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多金属钼/钨酸盐的水热合成、结构表征及性质研究

Hydrothermal Synthesis, Structure Characterization and Properties of Polymolybdates or Polytungstates

【作者】 王子梁

【导师】 王敬平;

【作者基本信息】 河南大学 , 无机化学, 2004, 硕士

【摘要】 本论文工作的主要目标是通过水热合成设计与制备结构新颖的多金属钼酸盐和Keggin结构类型的多金属钨酸盐。前者主要是制备有机配体键合的多金属钼酸盐;后者重点是探索出一个简易、有效的合成过渡金属或主族元素硅作杂原子的Keggin多金属钨酸盐的方法,然后通过变换过渡金属或有机配体的种类探讨对产物结构的影响,再对所得化合物的结构和组成通过物理测试手段进行表征,同时研究其在光、电、磁等方面的性质。 我们首次合成出一种4,4′-联吡啶桥联的哑铃型二聚五钼酸盐、一种偏钨酸盐、三种过渡金属作杂原子的Keggin多金属钨酸盐和两种金属单取代的一维链状Keggin多金属钨硅酸盐,它们的分子式、主要晶体数据、结构特征及性质研究如下: 1.4,4′-联吡啶桥联的哑铃型二聚五钼酸盐:[4,4′-H2bipy]3[4,4′-Hbipy]2[(Mo5O17)2(4,4′-bipy)]晶体属于三斜晶系,空间群P1。晶胞参数:a=10.578(2),b=11.047(2),c=16.576(3),α=79.86(3)°,β=75.34(3)°,γ=79.40(3)°,V=1824.8(6)3,Z=1,Dc=2.221gcm-3;μ=1.757 mm-1,R=0.0255,Rw=0.0578。该多阴离子[(Mo5O17)2(4,4′-bipy)]8-中,两个[Mo5O17]4-离子通过一分子4,4′-联吡啶桥联成哑铃型结构。热分析表明,阴离子[Mo5O17]4-骨架在409℃开始分解。 2.偏钨酸盐:[Cu(2,2′-bipy)3]2H2[H2W12O40]·4.5H2O晶体属于三斜晶系,空间群P1-。晶胞参数:a=13.929(3),b=17.493(4),c=19.210(4),α=86.39(3)°,β=68.77(3)°,γ=74.21(3)°,V=4195.2(15)3,Z=2,Dc=3.158 g cm-3,μ=16.970 mm-1,R=0.0785,Rw=0.0972。该化合物分子包含两个[Cu(2,2′-bipy)3]2+配离子和一个偏钨酸阴离子[H2W12O40]6-。 3.Keggin阴离子支撑过渡金属配合物:[Zn(2,2′-bipy)3]2[ZnW12O40Zn(2,2′-bipy)2]·H2O摘要三斜晶系,空间群p2(1)/n。晶体参数:a=26.257(5)A,b25.451(6),刀=97.83(3)o,F=10270(4)A,,z=4,Dc13.877(3)A,2 .83xgem一3,14.38Inun一,,尺=0.0660,尺w二0.1065。该多阴离子[znW12O4oZn(2,2‘-biny)z]“一中,Keggin阴离子[Z nw;20#0]“一作为二齿配体即通过一个端氧和一个二重桥氧与zn(2,2’一bipy)212+配位。