杂多化合物催化性能的研究——第四周期过渡金属取代的钼磷三元杂多…

过渡金属单取代的杂多化合物（ｎ－Ｃ４Ｈ９）４Ｎ ８－ｎ对以过氧化氢为氧化剂的环己烯氧化反应具有良好的催化性能。基于动力学、红外光谱及电化学方法的研究，对反应机理作了讨论。认为这类取代的杂多化合物与Ｈ２Ｏ２作用形成了活性中间体，活性中心为参与取代的过渡金属离子。     

钛取代的钨硅杂多配合物位置异构体的合成、表征及催化性能

钛取代的钨硅杂多配合物位置异构体的合成、表征及催化性能;钨钛杂多化合物;催化活性;环氧化反应     

杂多化合物催化性能的研究—第四周期过渡金属取代的钼磷三元杂多化合物在环己烯氧化反应中的催化作用

过渡金属单取代的杂多化合物［（ｎ－Ｃ４Ｈ９）４Ｎ］８－ｎ［ＰＺｎ＋ＢｒＭｏ１１Ｏ３９］（Ｚ＝Ｍ２＋ｎ、Ｆｅ３＋、Ｃｏ２＋、Ｎｉ２＋、Ｃｕ２＋）对以过氧化氢为氧化剂的环己烯氧化反应具有良好的催化性能．基于动力学、红外光谱及电化学方法的研究，对反应机理作了讨论．认为这类取代的杂多化合物与Ｈ２Ｏ２作用形成了活性中间体，活性中心为参与取代的过渡金属离子．     

缺位Dawson型K10Na2H2P2W16O60在环己烯氧化中的催化作用

合成了二缺位杂多化合物K10Na2H2P2W16O60·18H2O,用IR、UV-vis、XRD及TG表征了其结构,考察了该化合物在过氧化氢氧化环己烯反应中的催化作用.研究结果表明,溶剂种类和反应温度对二缺位杂多化合物的催化性能有显著的影响,在叔丁醇中主要生成环己烯酮,在丙酮中主要生成环己二醇.在乙腈中主要生成环氧环己烷,其选择性随着反应温度升高和催化剂用量增加而降低,环己烯酮的选择性则逐步升高.催化剂与产物可通过温控固-液相分离,可以重复使用.     

磷钼杂多蓝作为反应控制相转移催化剂

设计合成了第一个由磷钼杂多蓝作为反应控制相转移催化剂的反应体系,用于对环己烯进行催化环氧化,苯甲醇进行催化氧化.在体系中,催化剂以均相的方式催化反应,以多相的方式分离回收.催化剂显示了很高的催化活性和稳定性.在催化氧化苯甲醇的反应中,H₂O₂的利用率为100%,苯甲醛的选择性为100%.     

Keggin结构过氧铌钨磷杂多配合物的合成、表征及催化性能

钼钨的杂多化合物（HPC）在催化、电催化、分子材料、药物等诸多领域中已显示出独特的功能。含过氧金属离子取代的杂多阴离子在催化以过氧化氢为氧化剂的烯烃环氧化反应中具有很高的活性和选择性。近年来,含铌的杂多配合物由于良好的催化活性和抗病毒性,引起了人们的重视。本文合成了8种Keggin结构过氧铌钨磷杂多配合物,并用红外、紫外吸收光谱、极谱-循环伏安、及^183W NMR谱等测试手段对其结构和性质进行了确定和比较,考察了它们对烯烃环氧化反应的催化活性。     

双核烷基咪唑过氧磷钨酸盐相转移催化剂合成及催化烯烃环氧化性能

合成并表征了一类双核长链烷基咪唑阳离子修饰的过氧磷钨杂多酸盐催化剂[Dnmin]1.5PW4O24,考察了催化剂在过氧化氢为氧源的烯烃环氧化反应中的催化活性.研究表明,这类催化剂在反应过程中表现出相转移催化现象,并具有较高的催化活性和选择性.其中,双核十二烷基咪唑杂多酸盐催化剂[D12min]1.5PW4O24的活性最佳,其环己烯转化率和环氧环己烷选择性分别达到97.7%和96.3%.催化剂在经过简单离心分离后可重复使用,重复使用4次后环己烯转化率和环氧环己烷选择性仍可分别达到72.4%和97.2%.催化剂[D12min]1.5PW4O24在其它几种烯烃的环氧化反应中均表现出相转移催化特性,且具有较高的催化活性.     

