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1.
采用半微量相平衡方法研究了三元体系Y(ClO4)3.3H2O-B15C5-CH3OH在25℃的溶解度,测定了各饱和溶液的折光率。该体系在25℃生成三种化学计量的配合物,其组成分别为:4Y(ClO4)3.3B15C5.12H2O.12Ch3OH(I),Y(ClO4)3.2B12C5.3H2O.Ch3OH(Ⅲ),其中配合物(I)和(Ⅱ)是溶解不一致化合物。在甲醇溶剂中,分离制备了配合物(Ⅲ),在69-  相似文献   

2.
采用半微量相平衡方法研究了三元体系Y(ClO4)3·3H2O-B15C5—CH3OH在25℃的溶解度,测定了各饱和溶液的折光率.该体系在25℃生成三种化学计量的配合物,其组成分别为:4Y(ClO4)3·3B15C5·12H2O·12CH3OH(Ⅰ)、Y(ClO4)3·B15C5·3H2O·1.5CH3OH(Ⅱ)与Y(ClO4)3·2B15C5·3H2O·CH3OH(Ⅲ),其中配合物(Ⅰ)和(Ⅱ)是溶解不一致化合物.在甲醇溶剂中,分离制备了配合物(Ⅲ),在69—72℃下干燥得到配合物Y(ClO4)3·2B15C5·3H2O.利用IR光谱、电导测量及X-射线衍射分析对配合物进行了表征.  相似文献   

3.
蒸汽相法硼硅MFI沸石的合成与表征   总被引:2,自引:0,他引:2  
在三乙胺(Et3N)-乙二胺(EDA)-H2O蒸汽相中,无定形凝胶Na2O-B2O2-SiO2-H2O晶化生成硼硅MFI(ZSM—5)沸石.研究了硼硅MFI沸石的适宜晶化条件,以及氯化钠、碳酸钠和磷酸钠取代氢氧化钠作为钠源的影响.晶体结构参数、11BNMR、FT-IR的结果表明,由蒸汽相法合成的硼硅MFI沸石,其硼原子进入了沸石骨架.  相似文献   

4.
研究了硼改性的Hβ沸石表面酸性变化及其对丙烯与异丙醇醚化反应性能的影响。样品B2O3-Hβ的酸量随B2O3含量增加而增多。含量超过3%时酸量基本不变;对于B2O3-Hβ-Al2O3催化剂,B2O3使总酸量明显增大,并以L酸中心增加为主;Al2O3粘合剂的存在促进了B2O3与Hβ沸石间的相互作用;丙烯转化率及水的产率分别与L酸和B酸中心有很好的对应关系。丙烯与异丙醇的醚化反应主要在L酸中心上进行。  相似文献   

5.
碱金属和稀土溴化物Meyer反应的相化学研究(I)   总被引:2,自引:1,他引:2  
研究了四元体系CsBr-LaBr3-HBr(12%)-H2O(25℃)的相化学关系,绘制了相应的溶度图。在该体系中发现一种新型化合物5CsBr.2LaBr3.22H2O;对该人合物进行了偏光、X射线粉末衍射、TG及DTA等方面的,将本体系与四元系CsCl-LaCl3-HCl(13%)-H2O(25℃)相比较,发现两者在生命化合物的数量、种类和相化学行为方面均有较大的差异。  相似文献   

6.
由2-氰-5-氟-3H-4-嘧啶酮和取代苯酚钠在常压下反应,合成了7个未见文献报道的2-芳氧基-5-氟-3H-4-嘧啶酮化合物,产率70 ̄87%,结构经IR、^1H NMR和MS证实。  相似文献   

7.
用电结晶法合成了二苯基四硫富瓦烯(DBTTF)-十二钨杂多酸自由基盐,(DBTTF)6HSiW12O40·2H2O和(DBTTF)6PW12O40·5H2O,并用红外光谱、电子光谱和ESR谱进行了表征。测定了两个盐的磁化率、电导率和(DBTTF)6HSiW12O40·2H2O的单晶结构以及X-射线粉末衍射图。晶体属三斜晶系,P1空间群;晶胞参数为:a=13.774(2),b=14.196(2),c=15.628(3),α=104.48(1)°,β=103.97(1)°,γ=95.82(1)°,V=2828.4(8)3,Z=1,Dc=2.789mg/m3,R=0.0615。两种盐均为顺磁性物质,具有半导体的电传导性。  相似文献   

