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1.
The compound [NH4(NH3)4][Co(C2B9H11)2] · 2 NH3 ( 1 ) was prepared by the reaction of Na[Co(C2B9H11)2] with a proton‐charged ion‐exchange resin in liquid ammonia. The ammoniate 1 was characterized by low temperature single‐crystal X‐ray structure analysis. The anionic part of the structure consists of [Co(C2B9H11)2] complexes, which are connected via C‐H···H‐B dihydrogen bonds. Furthermore, 1 contains an infinite equation/tex2gif-stack-2.gif[{NH4(NH3)4}+(μ‐NH3)2] cationic chain, which is formed by [NH4(NH3)4]+ ions linked by two ammonia molecules. The N‐H···N hydrogen bonds range from 1.92 to 2.71Å (DHA = Donor···Acceptor angles: 136‐176°). Additional N‐H···H‐B dihydrogen bonds are observed (H···H: 2.3‐2.4Å).  相似文献   

2.
Dilute mixtures of C6H6 or C6D6 in He provide abundant [C6H6] or [C6D6] ions and small amounts of [C6H7]+ or [C6D7]+ ions as chemical ionization (CI) reagent ions. The C6H6 or C6D6 CI spectra of alkylbenzenes and alkylanilines contain predominantly M ions from reactions of [C6H6] or [C6D6] and small amounts of MH+ or MD+ ions from reactions of [C6H7]+ or [C6D7]+. Benzene CI spectra of aliphatic amines contain M, fragment ions and sample-size-dependent MH+ ions from sample ion-sample molecules reactions. The C6D6 CI spectra of substituted pyridines contain M and MD+ ions in different ratios depending on the substituent (which alters the ionization energy of the substituted pyridine), as well as sample-size-dependent MH+ ions from sample ion-sample molecule reactions. Two mechanisms are observed for the formation of MD+ ions: proton transfer from [C6D6] or charge transfer from [C6D6] to give M, followed by deuteron transfer from C6D6 to M. The mechanisms of reactions were established by ion cyclotron resonance (ICR) experiments. Proton transfer from [C6H6] or [C6D6] is rapid only for compounds for which proton transfer is exothermic and charge transfer is endothermic. For compounds for which both charge transfer and proton transfer are exothermic, charge transfer is the almost exclusive reaction.  相似文献   

3.
Metastable ion peak shapes, dimensions and relative abundances have been measured for the three fragmentations [C3H6]+· → [C3H4]+· + H2, [C3H6]+· → [C3H5]+ + H· and [C3H6]+· → [C3H3]+ + H2 + H·. [C3H6]+· ions were derived from propene, cyclopropane, tetrahydrofuran, cyclohexanone, 2-methyl but-1-ene and cis-pent-2-ene. Activation energies for these fragmentations have been evaluated. Three daughter ion dissociations ([C3H5]+ → [C3H3]+ + H2, [C3H5]+ → [C3H4]+· + H· and [C3H4]+· → [C3H3]+ + H·) have been similarly examined. Ion structures have been determined and the metastable energy releases have been correlated with the thermochemical data. It is concluded that the molecular ions of propene and cyclopropane become structurally indistinguishable prior to fragmentation and that differences in their metastable ion characteristics can be ascribed wholly to internal energy differences; the latter can be correlated with the photoelectron spectra of the isomers. The pathway for the consecutive fragmentation which generates the metastable ion peak (m/e 42 → m/e.39) has been shown to be It is likewise concluded that fragmentating [C3H6]+· ions generated from the various precursor molecules are also structurally indistinguishable and cannot be classified with either molecular ion of the isomeric C3H6 hydrocarbons.  相似文献   

