4 (1) by MA to form Ru(MA) 2 (PPh 3) 2 (5). After activation with CF 3SO 3H the catalytically active species contains only one phosphane ligand. The basic mechanistic features of the dimerization reaction have been revealed by 2H NMR spectroscopy involving the use of CF 3SO 3D. The deuterium-labelling studies indicate the intermediate formation of a ruthenium(II) hydride complex. Subsequent olefin insertions in this complex, followed by β-hydride elimination,lead to the linear dimeric products. 相似文献
4.
The methylene-bridged, mixed-chalogen compounds Fe 2(CO) 6(μ-SeCH 2Te) (1) and Fe 2(CO) 6(μ-SCH 2Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe 2(CO) 6(μ-SeTe) and Fe 2(CO) 6(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, 1H, 13C, 77Se and 125Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P2 1/ n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) Å 3, Z = 4, Dc = 2.599 g cm −3 and R = 0.030 ( Rw = 0.047). 相似文献
5.
The geometric structure of (CF 3S) 2C=C(SCF 3) 2 in the vapour phase was determined by electron diffraction. The molecule possesses D2 symmetry with the S---CF 3 bonds oriented perpendicular to the ethene plane, in alternating directions up-down-up-down. The following skeletal geometric parameters were obtained ( ra distances and angles, experimental uncertainties are 3σ values): C=C = 1.34Å (ass.), C(sp 2---S = 1.761(5)Å, S---C(sp 3) = 1.832(5)Å, S---C---C = 119.6(4)°, C---S---C = 100.6(13)°, and ø(C=C---S---C) = 90.9(11)°. The gas phase conformation differs considerably from the crystal structure, where the molecule possesses Ci symmetry and the CF 3 groups, which are bonded to cis-standing sulfur atoms, lie on the same side of the ethene plane with dihedral angles ø(C=C---S---C) of 117° and 127°. 相似文献
7.
Irradiation of the 30-electron Mo 2(η 5-C 5Me 5) 2(CO) 4 and Re 2(CO) 10 in toluene solution (containing H 2O) afforded (in 1–2% yields) a novel triangular metal cluster, (η 5-C 5Me 5) 3Mo 3(CO) 4(η 2-H)(η 3-O) (1), which was characterized by a single-crystal X-ray diffraction study. Compound 1, of pseudo Cs- m symmetry, has a triangulo-Mo 3(η 3-O) core with composite Mo---H---Mo and Mo---Mo electron-pair bonds along one unusually short edge (2.660(1) Å) and Mo--- electron-pair bonds along the other two edges (2.916(1) and 2.917(1) Å). The edge-bridged hydride ligand, which displays a characteristic high-field proton NMR resonance at δ −17.79 ppm, was not found from the crystallographic determination but was located via a quantitative potential-energy-minimization method. This procedure unambiguously established that the optimized hydrogen position, which corresponds to a distinct coordination site with identical Mo---H distances of 1.85 Å, is the only one that can be sterically occupied by a metal-bound hydride ligand. This 46-electron species is the first electron-deficient trimolybdenum cluster containing a monoprotonated Mo---Mo double bond; its existence is attributed to ligand overcrowding due to the bulky pentamethylcyclopentadienyl rings. Black (η 5- C 5Me 5) 3Mo 3(CO) 4(η 2-H)(η 3-O) · 1/2THF crystallizes with two formula species in a triclinic unit cell of P1 symmetry with a 8.603(4), b 11.115(4), c 19.412(11) Å, 80.69(4)°, β 101.10(4)°, and γ 98.88(3)° at −40° C. Least-squares refinement (RAELS with 221 variables) of one independent Mo 3 molecule and a centrosymmetrically-disordered THF molecule converged at R1( F) 5.62%, R2( F 6.88% for 8460 independent diffractometry data ( I0 ρ 3σ( I0 collected at −40° C with Mo- K radiation 相似文献
8.
Reaction of [Ru 3(CO) 12 with (CF 3) 2P---P(CF 3) 2 in p-xylene at 140°C yielded the compounds [Ru 4(CO) 13{μ-P(CF 3) 2} 2] (1), [Ru 4(CO) 14{μ-P(CF 3) 2} 2] (2) and [Ru 4(CO) 11{μ-P(CF 3) 2} 4] (3). Reaction with [(μ-H) 4Ru 4(CO) 12] under similar conditions yielded [(μ-H) 3Ru 4(CO) 12{μ-P(CF 3) 2}] (4). All four compounds have been characterised by X-ray crystallography. The fluxional behaviour of the hydrides in 4 has also been studied by variable-temperature NMR spectroscopy. Compounds 1, 2 and 4 were also obtained from the reactions of Ru 3(CO) 12 with (CF 3) 2PH in dichloromethane at 80°C. 相似文献
9.
