We have investigated the decomposition of P(CH3)3 in 13-MHz, radio-frequency discharges in He and H2. Relative concentrations of atomic phosphorus were estimated actinometrically by measuring P emission intensities, relative to Ar, while quantitative, relative P2 number densities were measured by ArF excimer laser-induced fluorescence. A radiative lifetime of 10.5±1.0 ns was measured for the v=11 level of the C1u+
state, resonantly excited by the 193 nm laser. Additions of P(CH3)3 to He discharges reduce the electron energy distribution as sensed by the quenching of optical emission from He and trace amounts of added Ar, and thereby causes the overall process P(CH3)3P+3CH3 to occur with maximum efficiency at very low (0.5%) P(CH3)3 additions. H2 discharges are 10 times less efficient at producing P and P2, due to the lower electron energies, and possibly to hydrogenation reactions. P2 production in both He and H2 discharges increases linearly with pressure up to at least 10 torr. Under optimum conditions, plasma decomposition of P(CH3)3 (and by analogy PH3) promises to be an attractive source of phosphorus for growth of phosporus-containing thin films. 相似文献
The influence of hydrogen-containing molybdenum and tungsten bronzes on the catalytic activity of palladium composite catalysts for the oxidation of H2, CO, and CH4 was studied. It was found that the composite catalysts containing HxMO3 phases (M = W or Mo), which were formed by the reduction of MoO3 and WO3 oxides with hydrogen in the presence of deposited Pd, showed higher catalytic activity in the oxidation of small molecules (H2, CO, and CH4) with excess oxygen than the traditional Pd/Al2O3 deposited catalyst with the same content of the deposited metal. It was shown that the thermal stability of the HxMO3 phases was the limiting factor influencing the activity of these composite catalysts. 相似文献
[Ag2(CH3CH2C(CH3)2COO)2] (1), [Ag2(CH3CH2C(CH3)2COO)2(PMe3)2] (2) and [Ag2(CH3CH2C(CH3)2COO)2(PEt3)2] (3) were prepared and characterized by MS-EI; 1H, 13C, 31P NMR, variable temperature IR (VT-IR) spectroscopy and thermal analysis. MS and VT-IR data analysis suggests bidentate bridging carboxylates and monodentately bonded phosphines in the solid phase. The same methods used for gas phase analysis of 1–2 proved [(CH3CH2C(CH3)2COO)Ag2]+ as the main ion, which could be transported in the gas phase during the CVD process. In the case of 3, similar intensity to the latter ion revealed [Ag{P(C2H5)}]+ and it is responsible for the CVD performance of 3. Thermal analysis results revealed that decomposition of 1–3 proceed in one endothermic process, with metallic silver formation between 197 and 220 °C. In the case of 1, VT-IR studies of the gaseous decomposition products demonstrate the presence of ester molecules and CO2, whereas for 2 the main gaseous product appeared to be acid anhydride. Therefore, 2 was not used as a silver CVD precursor. Metallic layers were produced from 3 in hot-wall CVD experiments, (between 200 and 280 °C), under a total reactor pressure of 2.0 mbar, using argon as a carrier gas. Thin films deposited on Si(1 1 1) substrate were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Silver films obtained at moderate temperature (220–250 °C) revealed a thickness below 50 nm, and were whitish colored and slightly matt. 相似文献
