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1.
The thermotropic phase transitions in the perovskite type layer compound (n-C10H21NH3)2MnCl4 and (n-C14H29NH3)2MnCl4 were synthesized and, at the same time, a series of their mixtures C10Mn-C14Mn were prepared. The experimental binary phase diagram of C10Mn-C14Mn was established by differential thermal analysis (DTA), IR and X-ray diffraction. In the phase diagram new material (n-C10H21NH3)(n-C14H29NH3)MnCl4 and two eutectoid invariants were observed, two eutectic points temperatures are about 29.8 and 27.9°C. Contrasting other similar system, there are three noticeable solid solution ranges (α, β, γ) at the left and right boundary and middle of the phase diagram.  相似文献   

2.
Phases and structural phase transitions of the compounds (CH3NH3)2MnCl4, (C2H5NH3)2MnCl4 and (C3H7NH3)2MnCl4 have been studied by means of thermoanalytical methods (DSC) and X-ray single crystal and powder diffraction data in the temperature range of 85–480°K at normal pressure. All phases show perovskite-like layer structures. The high temperature phases (α phase) correspond to the K2NiF4 type and may be regarded as the aristotype of each polymorphic compound. All transitions are reversible. Transition patterns are:
Based on the DSC peak-shape analysis and diffraction data a model of a tilting system of the MnCl6-octahedra layer is introduced in order to understand essential features of structures of different phases and their transition behavior. Single crystal film data of (C3H7NH3)2MnCl4 phases reveal some disorder phenomena. The ε phase exhibits a superstructure along [010] with a triplication of the shortest axis corresponding to the δ phase. The γ phase of this compound shows strong satellite reflections, due to a transverse distortion wave along the [100] lattice direction.  相似文献   

3.
Inorganic–organic hybrid perovskites, especially two‐dimensional (2D) layered halide perovskites, have attracted significant attention due to their unique structures and attractive optoelectronic properties, which open up a great opportunity for next‐generation photosensitive devices. Herein, we report a new 2D bilayered inorganic–organic hybrid perovskite, (C6H13NH3)2(NH2CHNH2)Pb2I7 ( HFA , where C6H13NH3+ is hexylaminium and NH2CHNH2+ is formamidinium), which exhibits a remarkable photoresponse under broadband light illumination. Structural characterizations demonstrate that the 2D perovskite structure of HFA is constructed by alternant stacking of inorganic lead iodide bilayered sheets and organic hexylaminium layers. Optical absorbance measurements combined with density functional theory (DFT) calculations suggest that HFA is a direct band gap semiconductor with a narrow band gap (Eg) of ≈2.02 eV. Based on these findings, photodetectors based on HFA crystal wafer are fabricated, which exhibit fascinating optoelectronic properties including large on/off current ratios (over 103), fast response speeds (τrise=310 μs and τdecay=520 μs) and high responsivity (≈0.95 mA W?1). This work will contribute to the design and development of new two‐dimensional bilayer inorganic–organic hybrid perovskites for high‐performance photosensitive devices.  相似文献   

4.
Spectroscopic measurements of the spectral lines in MnF2 and RbMnF3 have been carried out in the temperature range 10–300 K. Observations of exciton–magnon sidebands in the fine structures of the 6A1g  4T2g (4D) state of Mn2+ ions are reported at low temperatures. The temperature dependence of peak positions, oscillator strength and half line widths have been investigated for selected bands. The analysis of the temperature dependence of these parameters confirms that the fine structure of the D band is mainly attributed to spin–orbit interaction combined with spin multiplicity in the ordered state. The ratios for the separation energies between these lines are fitted with the ratios expected from Landé interval rule.  相似文献   

5.
The o‐substituted hybrid phenylphosphines, PPh2(o‐C6H4NH2) and PPh2(o‐C6H4OH), could be deprotonated with LDA or n‐BuLi to yield PPh2(o‐C6H4NHLi) and PPh2(o‐C6H4OLi), respectively. When added to a solution of (η5‐C5H5)Fe(CO)2I at room temperature, these two lithiated reagents produce a chelated neutral complex 1 (η5‐C5H5)Fe(CO)[C(O)NH(o‐C6H4)PPh2C,P‐η2] for the former and mainly a zwitterionic complex 2 , (η5‐C5H5)Fe+(CO)2[PPh2(o‐C6H4O?)] for the latter. Complex 1 could easily be protonated and then decarbonylated to give 4 [(η5‐C5H5)Fe(CO){NH2(o‐C6H4)PPh2N,P‐η2}+]. Complexes 1 and 4‐I have been crystallographically characterized with X‐ray diffraction.  相似文献   

6.
Systematic spectroscopic measurements of the spectral lines in MnF2 have been carried out in the temperature range 10–300 K. Observations of exciton and exciton–magnon sidebands in the fine structures of the 6A1g  4A1g, 4Eg (4G) state of Mn+2 ions are reported at low temperatures for MnF2. The fine structure of the C-band is mainly attributed to spin multiplicity in the ordered state. In addition, the pure exciton bands have been identified and the ratios for the separation energies between these lines are fitted with the ratios expected form Lande interval rule.  相似文献   