Potassium cobalt hexacyanoferrate(II), K 2CoFe(CN) 6 · 1.4H 2O, loses its water when heated up to 170°C, and the anhydrous compound begins to decompose above 230°C. The cyanide groups are evaporated off in the temperature range 230–350°C, and the solid products thus formed are K 2CO 3, Fe 2O 3, Co 3O 4 and CoFe 2O 4. In the range 550–900°C, the cobalt-containing compounds become CoO, and K 2CO 3 probably partly decomposes to K 2O, so that the product mixture at 900°C is K 2CO 3/K 2O, Fe 2O 3 and CoO. Above this temperature, K 2CO 3 decomposes to K 2O. 相似文献
10.
Reaction of (μ 3-CCH 3)CO 3(CO) 9 (I) with dppm (dppm = bis-(diphenylphosphino)methane) affords the cluster (μ 3-CCH 3)Co 3(CO) 7-dppm (II). The crystal and molecular structure of II have been determined at −160°C. The dppm ligand bridges one of the three metal—metal edges in the equatorial plane to give a five-membered ring, which adopts an envelope conformation. Cluster II functions as a catalyst for the hydroformylation of 1-pentene (80 bar of H2/CO (1/1); 110°C). The results indicate that the dppm bridging ligand stabilizes and activates the cluster for catalysis, and open the way to the synthesis of chiral clusters. 相似文献
11.
The crystal structure of bis(trifluoroacetato)-( N-methyl- meso-tetraphenylporphyrinato) thallium(III), Tl(N---Me---tpp)(CF 3CO 2) 2 (2), was established and the coordination sphere around the Tl 3+ ion is described as 4:3 tetragonal base–trigonal base piano stool seven-coordinate geometry in which the two cis CF 3CO 2 − groups occupy two apical sites. The plane of the three pyrrole nitrogen atoms [i.e. N(2), N(3) and N(4)] strongly bonded to Tl 3+ is adopted as the reference plane 3N. The pyrrole N(1) ring bearing the methyl group [i.e. C(45)H 3] is the most deviated one from the 3N plane making a dihedral angle of 23.3° whereas smaller angles of 9.9, 2.7 and 4.7° occur with pyrroles N(2), N(3), and N(4), respectively. Because of the larger size of the thallium(III) ion, Tl is considerably out of the 3N plane; its displacement of 1.02 Å is in the same direction as that of the two apical CF 3CO 2 − ligands. The intermolecular trifluoroacetate exchange process for 2 in CD 2Cl 2 solvent is examined through 19F and 13C NMR temperature-dependent measurements. In the slow-exchange region, the CF 3 and carbonyl (CO) carbons of the CF 3CO 2 − groups in 2 are separately located at δ 114.3 [ 1J(C–F)=290 Hz, 3J(Tl–C)=411 Hz] and 155.1 [ 2J(C–F)=37 Hz, 2J(Tl–C)=204 Hz], respectively, at −106 °C. In the same slow-exchange region, the fluorine atoms of 2, Tl(N---Me---tpp)(CF 3CO 2) + and the free CF 3CO 2 − are located at δ −73.76 [ 4J(Tl–F)=44 Hz], −73.30 [ 4J(Tl–F)=22 Hz], and −76.15 ppm at −97 °C, respectively. 相似文献
12.
This work presents chemical modeling of solubilities of metal sulfates in aqueous solutions of sulfuric acid at high temperatures. Calculations were compared with experimental solubility measurements of hematite (Fe 2O 3) in aqueous ternary and quaternary systems of H 2SO 4, MgSO 4 and Al 2(SO 4) 3 at high temperatures. A hybrid model of ion-association and electrolyte non-random two liquid (ENRTL) theory was employed to fit solubility data in three ternary systems H 2SO 4–MgSO 4–H 2O, H 2SO 4–Al 2(SO 4) 3–H 2O at 235–270 °C and H 2SO 4–Fe 2(SO 4) 3–H 2O at 150–270 °C. Employing the Aspen Plus™ property program, the electrolyte NRTL local composition model was used for calculating activity coefficients of the ions Al 3+, Mg 2+ Fe 3+ and SO 42−, HSO 4−, OH −, H 3O +, respectively, as well as molecular species. The solid phases were hydronium alunite (H 3O)Al 3(SO 4) 2(OH) 6, hematite Fe 2O 3 and magnesium sulfate monohydrate (MgSO 4)·H 2O which were employed as constraint precipitation solids in calculating the metal sulfate solubilities. A correlation for the equilibrium constants of the association reactions of complex species versus temperature was implemented. Based on the maximum-likelihood principle, the binary interaction energy parameters for the ionic species as well as the coefficients for equilibrium constants of the reactions were obtained simultaneously using the solubility data of the ternary systems. Following that, the solubilities of metal sulfates in the quaternary systems H 2SO 4–Fe 2(SO 4) 3–MgSO 4–H 2O, H 2SO 4–Fe 2(SO 4) 3–Al 2(SO 4) 3–H 2O at 250 °C and H 2SO 4–Al 2(SO 4) 3–MgSO 4–H 2O at 230–270 °C were predicted. The calculated results were in excellent agreement with the experimental data. 相似文献
13.