8.
胡益民  王修然 《合成化学》1999,7(2):191-193
以六氯代苯为原料,经过醚化,脱氯两个步骤合成了标题化合物,其结构经^1H NMR,IR,MS和元素分析确定,反应的最佳条件为:C6Cl6与CH3ONa的摩尔比为1:6,反应时间2.5h,产率67.5%。  相似文献   

9.
卢绍芳  黄建全 《结构化学》1995,14(5):482-487
三核钼簇Mo3S4(dtp)4.HO21(dtp=S2P(OC2H5)2)和对甲基苯磺酸反应,以C2H5OH做为介质,在CdCl2和PPh3参预下获得新颖的三核簇合物Mo(μ3-S)(μ-S)3-(μ-CH3C6H4SO3)(dtp).(C2H5OH)2.本文报导化合物2的晶体结构、红外光谱、紫外光谱研究结果。簇合物的分子结构存在一个非络合物的对甲基苯左侧酸基和两个Mo的桥式络合,颇为罕见。而簇分  相似文献   

10.
对羟基苯甲醛的液相催化氧化合成   总被引:6,自引:0,他引:6  
霍力  邝生鲁 《合成化学》1997,5(4):404-407
研究了活性炭负载磺化酞菁钴催化氧化对甲酚合成对羟基苯甲醛(PHB)的诸多影响因素,筛选到较好的反应条件:反应时间,12小时;温度,60℃;NaOH/对甲酚(mol比)为3.5∶1;催化剂,150ppm;对甲酚的转化率,97%;PHB收率,82.5%;选择性,85.1%。  相似文献   

11.
Single- and multibranched centrosymmetric derivatives incorporating B12 clusters [B12H11-N(H)=C(H)-C6H4-C6H4-C(H)=(H)N-B12H11]2- (3) and [1,3,5-(4-(B12H11-N(H)=C(H))-C6H4)-C6H3]3- (5) have been synthesized. Both derivatives were characterized by multinuclear NMR and ESI-MS analyses. To the best of our knowledge, compound 5 is the first example of a multicage derivative bearing three B12 units. Compounds 3 and 5 are only slightly yellowish colored. The UV-vis absorption curves of 3 and 5 show intense absorption bands at 360 and 314 nm, respectively. This result permits us to confirm the strong donor effect of the B12 cluster. The hypsochrome effect observed for compound 5 compared to that of compound 3 confirms the interest in multibranched derivatives for the preparation of two-photon absorption materials active in the visible range.  相似文献   

12.
We report the formation of icosahedral B(12)H(8) (+) through ion-molecule reactions of the decaborane ion [B(10)H(x)(+) (x=6-14)] with diborane (B(2)H(6)) molecules in an external quadrupole static attraction ion trap. The hydrogen content n of B(12)H(n)(+) is determined by the analysis of the mass spectrum. The result reveals that B(12)H(8)(+) is the main product. Ab initio calculations indicate that B(12)H(8)(+) preferentially forms an icosahedral structure rather than a quasiplanar structure. The energies of the formation reactions of B(12)H(14)(+) and B(12)H(12)(+) between B(10)H(x)(+) (x=6,8) ions, which are considered to be involved in the formation of B(12)H(n)(+), and a B(2)H(6) molecule are calculated. The calculations of the detachment pathway of H(2) molecules and H atoms from the product ions, B(12)H(14)(+) and B(12)H(12) (+), indicate that the intermediate state has a relatively low energy, enabling the detachment reaction to proceed owing to the sufficient reaction energy. This autodetachment of H(2) accounts for the experimental result that B(12)H(8)(+) is the most abundant product, even though it does not have the lowest energy among B(12)H(n)(+).  相似文献   