钯、铱单取代十二钼磷酸盐的制备及性质的研究

本文报道了Pd 、Ir 　取代的十二钼磷酸四丁基铵盐 (α (n Bu4 N) 5[PMo11Pd(OH2 )O39]、α (n Bu4 N) 3[PMo11Ir(OH2 )O39])的制备方法。IR、UV及31P NMR证实产物仍保持Keggin结构 ,并有一个Mo 为Pd 、Ir 所取代。电化学上 ,Ir 取代化合物存在三个清晰的多酸骨架氧化 还原峰而Pd 取代化合物由于电极吸附作用使它的氧化 还原峰无法被观察到。在两个取代化合物的烯烃催化氧化中醇、酮为主要产物。　值得注意的是 ,Pd 取代化合物催化的反应中苯酚取代环己烯酮而成为主要产物     

过氧杂多阴离子柱撑水滑石的合成、表征及催化性能的研究

通过离子交换法, 将含钛过渡金属离子一、三取代钨硅、钨磷过氧杂多配合物嵌入Zn2Al类水滑石中, 获得了柱撑化合物, 并用XRD, IR, XPS, 元素分析等手段对产物的结构和组成进行了表征。结果表明, 过氧杂多阴离子进入水滑石层间后, 水滑石的层间距从0.92nm增大到1.47nm, 且O2^2^-链没有被破坏。柱撑产物在环己烯氧化反应中显示优良的催化性能。     

α-和β-Cs_4H_3[SiW_9O_(37)Cr_3(H_2O)_3]·xH_2O的合成及其催化PhIO环氧化烯烃的性质

本文报道了α-和β-[SiW_9O_(37)Cr_3(H_2O)_3]~(7-)杂多阴离子铯、钾盐的合成、表征及其催化亚碘酰苯环氧化烯烃的性质.元素分析、磁化率、红外光谱及FAB质谱等数据表明,该杂多阴离子为三取代的Keggin结构.α-和β-[siW_9O_(37)aCr_3(H_2O)_3]~(7-)具有催化PhIO环氧化反-二苯乙烯、环己烯和苯乙烯生成相应环氧化物的性质。     

Diastereoselective Synthesis, Spectroscopy, and Electrochemistry of Ruthenium(II) Complexes of Substituted Pyrazolylpyridine Ligands

We report the synthesis of the hetero- and homoleptic ruthenium(II) complexes Ru(bpy)(2)L(2+), Ru(bpy)L(2)(2+) (bpy is 2,2'-bipyridine), and RuL(3)(2+) of six new bidentates L, the substituted pyrazolylpyridines 1-6 (1-substituted-3-(2-pyridinyl)-4,5,6,7-tetrahydroindazoles with substituents R = H, CH(3), Ph, or C(6)H(4)-4"-COOX where X = H, CH(3), or C(2)H(5)). These were fully characterized by (1)H- and (13)C-NMR spectroscopy and elemental analysis. The UV-visible spectra and redox properties of the complexes, some in the ruthenium(III) and reduced bipyridine oxidation states, are also discussed. The substituents R played a role in determining the stereochemistry of the Ru(bpy)L(2)(2+) and RuL(3)(2+) products. The reaction of Ru(DMSO)(4)Cl(2) with 3 equiv of L bearing aromatic substituents gave only meridional RuL(3)(2+) isomers. The one-step reaction of Ru(bpy)Cl(3).H(2)O with 2 equiv of L provided a mixture of the three possible Ru(bpy)L(2)(2+) isomers, from which one symmetric isomer (labeled beta) was isolated pure. A trans arrangement of the pyrazole groups was deduced by (1)H-NMR and confirmed by X-ray crystallography for one such stereomer (beta-[Ru(bpy)(5)(2)](PF(6))(2), R = C(6)H(4)-4"-COOC(2)H(5)). In contrast, Ru(DMSO)(4)Cl(2) reacted with 2 equiv of L and then 1 equiv of bpy to selectively form the other symmetric isomer (labeled alpha) where the pyridine groups of L are trans. Crystal data for beta-[Ru(bpy)(5)(2)](PF(6))(2) (C(52)H(50)N(8)O(4)F(12)P(2)Ru) with Mo Kalpha (lambda = 0.710 73 ?) radiation at 295 K: a = 28.442(13) ?, b = 18.469(15) ?, c = 23.785(9) ?, beta = 116.76(0) degrees, monoclinic, space group C2/c, Z = 8. Fully anisotropic (except for H and disordered F atoms), full-matrix, weighted least-squares refinement on F(2) gave a weighted R on F(2) of 0.2573 corresponding to R on F of 0.1031 for data where F > 4sigma(F ).     

