开放骨架磷酸铝合成中F~-对有机胺结构导向效应的影响

研究了在开放骨架磷酸铝合成中氟离子对乙二胺(en)和二乙烯三胺(deta)的结构导向效应的影响.在水热条件下,以乙二胺为结构导向剂,分别从摩尔组成为n(Al2O3)∶n(P2O5)∶n(en)∶n(H2O)=1.0∶1.5∶18.0∶147和n(Al2O3)∶n(P2O5)∶n(en)∶n(HF)∶n(H2O)=1.0∶1.5∶18.0∶3.0∶147的初始混合物中晶化出二维层状磷酸铝Al2P2O9·NH3(CH2)2NH3(Ui O-13)和Al F(HPO4)·NH2(CH2)2NH2(1);以二乙烯三胺为结构导向剂,分别从摩尔组成为n(Al2O3)∶n(P2O5)∶n(deta)∶n(H2O)=1.0∶4.0∶3.0∶153和n(Al2O3)∶n(P2O5)∶n(deta)∶n(HF)∶n(H2O)=1.0∶4.0∶3.0∶3.0∶153的初始混合物中晶化出了三维开放骨架磷酸铝Al4P5O20(H2O)2·C4N3H16(Al PO-CJ31)和一维链状磷酸铝Al2P4O10(OH)3F·C4N3H15(2),表明凝胶中的F-显著改变了乙二胺和二乙烯三胺的结构导向效应.详细对比分析了Ui O-13和化合物1以及AlPO-CJ31和化合物2的结构,探讨了F-对乙二胺和二乙烯三胺的结构导向效应的影响及F-与有机胺的协同结构导向效应.     

新型磷-钒-氧层状化合物[H2en]2[H3O]6[Co(H2O)2(VO)8(OH)4(PO4)8]的水热合成与晶体结构

金属磷酸盐材料在吸附、离子交换、离子传导和催化剂方面有潜在的应用前景[1～5]. 近年来, 通过水热反应合成了一些A-V-P-O化合物. 在这些化合物中, A一般为碱金属或有机阳离子, 如层状结构的[H2N(C4H8)2NH2][(VO)4(OH)4(PO4)2][6] 和[H2N(C2H4)3NH2][(VO)8(HPO4)3(PO4)4*(OH)2]*2H2O[6], 一维链状结构的 [H2NCH2CH2NH3(VO)(PO4)][7], 手性双螺旋结构的 [(CH3)2NH2]K4[(VO)10(H2O)2(OH)4(PO4)7]*H2O[8]以及具有三维骨架结构的化合物 [H3N(CH2)3NH3K(VO)3(PO4)3][9], [H3N(CH2)3NH3]2[V(H2O)2(VO)6(OH)2(HPO4)3(PO4)5]*3H2O[10]和[H3N(CH2)2NH3][(VO)3(H2O)2(PO4)2(HPO4)4][11].     

NH_4Al(SO_4)_2·12H_2O的热分解动力学研究

采用热分析(TG-DTA/DTG)、X射线衍射(XRD)研究了固态物质NH4Al(SO4)2.12H2O在氩气中的热分解过程。热分析结果表明,NH4Al(SO4)2.12H2O在氩气中分5步分解,其质量变化率与理论计算相吻合。XRD结果表明,NH4Al(SO4)2.12H2O热分解的最终产物为Al2O3。用Friedman法对各步分解过程的活化能Ea进行了计算,依此为初始值,采用多元非线性回归法得到各个分解步骤可能的动力学模型和参数。     