The synthesis of a new, paramagnetic closo-[(8-(-CH2CH2O)2-1,2-C2B9H10)(1′,2′-C2B9H11)-3,3′-Fe]0 (3) is reported. This compound can serve as a versatile building block for construction of both anionic and zwitterionic derivatives, as exemplified by the synthesis of a series of compounds of general formula closo-[(8-X-(CH2CH2O)2-1,2-C2B9H10)(1′,2′-C2B9H11)-3,3′-Fe], bearing organic end groups (X = NC5H5 (4), (C6H5)3P (5), OH (6), and 2-O(1-CH3O-C6H4) (7)) attached to the cluster by a diethyleneglycol spacer. Molecular structures of 3, 4, 5 and 7 were determined by single-crystal X-ray diffraction analysis and by the long-time neglected method of paramagnetic, high field NMR (1H, 13C and 11B) spectroscopy. 相似文献
Reactions of iodination of monosubstituted derivatives of B12H11X2–anion (X = OC(O)CH3, OH, SCN) were studied. The reactions were shown to proceed smoothly to give B12H10(OC(O)CH3)I2–((carboxy)(iodo)[decahydro[Ih1551-20-closo]dodecaborate(2–)] anion), B12H10(OH)I2–((hydroxo)(iodo)[decahydro[Ih1551-20-closo]dodecaborate(2–)] anion), and B12H10(SCN)I2–((thiocyanato)(iodo)[decahydro[Ih1551-20-closo]dodecaborate(2–)] anion) in high yields, irrespective of the solvent used (benzene, H2O–ROH, where R = C2H5, CH2CH2CH3).1相似文献
New boron substituted cobalta bis(dicarbollide)(1-) ion (1) derivatives of formula [(8,8′-(RPhP(O)(CH2)nC(O)N) < (1,2-C2B9H10)2-3,3′-Co]− (R = Ph or C8H17, n = 1, 3a, 3b; R = Ph, n = 2, 3c), [(8-(Ph2P(O)CH2C(O)NR)(1,2-C2B9H10))(1′,2′-C2B9H11)-3,3′-Co]− (R = H, C2H5, CH2C6H5, 5a-c) and [(8-(2RPhP(O)CH2C(O)N(1R)CH2-1,2-C2B9H10))(8′-CH3O-1′,2′-C2B9H10)-3,3′-Co]− (1R = Benzyl, 2R = Ph or C8H17, 7a,b) were prepared with the aim to develop a new class of efficient extraction agents for partitioning of polyvalent f-block elements, i.e. lanthanides and actinides from high-level activity nuclear waste. The anionic ligands were characterized by multinuclear NMR spectroscopy and MS, the structures of Cs3a and the calcium complex of 7a were determined by X-ray diffraction analysis. The crystallographic study of the Cs3a proved a formation of linear chains in the structure, where the metal cation is coordinated by oxygen atoms of the CMPO terminal groups. The X-ray structure of the Ca2+ complex of the ionic ligand 7a proved a 1:3 metal to ligand ratio. Presented also is the X-ray structure of the starting ammonium compound 6 used in the synthesis of 7a and 7b. With exception of 5c, these anionic ligands are of high extraction efficiency, the highest being found for 7a in low polar solvent mixture hexyl methyl ketone-dodecane 1:1. These properties qualify some of these derivatives for possible technological applications. 相似文献
Films of BCxNy were produced in a plasma-enhanced chemical vapor deposition process using trimethylborazine as precursor and with H2, He, N2, and NH3, respectively, as auxiliary gas. These films deposited on Si(100) wafers or fused quartz glass substrates were characterized
chemically by X-ray photoelectron spectroscopy and by synchrotron radiation-based total-reflection X-ray fluorescence combined
with near-edge X-ray absorption fine structure. Independent of the auxiliary gas, the B–N bonds are dominating. Furthermore,
B–C and N–C bonds were identified. Oxygen, present in the bulk (in contrast to the surface layer of some nanometers, where
molecular oxygen and/or water are absorbed) as an impurity, is bonded to boron or to carbon, respectively. The relation of
boron and nitrogen changes with the character of the auxiliary gas: cB/cN ≈ 4:3 (for H2 and He) and cB/cN ≈ 1 (for N2 or NH3). Furthermore, physical properties such as the refractive index and the optical band-gap energy were determined. 相似文献