4.
Reaction of [M(NH3)6]Cl3 (M = Co, Rh, Ir) and [Ir(NH3)5(OH2)]Cl3 with (NH4)2C2O4 · H2O in aqueous solution resulted in the isolation of [M(NH3)6]2(C2O4)3 · 4 H2O and [Ir(NH3)5(OH2)]2(C2O4)3 · 4 H2O, respectively. The complexes have been characterized by X‐ray crystallography, IR and UV/VIS spectroscopy. The isomorphous compounds crystallize in the orthorhombic space group Pnnm (No. 58). Four molecules of crystal water are involved in an extended three‐dimensional hydrogen bonding network. The librational modes of the lattice water around 600 cm–1 allow the characterization of [Ir(NH3)6]2(C2O4)3 · 4 H2O and [Ir(NH3)5(OH2)]2(C2O4)3 · 4 H2O, respectively, by IR spectroscopy. The band around 600 cm–1 shows a significant frequency shift in the IR spectra of the hexaammine and aquapentaammine complex of iridium(III) and, by that, a distinction is possible.  相似文献   

5.
Ternary clusters (NH3)·(H2SO4)·(H2O)n have been widely studied. However, the structures and binding energies of relatively larger cluster (n > 6) remain unclear, which hinders the study of other interesting properties. Ternary clusters of (NH3)·(H2SO4)·(H2O)n, n = 0-14, were investigated using MD simulations and quantum chemical calculations. For n = 1, a proton was transferred from H2SO4 to NH3. For n = 10, both protons of H2SO4 were transferred to NH3 and H2O, respectively. The NH4+ and HSO4 formed a contact ion-pair [NH4+-HSO4] for n = 1-6 and a solvent separated ion-pair [NH4+-H2O-HSO4] for n = 7-9. Therefore, we observed two obvious transitions from neutral to single protonation (from H2SO4 to NH3) to double protonation (from H2SO4 to NH3 and H2O) with increasing n. In general, the structures with single protonation and solvated ion-pair were higher in entropy than those with double protonation and contact ion-pair of single protonation and were thus preferred at higher temperature. As a result, the inversion between single and double protonated clusters was postponed until n = 12 according to the average binding Gibbs free energy at the normal condition. These results can serve as a good start point for studies of the other properties of these clusters and as a model for the solvation of the [H2SO4-NH3] complex in bulk water.  相似文献   

6.
Acetamide and thioacetamide react with the superacid solutions HF/MF5 (M = As, Sb) under formation of the corresponding salts [H3CC(OH)NH2]+MF6 and [H3CC(SH)NH2]+MF6 (M = As, Sb), respectively. The reaction of DF/AsF5 with acetamide and thioacetamide lead to the corresponding deuterated salts [H3CC(OD)ND2]+AsF6 and [H3CC(SD)ND2]+AsF6, respectively. The salts are characterized by vibrational and NMR spectroscopy, and in the case of [H3CC(OH)NH2]+AsF6 and [H3CC(SH)NH2]+AsF6 also by single‐crystal X‐ray analyses. The [H3CC(OH)NH2]+AsF6( 1 ) salt crystallizes in the triclinic space group P$\bar{1}$ with two formula units per unit cell, and the [H3CC(SH)NH2]+AsF6( 2 ) salt crystallizes in the monoclinic space group P21/c with four formula units per unit cell. In both crystal structures three‐dimensional networks are observed which are formed by intra‐ and intermolecular N–H ··· F and O–H ··· F or S–H ··· F hydrogen bonds, respectively. For the vibrational analyses, quantum chemically calculated spectra of the cations [H3CC(OH)NH2 · 3HF]+ and [H3CC(SH)NH2 · 2HF]+ are considered.  相似文献   