原位X射线衍射研究VOx和MoOx在Al2O3上的分散

 采用原位X射线衍射技术考察了机械研磨法和浸渍法制备的负载型VOx(MoOx)/Al2O3催化剂在空气中升温时的晶相变化. 结果表明,采用草酸络合浸渍法制备的VOx/Al2O3催化剂上前驱体(NH4)2［VO(C2O4)2］分散均匀,在升温至200～300 ℃时前驱体开始分解, 300～400 ℃是主要分解区间,到400 ℃时分解完全; VOx物种是通过晶相HxV2O5进行分散的. 机械研磨法制备的VOx/Al2O3催化剂在升温过程中虽然VOx与Al2O3之间存在相互作用,但并没有观察到明显的自发分散现象, V2O5一直以晶体氧化物形式存在. 在空气中升温至400 ℃时,浸渍法制备的MoOx/Al2O3催化剂上(NH4)6Mo2O24·4H2O已完全分解成MoO3. 机械研磨法制备的MoOx/Al2O3在加热过程中分解生成的MoO3与浸渍法得到的MoO3不完全相同,主要体现在(040)和(060)晶面的含量不同; 机械研磨法制得的催化剂在500 ℃下焙烧1 h的分散度小于浸渍法制备的催化剂.     

新型氨基酸-钨砷多金属氧酸盐K6［Cu(Ala)2*(H2O)2］2［Cu4(H2O)2(AsW9O34)2］*16H2O的合成与晶体结构

The novel amino-acid-containing polyoxometalate K6［Cu(Ala)2(H2O)2］2［Cu4(H2O)2\5(AsW9O34)2］*16H2O was synthesized from the rea ction of K10［Cu4(H2O)2(AsW9O34)2］*20H2O with β-alanine. Its structure has been determined by single crystal X-ray diffraction. It crystallizes in the triclinic space group P1, with a=1.196 3(2) nm, b=1.536 5(3) nm, c=1.591 4(3) nm, α=93.97(3)°, β=110.88(3)°, γ=101.07(3)°, V=2.651 8(9) nm3 and Z=1. Least-squares refinement of the structure leads to R and Rw factors of 0.067 3 and 0.162 8, respectively. An unusual structural feature of the compound is that the polyanion ［Cu4(H2O)2(AsW9O34)2］10- is linked with the amino-acid complex of Cu2+ by a μ-oxygen atom.     

预处理方法对钛硅沸石催化性能的影响

 采用不同的介质（HCl－H2O2,NH4F－H2O2,HNO3－H2O2,H2SO4－H2O2）对钛硅沸石TS－1进行预处理,并用IR,XRD,UV－Vis,XRF和27AlMASNMR对样品进行了表征;以丙烯环氧化为探针反应,考察了样品的催化性能．结果表明,经预处理后,TS－1中的TiO2均被脱除约20％,而Al几乎未被脱除;所脱除的TiO2为非骨架钛;环氧丙烷的选择性降低,但H2O2的有效利用率明显升高．特别是采用NH4F－H2O2预处理时,H2O2的转化率和有效利用率均提高10％．     

新型氨基酸—钨砷多金属氧酸盐K6[Cu（Ala）2·（H2O2）2]2[Cu4（H2O）2（AsW9O34）2]·16H2O

The novel amino-acid-containing polyoxometalate K6［Cu(Ala)2(H2O)2］2［Cu4(H2O)2\5(AsW9O34)2］*16H2O was synthesized from the rea ction of K10［Cu4(H2O)2(AsW9O34)2］*20H2O with β-alanine. Its structure has been determined by single crystal X-ray diffraction. It crystallizes in the triclinic space group P1, with a=1.196 3(2) nm, b=1.536 5(3) nm, c=1.591 4(3) nm, α=93.97(3)°, β=110.88(3)°, γ=101.07(3)°, V=2.651 8(9) nm3 and Z=1. Least-squares refinement of the structure leads to R and Rw factors of 0.067 3 and 0.162 8, respectively. An unusual structural feature of the compound is that the polyanion ［Cu4(H2O)2(AsW9O34)2］10- is linked with the amino-acid complex of Cu2+ by a μ-oxygen atom.     

