首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 296 毫秒
1.
A new method for the preparation of dialkylaminomethyl-phosphonous and-phosphinic acids, R2NCH2P(O)H(OH) and (R2NCH2)2P(O)OH, is described. This involves reaction of hypophosphorous acid with hydroxymethyl-dialkyl-amines or a mixture of formaldehyde and a secondary amine. and The crystalline acids form monohydrates which are stable up to the melting points of the acids. The IR. and 31P-NMR. spectra are reported.  相似文献   

2.
AlCl3 · 3NH3 — a Compound with the Crystal Structure of a Tetraammine Dichloro Aluminium-Diammine Tetrachloro Aluminate: [AlCl2(NH3)4]+[AlCl4(NH3)2]? . AlCl3 · 3 NH3 ? [AlCl2(NH3)4]+ [AlCl4(NH3)2]? forms during the reaction of two mole NH3 with AlCl3(NH3) at T ≥ 200°C. Repeated heating and cooling within 48 h between 200°C and 250°C gives a homogeneous product with total uptake of the necessary amount of NH3. Slow sublimation in a vacuum line apparatus at 200°C gives crystals of the triammoniate sufficient for a X-ray structure determination: The compound contains elongated [AlCl2(NH3)4]+ octahedra and compressed [AlCl4(NH3)2]? octahedra. Besides ionic bonding hydrogen bridge bonds with 3.369 Å ? d(N—H … Cl) ? 3.589 Å stabilize the atomic arrangement.  相似文献   

3.
On Phosphazo Compounds from Nitriles. IV. The Reaction of Tri, Di, and Monochloroacetonitrile with [Cl3P?N? PCl3]Cl. Improved Preparation of [Cl3P?N? PCl3]Cl Trichloroacetonitrile reacts with P2NCl7 to give Cl3C? CCl2? N?PCl2? N?PCl3 I , dichloroacetonitrile to give Cl2C?CCl? N?PCl2? N?PCl3 II , and chloroacetonitrile to give the ring compound III . Preparation, n.m.r. and mass spectra of the new compounds are described. The mechanism of formation is discussed. An improved procedure for the preparation of P2NCl7 is given.  相似文献   

4.
On Surface Compounds of Transition Metals. VIII. Complex Formation of a Coordinatively Unsaturated CrII Surface Compound with Nitrogen Oxides N2O forms with surface-Cr(II) a relatively unstable light blue compound of the stoichiometry 1:1, while addition of NO results in formation of a very stable dark brown, diamagnetic surface complex . By reaction with O2 this complex undergoes — depending on reaction temperature — either replacement of NO unter reoxidation of the metal (→Cr(VI)) or/and reaction of the ligand (→NO2). Direct reaction of NO2 with results in the same products as stepwise addition of NO and 1/2 O2. reacts with HCl/ROH under formation of the soluble, paramagnetic kation [Cr(NO)(ROH)n]2+, which is formulated as [Cr(II)(NO)]2+ ? [Cr(I)(NO+)]2+ accordingly to the e.s.r. spectra.  相似文献   

5.
The kinetics of oxidation of cis‐[CrIII(phen)2(H2O)2]3+ (phen = 1,10‐phenanthro‐ line) by IO4? has been studied in aqueous acidic solutions. In the presence of a vast excess of [IO4?], the reaction is first order in the chromium(III) complex concentration. The pseudo‐first‐order rate constant, kobs, showed a very small change with increasing [IO4?]. The dependence of kobs on [IO4?] is consistent with Eq. (i). (i) The pseudo‐first‐order rate constant, kobs, increased with increasing pH, indicating that the hydroxo form of the chromium(III) complex is the reactive species. An inner‐sphere mechanism has been proposed for the oxidation process. The thermodynamic activation parameters of the processes involved are also reported. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 563–568, 2011  相似文献   