A high yield synthesis of the carbonyl dithiocarbamato derivative Fe(CO) 2(η 2-S 2CNMe 2) 2 and Fe(η 2-S 2CNMe 2) 2 by photolysis with visible light of solutions containing Fe 2(CO) 9 or Fe 3(CO) 12 and [(η 5-C 5H 5)(CO) 3W(η 1-SCSNMe 2)] is reported. 相似文献
14.
The reaction between metallic barium and fluoroisopropanol or alcoholysis of [Ba(OPr i) 2] produces a pentanuclear fluoroalkoxide. Its X-ray structure determination showed its formulation to correspond to Ba 5(μ 5-OH)[μ 3-OCH(CF 3) 2] 4[μ 2-OCH(CF 3) 2] 4 [OCH(CF 3) 2](THF) 4(H 2O)·THF. The metallic core is based on a square pyramid encapsulating an hydroxo ligand. In addition to the barium---alkoxide bonds [2.53(3)–2.86(3) Å] neutral O-donors, four THF [2.82(2)–2.86(3) Å] and one H 2O [2.79(3) Å] and secondary barium---fluorine interactions [2.99(2)–3.31(2) Å] ensure high coordination numbers, from 9 to 11 for the metal centers. Hydrogen bonding between the apical fluoroisopropoxide, the water molecule and one THF molecule, non-bonded to a metal center, accounts for the stability of the hydrate and illustrates the Lewis acidity of fluoroalkoxides. Thermal decomposition leads to BaF 2. 相似文献
15.
Cp 2MoH 2 reacts with methyl acrylate in the presence of acetylenes (L = C 2H 2, C 2Me 2, HCC tBu, HCCSiMe 3, C 2(SiMe 3) 2, HCCCH 2OMe, HCCCH 2NMe 2) to form acetylene complexes Cp 2Mo(L) 5. Protonation takes place with CF 3CO 2H at −80°C to give short-lived cations [Cp 2MoH(L) + (8) (L = C 2Me 2, HCCSiMe 3, C 2(SiMe 3) 2). The structure of [Cp 2MoH{η 2-C 2(SiMe 3) 2}]PF 6(9) was determined by an X-ray diffraction study. 相似文献
16.
Toluene solutions of M 2(NMe 2) 6 (M = Mo, W) react with mesitylene selenol (Ar′SeH) to give M 2(SeAr′) 6 complexes. MO 2(OR) 6 (R = tBu, CH 2tBu) react with excess> 6 fold) Ar′SeH to give Mo 2 (SeAr′) 6, whilst W 2(OR) 6(py) 2 (R = iPr, CH 2tBu) react with excess (> 6 fold) Ar′SeH to give W 2(OR) 2(SeAr′) 4. Reaction of MO 2(OPr i) 6 with Ar′SeH produces Mo 2(OPr i) 2 (SeAr′) 4 which crystallizes in two different space groups. These areneselenato complexes are air-stable and insoluble in common organic solvents. X-ray crystallographic studies revealed that the Mo 2(SeAr′) 6 and W 2(SeAr′) 6 compounds are isostructural in the solid state and adopt ethane-like staggered configurations with the following important structural parameters, M---M (W---W/Mo---Mo) 2.3000(11)/2.2175(13) Å, M---Se 2.430 (av.)/2.440 (av.) Å, M---M---SE 97.0° (av.)°. In the solid state W 2(O iPr) 2(SeAr′) 4 adopts the anti-configuration with crystallographically imposed Ci symmetry and W---W 2.3077(7) Å, W---Se 2.435 (av.) Å, W---O 1.858(6) Å; W---W---SE 100.27(3)°, 93.8(3)° and W---W---O 108.41(17)°. Mo 2(OPr i) 2(SeAr′) 4 crystallizes in both P
and A2/ a space groups in which the molecules are isostructural with each other and the tungsten analogue. Important bond lengths and angles are Mo---Mo 2.180(24) Å, Mo---Se 2.432(av.) Å, Mo---O 1.872(9) Å, Mo---Mo---Se 99.39(9)°, 94.71(8)°, Mo---Mo---O 107.55(28)°. 相似文献
17.