水溶液中Al~(3+)第三水化层静态结构特征和~(27)Al-/~(17)O-/~1H-NMR特性的密度泛函理论研究

用密度泛函理论(DFT)量子化学计算方法对水溶液中Al 3+第三水化层的静态结构特征进行了系统研究。在Bock构建的含有第一、第二水化层Al(H2O)3+6·12H2O的基础上添加了第三水化层,系统考察了第三和第二水化层对第一水化层Al(H2O)3+6的键长、键角等结构参数,以及自然布居分析(NPA)电荷特性的影响,同时探讨了Al 3+(aq)配合物含有不同水化层时氢键网络结构,以及27Al-/17O-/1H-NMR的特性。     

多金属氧酸盐杂化催化剂光催化降解有机杀虫剂六氯苯

 通过自组装技术制备了一系列多金属氧酸盐-有机胺-分子筛杂化催化剂K5［M(H2O)PW11O39］-(EtO)3Si(CH2)3NH2-MCM-48,用XRD,ICP-AES,UV/DRS,FT-IR,31P MAS NMR和N2吸附等手段对其组成和结构进行了表征,并以有机杀虫剂六氯苯为探针分子考察了其光催化活性. 结果表明,多金属氧酸盐杂化催化剂的光催化降解活性高于直接光解,能有效地降解污水中的六氯苯,且易分离,可循环使用.     

磷酸铝分子筛[Al3P3O12F][C5H5NH]•0.2H2O的蒸气相合成与结构表征

采用蒸气相合成法以吡啶作为蒸气源, 在吡啶气氛下磷酸铝固态凝胶被转化为一种三维骨架结构的磷酸铝微孔化合物, 用X射线单晶衍射法测定了其晶体结构, [Al3P3O12F][C5H5NH]•0.2H2O微孔化合物属三斜晶系, 空间群P-1(2), 晶胞参数a＝9.127(2) Å, b＝9.185(3) Å, c＝9.346(2) Å, α＝85.563(14)°, β＝77.346(6)°, γ＝89.628(17)°, V＝762.2(4) Å3, Z＝2, Dc＝2.074 Mg/m3, Mr＝468.09, F(000)＝474, μ＝0.64 mm－1. 其和以前报道的磷酸铝分子筛UT-6具有相同的骨架结构, 起始凝胶组分中的氟离子参与了骨架生成(Al—F—Al), 骨架中有三种相互独立的8元环孔道互相交叉最终形成类似于AlPO4-CHA型沸石的笼型结构. XRD, TG-DTA研究结果表明, 合成的样品具有较高的热稳定性, 400 ℃煅烧后, 其骨架结构保持不变.     

Structural characterization of moganite-type AlPO4 by NMR and powder X-ray diffraction

Structural characterization of a new high-pressure AlPO(4) phase synthesized at 5 GPa and 1500 °C is reported. The phase is monoclinic (P2/a) with a = 8.7437(1) ?, b = 4.8584(1) ?, c = 10.8600(2) ?, β = 90.124(1)° (Z = 6). (31)P MAS NMR and two-dimensional (2D) (27)Al triple-quantum (3Q) MAS NMR revealed that it contains two tetrahedral P sites of 1:2 abundance ratio, and two tetrahedral Al sites with 1:2 ratio. 2D (31)P dipolar-recoupled double-quantum (DQ) MAS NMR and (27)Al → (31)P dipolar-based (through-space) and J coupling-based (through-bond) 3Q-heteronuclear correlation (HETCOR) experiments provided direct information on the linkages of these sites. The crystal structure was solved and refined from synchrotron powder X-ray diffraction data utilizing the information from NMR. The phase is isostructural to moganite, a rare SiO(2) polymorph, and its structure can be derived from the latter via an ordered replacement of tetrahedral Si sites by Al and P. The NMR parameters of the phase were also calculated by first-principles method, which are consistent with those observed. Contrary to the other moganite phases known to date (i.e., SiO(2) and PON), moganite-AlPO(4) has a higher-pressure stability field than the corresponding quartz phase. This is the first moganite-type phase found in the ABX(4) system.     

