用T-jump/FTIR研究MnCP、NiCP和PbCP的快速热分解(英)

0IntroductionCarbohydrazideisahydrazinederivativewithwhitecrystalofstrongreducingbehaviors.Becauseithasmanycoordinationatoms(fournitrogenatomsandoneoxygenatom),carbohydrazidecan,therefore,beusedasmultidentateligand.Itscoordinationcom鄄poundiswidelyusedint…     

Synthesis,Spectroscopic Characterization,and Oxidative C–C Coupling in New Copper(II) Salicylaldiminates Containing Sterically Hindered Phenol

New bis[N‐(2,6‐di‐tert‐butyl‐1‐hydroxyphenyl)salicylideneminato]copper(II) complexes bearing HO and CH₃O substituents on the salicyaldehyde moiety were prepared, and have been characterized by elemental analyses, IR, UV/Vis, ESR spectroscopy, and magnetic moments. It has been found that in the synthesis of CH₃O substituted complexes unlike HO bearing, the oxidative C–C coupling of coordinated salicylaldimine ligands take place. It has been suggested that the intermolecular H‐bonding is a dominant factor in controlling of oxidative C–C coupling conversion. The powder ESR spectra of CH₃O substituted compounds unlike of HO are typical of a triplet state Cu^II dimers with a half‐field forbidden (δM = ± 2) and the allowed (δM = ± 1) transitions at 300 and 113 K.     

Poly(dimethylsiloxane) networks modified with poly(phenylsilsesquioxane)s: Synthesis, structural characterisation and evaluation of the thermal stability and gas permeability

Self-supported translucent films constituted of semi-inorganic polymeric materials were prepared by sol-gel process from poly(phenylsilsesquioxane) (PPSQ) and poly(dimethylsiloxane) (PDMS), modified by diphenylsilanediol (DPS), phenyltriethoxysilane (PTES) and/or tetraethoxysilane (TEOS). These materials were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). Permeability to N₂, O₂, CH₄ and CO₂ and selectivity for a specific gas pair were investigated using the time-lag method. In the gas separation process high permeability and selectivity coefficients were observed, particularly for the membrane containing DPS and PTES as additives, which presented potential applications in the separation of CO₂/CH₄ and CO₂/N₂. The materials also showed good thermal stability, which could be correlated to the relative amounts between di-functional (D), tri-functional (T) and tetra-functional (Q) silicon units.     

Thermoanalytical investigations of tris(ethylenediamine)nickel(II) oxalate and sulphate complexes

Investigations on the thermal behaviour of [Ni(en)₃]C₂O₄·2H₂O and [Ni(en)₃]SO₄ have been carried out in air and helium atmosphere. Simultaneous TG/DTA coupled online with mass spectroscopy (MS) in helium atmosphere detected the presence of H₂, O, CO, N₂/CH₂=CH₂ and CO₂ fragments during the decomposition of tris(ethylenediamine)nickel(II) oxalate and H₂, O, NH, NH₂, NH₃ and N₂/CH₂=CH₂ fragments for tris(ethylenediamine)nickel(II) sulphate complex. The thermal events during the decomposition were monitored by temperature-resolved X-ray diffraction. In air, both the complexes give nickel oxide as the final product of the decomposition. In helium atmosphere, tris(ethylenediamine)nickel(II) oxalate gives nickel as the residue, whereas tris(ethylenediamine)nickel(II) sulphate gives a mixture of nickel and nickel sulphide phases as the final residue. Kinetic analyses of these complexes by isoconversional methods are discussed and compared.     