6.
Supported Organometallic Complexes. VI. Characterization und Reactivity of Polysiloxane-Bound (Ether-phosphane)ruthenium(II) Complexes The ligands PhP(R)CH2D [R = (CH3O)3Si(CH2)3; D = CH2OCH3 ( 1b ); D = tetrahydrofuryl ( 1c ); D = 1,4-dioxanyl ( 1d )] have been used to synthesize (ether-phosphane)ruthenium(II) complexes, which have been copolymerized with Si(OEt)4 to yield polysiloxane-bound complexes. The monomers cis,cis,trans-Cl2Ru(CO)2(P ~ O)2 ( 3b ) and HRuCl(CO)(P ~ O)3 ( 5b ) were treated with NaBH4 to form cis,cis,trans-H2Ru(CO)2(P ~ O)2 ( 4b ) and H2Ru(CO)(P ~ O)3 ( 6b ), respectively (P ~ O = η1-P coordinated; = η2- coordinated). Addition of Si(OEt)4 and water leads to a base catalyzed hydrolysis of the silicon alkoxy-functions and a precipitation of the immobilized counterparts 4b ′, 6b ′. The polysiloxane matrix resulting by this new sol gel route has been described under quantitative aspects by 29Si CP-MAS NMR spectroscopy. 4b ′ reacts with carbon monoxide to form Ru(CO)3(P ~ O)2 ( 7b ′). Chelated polysiloxane-bound complexes Cl2Ru( )2 ( 9c ′, d ′) and Cl2Ru( )(P ~ O)2 ( 10b ′, c ′) have been synthesized by the reaction of 1b–c with Cl2Ru(PPh3)3 ( 8 ) followed by a copolymerization with Si(OEt)4. The polysiloxane-bound complexes 9c ′, d ′ and 10b ′, c ′ react with one equivalent of CO to give Cl2Ru(CO)( )(P ~ O) ( 12b ′– d ′). Excess CO leads to the all-trans-complexes Cl2Ru(CO)2(P ~ O)2 ( 14b ′– d ′), which are thermally isomerized to cis,cis,trans- 3b ′– d ′. The chemical shift anisotropy of 31P in crystalline Cl2Ru( )2 ( 9a , R = Ph, D = CH2OCH3) has been compared with polysiloxane-bound 9d ′ indicating a non-rigid behavior of the complexes in the matrix.  相似文献   

7.
Phenyl Phosphonic Bis(methylamide) and its Reactions with Phosphorus (III) Halides Preparation of phenyl phosphonic bis(methylamide), I , from phenyl phosphonic dichloride and methylamine is described. I is characterized by its nmr, mass, and vibration spectra and by its reactions with PCl3, CH3PCl2, and C6H5PCl2. The two reactions mentioned last yield C6H5P(O)[N(CH3)P(CH3)Cl]2 ( IIIa ) and C6H5P(O)[N(CH3)P(C6H5)Cl]2 ( IIIb ), respectively.  相似文献   

8.
Ab initio calculations at the CCSD(T)/6‐311++G(2d,p)//B3LYP/6‐311++G(d,p) level of theory have been carried out for three prototypical rearrangement processes of organosilicon anion systems. The first two are reactions of enolate ions which involve oxygen–silicon bond formation via three‐ and four‐membered states, respectively. The overall reactions are: The ΔG (reaction) values for the two processes are +175 and +51 kJ mol?1, with maximum barriers (to the highest transition state) of +55 and +159 kJ mol?1, respectively. The third studied process is the following: (CH3O)C(?CH2)Si(CH3)2CH → (CH3)2(C2H5)Si? + CH2CO, a process involving an SNi reaction between ‐CH and CH3O‐ followed by silicon–carbon bond cleavage. The reaction is favourable [ΔG(reaction) = ?39 kJ mol?1] with the barrier for the SNi process being 175 kJ mol?1. The previous experimental and the current theoretical data are complementary and in agreement. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

9.
A variety of salts derivative of bis(2‐picolyl)amine, ‘dipic’ = [{(C5NH4)(CH2)}2NH] in various stages of protonation have been structurally characterized, showing a considerable diversity of hydrogen‐bonding modes and interactions. For the triprotonated species (protonating hydrogen atoms on all three nitrogen atoms) the arrays are haphazard ([picH3]X3, X = Cl(·H2O), I(·H2O), NO3, tfs (= trifluoromethanesulfonate)(·H2O). For the diprotonated species, diverse forms are also found: in [dipicH2]Br2, the central nitrogen atom and one of the peripheral are protonated, but in the remainder, both peripheral nitrogen atoms are protonated, leading to a propensity to chelating interactions with an anion (as in the mixed anion salts and , where does not interact) or a water molecule (in the I·2H2O salt) or anion (in the tfs salt) oxygen atom; in the nitrate salt, the ligand is twisted so that each pyridinium component interacts with an independent nitrate. By contrast, in the singly protonated species, [dipicH]X, the central nitrogen atom is protonated in all cases (X = Br, I, ClO4, thf). The tfs? salt is remarkable, containing a pair of cations with self‐interactions. In [picH]X only the aliphatic nitrogen is protonated (X = I?, , , tfa? (= trifluoroacetate)). A single example of a diprotonated species [picH2]Cl2 has also been defined.  相似文献   