SPAM-MQ-HETCOR: an improved method for heteronuclear correlation spectroscopy between quadrupolar and spin-1/2 nuclei in solid-state NMR

The recently introduced concept of soft pulse added mixing (SPAM) is used in two-dimensional heteronuclear correlation (HETCOR) NMR experiments between half-integer quadrupolar and spin-1/2 nuclei. The experiments employ multiple quantum magic angle spinning (MQMAS) to remove the second order quadrupolar broadening and cross polarization (CP) or refocused INEPT for magnetization transfer. By using previously unexploited coherence pathways, the efficiency of SPAM-MQ-HETCOR NMR is increased by a factor of almost two without additional optimization. The sensitivity gain is demonstrated on a test sample, AlPO(4)-14, using CP and INEPT to correlate (27)Al and (31)P nuclei. SPAM-3Q-HETCOR is then applied to generate (27)Al-(31)P spectra of the devitrified 41Na(2)O-20.5Al(2)O(3)-38.5P(2)O(5) glass and the silicoaluminophosphate ECR-40. Finally, the method allowed the acquisition of the first high resolution solid-state correlation spectra between (27)Al and (29)Si.     

Probing the local environments of phosphorus in aluminophosphate-based mesostructured lamellar materials by solid-state NMR spectroscopy

We have characterized a series of mesostructured aluminophosphate (AlPO)-based lamellar materials by several solid-state NMR techniques. In particular, we were able to estimate the average number of Al atoms and identify the nature of other ancillary groups in the second coordination sphere for each P site. Our work has shown that a combination of several dipolar coupling-based (31)P/(27)Al double-resonance techniques such as transfer of population in double-resonance (TRAPDOR), rotational echo double-resonance (REDOR), and heteronuclear correlation spectroscopy (HETCOR) as well as (1)H --> (31)P cross polarization (CP) can provide more detailed structural information regarding the local environments of P and Al atoms in AlPO-based mesostructured materials, which is not readily available from straightforward (31)P and (27)Al magic-angle spinning (MAS) experiments.     

Synthesis, crystal structure, and solid-state NMR spectroscopy of a new open-framework aluminophosphate (NH(4))(2)Al(4)(PO(4))(4)(HPO(4))xH(2)O

A new three-dimensional open-framework aluminophosphate (NH(4))(2)Al(4)(PO(4))(4)(HPO(4)).H(2)O (denoted AlPO-CJ19) with an Al/P ratio of 4/5 has been synthesized, using pyridine as the solvent and 2-aminopyridine as the structure-directing agent, under solvothermal conditions. The structure was determined by single-crystal X-ray diffraction and further characterized by solid-state NMR techniques. The alternation of the Al-centered polyhedra (including AlO(4), AlO(5), and AlO(6)) and the P-centered tetrahedra (including PO(4) and PO(3)OH) results in an interrupted open-framework structure with an eight-membered ring channel along the [100] direction. This is the first aluminophosphate containing three kinds of Al coordinations (AlO(4), AlO(5), and AlO(6)) with all oxygen vertexes connected to framework P atoms. (27)Al MAS NMR, (31)P MAS NMR, and (1)H --> (31)P CPMAS NMR characterizations show that the solid-state NMR techniques are an effective complement to XRD analysis for structure elucidation. Furthermore, all of the possible coordinations of Al and P in the aluminophosphates with an Al/P ratio of 4/5 are summarized. Crystal data: (NH(4))(2)Al(4)(PO(4))(4)(HPO(4))xH(2)O, monoclinic P2(1) (No. 4), a = 5.0568(3) A, b = 21.6211(18) A, c = 8.1724(4) A, beta = 91.361(4) degrees , V = 893.27(10) A(3), Z = 2, R(1) = 0.0456 (I > 2 sigma(I)), and wR(2) = 0.1051 (all data).     