7.
The reactions of Ru+ with C2H6, C3H8, HC(CH3)3, and c-C3H6 at hyperthermal energies have been studied using guided ion beam mass spectrometry. It is found that dehydrogenation is efficient and the dominant process at low energies in all four reaction systems. At high energies, C-H cleavage processes dominate the product spectrum for the reactions of Ru+ with ethane, propane, and isobutane. C-C bond cleavage is a dominant process in the cyclopropane system. The reactions of Ru+ are compared with those of the first-row transition metal congener Fe+ and the differences in behavior and mechanism are discussed in some detail. Modeling of the endothermic reaction cross sections yields the 0-K bond dissociation energies (in eV) of D 0(Ru-H)=2.27±0.15, D 0(Ru+-C)=4.70±0.11, D 0(Ru+-CH)=5.20±0.12, D 0(Ru+-CH2)=3.57±0.05, D 0(Ru+-CH3)=1.66±0.06, D 0(Ru-CH3)=1.68±0.12, D 0(Ru+-C2H2)=1.98±0.18, D 0(Ru+-C2H3)=3.03±0.07, and D 0(Ru+-C3H4)=2.24±0.12. Speculative bond energies for Ru+=CCH2 of 3.39±0.19 eV and Ru+=CHCH3 of 3.19±0.15 eV are also obtained. The observation of exothermic processes sets lower limits for the bond energies of Ru+ to ethene, propene, and isobutene of 1.34, 1.22, and 1.14 eV, respectively.  相似文献   

8.
In sodium hexa­amminecobalt(III) tetra­kis­(4‐fluoro­benzoate) monohydrate, Na[Co(NH3)6](C7H4FO2)4·H2O, determined at 180 K, [Co(NH3)6]3+ cations lie on centres of inversion and form layers in which their C4 axes lie perpendicular to the layer planes. 4‐Fluoro­benzoate anions lie on twofold axes and general positions and adopt near‐planar geometries. Na+ cations and water mol­ecules lie on twofold axes, forming [NaO5] square pyramids that lie between the [Co(NH3)6]3+ cations. The second‐sphere inter­actions between [Co(NH3)6]3+ cations and 4‐fluorobenzoate anions comprise edge‐to‐face and vertex‐to‐face arrangements. The structure is closely comparable with that of the benzoic acid salt, demonstrating that fluorination of the anion in the para position has no significant influence on the second‐sphere inter­actions and minimal influence on the gross crystal structure.  相似文献   

9.
Collisionally activated decompositions and ion-molecule reactions in a triple-quadrupole mass spectrometer are used to distinguish between cis- and trans-1,2-cyclopentanediol isomers. For ion kinetic energies varying from 5 eV to 15 eV (laboratory frame of reference), qualitative differences in the daughter ion spectra of [MH]+ are seen when N2 is employed as an inert collision gas. The cis ?1,2-cyclopentanediol isomer favors H2O elimination to give predominantly [MH- H2O]+. In the trans isomer, where H2O elimination is less likely to occur, the rearrangement ion [HOCH2CHOH]+ exists in significantly greater abundance. Ion-molecule reactions with NH3 under single-collision conditions and low ion kinetic energies can provide thermochemical as well as stereochemical information. For trans ?1,2-cyclopentanediol, the formation of [NH4]+ by proton transfer is an exothermic reaction with the maximum product ion intensity at ion kinetic energies approaching 0 eV. The ammonium adduct ion [M + NH4]+ is of greater intensity for the trans isomer. In the proton transfer reaction with the cis isomer, the formation of [NH4]+ is an endothermic process with a definite translational energy onset. From this measured threshold ion kinetic energy, the proton affinity of cis ?1,2-cyclopentanedioi was estimated to be 886 ± 10 kJ mol?1.  相似文献   

10.
For compounds C6H5X (X?Cl, Br, I) under chemical ionization conditions, methylamine causes ipso substitution of X by [NH2CH3]+ and by [NH2]+˙. C6H5F is less reactive; it gives some [C6H5NH2]+˙. Nitrobenzene gives an adduct ion [M+CH3NH3]+, a reduction product ion [C6H5NO2]+˙, and an ion at m/z93, probably a substitution product [C6H5NH2]+˙, but no [C6H5NH2CH3]+. It is also shown that the ion m/z94, formed from nitrobenzene with ammonia as reagent gas, is a substitution product rather than a reduction product ion. Carbonyl compounds C6H5. CO. X give adduct ions and some substitution, mainly [C6H5NH2]+˙.  相似文献   