Onium salts of sulfur-containing oxyanions resulting from reaction of sulfur(IV) oxide with aqueous solutions of 1,2-diamines and morpholine

Reaction products have been isolated from SO₂–L–H₂O–О2 systems (L = ethylenediamine, N,N,N′,N′-tetramethylethylenediamine, piperazine, and morpholine) as onium salts [H₃NCH₂CH₂NH₃]SO₄, [(CH₃)₂NHCH₂CH₂NH(CH₃)₂]SO₄, [(CH₃)₂NHCH₂CH₂NH(CH₃)₂]S₂O₆ ? H₂O, [C₄H₈N₂H₄]SO₃ ? H₂O, [C₄H₈N₂H₄]S₂O₆, [C₄H₈N₂H₄]SO₄ ? H₂O, [O(C₂H₄)₂NH₂]₂SO₄ ? H₂O. The prepared compounds have been characterized by X-ray diffraction analysis, X-ray powder diffraction, IR and mass spectroscopy.     

Synthesis and structural characterization of tris (methacrylato)chromium(III)

A straightforward synthetic route to produce tris(methacrylato)chromium(III), Cr(O₂C(CH₃)C=CH₂)₃, by reacting sodium methacrylate with an aqueous solution of CrCl₃ gave a blue microcrystalline powder, insoluble in most common solvents. Electronic spectroscopy (UV-Vis), electron paramagnetic resonance (EPR), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), were employed to characterize Cr(O₂C(CH₃)C=CH₂)₃. Morphology and elemental composition of this compound were determined using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX), respectively. Spherical particles of approximately 2.5 µm in diameter were obtained. Thermal stability of the product was investigated via thermogravimetric analysis (TGA). The spectroscopic studies revealed that the coordination sphere around the chromium ion corresponds to a chelating bidentate carboxylate-Cr(III) complex. Thermal stability above 350°C, and spherical shape particles of few micrometers in diameter, suggest a potential application of this novel compound as a catalyst in oxidation reactions.     

Multi-frequency S2FTIR PA spectral depth profiling by use of sinusoidal phase modulation and harmonic demodulation up to 2250 Hz (10th harmonic)

Multi-frequency phase modulation for step-scan Fourier transform infrared photoacoustic spectroscopy (S²FTIR PAS) is demonstrated using a single frequency sinusoidal modulation of the interferometer movable mirror with modulation amplitude 5.2 λ_He-Ne. A digital signal processing (DSP) lock-in amplifier is used to demodulate the photoacoustic response at the fundamental phase modulation frequency and its harmonic frequencies. Because the phase modulation is sinusoidal and of the appropriate amplitude, all the even and odd harmonics (up to the 10th harmonic) can be detected with good signal-to-noise ratio (SNR). Applications of this multi-frequency phase modulation approach for photoacoustic depth profiling are demonstrated by the study of a simple two-layered polymer sample. The sampling depth multiplexing advantage (as compared to that obtained with other types of phase modulation) is clearly demonstrated with the analysis of the phase and magnitude of signals at the fundamental frequency and all the harmonic frequencies. This is the first report of using the sinusoidal phase modulation method to easily obtain multi-frequency and high-frequency light modulation for FTIR PAS depth profiling. Although these data have been obtained sequentially, it would be possible (with considerable economy of time) to obtain them simultaneously by use of the internal digital signal processing capability of the instrument.     

Experimental and theoretical study of N-(2-hydroxyethyl)morpholine betaine

N-(2-hydroxyethyl)morpholine betaine (HEMB) has been characterized by a single crystal X-ray analysis, FTIR spectroscopy and DFT calculations. The crystals are monoclinic, space group P2₁/c with a=10.273(2), b=9.360(2), c=9.447(2) Å and β=104.72(3)Å. Two molecules of HEMB form a centrosymmetric dimer (X2) connected by a pair of hydrogen bonds between the CH₂CH₂OH and COO⁻ groups, with the O?O distance of 2.672(2) Å. The morpholine ring adopts a chair conformation with the CH₂CH₂OH group in the axial and the CH₂COO⁻ group in the equatorial position. The structures of the dimer, B2, and two monomers, B1a and B1b, have been optimized by the B3LYP approach using the 6-31G(d,p) basis set. The computed structure of B2, agrees well with the experimental X2. From two stable monomeric conformers the more favored is B1a, with the intramolecular hydrogen bond with the O-H?O distance of 2.566 Å. The effects of hydrogen bonding and electrostatic interactions on the conformation of the molecules investigated have been discussed. The FTIR spectrum shows a broad absorption in the 3300-2600 cm⁻¹ region, typical of moderate O-H?O hydrogen bonds.     