10.
The three new thioantimonates(V) [Ni(chxn)3]3(SbS4)2·4H2O ( I ), [Co(chxn)3]3(SbS4)2·4H2O ( II ) (chxn is trans‐1,2‐diaminocyclohexane) and [Co(dien)2][Co(tren)SbS4]2·4H2O ( III ) (dien is diethylenetriamine and tren is tris(2‐aminoethyl)amine) were synthesized under solvothermal conditions. Compounds I and II are isostructural crystallizing in space group C2/c. The structures are composed of isolated [M(chxn)3]2+ complexes (M = Ni, Co), [SbS4]3? anions and crystal water molecules. Short S···N/S···O/O···O separations indicate hydrogen bonding interactions between the different constituents. Compound III crystallizes in space group and is composed of [Co(dien)2]2+ and [Co(tren)SbS4]? anions and crystal water molecules. In the cationic complex the Co2+ ion is in an octahedral environment of two dien ligands whereas in [Co(tren)SbS4]? the Co2+ ion is in a trigonal bipyramidal coordination of four N atoms of tren and one S atom of the [SbS4]3? anion, i.e., two different coordination polyhedra around Co2+ coexist in this compound. Like in the former compounds an extended hydrogen bonding network connects the complexes and the water molecules into a three‐dimensional network.  相似文献   

11.
A New Rare‐Earth Metal(III) Fluoride Oxoselenate(IV): YF[SeO3] Just two representatives of the rare‐earth metal(III) fluoride oxoselenates(IV) with the formula type MF[SeO3] (M = La and Lu) exist so far, whereas for the intermediate lanthanoids only M3F[SeO3]4‐type compounds (M = Gd and Dy) were accessible. Because of the similar radius of Y3+ to the radii of the heavier lanthanoid cations, a missing link within the MF[SeO3] series could be synthesized now with the example of yttrium(III) fluoride oxoselenate(IV). Contrary to LuF[SeO3] with its triclinic structure, YF[SeO3] crystallizes monoclinically in space group P21/c (no. 14, a = 657.65(7), b = 689.71(7), c = 717.28(7) pm, β = 99.036(5)° and Z = 4). A single Y3+ cation occupying the general site 4e is surrounded by six oxide and two fluoride anions forming [YO6F2]11? polyhedra (d(Y–O) = 228–243 plus 263 pm, d(Y–F) = 219–220 pm). These are linked via common O···O edges to chains running along [010] and adjacent chains get tied to each other by sharing common O3···O3 and O3···F edges which results in sheets parallel to (100). The Se4+ cations connect these sheets as ψ1‐tetrahedral [SeO3]2? anions (d(Se–O) = 168–174 pm) for charge balance via all oxygen atoms. Despite the different coordination numbers of seven and eight for the rare‐earth metal(III) cations the structures of LuF[SeO3] and YF[SeO3] appear quite similar. The chains containing pentagonal bipyramids [LuO5F2]9? are connected to layers running parallel to the (100) plane again. In fact it is only necessary to shorten the partial structure of the straight chains along [001] to achieve the angular chains in YF[SeO3]. As a result of this shortening one oxide anion at a time moves into the coordination sphere of a neighboring Y3+ cation and therefore adds up the coordination number for Y3+ to eight. For the synthesis of YF[SeO3] yttrium sesquioxide (Y2O3), yttrium trifluoride (YF3) and selenium dioxide (SeO2) in a molar ratio of 1 : 1 : 3 with CsBr as fluxing agent were reacted within five days at 750 °C in evacuated graphitized silica ampoules.  相似文献   