11.
Breakdown graphs have been constructed from charge exchange data for the epimeric 2-methyl-, 3-methyl- and 4-methyl-cyclohexanols. Although the breakdown graphs for epimeric pairs are essentially identical above ~12 eV recombination energy, significant differences are observed for the epimeric 2-methyl- and 4-methyl-cyclohexanols at low internal energies. For the 2-methylcyclohexanols the ratio ([M? H2O]/[M])cis/([M? H2O]/[M])trans is 3.2 in the [C6F6] charge exchange mass spectra. This is attributed to both energetic and conformational effects which favour the stereospecific cis-1,4-H2O elimination for the cis epimer. The breakdown graph for trans-4-methylcyclohexanol shows a sharp peak in the abundance of the [M? H2O] ion at ~10 eV recombination energy which is absent from the breakdown graph for the cis epimer. This peak is attributed to the stereospecific cis-1,4-elimination of water from the molecular ion of the trans isomer; the reaction appears to have a low critical energy but a very unfavourable frequency factor, and alternative modes of water loss common to both epimers are observed at higher energies. As a result, in the [C6F6] charge exchange mass spectra the ([M? H2O]/[M])trans/([M? H2O]/[M])cis ratio is ~24, compared to the value of 13 observed in the 70 eV EI mass spectra. No differences are observed in either the metastable ion abundances or the associated kinetic energy releases for epimeric molecules.  相似文献   

12.
Compounds C6H5X(X ? F, Cl, Br, NO2, CN, OCH3) have been studied under chemical ionization conditions with ammonia as reagent gas. A pulsed electron beam and time resolved ion collection has allowed the determination of the reaction leading to the formation of [C6H5NH3]+ (m/z 94). [NH4]+ reacts with C6H5X(X ? F, Cl, Br) to yield m/z 94 but C6H5X (X ? CN, NO2) forms this ion only by reactions involving either [NH3]+ or [C6H5X]+. C6H5OCH3 does not form m/z 94.  相似文献   

13.
Single-crystalline materials of Li[H2N3C3O3] · 1.75 H2O and Mg[H2N3C3O3]2 · 8 H2O were obtained by dissolving stoichiometric amounts of the respective carbonates with cyanuric acid in boiling water followed by gentle evaporation of excess water after cooling to room temperature. Even though both of these compounds crystallize in the triclinic space group P1 according to X-ray structure analyses of their colorless and transparent single crystals, they adopt two new different structure types. Li[H2N3C3O3] · 1.75 H2O exhibits the unit-cell parameters a = 884.71(6) pm, b = 905.12(7) pm, c = 964.38(7) pm, α = 67.847(2)°, β = 62.904(2)° and γ = 68.565(2)° (Z = 4), whereas the lattice parameters for Mg[H2N3C3O3]2 · 8 H2O are a = 691.95(5) pm, b = 1055.06(8) pm, c = 1183.87(9) pm, α = 85.652(2)°, β = 83.439(2)° and γ = 79.814(2)° (Z = 2). In both cases, the singly deprotonated isocyanuric acid forms monovalent anions consisting of cyclic [H2N3C3O3] units, which are arranged in ribbons typical for most hitherto known monobasic isocyanurate hydrates. The structures are governed by the oxophilic strength of the respective cation which means that they fulfil their oxophilic coordination requirements either solely with water molecules ([Mg(OH2)6]2+ for Mg2+) or with crystal water and one or two direct coordinative contacts to carbonyl oxygen atoms (O(cy)) of [H2N3C3O3] anions ([(Li(OH2)2–3(O(cy)1–2]+ for Li+). In both structures occur dominant hydrogen bonds N–H ··· O within the anionic [H2N3C3O3] ribbons as well as hydrogen bonds O–H ··· O between these ribbons and the hydrated Li+ and Mg2+ cations.  相似文献   