Protonated Melonate Ca[HC6N7(NCN)3]·7H2O – Synthesis,Crystal Structure,and Thermal Properties

Calcium hydrogenmelonate heptahydrate Ca[HC₆N₇(NCN)₃] · 7H₂O was obtained by metathesis reaction in aqueous solution. The structure of the molecular salt was elucidated by single‐crystal X‐ray diffraction. The crystal structure consists of alternating layers of planar monopronated melonate ions, Ca²⁺ and crystal water molecules. The anions of adjacent layers are staggered so that no π–π stacking occurs. The melonate entities are interconnected by hydrogen bonds within and between the layers. Ca[HC₆N₇(NCN)₃] · 7H₂O was investigated by solid‐state NMR and FTIR spectroscopy, TG and DTA measurements.     

Multi-frequency S2FTIR PA spectral depth profiling by use of sinusoidal phase modulation and harmonic demodulation up to 2250 Hz (10th harmonic)

Multi-frequency phase modulation for step-scan Fourier transform infrared photoacoustic spectroscopy (S²FTIR PAS) is demonstrated using a single frequency sinusoidal modulation of the interferometer movable mirror with modulation amplitude 5.2 λ_He-Ne. A digital signal processing (DSP) lock-in amplifier is used to demodulate the photoacoustic response at the fundamental phase modulation frequency and its harmonic frequencies. Because the phase modulation is sinusoidal and of the appropriate amplitude, all the even and odd harmonics (up to the 10th harmonic) can be detected with good signal-to-noise ratio (SNR). Applications of this multi-frequency phase modulation approach for photoacoustic depth profiling are demonstrated by the study of a simple two-layered polymer sample. The sampling depth multiplexing advantage (as compared to that obtained with other types of phase modulation) is clearly demonstrated with the analysis of the phase and magnitude of signals at the fundamental frequency and all the harmonic frequencies. This is the first report of using the sinusoidal phase modulation method to easily obtain multi-frequency and high-frequency light modulation for FTIR PAS depth profiling. Although these data have been obtained sequentially, it would be possible (with considerable economy of time) to obtain them simultaneously by use of the internal digital signal processing capability of the instrument. Received: 8 January 1998 / Accepted: 22 February 1998     

Synthesis,Characterization, and Energetic Properties of Nitroso Compounds

Sodium and potassium methyl(nitroso)amide (M[CH₃N₂O], M = Na ( 1 ), K ( 2 )) were prepared by the reaction of monomethylhydrazine with iso‐pentyl nitrite or n‐butyl nitrite and a suitable metal ethoxide (M[CH₃CH₂O], M = Na, K) in an ethanol‐ether mixture. The reaction of monomethylhydrazine with a small excess of iso‐pentyl nitrite or n‐butyl nitrite and in the absence of a metal ethoxide led to the formation of N‐nitroso‐N‐methylhydrazine (CH₃(NO)N–NH₂, ( 3 )). Alternatively, compound 3 was prepared by the amination reaction of 1 or 2 using the sodium salt of HOSA in ethanol solution. Compounds 1–3 were characterized using elemental analysis, differential scanning calorimetry, mass spectrometry, vibrational (infrared and Raman) and UV spectroscopy and multinuclear (¹H, ¹³C and ¹⁵N) NMR spectroscopy. For compounds 1–3 , several physical and chemical properties of interest and sensitivity data were measured and for compound 3 thermodynamic and explosive properties are also given. Additionally, the solid‐state structure of compound 3 was determined by single‐crystal X‐ray analysis and the structures of the cis‐ and trans‐[CH₃N₂O]^– anions and that of 3 were optimized using DFT calculations and used to calculate the NBO charges.     

