The reaction of N3H7SO4 with barium compounds BaX2 in aqueous solutions yields under precipitation of BaSO4 solutions which contain the corresponding salts of triazane N3H6X (X = NO, ClO, Cl?, CH3COO?, N3, CN?, Br?, OH?). Due to the instability of the triazanium ion, NH2? NH2? \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm N}\limits^{\rm + } $\end{document}H2, the solid triazanium salts could only be isolated in mixture with the also formed BaSO4. The properties of these compounds are described. 相似文献
The anions [(TeCF3)2X]? (X = Cl, Br, I) resemble the trihalides [I2X]? in the solid state and show similar dynamic behaviour in solution. All three compounds crystallize iso‐structurally in the triclinic space group with Z = 2 and exhibit cell dimensions according to the sizes of the halogen atoms. 相似文献
Some classes of organometallic catalysts what induce stereospecific polymerization of methacrylonitrile have been found. They include organolithium aluminum compounds of the type LiAlR4, Li[R3AlOAlR2], and Li[R3AlN(R)AlR2], organosodium aluminum compounds of the type NaAlR4, organolithium zinc compounds of the type LiZnR3 and Li2ZnR4, organomagnesium aluminum compounds of the type RMg[AlR4] and Mg[AlR4]2, and organomagnesium compounds containing an Mg? N bond, such as and their related compounds. One of the features of the polymerization with these catalysts was that the crystalline polymers were formed at moderately high temperatures. Total conversion, solubility index, and molecular weight of the polymer increased with increasing polymerization temperature, as observed in the case of polymerization with diethylmagnesium catalyst. Catalysts with an Mg? N bond were found to be highly effective for the stereospecific polymerization. The acetone-insoluble fractions of the polymers gave x-ray diagrams identical to the crystalline polymer produced with diethylmagnesium. This indicates that the acetone-insoluble crystalline polymers produced with these catalysts have an isotactic structure. The viscosity–molecular weight relationship for crystalline polymer was conveniently determined in Cl2CHCOOH at 30°C.; [η] = 2.27 × 10?4M0.754. 相似文献
In this study, a new bidentate Schiff base ligand (L) entitled as N,N’-bis(dimethylaminocinnamaldehyde)-2,2-dimethyl-1,3-propanediamine and its mercury complexes were synthesized. The Schiff base ligand and its complexes were characterized using FT-IR, 1H-, 13C-NMR spectroscopy, molar conductivity and electronic spectral study. Regarding physical and spectral data, the general formula for the complexes was suggested as HgLX2 (L = Schiff base ligand and X = Cl?, Br?, I?, SCN?, N3?). For structural identification of these complexes, crystal structure of mercury iodide complex was analyzed as typical one. In the structure of this complex, Hg ion is surrounded by 2 iodide ions and 2 N atoms from the Schiff base ligand to form a four-coordinated mercury complex in triclinic system with space group of P1. Angular index (τ4) value was evaluated equal to 0.85, so the geometry around the mercury ion in this complex can be described as trigonal pyramid. A layered supramolecular structure for HgLI2 complex is stabilized by C–H···I and C–H···π interactions in solid state. DFT study on the ligand and its complexes was also carried out, and then some calculated and experimental structural parameters of HgLI2 were compared. Thermal behaviors of the titled compounds were investigated by thermogravimetric analyses. Furthermore, biological properties of the ligand and its complexes were examined against some Gram-negative and Gram-positive bacteria and also against 2 fungi. Finally, the interaction of the ligand and its complexes with DNA was investigated by electrophoresis method. 相似文献