14.
Collisional activation spectra of [C8H8]+·, [C8H8]2+, [C6H6]+· and [C6H5]+ ions from fifteen different sources are reported. Decomposing [C8H8]+· ions of ten of these precursors isomerise to a mixture of mainly the cyclooctatetraene and, to a smaller extent, the styrene structure. Three additional structures are observed with [C8H8]+· ions from the remaining precursors. [C8H8]2+., [C8H8]+·, [C6H6]+· and [C6H5]+· ions mostly decompose from common structures although some exceptions are reported.  相似文献   

15.
Two different hydrogen-bonded inclusion compounds, [2,4,6-C5H2N(COO?)3]0.5·[C(NH2) 3 + ]0.5·[(C2H5)4N+]·2H2O (1) and [2,4,6-C5H2N(COO?)3]·[C(NH2) 3 + ]·[(C2H5)4N+]·[(C3H7)4N+]·6H2O (2) are reported in this paper, in which 2,4,6-pyridine-tricarboxylic anions, guanidiniums and water molecules jointly construct host lattices while tetraalkylammonium cations are accommodated as guest species. Both two compounds formed sandwich-like hydrogen-bond inclusion compounds. In compound 1, the dimers composed of 2,4,6-pyridine-tricarboxylic anions and guanidiniums form 2D hydrogen-bonded layers by connecting with water molecules. In compound 2, 2,4,6-pyridine-tricarboxylic anions, guanidiniums and water molecules contribute to generate an undulate rosette hydrogen-bonded architecture. Interestingly, in compound 2, there are two species of guest molecules, tetraethylammonium and tetrapropylammonium, which are alternately arranged between the neighboring layers. Mixed guest cations accommodated in hydrogen-bonded inclusion compounds are seldom seen.  相似文献   

16.
Synthesis and Crystal Structures of [P(C6H5)4][1-(NH3)B10H9] and Cs[(NH3)B12H11] · 2CH3OH The reduction of [1-(NO2)B10H9]2? with aluminum in alkaline solution yields [1-(NH3)B10H9]? and by treatment of [B12H12]2? with hydroxylamine-O-sulfonic acid [(NH3)B12H11]? is formed. The crystal structures of [P(C6H5)4][1-(NH3)B10H9] (triclinic, space group P1 , a = 7.491(2), b = 13.341(2), c = 14.235(1) Å, α = 68.127(9), β = 81.85(2), γ = 86.860(3)°, Z = 2) and Cs[(NH3)B12H11] · 2CH3OH (monoclinic, space group P21/n, a = 14.570(2), b = 7.796(1), c = 15.076(2) Å, β = 111.801(8)°, Z = 4) reveal for both compounds the bonding of an ammine substituent to the cluster anion.  相似文献   

17.
Two new three‐dimensional frameworks with zeolite‐like channels were prepared in the presence of 1,6‐diaminohexane. Cu1.5(H3N–(CH2)6–NH3)0.5[C6H2(COO)4] · 5H2O ( 1 ) crystallizes in the triclinic space group P$\bar{1}$ with a = 772.56(7), b = 1110.36(7), c = 1111.98(8) pm, α = 98.720(7)°, β = 108.246(9)°, and γ = 95.559(7)°. Cu2(H3N–(CH2)6–NH3)0.5(OH)[C6H2(COO)4] · 3H2O ( 2 ) crystallizes in the monoclinic space group P2/c with a = 1159.34(11), b = 1059.44(7), c = 1582.2(2) pm, and β = 106.130(11)°. The Cu2+ coordination polyhedra are connected by [C6H2(COO)4]4– anions to yield three‐dimensional frameworks with wide centrosymmetric channel‐like voids. Complex 1 reveals voids extending along [100] with diagonals of 900 pm and 300 pm, whereas in complex 2 the diagonal of the nearly rectangular crossection of the channels extending parallel to [001] is 900 pm. The negative excess charges of the frameworks are compensated by [H3N–(CH2)6–NH3]2+ cations, which occupy the voids along with water molecules. The [H3N–(CH2)6–NH3]2+ cations are not connected to Cu2+ and have served as templates.  相似文献   