New polyfunctional silicon-containing amines C6[CH2CH2SiMe(OCH2CH2NR2)2]6 (R = H,Me) and their reactions with cobalt(ii) chloride and dicobalt octacarbonyl

Hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene and hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene C₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆ (4, R = H; 5, R = Me) were prepared from hexakis(methyldichlorosilylethyl)benzene C₆(Cl₂MeSiCH₂CH₂)₆ and 2-aminoethanol or N,N-dimethyl-2-aminoethanol, respectively. Compounds 4 and 5 react with anhydrous cobalt (ii) chloride to give poorly soluble dodecachloro{hexakis[bis(2-aminoethoxy)methylsilylethyl]benzene}hexacobalt and dodecachloro{hexakis[bis(N,N-dimethyl-2-aminoethoxy)methylsilylethyl]benzene}hexacobalt {Co₆[(NR₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}Cl₁₂ (R = H or Me), respectively. Polyfunctional amine 4 reacts with dicobalt octacarbonyl to produce hexakis[bis(2-aminoethoxy)methylsilylethyl]benzenedicobalt(ii) tetrakis(tetracarbonylcobaltate) {Co₂[(NH₂CH₂CH₂O)₂SiMeCH₂CH₂]₆C₆}[Co(CO)₄]₄. N,N-Dimethyl-substituted polyfunctional amine 5 is lowly reactive in the reaction with Co₂(CO)₈, whereas the simplest model of this compound, viz., bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane (NMe₂CH₂CH₂O)₂SiMe₂, slowly reacts with Co₂(CO)₈ to give tris[bis(N,N-dimethyl-2-aminoethoxy)dimethylsilane]cobalt(ii) bis(tetracarbonylcobaltate) {Co[(NMe₂CH₂CH₂O)₂SiMe₂]₃}[Co(CO)₄]₂. Thermal decomposition and transformations of the resulting complexes under the action of oxygen and water were studied.     

Synthesis and structure of N-(hydroxyethyl)ethylenediammonium sulfite monohydrate

A reaction between sulfur(IV) oxide and aqueous N-(2-hydroxyethyl)ethylenediamine yields onium sulfite of composition (HOCH₂CH₂NH₂CH₂CH₂NH₃)SO₃ · H₂O, which has been characterized by X-ray diffraction, IR spectroscopy, and mass spectrometry. The three-dimensional structure of the salt is stabilized by numerous hydrogen bonds, such as NH…O and OH…O.     

3‐Rhoda‐1,2‐diazacyclopentanes: A Series of Novel Metallacycle Complexes Derived From CN Functionalization of Ethylene

Rh‐containing metallacycles, [(TPA)Rh^III(κ²‐(C,N)‐CH₂CH₂(NR)₂‐]Cl; TPA=N,N,N,N‐tris(2‐pyridylmethyl)amine have been accessed through treatment of the Rh^I ethylene complex, [(TPA)Rh(η²‐CH₂CH₂)]Cl ([ 1 ]Cl) with substituted diazenes. We show this methodology to be tolerant of electron‐deficient azo compounds including azo diesters (RCO₂N?NCO₂R; R=Et [ 3 ]Cl, R=iPr [ 4 ]Cl, R=tBu [ 5 ]Cl, and R=Bn [ 6 ]Cl) and a cyclic azo diamide: 4‐phenyl‐1,2,4‐triazole‐3,5‐dione (PTAD), [ 7 ]Cl. The latter complex features two ortho‐fused ring systems and constitutes the first 3‐rhoda‐1,2‐diazabicyclo[3.3.0]octane. Preliminary evidence suggests that these complexes result from N–N coordination followed by insertion of ethylene into a [Rh]?N bond. In terms of reactivity, [ 3 ]Cl and [ 4 ]Cl successfully undergo ring‐opening using p‐toluenesulfonic acid, affording the Rh chlorides, [(TPA)Rh^III(Cl)(κ¹‐(C)‐CH₂CH₂(NCO₂R)(NHCO₂R)]OTs; [ 13 ]OTs and [ 14 ]OTs. Deprotection of [ 5 ]Cl using trifluoroacetic acid was also found to give an ethyl substituted, end‐on coordinated diazene [(TPA)Rh^III(κ²‐(C,N)‐CH₂CH₂(NH)₂‐]⁺ [ 16 ]Cl, a hitherto unreported motif. Treatment of [ 16 ]Cl with acetyl chloride resulted in the bisacetylated adduct [(TPA)Rh^III(κ²‐(C,N)‐CH₂CH₂(NAc)₂‐]⁺, [ 17 ]Cl. Treatment of [ 1 ]Cl with AcN?NAc did not give the Rh?N insertion product, but instead the N,O‐chelated complex [(TPA)Rh^I ( κ²‐(O,N)‐CH₃(CO)(NH)(N?C(CH₃)(OCH?CH₂))]Cl [ 23 ]Cl, presumably through insertion of ethylene into a [Rh]?O bond.     