Nest-shaped cluster [MoOICu 3S 3(2,2′-bipy) 2] (1) was synthesized by the treatment of (NH 4) 2MoS 4, CuI, ( n-Bu) 4NI, and 2,2′-bipyridine (2,2′-bipy) through a solid-state reaction. It crystallizes in monoclinic space group P2 1/ n, a=9.591(2) Å, b=14.820(3) Å, c=17.951(4) Å, β=91.98(2)°, V=2549.9(10) Å 3, and Z=4. The nest-shaped cluster was obtained for the first time with a neutral skeleton containing 2,2′-bipy ligand. The non-linear optical (NLO) property of [MoOICu 3S 3(2,2′-bipy) 2] in DMF solution was measured by using a Z-scan technique with 15 ns and 532 nm laser pulses. The cluster has large third-order NLO absorption and the third-order NLO refraction, its 2 and n2 values were calculated as 6.2×10 −10 and −3.8×10 −17 m 2 W −1 in a 3.7×10 −4 M DMF solution. 相似文献
18.
The reaction of Pt(PPh 3) n ( n = 3 or 4) with [(CF 3) 3Ge] 2Hg or (CF 3) 3GeHgPt(PPh 3) 2Ge(CF 3) 3 (I) gives a stable diplatinum complex [(CF 3) 3GePt(PPh 3) 2] 2Hg (II). X-Ray analysis has established that compound II contains a Ge---Pt---Hg---Pt---Ge chain of C2 symmetry. Both of the Pt atoms have distorted square-planar coordinations. The bond lengths are: Pt---Hg, 2.630(2) and 2.665(2) Å; Ge---Pt, 2.410(4) and 2.407(4) Å. Compound II reacts with dihydrogen in THF solution under mild conditions to give mercury and the hydride (CF3)3GePt(PPh3)2H. On interaction of II with R2Hg organomercurials (R = Cl, Et, GeEt3, Ge(CF3)3, Ge(C6F5)3) an unknown reaction takes place: Pt(PPh3)2 moieties migrate from the polymetallic grouping into the substrate with the formation of the corresponding RHgPt(PPh3)2R complexes or their demercuration products, R2Pt(PPh3);, (R = Cl, Et). The latter react further with complex I formed in the first step of the process to give Hg and (CF3)3GePt(PPh3)2R. The reaction schemes are discussed. 相似文献
19.
Treatment of ruthenium complexes [CpRu(AN) 3][PF 6] (1a) (AN=acetonitrile) with iron complexes CpFe(CO) 2X (2a–2c) (X=Cl, Br, I) and CpFe(CO)L′X (6a–6g) (L′=PMe 3, PMe 2Ph, PMePh 2, PPh 3, P(OPh) 3; X=Cl, Br, I) in refluxing CH 2Cl 2 for 3 h results in a triple ligand transfer reaction from iron to ruthenium to give stable ruthenium complexes CpRu(CO) 2X (3a–3c) (X=Cl, Br, I) and CpRu(CO)L′X (7a–7g) (L′=PMe 3, PMe 2Ph, PMePh 2, PPh 3, P(OPh) 3; X=Br, I), respectively. Similar reaction of [CpRu(L)(AN) 2][PF 6] (1b: L=CO, 1c: P(OMe) 3) causes double ligand transfer to yield complexes 3a–3c and 7a–7h. Halide on iron, CO on iron or ruthenium, and two acetonitrile ligands on ruthenium are essential for the present ligand transfer reaction. The dinuclear ruthenium complex 11a [CpRu(CO)(μ-I)] 2 was isolated from the reaction of 1a with 6a at 0°C. Complex 11a slowly decomposes in CH 2Cl 2 at room temperature to give 3a, and transforms into 7a by the reaction with PMe 3. 相似文献
20.
The adducts of O 2 and SO 2 with trans-MeOIr(CO)(PPh 3) 2 are formed in equilibria and have been characterized. Reaction of the SO 2 adduct, Ir(OMe)(SO 2)(CO)(PPh 3) 2 with dioxygen leads to the sulfato complex, Ir(Ome)(CO)(PPh 3) 2(SO 4), the structure of which has been determined. Ir(Ome)(CO)(PPh 3) 2(SO 4) 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) Å 3 and Z = 2. Diffraction data for 2θ = 4.5–45.0° (Mo- K) were collected with a Syntex P2 1 diffractometer and the structure was solved (assuming space group P2 1/ 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 ¦F O¦ > 6σ(¦ F¦)). The iridium(III) atom has a distorted octahedral coordination sphere with trans PPh 3 ligands and a cis-chelating bidentate O, O′-SO 4 group; the structure is completed by mutually cis OMe and CO ligands. 相似文献
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