A set of pentacoordinated dimethyltin(IV) complexes of flexible N‐protected amino acids and fluorinated β‐diketone/β‐diketones was screened for their antibacterial activity against Pseudomonas aeruginosa , Staphylococcus aureus and Streptomyces griseus . These pentacoordinated complexes of the type Me2SnAB (where : R = CH(CH3)C2H5, A1H; CH2CH(CH3)2, A2H; CH(CH3)2, A3H; CH2C6H5, A4H; and BH = R'C(O)CH2C(O)R″: R′ = C6H5, R″ = CF3, B1H; R′ = R″ = CH3, B2H; R′ = C6H5, R″ = CH3, B3H; R′ = R″ = C6H5, B4H) were generated by the reactions of dimethyltin(IV) dichloride with sodium salts of flexible N‐protected amino acids (ANa) and fluorinated β‐diketone/β‐diketones (BNa) in 1:1:1 molar ratio in refluxing dry benzene solution. Plausible structures of these complexes were elucidated on the basis of physicochemical and spectral studies. 119Sn NMR spectral data revealed the presence of pentacoordinated tin centres in these dimethyltin(IV) complexes. 相似文献
The reaction of (p-cymene)Ru2(μ-S2)(S2C2B10H10)2 (I) with HC≡CCH(OH)(CH3)2 in dichloromethane led to addition complexes, (p-cymene)Ru2(μ-S2)(S2C2B10H10)2(R1C=CR2) (R1 = H, R2 = C(OH)(CH3)2 (II); R1 = C(OH)(CH3)2, R2 = H (III)). In boiling chloroform both complexes II and III spontaneously lose water to generate two geometrical isomers (p-cymene)Ru2(μ-S2)(S2C2B10H10)2(R1C=CR2) (R1 = H, R2 = C(CH3)=CH2 (IV); R1 = C(CH3)=CH2, R2 = H (V)), respectively. Complexes IV and V could be interconverted in boiling toluene. All these complexes were characterized by elemental analysis, mass spectrometry, and NMR spectroscopy. The molecular structure of complex IV has been determined by X-ray crystallography (CIF file CCDC no. 1443964). Complex IV crystallizes in monoclinic system, space group P21/c with a = 10.3717(9), b = 20.3982(17), c = 18.6428(13) Å, β = 111.096(4)°, C19H40B20Ru2S6, Mr = 879.27, V = 3679.8(5) Å3, ρc = 1.587 g/cm3, Z = 4, F(000) = 1752, μ(MoKα) = 1.179 mm–1, R = 0.0416 and wR = 0.0848 for 4602 observed reflections (I > 2σ(I)). 相似文献
Rhodacarboranes closo-3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H11 and closo-(2,3-C7H7CH2)-3,1,2-RhC2B9H11 are catalysts for the alcoholysis of hydridesilanes. Closo-3,3-(2,3-C7H7CH2)-3,1,2-RhC2B9H11 displays greater activity than closo-3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H11 though both rhodacarboranes catalyze the alcoholysis of hydridesilanes more efficiently than (Ph3P)3RhCl.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1657–1660, July, 1992. 相似文献
11 and 12 molar reactions of tin(IV) chloride with theSchiff bases, HO–C6H4CHNROH [where R=–(CH2)2–, –CH2–, –CH(CH3)–, –(CH2)3–, and –CH(C2H5)CH2–] have been studied in different stoichiometric ratios and derivatives of the type SnCl4(SBH2) and SnCl4(SBH2)2 (whereSBH2 represents theSchiff base molecule) have been isolated. These have been characterised by elemental analysis, conductivity measurements and I.R. spectral studies. 相似文献
Treatment of [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(COD) (1) with phosphites, phosphines, amines or N-heterocyclic carbene in THF afforded the COD displacement complexes [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[P(OEt)3]2 (2), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[PPh2(OEt)]2 (3), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[NH2CH2CH2Pri]2 (4), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NH2Prn)2 (5), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru (η2-NH2CH2CH2NH2) (6), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[η2-NH(CH3)CH2CH2NH(CH3)] (7) or [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[NHC]2 (8, NHC = 1,3,4,5-tetramethylimidazol-2-yilidene), respectively. Ruthenium-amine complexes were much