Crystallization of AlPO4-5 aluminophosphate molecular sieve prepared in fluoride medium: a multinuclear solid-state NMR study

In the present work, multinuclear solid-state NMR techniques, combined with powder X-ray diffraction (PXRD) and infrared (IR) spectroscopy, are employed to monitor the crystallization of AlPO4-5 aluminophosphate prepared in the presence of HF under hydrothermal condition. The crystallization process is characterized by the evolution of intermediate gels, in which the long-rang ordering arrangement is probed by PXRD, revealing the threshold of the crystallization around 120 min. The appearance of 31P signals at ca. -22 and -29 ppm due to the structural P-O-Al unit and 19F signal at -120 ppm due to the structural F-Alpen-O-P unit in the NMR spectra of the series gels indicates that the crystalline framework is starting to form. The onset of the crystallization is also evidenced by the presence of the pentacoordinated Al in the structural F-Alpen-O-P unit which is considered to be associated with the ordered framework. More information about the local ordering of the gels is obtained from two-dimensional 27Al --> 31P heteronuclear correlation (HETCOR) and 31P/27Al double-resonance experiments. In combination with 1H --> 31P cross-polarization/magic-angle spinning (CP/MAS) experiments, two microdomains can be identified in the 120 min heated gel. A possible evolution mechanism of the gels consisting of three successive stages is proposed for the crystallization process.     

柱撑化合物Zn2Al-PW11Z的结构模型及酯化活性

杂多化合物是性能优异的酸型和氧化型或双功能催化剂[1－4]，而通式为的阴离子粘土通常具有减催化或还原催化性能[5，6]．因此，从在分子及原子水平上设计催化剂，调控催化性能观点出发，人们期望将体积较大的杂多阴离子嵌入阴离子粘土层间，合成大层间距的新型柱撑微孔材料．1988年Pinnavaia等人[7]首次报导了Zn2Al－V10O28是具有2．0nm孔径分布的中微孔材料．最近，笔者将单取代型Keggin结构杂多阴离子GeW11O39Z（H2O）6－（其中Z＝Ni2 和Cu2 ）和缺位Keggin结构的GeW11O嵌入Zn2Al－NO3层间，合成了通道高度为0．9nm的新型柱撑…     

Synthesis and characterization of a novel cyclic aluminophosphinate: structure and solid-state NMR study

We present the structure and a multinuclear solid-state NMR study of a new cyclic aluminophosphinate. The crystallographic structure of [Al(2)(HC(6)H(5)PO(2))(2)(C(4)H(9)OH)(8)]Cl(4) (compound 1) was obtained at low temperature (a = 11.830(7) A, b = 14.216(6) A, c = 17.790(6) A, beta = 91.25(4) degrees, monoclinic, P21/c, Z = 2). (13)C IRCP (inversion recovery cross polarization) and NQS (non quaternary suppression) NMR experiments allowed the complete assignment of the quaternary carbon atom of the phenyl ring and the precise determination of the isotropic /(1)J(P-C)/ coupling constant. (31)P CP MAS dynamics was carefully studied by varying the contact time. Dipolar oscillations even at slow MAS were observed. Up to 11 kHz, these oscillations were more pronounced, and the P-H distance was easily extracted. (27)Al NMR quadrupolar parameters for 1 were obtained with very good accuracy, and unusual satellite transition splitting was observed. Furthermore, the isotropic lines of the inner and outer transitions were clearly observable, leading to the unambiguous determination of the quadrupolar parameters.     