A new method for preparing （2Z, 4Z, 6Z）-diethyl-4,5- oxepinedicarboxylates and some 1H-azepine analogues

A new method for preparing (2Z, 4Z, 6Z)-4,5-diethyloxepinodicarboxylate by one-step is described. The synthesis of several oxepines and azepines derivatives was carried out by the reaction of substituted furans or pyrroles with diethyl acetylenedicarbox-ylate in boiling toluene. The effect factors for this reaction were discussed and reaction condition was optimized.     

Investigation of hydrothermal routes to mixed-metal cerium titanium oxides and metal oxidation state assignment using XANES

The reaction between TiF(3) or TiO(2) and Ce(3+) in sodium hydroxide solutions yields highly crystalline NaCeTi(2)O(6) at room temperature and under mild hydrothermal conditions (T < or = 240 degrees C). There is no evidence for the formation of ternary Ce-Ti-O materials by this method, and the use of bases other than NaOH always produces poorly crystalline materials. The material NaCeTi(2)O(6) has a distorted perovskite structure with sodium and cerium ions randomly occupying the A sites: Pnma, a = 5.4517(8) A, b = 7.7292(6) A, c =5.4573(3) A. XANES spectroscopy at the Ti K edge and Ce L(III) edge, with reference to crystalline model compounds, reveals that cerium is found solely as Ce(III) and titanium as Ti(IV) in NaCeTi(2)O(6). Isomorphous substitution of Ce(3+) by Nd(3+) or Ti(4+) by V(4+) is found to be very facile under hydrothermal conditions (at a temperature of 240 degrees C), by addition of appropriate amounts of metal salts to the hydrothermal reaction mixtures. The series NaCe(1-x)Nd(x)Ti2O6 (0 < or = x < or = 1) and NaCeTi(2-x)V(x)O6 (0 相似文献   

Nickel(II) and iron(II) triple helicates assembled from expanded quaterpyridines incorporating flexible linkages

In the present study the interaction of Fe(II) and Ni(II) with the related expanded quaterpyridines, 1,2-, 1,3- and 1,4-bis-(5'-methyl-[2,2']bipyridinyl-5-ylmethoxy)benzene ligands (4-6 respectively), incorporating flexible, bis-aryl/methylene ether linkages in the bridges between the dipyridyl domains, was shown to predominantly result in the assembly of [M(2)L(3)](4+) complexes; although with 4 and 6 there was also evidence for the (minor) formation of the corresponding [M(4)L(6)](8+) species. Overall, this result contrasts with the behaviour of the essentially rigid 'parent' quaterpyridine 1 for which only tetrahedral [M(4)L(6)](8+) cage species were observed when reacted with various Fe(II) salts. It also contrasts with that observed for 2 and 3 incorporating essentially rigid substituted phenylene and biphenylene bridges between the dipyridyl domains where reaction with Fe(II) and Ni(II) yielded both [M(2)L(3)](4+) and [M(4)L(6)](8+) complex types, but in this case it was the latter species that was assigned as the thermodynamically favoured product type. The X-ray structures of the triple helicate complexes [H(2)O?Ni(2)(4)(3)](PF(6))(4)·THF·2.2H(2)O, [Ni(2)(6)(3)](PF(6))(4)·1.95MeCN·1.2THF·1.8H(2)O, and the very unusual triple helicate PF(6)(-) inclusion complex, [(PF(6))?Ni(2)(5)(3)](PF(6))(3)·1.75MeCN·5.25THF·0.25H(2)O are reported.     