A new series of di- and tri-organotin(IV) compounds with the general formula R4?n SnLn, where R?=?Me (1,2), Et (3), n-Bu (4,5), n-Oct (6), Ph (7) and L?=?(E)-3-(4-methoxyphenyl)-2-(4-chlorophenyl)-2-propenoate, were synthesized by reaction of silver salt of ligand or ligand acid with diorganotin dichloride/oxide and triorganotin chloride in 2:1 and 1:1 molar ratio, respectively. These compounds were characterized by elemental analyses, FT-IR, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry. The spectroscopic results revealed that all the diorganotin(IV) compounds possess trigonal bipyramidal structures in solution and octahedral geometry in the solid state around the tin atom. A linear polymeric trigonal bipyramidal structure in the solid state and a tetrahedral environment around the tin atom in non-coordinating solvents has been proposed for the triorganotin(IV) compounds. All synthesized compounds were tested in vitro against a number of microorganisms to assess their biocidal activity. These studies revealed that ligand acid and some of its organotin compounds show promising activity against different strains of bacteria and fungi but lowered than reference drugs. 相似文献
The dynamic behavior of the N,N,N′,N′‐tetramethylethylenediamine (tmeda) ligand has been studied in solid lithium‐fluorenide(tmeda) ( 3 ) and lithium‐benzo[b]fluorenide(tmeda) ( 4 ) using CP/MAS solid‐state 13C‐ and 15N‐NMR spectroscopy. It is shown that, in the ground state, the tmeda ligand is oriented parallel to the long molecular axis of the fluorenide and benzo[b]fluorenide systems. At low temperature (<250 K), the 13C‐NMR spectrum exhibits two MeN signals. A dynamic process, assigned to a 180° rotation of the five‐membered metallacycle (π‐flip), leads at elevated temperatures to coalescence of these signals. Line‐shape calculations yield ΔH?=42.7 kJ mol?1, ΔS?=?5.3 J mol?1 K?1, and =44.3 kJ mol?1 for 3 , and ΔH?=36.8 kJ mol?1, ΔS?=?17.7 J mol?1 K?1, and =42.1 kJ mol?1 for 4 , respectively. A second dynamic process, assigned to ring inversion of the tmeda ligand, was detected from the temperature dependence of T1ρ, the 13C spin‐lattice relaxation time in the rotating frame, and led to ΔH?=24.8 kJ mol?1, ΔS?=?49.2 J mol?1 K?1, and =39.5 kJ mol?1 for 3 , and ΔH?=18.2 kJ mol?1, ΔS?=?65.3 J mol?1 K?1, and =37.7 kJ mol?1 for 4 , respectively. For (D12)‐ 3 , the rotation of the CD3 groups has also been studied, and a barrier Ea of 14.1 kJ mol?1 was found. 相似文献
MINDO/3 calculations have been made of the molecular structures and energies of seven isomeric forms of the molecular cation (CCl4)+, of the mass spectral fragment pairs: and also of a number of neutral fragment pairs. Reaction energy profiles have been calculated for two fragmentations of (CCl4)+, into [(CCl2)+ + Cl2], and into [(CCl3)+ + Cl?], in the latter of which the reaction proceeds via a rather stable intermediate; for the fragmentation of three electronic states of (CCl3)+ into [(CCl2)+ + Cl?], where the ground singlet state and first triplet state of (CCl3+ yield the ground doublet state of (CCl2)+, but the first excited singlet of (CCl3)+ yields the first excited doublet of (CCl2)+ ; and for the fragmentation of the ground state of (CCl3)+ into [(CCl)+ + Cl2]. 相似文献
Preparation and Spectroscopic Characterization of Fluoro-Chloro-Iridates(V) By careful oxidation of the pure fluoro-chloro iridates(IV) with BrF3 in dichloromethane the corresponding pentavalent complexes [IrF5Cl]?, cis-[IrF4Cl2]?, and fac-[IrF3Cl3]? are formed without replacements of Cl ligands. The vibrational spectra of these mixed ligand complexes are assigned according to point groups C4v, C2v, and C3v. The increased bond strength compared with the corresponding IrIV compounds is indicated by a significant shift to higher energy by about 5–15%. The anomalous intensities of some of the Raman active fundamentals are attributed to the resonance Raman effect. The electronic absorption spectra are measured on the solid tetraethylammonium salts of the fluoro-chloro iridates(V) at 10 K. The strong bands in the UV/VIS region are assigned to charge transfer transitions from π(t1u, t2u) and σ(t1u) Cl orbitals into the π(t)IrV level. The intraconfigurational transitions within the t configuration of IrV are split by spin orbit coupling and lowered symmetry, observed in the ranges 3000, 5100–6400, 10900–13000, and 18200 cm?1. The O? O transitions are deduced from the vibrational fine structure; in some cases they are confirmed by electronic Raman bands. With increasing number of F ligands all absorption bands are shifted systematically to higher energies. 相似文献