New crystalline aluminum alkoxide oxide fluorides: evidence of the mechanism of the fluorolytic sol-gel reaction

This study reports three new crystalline aluminum isopropoxide oxide fluorides with molar ratios of Al:F equal to 1:1 and 1:1.25. These are the first three representatives isolated without the incorporation of external donor molecules. Compound 1 Al(4)F(4)(μ(4)-O)(μ-O(i)Pr)(5)[H(O(i)Pr)(2)] contains a tetranuclear unit consisting of two different five fold coordinated AlFO(4)-units, with F exclusively in the terminal position. Compound 2, Al(4)F(4)(μ(4)-O)(μ-O(i)Pr)(5)[H(O(i)Pr)(2)]·Al(5)F(5)(μ(5)-O)(μ-O(i)Pr)(8), contains both a tetranuclear unit (as in 1) and a pentanuclear Al-unit. Al-atoms in the latter are five- and six fold coordinated. Compound 3, Al(16)F(20)(μ(4)-O)(4)(μ-O(i)Pr)(20)·2((i)PrOH), exhibits a slightly higher fluorination degree and contains an oligomeric chain of four F-linked tetranuclear Al-units. In addition to X-ray structure analysis, compound 1 was characterized by different solid state MAS NMR techniques, including (27)Al triple quantum MAS NMR and (1)H, (1)H→(13)C CP, (19)F and (27)Al MAS NMR. On the basis of the collected data, a reliable decomposition of (27)Al single pulse MAS NMR spectra and an unambiguous assignment of the resonances to the respective structural AlFO(4)-units are given. The new crystalline aluminum isopropoxide oxide fluorides are direct evidence of the fluorolytic sol-gel mechanism previously discussed.     

用固体核磁共振研究Al/P>1的磷酸铝分子筛AlPO4-5

用固体高分辩核磁共振（ＮＭＲ）方法对一系列Ａｌ／Ｐ＞１的新型磷酸铝分子筛ＡｌＰＯ４－５中磷和铝的结构状态及联结方式进行了研究，＾２７Ａｌ和＾３１Ｐ ＮＭＲ都给出了在分子筛骨架中存在有Ａｌ－Ｏ－Ａｌ联结方式的实验证据，寓示着在该体系中Ｐ和Ａｌ的排布不再遵循Ｌｏｅｗｅｎｓｔｅｉｎ规则。     

Characterization of active phosphorus surface sites at synthetic carbonate-free fluorapatite using single-pulse 1H, 31P, and 31P CP MAS NMR

The chemically active phosphorus surface sites defined as PO(x), PO(x)H, and PO(x)H2, where x = 1, 2, or 3, and the bulk phosphorus groups of PO4(3-) at synthetic carbonate-free fluorapatite (Ca5(PO4)3F) have been studied by means of single-pulse 1H,31P, and 31P CP MAS NMR. The changes in composition and relative amounts of each surface species are evaluated as a function of pH. By combining spectra from single-pulse 1H and 31P MAS NMR and data from 31P CP MAS NMR experiments at varying contact times in the range 0.2-3.0 ms, it has been possible to distinguish between resonance lines in the NMR spectra originating from active surface sites and bulk phosphorus groups and also to assign the peaks in the NMR spectra to the specific phosphorus species. In the 31P CP MAS NMR experiments, the spinning frequency was set to 4.2 kHz; in the single-pulse 1H MAS NMR experiments, the spinning frequency was 10 kHz. The 31P CP MAS NMR spectrum of fluorapatite at pH 5.9 showed one dominating resonance line at 2.9 ppm assigned to originate from PO4(3-) groups and two weaker shoulder peaks at 5.4 and 0.8 ppm which were assigned to the unprotonated PO(x) (PO, PO2-, and PO3(2-)) and protonated PO(x)H (PO2H and PO3H-) surface sites. At pH 12.7, the intensity of the peak representing unprotonated PO(x) surface sites has increased 1.7% relative to the bulk peak, while the intensity of the peaks of the protonated species PO(x)H have decreased 1.4% relative to the bulk peak. At pH 3.5, a resonance peak at -4.5 ppm has appeared in the 31P CP MAS NMR spectrum assigned to the surface species PO(x)H2 (PO3H2). The results from the 1H MAS and 31P CP MAS NMR measurements indicated that H+, OH-, and physisorbed H2O at the surface were released during the drying process at 200 degrees C.