Synthesis, Structure, and Magnetic Properties of Transition Metal Complexes of the Nitroxide 2,5-Dihydro-4,5,5-trimethyl-2,2-bis(2-pyridyl)imidazole-1-oxyl

With the radical 2,5-dihydro-4,5,5-trimethyl-2,2-bis(2-pyridyl)imidazole-1-oxyl (L) a series of transition metal complexes have been prepared: [ML(2)](SbF(6))(2) with M(2+) = Mn(2+) (1), Fe(2+) (2), Co(2+) (3), Ni(2+) (4), Cu(2+) (5), and Zn(2+) (6), Cu(L)(Cl)(2)(MeOH) (7), and Cu(L)SO(4).H(2)O (8). The structures of 1, 3, and 6 were determined by X-ray structural analyses. In these compounds the tridendate L is coordinated to the metal ion by the two pyridine nitrogen donors and by the oxygen atom of the nitroxide group. The N-O bond distances are 1.25(2) ? (1), 1.267(13) ? (3), and 1.260(11) ? (6). The M-O-N angles are 117.0(10) degrees (1), 114.5(8) degrees (3), and 114.2(7) degrees (6). Crystal data: space group P2(1)/n, for 1, 3, and 6; compound 1, a = 10.806(3) ?, b = 14.101(6) ?, c = 14.253(4) ?, beta = 108.82(2) degrees, V = 2055.7(12) ?(3), Z = 2, R(1) = 0.0677, wR(2) = 0.1512. Compound 3, a = 10.761(4) ?, b = 14.253(6) ?, c = 14.108(5) ?, beta = 111.16(3) degrees, V = 2017.9(13) ?(3), Z = 2, R(1) = 0.0702, wR(2) = 0.1460; compound 6, a = 10.788(2) ?, b = 14.147(3) ?, c = 14.196(3) ?, beta = 109.93(3) degrees, V = 2036.8(7) ?(3), Z = 2, R(1) = 0.0573, wR(2) = 0.1194. Magnetic measurements of 1, 2, 5, and 8 show strong antiferromagnetic interaction between the spin of the metal ion and the spin of the radical which increases at lower temperatures. For 6 the magnetic moment corresponds to two noninteracting spins in the temperature range 60-300 K.     

Reactivity and spectroscopy of the {Ru(DMAP)5} fragment: an {Ru(NH3)5} analogue

Reaction of trans-Ru(DMSO)4Cl2 with DMAP (DMAP = 4-dimethylaminopyridine) yields the yellow [Ru(DMAP)6](2+) cation in good yield. The crystal and molecular structure of [Ru(DMAP)6]Cl2.6CH3CH2OH was determined by X-ray diffraction methods. The complex crystallizes in the trigonal R3 space group with a = b = 16.373(1), c = 20.311(1) A, gamma = 120 degrees , and Z = 3 molecules per unit cell. The reaction of [Ru(DMAP)6](2+) in aerobic water gives the red [Ru(III)(DMAP)5(OH)](2+) cation. This complex shows a chemical behavior similar to [Ru(III)(NH3)5Cl](2+) and allows the preparation of a family of [Ru(DMAP)5L](n+) complexes. Their electronic properties indicate that the {Ru(II)(DMAP)5} fragment is a weaker pi-donor than {Ru(II)(NH 3)5}. Our density functional theory (DFT) calculations show that in {Ru(II)(DMAP)5} the DMAP ligands can compete for the pi electron density of the ruthenium making the fragment a weaker pi-donor.     