The first transition metal iodato peroxido complex, K3[V2O2(O2)4(IO3)]·H2O (I), was prepared by crystallization from the KVO3 — KIO3 — H2O2 — H2O — ethanol (HNO3) solution. The dinuclear anion is immediately decomposed in aqueous solution; the 51V NMR spectrum exhibits signals corresponding to [VO(O2)2(H2O)]?, [V2O2(OH)(O2)4]3? and H2VO4? species only. The IR and Raman spectra contain all characteristic bands of the VO(O2)2 group and the coordinated IO3? ligand. Based on the positions of bands assigned to the vibrations of the VO(O2)2 groups a pentagonal pyramidal arrangement around the vanadium atoms can be supposed. The crystal structure was solved from X-ray synchrotron powder data by direct space method and refined by energy minimization in the solid state employing a hybrid PBE0 functional. This crystal and molecular structure, has confirmed the presence of hexacoordinated vanadium atoms and revealed asymmetric dinuclear structure of the [V2O2(O2)4(IO3)]3? ion. The coordination spheres of vanadium atoms are different — the IO3? anion is coordinated only to one vanadium center. A thermal analysis of the complex confirmed the presence of water molecules in the crystal structure and revealed a considerable stability of the dehydrated complex. 相似文献
A systematic fluorescence and flash photolytic investigation of a series of covalently linked fullerene / ferrocene based donor-bridge-acceptor dyads is reported as a function of the nature of the bridge between the donor site and acceptor site. The fluorescence of the investigated dyads 2 (Φrel = 0.17 × 10?4, 3 (Φrel = 0.78 × 10?4), 4 (Φrel = 1.5 × 10?4), 5 (Φrel = 0.7 × 10?4), and 6 (Φrel = 2.9 × 10?4) were substantially quenched, relative to N-methyl fulleropyrrolidine (1) (Φrel = 6.0 × 10?4). Photolysis of N-methyl fulleropyrrolidine (1) in toluene revealed formation of the excited singlet state which was followed by a rapid intersystem crossing to the excited triplet state. On the other hand, the fate of the excited singlet state of 2, 3, 4, 5, and 6 was found to be governed by rapid intramolecular quenching, with rate constants of 28×109 s?1, 6.9×109 s?1, and 3.4×109 s?1, 14×109 s?1, 2.3×109 s?1 respectively. The electron transfer process and the charge separation were confirmed by monitoring the characteristic π-radical anion bands at λmax = 400 and 1055 nm in degassed benzonitrile with τ1/2 = 1.8 μs (3) and 2.5 μs (4). 相似文献
Kinetics of the complex formation of chromium(III) with alanine in aqueous medium has been studied at 45, 50, and 55°C, pH 3.3–4.4, and μ = 1 M (KNO3). Under pseudo first-order conditions the observed rate constant (kobs) was found to follow the rate equation: Values of the rate parameters (kan, k, KIP, and K) were calculated. Activation parameters for anation rate constants, ΔH≠(kan) = 25 ± 1 kJ mol?1, ΔH≠(k) = 91 ± 3 kJ mol?1, and ΔS≠(kan) = ?244 ± 3 JK?1 mol?1, ΔS≠(k) = ?30 ± 10 JK?1 mol?1 are indicative of an (Ia) mechanism for kan and (Id) mechanism for k routes (‥substrate Cr(H2O) is involved in the k route whereas Cr(H2O)5OH2+ is involved in k′ route). Thermodynamic parameters for ion-pair formation constants are found to be ΔH°(KIP) = 12 ± 1 kJ mol?1, ΔH°(K) = ?13 ± 3 kJ mol?1 and ΔS°(KIP) = 47 ± 2 JK?1 mol?1, and ΔS°(K) = 20 ± 9 JK?1 mol?1. 相似文献