Synthesis,spectroscopic and X-ray crystallographic properties of manganese compounds of keto- and enol-coordinated di-2-pyridyl ketone benzoyl hydrazone (dpkbh). Reactions of [Mn(CO)5Br] with dpkbh

Reactions between [Mn(CO)₅Br] and dpkbh in low boiling solvents in air gave fac-[Mn^I(CO)₃(κ²-N_py,N_im-dpkbh)Br]·H₂O, [Mn^IIBr₂(κ³-N_py,N_im,O-dpkbh)], and [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂]·0.5H₂O (N_im = imine nitrogen and N_py = pyridyl nitrogen). Crystallization of fac-[Mn^I(CO)₃(κ²-N_py,N_im-dpkbh)Br]·H₂O from dmso or CH₃CN produced dark red crystals of [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂]·nX (X = dmso, n = 1 and X = H₂O, n = 0.22). This is in contrast to the reaction of [Re(CO)₅Cl] with dpkbh in refluxing toluene to form fac-[Re^I(CO)₃(κ²-,N_py,N_py-dpkbh)Cl] which can be crystallized from CH₃CN, dmso or dmf to form fac-[Re^I(CO)₃(κ²-,N_py,N_py-dpkbh)Cl]·nX (X = CH₃CN, n = 0 and solvate = dmso or dmf, n = 1). Infrared spectral measurements are consistent with keto coordination of dpkbh to Mn(I) in fac-[Mn^I(CO)₃(κ²-N_py,N_im-dpkbh)Br]·H₂O and Mn(II) in [Mn^IIBr₂(κ³-N_py,N_im,O-dpkbh)] plus enol coordination of the amide-deprotonated dpkbh, to the Mn(II) center in [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂]·0.5H₂O. Electronic absorption spectral measurements in non-aqueous solvents indicate sensitivity of fac-[Mn^I(CO)₃(κ²-N_py,N_im-dpkbh)Br]·H₂O and [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂]·0.5H₂O to changes in their outer-shell environments. X-ray crystallographic analyses elucidated the identities of [Mn^IIBr₂(κ³-N_py,N_im,O-dpkbh)] and [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂]·nX and divulged weaker coordination of [dpkbh] to Mn(II) in [Mn^IIBr₂(κ³-N_py,N_im,O-dpkbh)] and stronger coordination of [dpkbh-H]^? to Mn(II) in [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂]·0.22H₂O. Low-temperature X-ray structural analyses were employed to account for the disorder in the structure of [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂] and the short NH bond distance observed in the structure of [Mn^IIBr₂(κ³-N_py,N_im,O-dpkbh)]. A PLATON Squeeze treatment was invoked to account for the fractional occupancy of lattice water in the structure of [Mn^II(κ³-N_py,N_im,O-dpkbh-H)₂].     