Study of the ligand substitution reactions of cis,cis-[(bpy)(2)(L)RuORu(L')(bpy)(2)](n+) (L,L' = H(2)O,OH(-), NH(3)) using electrospray ionization mass spectrometry and (1)H NMR

We have successfully applied electrospray ionization mass spectrometry (ESI-MS) and (1)H NMR analyses to study ligand substitution reactions of mu-oxo ruthenium bipyridine dimers cis,cis-[(bpy)(2)(L)RuORu(L')(bpy)(2)](n+) (bpy = 2,2'-bipyridine; L and L' = NH(3), H(2)O, and HO(-)) with solvent molecules, that is, acetonitrile, methanol, and acetone. The results clearly show that the ammine ligand is very stable and was not substituted by any solvents, while the aqua ligand was rapidly substituted by all the solvents. In acetonitrile and acetone solutions, the substitution reaction of the aqua ligand(s) competed with a deprotonation reaction from the ligand. The hydroxyl ligand was not substituted by acetonitrile or acetone, but it exchanged slowly with CH(3)O(-) in methanol. The substitution reaction of the aqua ligands in [(bpy)(2)(H(2)O)Ru(III)ORu(III)(H(2)O)(bpy)(2)](4+) was more rapid than that of the hydroxyl ligand in [(bpy)(2)(H(2)O)Ru(III)ORu(IV)(OH)(bpy)(2)](4+). In methanol, slow reduction of Ru(III) to Ru(II) was observed in all the mu-oxo dimers, and the Ru-O-Ru bridge was then cleaved to give mononuclear Ru(II) complexes.     

Site selectivity in the reactions of the hexanuclear platinum cluster [Pt6(mu-PtBu2)4(CO)6][CF3SO3]2

The previously reported hexanuclear cluster [Pt(6)(mu-PtBu(2))(4)(CO)(6)](2+)[Y](2) (1-Y(2): Y=CF(3)SO(3) (-)) contains a central Pt(4) tetrahedron bridged at each of the opposite edges by another platinum atom; in turn, four phosphido ligands bridge the four Pt-Pt bonds not involved in the tetrahedron, and, finally, one carbonyl ligand is terminally bonded to each metal centre. Interestingly, the two outer carbonyls are more easily substituted or attacked by nucleophiles than the inner four, which are bonded to the tetrahedron vertices. In fact, the reaction of 1-Y(2) with 1 equiv of [nBu(4)N]Cl or with an excess of halide salts gives the monochloride [Pt(6)(mu-PtBu(2))(4)(CO)(5)Cl](+)[Y], 2-Y, or the neutral dihalide derivatives [Pt(6)(mu-PtBu(2))(4)(CO)(4)X(2)] (3: X=Cl; 4: X=Br; 5: X=I). Moreover, the useful unsymmetrically substituted [Pt(6)(mu-PtBu(2))(4)(CO)(4)ICl] (6) was obtained by reacting equimolar amounts of 2 and [nBu(4)N]I, and the dicationic derivatives [Pt(6)(mu-PtBu(2))(4)(CO)(4)L(2)](2+)[Y](2) (7-Y(2): L=(13)CO; 8-Y(2): L=CNtBu; 9-Y(2): L=PMe(3)) were obtained by reaction of an excess of the ligand L with 1-Y(2). Weaker nitrogen ligands were introduced by dissolving the dichloride 3 in acetonitrile or pyridyne in the presence of TlPF(6) to afford [Pt(6)(mu-PtBu(2))(4) (CO)(4)L(2)](2+)[Z](2) (Z=PF(6) (-), 10-Z(2): L=MeCN; 11-Z(2): L=Py). The "apical" carbonyls in 1-Y(2) are also prone to nucleophilic addition (Nu(-): H(-), MeO(-)) affording the acyl derivatives [Pt(6)(mu-PtBu(2))(4)(CO)(4)(CONu)(2)] (12: Nu=H; 13: Nu=OMe). Complex 12 is slowly converted into the dihydride [Pt(6)(mu-PtBu(2))(4)(CO)(4)H(2)] (14), which was more cleanly prepared by reacting 3 with NaBH(4). In a unique case we observed a reaction involving also the inner carbonyls of complex 1, that is, in the reaction with a large excess of the isocyanides R-NC, which form the corresponding persubstituted derivatives [Pt(6)(mu-tPBu(2))(4)(CN-R)(6)](2+)[Y](2), (15-Y(2): R=tBu; 16-Y(2) (2-): R=-C(6)H(4)-4-C triple bond CH). All complexes were characterized by microanalysis, IR and multinuclear NMR spectroscopy. The crystal and molecular structures of complexes 3, 5, 6 and 9-Y(2) are also reported. From the redox viewpoint, all complexes display two reversible one-electron reduction steps, the location of which depends both upon the electronic effects of the substituents, and the overall charge of the original complex.     