13.
Lee TB  McKee ML 《Inorganic chemistry》2012,51(7):4205-4214
The reduction potentials (E°(Red) versus SHE) of hypercloso boron hydrides B(n)H(n) (n = 6-13) and B(12)X(12) (X = F, Cl, OH, and CH(3)) in water have been computed using the Conductor-like Polarizable Continuum Model (CPCM) and the Solvation Model Density (SMD) method for solvation modeling. The B3LYP/aug-cc-pvtz and M06-2X/aug-cc-pvtz as well as G4 level of theory were applied to determine the free energies of the first and second electron attachment (ΔG(E.A.)) to boron clusters. The solvation free energies (ΔG(solv)) greatly depend on the choice of the cavity set (UAKS, Pauling, or SMD) while the dependence on the choice of exchange/correlation functional is modest. The SMD cavity set gives the largest ΔΔG(solv) for B(n)H(n)(0/-) and B(n)H(n)(-/2-) while the UAKS cavity set gives the smallest ΔΔG(solv) value. The E°(Red) of B(n)H(n)(-/2-) (n = 6-12) with the G4/M06-2X(Pauling) (energy/solvation(cavity)) combination agrees within 0.2 V of experimental values. The experimental oxidative stability (E(1/2)) of B(n)X(n)(2-) (X = F, Cl, OH, and CH(3)) is usually located between the values predicted using the B3LYP and M06-2X functionals. The disproportionation free energies (ΔG(dpro)) of 2B(n)H(n)(-) → B(n)H(n) + B(n)H(n)(2-) reveal that the stabilities of B(n)H(n)(-) (n = 6-13) to disproportionation decrease in the order B(8)H(8)(-) > B(9)H(9)(-) > B(11)H(11)(-) > B(10)H(10)(-). The spin densities in B(12)X(12)(-) (X = F, Cl, OH, and CH(3)) tend to delocalize on the boron atoms rather than on the exterior functional groups. The partitioning of ΔG(solv)(B(n)H(n)(2-)) over spheres allows a rationalization of the nonlinear correlation between ΔG(E.A.) and E°(Red) for B(6)H(6)(-/2-), B(11)H(11)(-/2-), and B(13)H(13)(-/2-).  相似文献   

14.
Two series of compounds, 9-X-1,7-(Me(2)S)(2)B(12)H(9) and 9,10-X(2)-1,7-(Me(2)S)(2)B(12)H(8) (X = Cl, Br, I), have been synthesized from reactions of 1,7-(Me(2)S)(2)B(12)H(10) with various halogenating reagents. In addition, reactions of 1,7-(Me(2)S)(2)B(12)H(10) with 2,4-(NO(2))(2)C(6)H(3)SCl and PhSeBr resulted in 9-(2',4'-(NO(2))(2)C(6)H(3)S)-1,7-(Me(2)S)(2)B(12)H(9) and 9,10-(PhSe)(2)-1,7-(Me(2)S)(2)B(12)H(8), respectively. X-ray studies of the dibromo, monoiodo, and aryl thioether derivatives show that electrophilic substitution in 1,7-(Me(2)S)(2)B(12)H(10) takes place at positions 9 and 10, as in the case of the meta-carborane 1,7-C(2)B(10)H(12). From 1,12-(Me(2)S)(2)B(12)H(10) the halides 2-X-1,12-(Me(2)S)(2)B(12)H(9) (X = Br, I) were prepared. For both 1,7- and 1,12-(Me(2)S)(2)B(12)H(10) the best iodination results were obtained using iodine monochloride in refluxing acetonitrile. In the presence of 5 mol % (PPh(3))(2)PdCl(2) the iodides 9-I-1,7-(Me(2)S)(2)B(12)H(9), 2-I-1,12-(Me(2)S)(2)B(12)H(9), and 9,10-I(2)-1,7-(Me(2)S)(2)B(12)H(8) react with RMgX (R = Me, Ph, Bn; X = Cl, Br) in THF to yield the corresponding B-alkyl- and B-aryl-substituted products in good yields without using CuI as a cocatalyst. The bromo derivative 9-Br-1,7-(Me(2)S)(2)B(12)H(9) did not react under similar conditions. No interference from the nearby Me(2)S substituent was observed in palladium-catalyzed substitution of iodide in 2-I-1,12-(Me(2)S)(2)B(12)H(9). Presumably due to the intramolecular activation of an aryl C-H bond of the benzyl substituent in the intermediate palladium complex, the yield of 9,10-Bn(2)-1,7-(Me(2)S)(2)B(12)H(8) was significantly lower than those of the dimethyl and diphenyl derivatives. The molecular structures of 9-R-1,7-(Me(2)S)(2)B(12)H(9) (R = Ph, Bn) and 2-Bn-1,12-(Me(2)S)(2)B(12)H(9) were obtained by single-crystal X-ray analysis.  相似文献   