more labile than 1. Upon exposure to moisture, 5 was converted into [{η5:σ-Me2C(C5H4)(C2B10H10)}Ru(μ-H2O)]2 (9). Reactions of 5 with PR3 (R = PPh3, Cy), TMEDA (TMEDA = N,N,N′,N′-tetramethylethylenediamine) and CH3CN afforded the corresponding amine replacement products[η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NH2Prn)(PPh3) (10), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NH2Prn)(PCy3) (11), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(TMEDA) (12) and [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NCCH3)2 (13). These results indicated that the steric factor dominated these substitution reactions. The electrochemical studies showed that the electron richness of the Ru atom decreased in the order L2Ru(NHC)2 > L2Ru(amine)2 > L2Ru(NCMe)2 > L2Ru(P)2. All of these complexes were fully characterized by various spectroscopic techniques and elemental analyses. The molecular structures of 2, 3, 5-10, 12 and 13 were further confirmed by single-crystal X-ray analyses. 相似文献
Linear isotherm regularity works very well for fluids at high densities, and it has been shown that it is compatible with the EOSs based on statistical–mechanical theory. On the other hand, at low densities, the first few terms of virial EOS have the most contribution to express the deviations from ideal behavior. For finding similarities between dense and dilute states, experimental p–v–T data of 14 fluids (He, Ne, Ar, Kr, H2, O2, N2, CO, NH3, CH3OH, CH4, C2H4, C2H6 and C3H8) are examined. Comparing the thermal dependencies of the attraction and repulsion terms (A and B) of the LIR with the second and third virial coefficients (B2 and B3) in liquid and supercritical regions (0.7 < Tr < 3.0) shows a remarkable similarity. Square-well potential is applied to examination and comparison of theoretical results with experimental results. It is shown that in liquid and supercritical regions, (1) the short-range potential governs among particles in dense fluids, and the long-range interactions become important in the less dense fluid, (2) similar to Boyle temperature, TB, in dilute state, there is a temperature as T′B (in dense fluids) that the attractive forces and the repulsive forces acting on the dense-fluid particles balance out; thus, probably there is a maximum σ (molecular diameter) at nearly 2Tc (T′B), and (3) in the liquid and supercritical regions (0.7 < Tr < 3.0), in the first-order approximation, there are no significant interactions higher than triple interactions in dense-fluid particles. 相似文献
The spectra of flowing microwave post-discharge excited in N2 and N2 + CH4(N2 + C2H2) gas mixtures have been studied at low temperature (77 K). The molecular spectra of CN emitted by the collision-induced N + C and N + CH chemiluminescent reactions in the low-temperature afterglow system have been thoroughly investigated. The intensity of different CN (B2+-X2+) vibrational bands is very sensitive to low hydrocarbon concentration in nitrogen used as the working gas. Detection of hydrocarbon species has been demonstrated from concentrations of CH4 and C2H2 in N2 greater than 1010 molecules · cm–3. 相似文献
The reaction of compound [Ru3(CO)10(μ-Cl)(μ-AuPPh3)] (1) with terminal alkynes HCCR; (R = C6H4-4-CH3, C6H3-2,5-(CH3)2, C6H2-2,4,5-(CH3)3, C(CH3) = CH2, Si(CH3)3), under very mild conditions yielded isostructural compounds [Ru3(CO)9(μ-AuPPh3)(μ3-η2-⊥-CCR)] (R = C6H4-4-CH3 (2), C6H3-2,5-(CH3)2 (3), C6H2-2,4,5-(CH3)3 (4), C(CH3)CH2 (5), Si(CH3)3) (6)) respectively; where the alkynes suffer oxidative additions to the metallic fragment coordinating as acetylide groups in a μ3-η2-perpendicular fashion by breaking the C(sp)-H bond of the alkynes. The AuPPh3 fragment remains without change in all compounds. All of these clusters have been characterized in solution by i.r. and n.m.r. spectroscopy and their structures have been established by single crystal X-ray diffraction studies. 相似文献