取代苯甲醛的取代基在硝基苄基鏻参与的Wittig反应中对二苯乙烯分子构型的影响

用硝基苄基鏻与取代苯甲醛经Wittig反应合成了一系列含硝基的二苯乙烯型化合物.研究表明,用硝基苄基鏻在二氯甲烷中进行这类Wittig反应时,随着苯甲醛的取代基不同,得到二苯乙烯主要产物的构型不同,取代基为NMe2,OMe,Me,Cl,H等时主要得到E式产物,取代基为CN和NO2等时主要得到Z式产物;进一步比较3种苄基鏻原料分别与6种不同取代苯甲醛反应后产物的Z/E比,发现用含硝基的苄基鏻作原料时,随苯甲醛上取代基的吸电子效应减小,产物的Z/E比也减小,而用苄基鏻或对甲基苄基鏻作原料时,没有观察到这种Z/E比减小的趋势.通过测定产物的晶体结构,确证了6个目标化合物的分子构型,另外通过核磁共振谱、气-质联用色谱、紫外光谱和红外光谱对各二苯乙烯化合物的结构进行了详细表征.     

Fenton chemistry of 1,3-dimethyluracil

Hydroxyl radicals were generated in the Fenton reaction at pH 4 (Fe(2+) + H(2)O(2) --> Fe(3+) + .OH + OH-, k approximately equal to 60 L mol(-1) s(-1)) and by pulse radiolysis (for the determination of kinetic data). They react rapidly with 1,3-dimethyluracil, 1,3-DMU (k = 6 x 10(9) L mol(-1) s(-1)). With H(2)O(2) in excess and in the absence of O(2), 1,3-DMU consumption is 3.3 mol per mol Fe(2+). 1,3-DMUglycol is the major product (2.95 mol per mol Fe(2+)). Dimers, prominent products of .OH-induced reactions in the absence of Fe(2+)/Fe(3+) (Al-Sheikhly, M.; von Sonntag, C. Z. Naturforsch. 1983, 31b, 1622) are not formed. Addition of .OH to the C(5)-C(6) double bond of 1,3-DMU yields reducing C(6)-yl 1 and oxidizing C(5)-yl radicals 2 in a 4:1 ratio. The yield of reducing radicals was determined with tetranitromethane by following the buildup of nitroform anion. Reaction of 1 with Fe(3+) that builds up during the reaction or with H(2)O(2) gives rise to a short-chain reaction that is terminated by the reaction of Fe(2+) with 2, which re-forms 1,3-DMU. In the presence of O(2), 1.1 mol of 1,3-DMU and 0.6 mol of O(2) are consumed per mol Fe(2+) while 0.16 mol of 1,3-DMU-glycol and 0.17 mol of organic hydroperoxides (besides further unidentified products) are formed. In the presence of O(2), 1 and 2 are rapidly converted into the corresponding peroxyl radicals (k = 9.1 x 10(8) L mol(-1) s(-1)). Their bimolecular decay (2k = 1.1 x 10(9) L mol(-1) s(-1)) yields approximately 22% HO(2)./O(2).(-) in the course of fragmentation reactions involving the C(5)-C(6) bond. Reduction of Fe(3+) by O(2).(-) leads to an increase in .OH production that is partially offset by a consumption of Fe(2+) in its reaction with the peroxyl radicals (formation of organic hydroperoxides, k approximately 3 x 10(5) L mol(-1) s(-1); value derived by computer simulation).