15.
Thermochemical parameters of the closo boron hydride BnHn2- dianions, with n=5-12, the B3H8- and B11H14- anions, and the B5H9 and B10H14 neutral species were predicted by high-level ab initio electronic structure calculations. Total atomization energies obtained from coupled-cluster CCSD(T)/complete basis set (CBS) extrapolated energies, plus additional corrections were used to predict the heats of formation of the simplest BnHmy- species in the gas phase in kcal/mol at 298 K: DeltaHf(B3H8-)=-23.1+/-1.0; DeltaHf(B5H52-)=119.4+/-1.5; DeltaHf(B6H62-)=64.1+/-1.5; and DeltaHf(B5H9)=24.1+/-1.5. The heats of formation of the larger species were evaluated by the G3 method from hydrogenation reactions (values at 298 K, in kcal/mol with estimated error bars of+/-3 kcal/mol): DeltaHf(B7H72-)=51.8; DeltaHf(B8H82-)=46.1; DeltaHf(B9H92-)=24.4; DeltaHf(B10H102-)=-12.5; DeltaHf(B11H112-)=-11.8; DeltaHf(B12H122-)=-86.3; DeltaHf(B11H14-)=-57.3; and DeltaHf(B10H14)=18.7. A linear correlation between atomization energies of the dianions and energies of the BH units was found. The heats of formation of the ammonium salts of the anions and dianions were predicted using lattice energies (UL) calculated from an empirical expression based on ionic volumes. The UL values (0 K) of the BnHn2- dianions range from 319 to 372 kcal/mol. The values of UL for the B3H8- and B11H14- anions are 113 and 135 kcal/mol, respectively. The calculated lattice energies and gas-phase heats of formation of the constituent ions were used to predict the heats of formation of the ammonium crystal salts [BnHmy-][NH4+]y. These results were used to evaluate the thermodynamics of the H2 release reactions from the ammonium hydro-borate salts.  相似文献   

16.
A variety of S-alkylated products was prepared by alkylation of methyl thioethers [MeSB(12)H(11)](2-) (5), [1-(MeS)-2(7,12)-(Me(2)S)B(12)H(10)](-) (6-8), and [1,2(7,12)-(MeS)(2)B(12)H(10)](2-) (9-11) with alkyl halides and tosylates in acetonitrile. Since these methyl thioethers can be prepared easily in B-10-enriched form on a large scale and due to their chemical versatility, they are potentially very attractive boron entities for the design and synthesis of therapeutics for boron neutron capture therapy of cancer. It was found that alkylation of 6-8 can be complicated by an equilibrium which establishes between, on the one hand, one of the former species and, on the other hand, 1,2(7,12)-(Me(2)S)(2)B(12)H(10) (2-4) and [1,2(7,12)-(MeS)(2)B(12)H(10)](2-) (9-11). A boronated phosphonate 1-(MeS(CH(2))(4)P(O)(OEt)(2))-7-(Me(2)S)B(12)H(10) (14g) and a gem-bisphosphonate 1-(MeS(CH(2))(3)CH[P(O)(OEt)(2)](2))-7-(Me(2)S)B(12)H(10) (14h) were prepared from thioether 7 and the corresponding iodide and tosylate, respectively, and subsequently converted to their sodium salts. The propargyl sulfonium salts obtained by alkylation of thioethers 7, 8, 10, and 11 with propargyl bromide have been further converted to two- and three-cage oligomers containing both ortho-carborane and dodecaborane moieties. Methyl thioethers derived from closo-[B(12)H(12)](2-) are excellent participants in Michael addition reactions in the presence of a strong acid. The sulfonium salts with tertiary alkyl and vinyl substituents have been prepared by this method. Methyl thioethers 5-11 react with hydroxylamine-O-sulfonate yielding the corresponding aminosulfonium salts, albeit in lower yields as compared to those in the alkylation reactions. Several derivatives of methyl thioethers 5-11 have been characterized by single-crystal X-ray diffraction.  相似文献   

17.
The arachno-[B6H11]- solution structure at -25 degrees C was clarified as fluxional compound 2 by applying the ab initio/IGLO/NMR method. The anion 2 can be derived from arachno-B6H12, 1, by the removal of the B2/B3 bridging hydrogen (2). No minimum on the potential energy surface could be found for an asymmetric complex, a, between [B5H8]- and BH3, which had been proposed originally. A Cs-symmetric [mu-(BH3)B5H8]- complex, A, only 3.2 kcal mol-1 higher in energy than 2, is the intermediate in the fluxional rearrangement observed on the NMR time scale. The transition structure [D] connecting 2 (Erel = 0.0) and A (Erel = 3.2) has a relative energy of 9.7 kcal mol-1. The elimination of both a and A as "most stable structure" candidates of arachno-[B6H11]- reinforces the early geometrical bonding systematics for boranes and carboranes.  相似文献   