7.
On the Structure of Isopropylammonium Trichloro Manganate(II) (CH3)2CHNH3MnCl3 · 2 H2O The crystal structure of (i-C3H7NH3)MnCl3 · 2 H2O has been determined by X-ray diffraction and the parameters refined by leastsquares calculations. (i-C3H7NH3)MnCl3 · 2 H2O is monoclinic, space group P21/c with a = 1410(3), b = 584(1) and c = 1299(2) pm, β = 110.5(1)°. There are four formula units per unit cell. The manganese is octahedrally coordinated by four chlorine atoms and two water molecules in “trans” position. The structure contains discrete dioctahedra Mn2Cl6(H2O)42?.  相似文献   

8.
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   

9.
锐钛相虫蛀状介孔二氧化钛的表征   总被引:3,自引:0,他引:3  
0IntroductionMesostructuredtitania(TiO2)hasattractedagreatdealofattention,inviewofcontrolleddelivery,catalytic,photocatlytic,orenergyconversionapplica-tions犤1犦.Theuseoftitaniumisopropoxidebis-acetylace-tonateprecursors,combinedwithalkylphosphatean-ionicsurfactantsastemplate,ledtothefirstdocu-mentedpuremesoporousTiO2犤2犦.Insubsequentyears,moresyntheticstrategieshavebeendevelopedusingavarietyofstructure-directingagents,forexample,car-boxylicacids犤3犦,alkylamine犤4犦,aminium犤5犦,blockcop-o…  相似文献   

10.
The synthesis and characterization of the ditopic bis(pyrazol‐1‐yl)borate ligand Li2[p‐C6H4(B(C6F5)pz2)2] is reported (pz = pyrazol‐1‐yl). Compared to the corresponding t‐butyl derivative Li2[p‐C6H4(B(t‐Bu)pz2)2], the C6F5‐substituted scorpionate is significantly more stable towards hydrolysis. Reaction of Li2[p‐C6H4(B(C6F5)pz2)2] with two equivalents of MnCl2 leads to the formation of coordination polymers {(MnCl2)2(Li(THF)3)2[p‐C6H4(B(C6F5)pz2)2]} featuring penta‐coordinate MnII ions chelated by one bis(pyrazol‐1‐yl)borate fragment and further bonded to three chloride ions. Two of the three chloride ions are also coordinated to a neighbouring MnII ion; the third chloro ligand is shared between the MnII centre and a Li(THF)3 moiety.  相似文献   

11.
The overall conformation of the title compound, C13H24O10, is described by the glycosidic torsion angles ?H (H1g—C1g—O2r—C2r) and ψH (C1g—O2r—C2r—H2r), which have values of 13.6 and 16.1°, respectively. The former is significantly different from the value predicted by consideration of the exo‐anomeric effect (?H~ 60°) and from that in solution (?H~ 50°), as determined previously by NMR spectroscopy. An intramolecular O3r—H?O2g hydrogen bond may help to stabilize the conformation in the solid state. The orientation of the hydroxy­methyl group of the glucose residue is gauchegauche, with a torsion angle ω (O5g—C5g—C6g—O6g) of ?70.4 (4)°. Both pyranose rings are in their expected chair conformations, i.e.4C1 for d ‐glucose and 1C4 for l ‐rhamnose.  相似文献   

12.
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   

13.
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   

14.
A five-coordinate copper complex with the tripod ligand tris(1H-benzimidazol-2-ylmethyl)amine (ntb), of composition [Cu(ntb)(H2O)] (C1O4)2?·?C5H4N2O3?·?H2O (C5H4N2O3?=?4-nitropyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and U.V. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the CuII is bonded to a tris(1H-benzimidazol-2-ylmethyl)amine (ntb) ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal–bipyramidal coordination geometry with approximate C 3 molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasi-reversible Cu+2/Cu+ couple. Electron spin resonance data confirm a trigonal-bipyramidal structure and with g 2?<?g ζ and a very small value of A 2 (20?×?10?4?cm?1).  相似文献   

15.
Multiferroic materials coupling ferroelasticity and ferromagnetism show strong magnetoelastic effects as magnetization is induced by mechanical stress or alternately strain induced by applying a magnetic field. These effects were reported for inorganic multiferroics such as LaCox Sr1−x O3. (C6H5C2H4NH3)2FeIICl4 is the first example of an organic–inorganic perovskite to exhibit such effects below the canted antiferromagnetism at T C=98 K and ferroelasticity at T C=433 K. This is shown by switching the magnetic hysteresis on and off by uniaxial pressure through the strong coupling of the magnetic and elastic domains. The spin‐canting direction was controlled by mechanical stress in the heating and cooling cycles. This unique observation gives additional impetus in the search for coupled hysteretic effect in organic–inorganic multiferroics.  相似文献   