The formation of ternary nitridometalates from the elements in the case of the systems Li—Cr, V, Mn—N leads to compounds which contain the transition metals in the highest (VV, CrVI) or a comparably high (MnV) oxidation state. In the corresponding calcium and strontium systems, the transition metals show a lower oxidation state (VIII, CrIII, MnIII). Transition metals with intermediate oxidation states (CrV, MnIV) are present in the quaternary (mixed cation) compounds Li4Sr2[CrN6], Li6Ca2[MnN6], and Li6Sr2[MnN6] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3), as well as in the solid solution series Li6(Ca1—xSrx)2[MnN6]. 相似文献
Quantum mechanical and Rice-Ramsperger-Kassel-Marcus (RRKM) calculations are carried out to study the thermal unimolecular decomposition of oxetane (1), 2-methyloxetane (2), and 2,2-dimethyloxetane (3) at the MPW1PW91/6-311 + G** level of theory. The results of the calculations reveal that decomposition reaction of compounds 1?C3 yields formaldehyde and the corresponding substituted olefin. The predicted high-pressure-limit rate constants for the decomposition compounds 1?C3 are represented as 6.61 × 1013exp(?32472/T), 9.33 × 1013exp(?29873/T), and 4.79 × 1013exp(?27055/T) s?1, respectively. The fall-off pressures for the decomposition of compounds 1?C3 are found to be 9.42 × 10?2, 3.67 × 10?3, and 7.26 × 10?4 mm Hg, respectively. As the fall-off pressure of the decomposition process of compounds 1?C3 are in the following order: P1/2(1) > P1/2(2) > P1/2(3); therefore the decomposition rates are as follow: rate(1) < rate(2) < (3). 相似文献
The reactions of organoantimony chlorides L1,2SbCl21 and 2 ([2,6-(ROCH2)2C6H3]−, R = Me; L1 and R = t-Bu; L2) with silver salts of selected carboxylic acids resulted to corresponding organoantimony carboxylates L1,2Sb(OOCR′)2, 1a-c (for L1) and 2a-c (for L2), where R′ = CH3 for 1a, 2a; R′ = CHCH2 for 1b, 2b and R′ = CF3 for 1c, 2c. All compounds were characterized by the help of elemental analysis, ESI-MS, 1H and 13C NMR spectroscopy. The solid state structure investigation using single crystal X-ray diffraction techniques (2a, c) and IR spectroscopy revealed significant differences in coordination mode of both O,C,O chelating ligand and carboxylic groups in this set of compounds. The structure of all compounds in solution of non-coordinating solvent (CDCl3) was determined by means of variable temperature 1H, 13C, 19F NMR spectroscopy and IR spectroscopy. 相似文献
Sodium zirconium arsenate phosphates NaZr2(AsO4)x(PO4)3?x were synthesized by precipitation technique and studied by X-ray diffraction and IR spectroscopy. In the series of NaZr2(AsO4)x(PO4)3?x, continuous substitution solid solutions are formed (0 ≤ x ≤ 3) with the mineral kosnarite structure. The crystal structure of NaZr2(AsO4)1.5(PO4)1.5 was refined by full-profile analysis: space group R\(\bar 3\)c, a = 8.9600(4)Å, c = 22.9770(9) Å, V = 1597.5(1) Å3, Rwp = 4.55. The thermal expansion of the arsenate-phosphate NaZr2(AsO4)1.5(PO4)1.5 and the arsenate NaZr2(AsO4)3 was studied by thermal X-ray diffraction in the temperature range of 20–800°C. The average linear thermal expansion coefficients (αav = 2.45 × 10?6 and 3.91 × 10?6 K?1, respectively) indicate that these salts are medium expansion compounds. 相似文献
The effect of H2 on propylene polymerization initiated by a MgCl2/EB/PC/AlEt3/TiCl4–3 AlEt3/MPT catalyst was studied. Hydrogen increases significantly the initial rate during the early stage of the polymerization to give a higher yield of polymer than reactions without H2. But H2 reduces the yield toward the latter stages so that the net effect on the total yield can be quite small. There is no appreciable effect of H2 on either the isotacticity index or polydispersity of the products. It decreases molecular weight proportional to (pH2)1/2. The chain transfer by H2 resulted in a decrease of total metal polymer bond concentration with time of polymerization. The rate constants of hydrogen chain transfer for the two kinds of isospecific and nonspecific sites are = 5.1 × 10?3, = 2.7 × 10?3, = 7.5 × 10?3, = 4.4 × 10?3, in units of torr1/2 sec?1 at 50°. Hydrogen assists in the deactivation of the catalytic sites as does propylene; rates of the former and the latter vary with (pH2)1/2 and [C3H6]1/2, respectively, with k = (12.1 ± 0.9) M?1 torr?1/2 sec?1 and k = (65.3 ± 3.3) M?3/2 sec?1 at 50° and A/T = 167. The mechanism for deactivation of catalytic sites are discussed. 相似文献