12.
Precipitation of PdII as [Pd(NH3)2Cl2] and the Behaviour of Various Impurities The dependence of [Pd(NH3)2Cl2] precipitation upon reaction conditions (pH, Cl? content, reaction time, temperature) has been studied. The dependence of residual Pd content in the mother liquor upon these parameters was found to be significant only for the precipitation temperature (cPd at 20°C: 1.65 ± 0.11 mM; at 50°C: 6.70 ± 0.58 mM). The increase of Pd concentration was due to the formation of Pd(NH3)Cl3?. Among the impurities studied Cr, Ru, and Au were largely precipitated in the NH3 medium. In subsequent precipitation of [Pd(NH3)2Cl2] the following order of coprecipitation was found: The first four elements could be separated only incompletely by repeated reprecipitation. The coprecipitation of the platinum-group metals and of Au was highly dependence upon preceding formation of ammine complexes of these elements. The considerable coprecipitation of PtIV is presumably due to the formation of mixed Pd/Pt compounds, whereas the other impurities are adsorbed by [Pd(NH3)2Cl2].  相似文献   

13.
CuYS2: A Ternary Copper(I) Yttrium(III) Sulfide with Chains {[Cu(S1)3/3(S2)1/1]3–} of cis ‐Edge Connected [CuS4]7– Tetrahedra Pale yellow, lath‐shaped single crystals of the ternary copper(I) yttrium(III) sulfide CuYS2 are obtained by the oxidation of equimolar mixtures of the metals (copper and yttrium) with sulfur in the molar ratio 1 : 1 : 2 within fourteen days at 900 °C in evacuated silica ampoules, while the presence of CsCl as fluxing agent promotes their growth. The crystal structure of CuYS2 (orthorhombic, Pnma; a = 1345.3(1), b = 398.12(4), c = 629.08(6) pm, Z = 4) exhibits chains of cis‐edge linked [CuS4]7– tetrahedra with the composition {[Cu(S1)3/3(S2)1/1]3–} running along [010] which are hexagonally bundled as closest rod packing. Charge equalization and three‐dimensional interconnection of these anionic chains occur via octahedrally coordinated Y3+ cations. These are forming together with the S2– anions a network [Y(S1)3/3(S2)3/3] of vertex‐ and edge‐shared [YS6]9– octahedra with ramsdellite topology. The metall‐sulfur distances of the [CuS4]7– tetrahedra (230 (Cu–S2), 232 (Cu–S1), and 253 pm (Cu–S1′, 2 × )) cover a very broad interval, whilst these (Y–S: 267–280 pm) within the [YS6]9– octahedra range rather closely together.  相似文献   

14.
The kinetics of solvolysis of the title compound (QAc) in undried DMSO-d6 to give 4-(1-ethoxycarbonyl-1-cyano)methylquinoline (QH) and HOAc at ambient temperature were investigated by 1H nmr spectrometry. With a limited excess of water the solvolysis follows a three-step process of $ {\rm QAc} + {\rm H}_2 {\rm O}\mathop \to \limits^{k_1} {\rm QH} + {\rm HOAc}, $ , and $ {\rm Ac}_{\rm 2} {\rm O} + {\rm H}_2 {\rm O}\mathop \to \limits^{k_3} {\rm 2\,HOAc}, $ where k2 > k1 and k3 < k1. Addition of pyridine-d5 to the reaction mixture markedly catalyzes the overall solvolysis, while addition of CF3CO2D to the reaction mixture simplifies the kinetics to pseudo first-order in [QAc] with k = 4.3 × 10?3 min?1.  相似文献   

15.
The reduction of tris(pyridine‐2‐carboxylato)manganese(III) by dithionite has been investigated within the temperature window 288–303 K and at pH range 5.22–6.10 in sodium picolinate–picolinic acid buffer medium. The reaction obeys the following stoichiometry: The reaction is described in terms of a mechanism that involves an initial complex formation between S2O42? and [MnIII(C5H4NCO2)3] followed by S–S bond cleavage to give 2HSO3? and [MnII(C5H4NCO2)2(H2O)2] as the products via the formation of SO2●? radical anion. Kinetics and spectrophotometric evidences are cited in favor of the suggested mechanism. Thermodynamic parameters associated with the equilibrium step and the activation parameters with the rate‐determining step have been computed.  相似文献   