4.Keggin结构钨锌酸盐:(4,4’一玩bipy)2(4,4‘一Hbipy)2(Z nw:2040)·6HZo晶体属于三斜晶系,空间群尸21/e。晶体参数:a=15.637(4)A,b=14.003(3)A,c一26.470(5)A,刀一04.75(3)’,犷一 6650(2)A,,z一4,Dc一3.63ogcm“,,群二21,o32mm一’,尺== 0.0651,天w一0.0606。热分析表明,[znwlZo4。]6一阴离子骨架在587oC开始分解。5.Keggin结构钨钻酸盐:Ieo(2,2’一bipy)3]2H2[CoW盈2040]·9.5H2o晶体属于三斜晶系,空间群Pl。晶体参数:a二l4.482(3)人,b二17.520(4)入,。二19.177(4)A,a=80.98(3)。刀=69.67(3)。,7=72.31(3)犷=4316.2(15)A3,z=2,D。二3.179gcm一3,产一16.580 mm一,,尺一0.0513,尺w一0.1205。电子自旋共振光谱表明,化合物中存在两种类型的c了十离子:高自旋态(g二5.5,4.2)和低自旋态(g二2.0)。当温度从110K升至室温时由于零场分裂造成g二5.5处的信号消失;热分析表明,[cowlZo4o]“.阴离子骨架在56o.4oe开始分解。6,镍取代的一维链状众ggin钨硅酸盐:[Ni(DETA)2]3IsiNiw一1039]·2.5H2o单斜晶系,空间群pn。晶体参数:a一20.926(2)A,吞=23.022(5)A,e=13.221(3)A,刀一94.27(3)o,V一33 16.4(21)A3,z一2,Dc一3.579 gcm一3,产== 20.216,天-0.0515,Rw一0.1142。[ siNiw】,039]6“阴离子通过Ni一。一w桥连接成一维链状结构。7.钠取代的一维链状Keggin钨硅酸盐:[HZen]2[Bao.15(HZO)2(HenZ)]Hl.7[SINaW】;039]·ZHZO单斜晶系,空间群pZI。晶胞参数:a=1 2.540(3)A,b=11一74(2)A,c=16.693(3)A,刀=9 1 .14(3)O,犷=2394.4(s)A3,z=2,口‘=4.231 gcm一,召=26.574,尺==河南大学无机化学专业2001级硕士研究生毕业论文:王子梁0.0553,尺w一0.1392。[siNawl,039]6一阴离子通过Na一。一w桥连接成一维链状结构。 结论1.合成了一种4,4’一联毗咤桥联的哑铃型二聚五铝酸盐、一种偏钨酸盐、三种过渡金属作杂原子的Keggin多金属钨酸盐和两种金属单取代的一维链状Keggin多金属钨硅酸盐。成功的探索出一个简易、有效的合成过渡金属作杂原子的Keggin多金属钨酸盐的方法。研究发现:只有在MCI:和M(Ac)2[M=过渡金属」共同出现在反应体系中才能生成过渡金属作杂原子的Keggin多阴离子,这可能是二者之间存在某种协同作用;此外,有机配体的不同对晶体结构影响较大。2.对所得化合物分别用元素分析、IR、UV、TG一DTA、EPR和单晶X一射线衍射进行结构表征和性质研究,并得出了一些有意义的结论。 本论文较好的完成了预设的目标,但是还存在着不足之处,由于水热条件下合成出的晶体难以溶于水和一般的有机溶剂,导致无