16.
Phenoxarsin-10-yl derivatives of 2-amino-cyclopent-1-ene-1-carbodithioic acid, (ACDA), and its N-alkyl derivativesO(C6H4)2 AsS2C—C5H6— NHR-2 (R = H, CH2CH3, CH2C6H11,), have been prepared by reacting O(C6H4)2AsCI with the corresponding ACDA 1,1-dithioic acid. The compounds were obtained by stirring stoichiometric amounts of the reagents in ethanol, over 24 h, at room temperature. The scale of the preparations were in the order of 2 mmol and the yields of the compounds ca 75%. The reactions were carried out in absolute ethanol. The compounds were characterized by IR, mass and NMR (1H, 13C) spectroscopy. The molecular structure of O(C6H4)2AsS2C—C5H6—NH2-2 was determined using X-ray diffractometry, achieving an R-value of 6.3%; this compound is monomeric and contains an asymmetric monometallic biconnective 1,1-dithiolato ligand [As—S(1) 2.272(2) å, As … S(2) 3.125(2) å]. An intramolecular hydrogen bond is established between one hydrogen atom of the NH2 group and the sulfur [S(2)] atom involved in the secondary interaction to arsenic. The dihedral angle (150.3(3)°) of the phenoxarsine moiety is practically unaffected by substitution of chlorine on arsenic by the carbodithioato ligand.  相似文献   

17.
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   

18.
The thermolysis and reactions of the polymeric high spin MnII and FeII complexes [Mn(μ-OOCBut)2(HOEt)]n (1) and [Fe(μ-OOCBut)2]n (3) with pivalic acid and o-phenylenediamines 1,2-(NH2)2C6H2R2 (R = H or Me) were studied. The synthesis of compound 1 performed with a deficiency of pivalate anions affords the antiferromagnetic chloropivalate polymer { (MeCN)(HOOCBut)(H2O)Mn5Cl(OH)(OOCBut)8·MeCN}n. The reaction of 1 with an excess of pivalic acid produces the antiferromagnetic polymer [Mn4(OOCBut)8(HOOCBut)2]n. The analogous reaction of pivalic acid with polymer 3 gives the mononuclear complex Fe(η 1-OOCBut)21-HOOCBut)4 containing the high spin iron(II) atom as the major product. Study of the reactions of 3 with a deficiency (<1: 1) and an excess (>1: 1) of diamines demonstrated that the polymer {[(η2-(NH2)2C6H4)2Fe(μ-OOCBut)2][Fe2(μ-OOCBut)4] · · 2MeCN}n is generated as the major product in the former case, whereas the mononuclear complexes Fe(η1-OOCBut)21-(NH2)2C6H4]4 and Fe(η1-OOCBut)22-(NH2)2C6H2Me2][η1-(NH2)2C6H2Me2]2 are predominantly obtained in the latter case. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 779–792, May, 2006.  相似文献   

19.
The organic‐inorganic hybrid nonlinear optical (NLO) material NH4B(d‐ (+)‐C4H4O5)2 · H2O (NBC) was synthesized in a borate‐carboxylic acid system. Its structure was determined by single crystal X‐ray diffraction. It crystallizes in the orthorhombic system, space group Pna21 (No. 33), with cell parameters a = 11.484(6) Å, b = 5.354(3) Å, c = 21.079(12) Å, V = 1296.0(12), Z = 4. It exhibits a three‐dimensional pseudo tunnel structure consisting of fundamental building block [B(d‐ (+)‐C4H4O5)2] anions. The small cavities are occupied by the H2O molecules and NH4+ cations, which stabilize the whole structure by O–H ··· O and N–H ··· O hydrogen bonds. The powder X‐ray diffraction (PXRD) of the crystal was also recorded. Elemental analyses, FT‐IR and FT‐Raman spectra analyses, thermal analysis, and diffuse‐reflectance spectra for the compound are also presented, as are band structures and density of states calculation. Nonlinear optical measurements indicate that the material has second harmonic generation (SHG) properties and is phase‐matchable.  相似文献   

20.
The new compound (NH3CH2CH2NH3)2{Na2[μ2-(C6H4O2)2](C6H4OOH)2} has been synthesized and characterized by elemental analysis, IR, UV, NMR and single crystal X-ray diffraction. The yellow crystals crystallized in the triclinic system with space group P-1 and a=0.6091(2) nm, b= 1.0274(3) nm, c= 1.2466(4) nm, α=89.073(6)°, β=89.376(6)°, γ=78.873(5)°, V=0.7653(4) nm^3, Z= 1, R1=0.0568, wR2=0.1198. Every sodium ion coordinates in trigonal prismatic fashion with two O atoms from a terminal chelating catecholato ligand and four O atoms from bridging P2 catecholato ligands, Two neighboring NaO6 trigonal prisms are face-shared and centrosymmetric with regard to the inversion center consisting of four tri-bridging O atoms to form a binuclear cluster {Na2[μ2-(C6H4O2)2]}^2- anion. The comparison of ^13C NMR spectrum of tlie complex in solid state with that in solution indicated that the rapid exchange between the bridging [μ2-(C6H4O2]^2- and terminal [C6H4OOH]^- ligands was present in solution.  相似文献   

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