Heterobimetallische Komplexe von Lithium,Aluminium und Gold mit dem N‐[2‐N′,N′‐(Dimethylaminoethyl)‐N‐methyl‐aminoethyl]‐ferrocenyl‐Liganden (η5‐C5H5)Fe{η5‐C5H3[CH(CH3)N(CH3)CH2CH2NMe2]‐2}

Heterobimetallic Complexes of Lithium, Aluminum, and Gold with the N ‐[2‐ N ′, N ′‐(dimethylaminoethyl)‐ N ‐methyl‐aminoethyl]‐ferrocenyl Ligand (η⁵‐C₅H₅)Fe{η⁵‐C₅H₃[CH(CH₃)N(CH₃)CH₂CH₂NMe₂]‐2} N‐[2‐N′,N′‐(dimethylaminoethyl)‐N‐methyl‐aminoethyl]ferrocene FcN,NH ( 1 ) reacts with ⁿBuLi under formation of the lithium organyl (FcN,N)Li ( 2 ). At reactions of 2 with AlBr₃ and AuCl · PPh₃ the heterobimetallic organo derivatives (FcN,N)AlBr₂ ( 3 ), (FcN,N)Au · PPh₃ ( 4 ) are formed. A detailed characterization of 2 – 4 was carried out by single crystal x‐ray analyses as well as by NMR and Mößbauer spectroscopy.     

Hexachlorocuprate(II) Anion: Vibration Spectra and Structure

For the complexes (CH₈N₄)₂[CuCl₆], (C₂H₉N₅)₂[CuCl₆] · 2H₂O, and (CH₈N₄O)₄[CuCl₆]Cl₄, where (CH₈N₄)²⁺, (C₂H₉N₅)²⁺, and (CH₈N₄O)²⁺ are the aminoguanidinium, biguanidium, and carbohydrazidium cations, respectively, IR and Raman spectra were taken and analyzed in the region of Cu—Cl vibrations. Polarization measurements of the Raman spectra of (CH₈N₄O)₄[CuCl₆]Cl₄ single crystals were performed with the purpose of assigning the vibrations to symmetry types. Vibration spectra were calculated for the hexachlorocuprate ion in the given series of compounds, and the spectra of the examined complexes were compared with spectra of the previously known compounds incorporating the hexachlorocuprate(II) ion.     

Reactions of bis(2,4-pentanedionato)diaquacobalt(II). Part 1. Formation of dioxygen and carbonato-complexes

Summary Oxygenation of [Co(pd)₂(H₂O)₂] (Hpd = 2,4-pentanedione) in the presence of triphenylphosphine forms [Co(pd)₃] and a peroxo-complex that shows strong v(O-O) at 865 cm^–1. The mechanism of Co-pd cleavage and the concomitant formation of [Co(pd)₃] are discussed. With guanidine carbonate the title compound forms a carbonato-complex, (CH₅N₃H)₂-[Co(CH₅N₃)(CO₃)₂] · H₂O, which is the violet component of the so-called blue-violet pair of the complexes of the general formula [CoA₂(CO₃)₂]^2– (A₂ = ethylenediamine or 2NH₃). The carbonato-complex is assigned either a square-pyramidal geometry with monodentate CH₅N₃ or a polymeric octahedral structure with a bridging CH₅N₃ group.     

Syntheses and Crystal Structures of Two 3D Lead(II) Coordination Polymers with Isonicotinic Acid N‐Oxide and Pseudohalides

Two novel 3D lead(II)‐azido and ‐thiocyanato coordination polymers with isonicotinate acid N‐oxide (INO) as the coligand were synthesized and characterized by elemental analysis, IR, and ¹H NMR spectroscopy and were also studied using X‐ray crystallography technique. These complexes have the formulas [Pb(INO)(NCS)]_n ( 1 ) and [Pb(INO)(N₃)(H₂O)]_n ( 2 ).     

Bromodifluoroacetyl fluoride,CF2BrC(O)F: Experimental and theoretical studies

Bromodifluoroacetyl fluoride, CF₂BrC(O)F, was prepared through the gas-phase reaction of bromotrifluoroethene, CF₂CFBr, with molecular oxygen initiated either by NO₂ or CF₃OF. The compound was experimentally studied by FTIR spectroscopy of the gas phase and also isolated in Ar and N₂ matrices at low temperature. The energy differences between the possible conformers were theoretically studied, as well as the vibrational spectra of the conformers.