16.
Fluoridolysis of N-Phosphoryl Phosphazenes In the reaction of the N-phosphoryl phosphazenes X3P?N? P(Y)X2 (X = Cl, PhO, Et2N, CF3CH2O, PrS, Ph; Y = O, S) ( 1 – 18 ) with Et3N · nHF (n ≈? 3 or 0.6) fluoro derivatives of N-phosphoryl phosphazenes (see table 2) as well as N-phosphorylated imiddotetrafluorophosphates, [F4P?N? P(Y)Cl2]? (Y = O, S), and imidopentafluorophosphates, [F5P? N? P(Y)X2]2? or [F5P? NH? P(O)X2]? (see table 3), are formed. t-BuNHPCl2?N? POCl2 reacts in acetonitrile with Et3N or i-Pr2EtN to form a product, representing probably the diazadiphosphetine ( 5 b ).  相似文献   

17.
Pulsed laser photolysis of O3 in a large excess of N2 has been used to generate O(3P) atoms in the presence of OCS. By observing chemiluminescence from the small fraction of electronically excited SO2 formed in the reaction of SO with O3, rate constants of (1.7 ± 0.2) × 10?14 and (8.7 ± 1.6) × 10?14 cm3/molecule sec have been determined at 296 ± 4 K for the reactions and In addition, it has been shown that any reaction between SO and OCS has a rate constant 10?14 cm3/molecule sec.  相似文献   

18.
The kinetics of the reaction of O + CH3OCH3 were investigated using fast-flow apparatus equipped with ESR and mass-spectrometric detection. The concentration of O(3P) atoms to CH3OCH3 was varied over an unusually large range. The rate constant for reaction was found to be k = (5.0 ± 1.0) × 1012 exp [(?2850 ± 200/RT)] cm3 mole?1 sec?1. The reaction O + CH3OH was studied using ESR detection. Based on an assumed stoichiometry of two oxygen atoms consumed per molecule of CH3OH which reacts, we obtain a value of k = (1.70 ± 0.66) × 1012 exp [(?2,280 ± 200/RT)] cm3 mole?1 sec?1 for the reaction The results obtained in this study are compared with the results from other workers on these reactions. The observation of essentially equal activation energies in these two reactions is indicative of approximately equal C? H bond strengths in CH3OCH3 and CH3OH. This is in agreement with recent measurements of these bond energies.  相似文献   

19.
Nitrosyl-tetrachloro-dichlorophosphate-molybdate(+II); Preparation, I.R. Spectrum and Crystal Structure of (AsPh4)2[Mo(NO)Cl4(O2PCl2)] The title compound is prepared by the reaction of AsPh4[Mo(NO)Cl4] with AsPh4? [PO2Cl2] in dichloromethane solution. It forms orange crystals which are only little sensitive to moisture. The complex crystallizes triclinic in the space group P1 with two formula units in the unit cell. The structure was solved by X-ray diffraction methods (2498 observed, independent reflexions, R = 5.4%). The compound consists of AsPh4 cations and [Mo(NO)Cl4(PO2Cl2)]2? anions. The NO ligand is coordinated in linear array \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {{\rm MO}}\limits^ \ominus = \mathop {\rm N}\limits^ \oplus = {\rm O}(177^{\circ}) $\end{document}. The dichlorophosphate group is coordinated in trans position to the NO ligand with one of its oxygen atoms. The Mo?N bonding of the NO ligand causes the bond angle NMoCl of 93.2° in average. The IR spectrum is recorded and assigned.  相似文献   

20.
The 1H-NMR spectra of symmetric compounds with two phosphorus atoms of the type R? X? P? Y? P? X? R, R = CH3, C2H5, X = —, O, NCH3, NCH2—, Y = NCH3, have been determined. After elimination of eventual couplings within the alkyl protons these spectra always show triplets in the case of trivalent phosphorus and doublets in the case of pentavalent phosphorus atoms. Since this paper establishes an unequal coupling between the alkyl protons and the two phosphorus nuclei, it is concluded that these compounds show a degenerate, however deceivingly simple, coupling: The spectra of symmetric diorgano diphosphines can be interpreted via the same mechanism. Calculations to substantiate these findings are reported.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号