The propagation rate of polystyryl-barium was studied in THF at 20°, in the presence of small amounts of lithium chloride. These kinetic results furnish a new method for the determination of triple ion formation in both mono- and α,ω-dicarbanionic polystyryl-barium. The constant of triple ion association of monocarbanionic (PS?)2Ba, KT, was found to be 3.7 × 105 l M?1, close to the value calculated from published data. The triple ion association constant of α,ω-dicarbanionic PS2?Ba2+, KDT, is about 1.2 × 106 l M?1. Taking into account the cyclic structure of α,ω-dicarbanionic PS2?Ba2+ and a statistical factor 3 between KT and KDT, it is concluded that mono- and dicarbanionic polystyryl-barium have similar abilities for triple ion formation. Nevertheless, stronger associations are observed for dicarbanionic oligomers with a degree of polymerization lower than 5–7. 相似文献
Kinetics of protonation of Li+, Na+, K+, and Cs+ salts of anthracene radical anions (A?·,Cat+) and dianions (A2?, 2Cat+) by MeOH and MeOD in tetrahydrofuran (THF) and dimethoxyethane (DME) led to the determination of the isotope effect (kH/kD) in the following reactions: Studies of cation and solvent influence on the rate constants of these reactions and on the magnitude of the isotope effect permitted us to draw some conclusions about the structure of the pertinent transition states. It seems that only the tight A?·,Na+ pairs participate in the protonation, and on this basis the fraction of tight ion paris of A?·,Na+ in DME was estimated. Our results have been compared with data reported in the literature. 相似文献
Eight 2-(9-phenanthrenyl)-, 2-(9-anthryl)- and 2-(1-pyrenyl)-1-alkyl-benzimidazole compounds, three 2-(9-anthryl)-1-alkylphenanthroimidazole compounds and five 4,5-diphenyl-1-alkyl-2-(9-anthryl)imidazole compounds were synthesized by alkylation reactions of the corresponding benzimidazole, phenanthroimidazole or imidazole compounds. 2-(10-Bromo-9-anthryl)-1-alkyl-benzimidazole compounds were prepared by bromination reaction of 2-(9-anthryl)-1-alkylbenzimidazole compounds. All the synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR, MS or HRMS; their absorption coefficients (), maximum absorption λamax, fluorescence emission maximum λem, Stokes shifts and fluorescence quantum yields (ΦF) in ethyl acetate were determined; their fluorescent lifetimes (T1 and T2) were measured in ethyl acetate and in solid state, respectively. The crystal structure of 2-(9-anthryl)-1-n-butyl-4,5-diphenylimidazole (12a) was determined to be triclinic, space group P-1 types, using single crystal X-ray crystallography technique. The results showed that these compounds exhibited moderate fluorescence-emission abilities and higher solubility in most organic solvents than their corresponding starting materials. The relationships between the optical behaviors and structures for these compounds were discussed. 相似文献
The sublimation pressure of ThI4 has been measured by the Knudsen effusion method and found to be . Simultaneously with the sublimation of ThI4 there is a small dissociation to lower iodide and iodine. The dissociation pressure associated with the reaction 2 ThOI2 = ThO2 + ThI4 is The molar heat capacity of solid ThI4 has been determined calorimetrically to be 146 J K?1 mol?1, the heat of fusion is approximately 48 kJ mol?1. The standard entropy of solid ThOI2 is calculated to be 145 J K?1 mol?1. 相似文献