18.
1 NTRODUCTION Pagodane ([1.1.1.1]-pagodane) is the trivial name assigned to the D2h-symmetry undecacyclic poly- quinane undecacyclo-[9.9.0.01,5.02,12.02,18.03,7.06,10. 08,12.011,15.013,17.316,20]-eicosane (Fig. 1). It has been synthesized[1] and subsequently studied by Prinzbach and co-workers for more than twenty years[2, 3]. Des- cribed as a waxy solid melting without decomposi-tion and stable to at least 600 ℃ in gas phase, pa- godane is interesting for its exotic structure and as an…  相似文献   

19.
The closo-[B12H12-n(OH)n]2- (n = 1-4) ions have been synthesized by the reaction of cesium dodecahydro-closo-dodecaborate(2-), Cs21, with aqueous sulfuric acid. Variation of the reaction temperature, time, and acid concentration results in the stepwise introduction of from one to four hydroxyl groups. Each individual hydroxylation step proceeds regioselectively, affording only one isomer per step. Further substitution of the hydroxylated cluster preferentially takes place at a B-H vertex meta to a B-OH vertex. The closo-[B12H12-n(OH)n]2- (n = 1-4) species, designated 2-5, respectively, are characterized by one- and two-dimensional 11B NMR spectroscopy, IR spectroscopy, and high-resolution fast atom bombardment (FAB) mass spectrometry. A rationale that qualitatively explains the influence of the hydroxyl group on the chemical shifts of the individual boron vertices is developed. Furthermore, the solid state structures of closo-[B12H11(OH)]2-, 2, and closo-1,7-[B12H10(OH)2]2-,3, are determined by X-ray diffraction. Crystallographic data are as follows: For [MePPh3](2)2, monoclinic, space group P2(1)/n, a = 890.1(5) pm, b = 1814(1) pm, c = 1270.5(7) pm, beta = 101.66(2) degrees, Z = 2, R = 0.055; for [MePPh3](2)3, monoclinic, space group P2(1)/n, a = 887.6(4) pm, b = 1847.2(8) pm, c = 1271.1(5) pm, beta = 101.17(1) degrees, Z = 2, R = 0.065. In addition, synthetic routes to O-derivatized species of the anions 2-5 such as closo-[B12H11(OTiCpCl2)]2-, 7, closo-1,7-[B12H10(OTiCpCl2)2]2-, 8, closo-1,7,9-[B12H9(OTiCpCl2)3]2-, 9, closo-[B12H11(OCONHPh)]2-, 10, and closo-1,7-[B12H10(OSO2Me)2]2-, 11, are described. The crystal structures of 7 and 11 are determined by single-crystal X-ray diffraction. Crystallographic data are as follows: For [MePPh3](2)7, monoclinic, space group Cc, a = 2530.5(2) pm, b = 1653.3(1) pm, c = 1281.3(1) pm, beta = 118.79(2) degrees, Z = 4, R = 0.085; for [HPy](2)11, monoclinic, space group P2(1)/n, a = 1550.9(8) pm, b = 993.1(5) pm, c = 1726.5(9) pm, beta = 112.36(2) degrees, Z = 4, R = 0.061.  相似文献   

20.
The reaction of cyanogen chloride with [1-(4-C(7)H(7))-12-(C(5)H(3)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (7) was found to yield two new C(5)-substituted carborane cluster-based compounds, [1-(4-C(7)H(7))-12-(C(5)H(2)-3-(CN)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (8) and [1-(4-C(7)H(7))-12-(C(5)H-2,4-(CN)(2)-3,4-(CH(3))(2))-C(2)B(10)H(10)] (9). This cyano-substitution pattern is in contrast to the known substitution for the analogous organic quinarene[5.6.7] system. The observed unique cluster-based products may be understood by a combination of steric and electronic effects. Compounds 8 and 9 were characterized by complete multinuclear NMR, (1)H-(1)H COSY NMR, (1)H-(13)C HMQC NMR, FTIR, UV-Vis, IR, MS data and a single crystal analysis for 8 [X-ray data for 8: C(17)H(25)B(10)N, monoclinic, space group P2(1)/n with cell constants a = 8.6794(17) ?, b = 11.021(2) ?, c = 43.175(9) ?, β = 91.00(3)°, V = 4129.2(14) ?(3), Z = 8, R(1) = 0.0729, wR(2) = 0.1464].  相似文献   

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