【Abstract】 The main aim of the paper is to design and prepare some novel polymolybdates and Keggin polytungstates. The former is to prepare polymolybdates coordinated’ directly by organic ligands using Na2MoO4 and MoO3 precursors; The latter plays emphasis on exploiting a simple and effective routine to synthesize Keggin polytungstates in which the transition metal or Si acts as the heteratom by reaction precursor Na2WO4.We have synthesized a 4,4’-bipyridine bridging dumbbell-like polymolybdates a metatungstate three Keggin-type polytungstates in which the heteroatom are transition metal and two mono-substituted Keggin tungstosilicates. Their main crystal data, structure feature and properties are listed as following:1. A 4,4’-bipyridine bridging dumbbell-like dimeric pentamolybdate: [4,4’-H2bipy]3[4,4’-Hbipy]2[(Mo5On)2(4,4’-bipy)]Triclinic, P1 space group with a = 10.578(2) A, b = 11.047(2) A, c - 16.576(3), a = 79.86(3)2,B = 75.34(3)°, r=79.40(3)°, V= 1824.8(6) A3, Z = 1,DC = 2.221 gcm-3, u = 1.757 mm-1, R = 0.0255, Rw = 0.0578. In the complex two [Mo5O17]4- ion units are buttressed by a 4,4’-bipyridine ligand to form a dumbbell-like polyanion [(Mo5O17)2(4,4’-bipy)]8-. Thermal analysis indicate that anion [MO5O17]4- begin discompose at 409℃.2. Ametatungstate: [Cu(2,2’-bipy)3]2H2[H2W12O40] 4.5H2OTriclinic, Pi space group, a = 13.929(3) A, b = 17.493(4) A, c = 19.210(4) A, a = 86.39(3)°, B = 68.77 (3)°, r = 74.21(3)°, V= 4195.2(15) A3, Z= 2, Dc = 3.158 g cm-3, u = 16.970 mm-1, R= 0.0785, Rw = 0.0972. The compound is composed of one metatungstate anion, two copper-bipyridyl cations and four and a half crystallography water molecules.3. a-Keggin unit supported zinc-bipyridyl complex: [Zn(2,2’-bipy)3]2[ZnW12O40 Zn(2,2’-bipy)2] H2OTriclinic, P2(1)/n space group, a = 26.257(5) A, b = 13.877(3) A, c = 28.451(6), B = 97.83(3)°, V= 10270(4) A3, Z= 4, Dc = 2.831gcm-3,u = 14.381mm-1, R= 0.0660, Rw = 0.1065. In the novel polyanion [ZnW12O40Zn(2,2’-bipy)2]6-, the Keggin anion [ZnW12O40]6- acts as a bidentate ligand towards [Zn (2,2’-bipy)2]2+ cation through a terminal oxygen and a bridging oxygen.4. A Keggin-type tungstozincates (4,4’-H2bipy)2(4,4’-Hbipy)2(ZnW12O40) 6H2O Triclinic, P21/c space group, a = 18.637(4) A, b = 14.003(3) A, c = 26.470(5) A, B = 104.78(3)°, V=6680(2)A3,Z = 4, Dc = 3.630gcm-3,u = 21.032mm-1,R = 0.0651,Rw = 0.0606. The thermal analysis shows that Keggin anion [ZnW12O40]6- start to decompose at 587℃.5. A Keggin-type tungstocobaltate: [Co(2,2’-bipy)3]2H2[CoW12O40] 9.5H2O Triclinic, P1 space group, a = 14.482(3) A,b = 17.520(4) A, c = 19.177(4) A, a = 80.98(3)° B = 69.67(3)°, r =71.31(3) V= 4316.2(15) A3, Z= 2, Dc = 3.179gcm-3, u = 16.580 mm-1, R - 0.0513, Rw = 0.1205. EPR spectra reveal two Co2+ coordination environments: high spin state (g = 5.1, 4.2) and low spin state (g = 2.0) exhibiting in the title compound. Furthermore, when the temperature increases from 110K to room temperature, the signal g = 5.1 of high spin Co2+ disappears caused by the zero-field splitting. Thermal analysis indicates that Keggin anion skeleton begin to discompose at 560.4℃.6. A nickel substituted Keggin tungstosilicate: [Ni(DETA)2]3[SiNiW11O39]-2.5 H2OMonoclinic, Pn space group, a = 10.926(2) A, b = 23.022(5) A, c = 13.221 (3) A, B = 94.27(3)°, V= 3316.4(11)A3,Z = 2, Dc= 3.579gcm-3,u = 20.216, R=0.0515, Rw - 0.1142. [SiNiW11O40]6- unit connects with other adjacent units via Ni-O-Wbridges constructing an infinitely one-dimensional chain-like structure.7. A sodium substituted Keggin tungstosilicate: [H2en]2[Ba0.15(H2O)2(Hen2)]H1.7[SiNaW11O39] 2H2OMonoclinic, P21 space group, a = 12.840(3) A, b = 11.174(2) A, c = 16.693(3) A, B= 91.14(3)°, V= 2394.4(8) A3,Z= 2,DC = 4.231 gcm-3,u = 26.574, R= 0.0583, Rw- 0.1392. [SiNaW11O40]7- unit connects with other adjacent units via Na-O-Wbridges constructing an infinitely one-dimensional chain-like structure.ConclusionsA 4,4’-bipyridine bridging dumbbell-like dimeric penta

  • 【网络出版投稿人】 河南大学
  • 【网络出版年期】2004年 03期
  • 【分类号】O614
  • 【被引频次】2
  • 【下载频次】367
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