18.
Abstract

New inclusion complexes (n-C4H9)3(CH3)N+HC2O-4.(NH2)2CS+HC2O? 4·(NH2)2CS·(½)H2C2O4 (1), [(C2H5)3(n-C3H7) N+]2CO2- 3·6(NH2)2CS (2) and 2[(CH3)3(C6H5)N+]2 CO2- 3·11(NH2)2CS. H2O (3) have been prepared and characterized by X-ray crystallography. Crystal data, MoKα radiation: 1, space group Fdd2, a=18.603(3), b=63.661(8), c=7.830(1)Å, Z=16, and RF =0.0648 for 1297 observed data; 2, space group P 1, a=12.593(2), b=13.075(2), c=16.238(2) Å, α=76.16(1), β=71.17(1), γ=66.32(1)°, Z=2, and RF =0.041 for 4570 observed data; 3, space group P 1, a=11.605(2), b=17.059(3), c=22.779(5) Å, α=109.46(3), β=92.72(3), γ=107.07(3)°, Z=2, and R F =0.081 for 5105 observed data. In the crystal structure of 1, the thiourea molecules, hydrogen oxalate ions and oxalic acid molecules build a three-dimensional network containing two fused channel systems that are arranged alternately along the [101] and [101] directions, with the tri-n-butylmethylammonium cations arranged in a zigzag column within each channel. Compound 2 features a three-dimensional open host structure in which two channel systems extend parallel to the [100] and [010] directions, which accommodate stacked columns of triethyl-n-propylammonium cations. In the crystal structure of 3, infinite thiourea chains and thiourea-carbonate layers are connected to generate a unidirectional channel host lattice that accommodates straight columns of trimethylphenylammonium cations.  相似文献   

19.
The structures of orthorhombic bis[pentaammineaquacobalt(III)] tetra‐μ2‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Ibam), [Co(NH3)5(H2O)]2[Zr3F18]·6H2O, (I), and bis[hexaamminecobalt(III)] tetra‐μ2‐fluorido‐tetradecafluoridotrizirconium(IV) hexahydrate (space group Pnna), [Co(NH3)6]2[Zr3F18]·6H2O, (II), consist of complex [Co(NH3)x(H2O)y]3+ cations with either m [in (I)] or and 2 [in (II)] symmetry, [Zr3F18]6− anionic chains located on sites with 222 [in (I)] or 2 [in (II)] symmetry, and water molecules.  相似文献   

20.
Complexes of the Alkali Metal Tetraphenylborates with Macrocyclic Crown Ethers Alkali metal tetraphenylborates, MB(C6H5)4 (M = Li to Cs), react in tetrahydrofuran with macrocyclic crown ethers to give complexes of the general formula MB(C6H5)4(crown)m(THF)n. Suitable single crystals for X‐ray structure analysis were grown from a solvent mixture of tetrahydrofuran and n‐hexane. The salt like complexes [Li(12‐crown‐4)(thf)][B(C6H5)4] ( 1 ), [Na(15‐crown‐5)(thf)][B(C6H5)4] ( 2 ), and [Cs(18‐crown‐6)2][B(C6H5)4] · THF ( 6 ), the mononuclear molecular complexes [KB(C6H5)4(18‐crown‐6)(thf)] ( 3 ), [RbB(C6H5)4(18‐crown‐6)] ( 4 ), and [CsB(C6H5)4(18‐crown‐6)] · THF ( 5 ), and the compound [CsB(C6H5)4(18‐crown‐6)]2[Cs(18‐crown‐6)2][B(C6H5)4] ( 7 ), which contains a binuclear molecule ([CsB(C6H5)4(18‐crown‐6)]2) beside a [Cs(18‐crown‐6)2]+ cation and a [B(C6H5)4]? anion, are described. All compounds are charactarized by infrared spectra, elemental analysis, NMR‐spectroscopy, and X‐ray single crystal structure analysis.  相似文献   

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