Sulfur and oxygen functionalized cyclopentandienyl half-sandwich cobalt dicarbonyl complexes [η5-C5H4(CH2)2SCH2CH3]Co(CO)2 (3) and [η5-C5H4(CH2)2OCH3]Co(CO)2 (7) were prepared. Oxidation of 3 or 7 with I2 led to formation of 18-electron complexes [η5-C5H4(CH2)2SCH2CH3]CoI2 (4) and [η5-C5H4(CH2)2OCH3]Co(CO)I2 (8). The reactions of diiodide complex (4) with dilithium 1,2-dicarba-closo-dodecaborane(12)-1,2-dichalcogenolates [(THF)3LiE2C2B10H10Li(THF)]2 [E=S (1a), Se (1b)] afforded 18-electron mononuclear complexes [η5-C5H4(CH2)2SCH2CH3]Co(E2C2B10H10) [E=S (5a), Se (5b)] in which sulfur atoms of side-chain were attached via an intramolecular coordination. Complex 7 reacted with 1a and 1b to give the binuclear complexes {[η5-C5H4(CH2)2OCH3]Co(E2C2B10H10)}2 [E=S (10a), Se (10b)]. The molecular structures of 5a and 10b were determined by X-ray crystallographic analysis. According to the X-ray structure analyses, 10b contains two o-carborane diselenolate bridges, and each Cp′Co fragment is attached to one terminal and two bridging selenolato ligands. The central Co2Se2 four-membered ring is planar, and the direct metal-metal interaction is absent. 相似文献
The oxonium derivative P(C6H5)4[2-B10H9O(CH2)4] (1) has been prepared from [B10H10]2− by a solvent-addition reaction route, promoted by Et2O · BF3. Its structure has been confirmed by single crystal X-ray analysis. 1 is assumed to be a useful synthon for the derivative chemistry of [B10H10]2−. As an illustration, ring-opening reaction occurred in presence of the strong nucleophilic agent OH−, giving the monoanionic derivative [P(C6H5)4]2[2-B10H9O(CH2)4OH] (2). 相似文献
This paper describes the study of chemical bonds in amorphous hydrogen rich boron/carbon (a-B/C:H) films by electron probe microanalysis. The films were deposited on Si single crystals by plasma chemical vapour deposition with a precursor-carborane (C2B10H12) in a laboratory setup. A film thickness and B/C ratio up to a value of 8000 Å and 4, respectively, have been obtained. The analysis of boron and carbon X-ray emission spectra has shown that the nearest order in the films is characterized by the coexistence of C-C, B-C and B-B bonds for B/C 1 and of B-B and B-C bonds for B/C 4. After two years exposure in air the oxygen content in the films increases from 2–5 to 15–20 at.%. 相似文献
The reactions of ozone with propene and isobutene have been studied in the gas phase at 298°K and 530 Pa (4 torr) using a stopped-flow reactor coupled to a photoionization mass spectrometer. Reactant and product concentrations were followed as a function of reaction time. The major reaction products monitored were CH2O, CH3CHO, CO2, and H2O from the propene reaction, and CH2O, (CH3)2CO, CO2, and H2O from the isobutene reaction. The observations were interpreted on the basis of the Criegee mechanism for ozonolysis in solution: for which we find kA≈kB.In the gas phase the carbene peroxy radical is postulated to isomerize and decompose into molecular and free-radical products. 相似文献
The reaction of RSiCl3 (R=CH3, C2H5, C6H5) and R2SiCl2 (R=CH3) with one mole of the phosphenimidous amides R2N–P=NR [R=R=Si(CH3)3; R=Si(CH3)3, R=C(CH3)3] yieds a four membered PN2Si-ring system under elimination of (CH3)3SiCl. 相似文献
