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1.
1 INTRODUCTION The synthesis of chiral clusters containing four different atoms at the vertexes of the tetrahedron has been extensively studied because the chiral cluster can induce an asymmetric catalysis potentially[1]. Until now, many tetrahedron-type chiral clusters have been reported, but only a few of the reactions about the organic group in these clusters were investi- gated[2~4]. In this paper, we described the syntheses of clusters 3 and 4, and the structure of the former. 2 …  相似文献   

2.
张玉华  袁建超 《结构化学》2001,20(5):363-368
1 INTRODUCTIONTransition metal clusters have been attracting intensive attention largely because they are suggested as active catalysts in a variety of homogeneous catalyzed reactions. However, no unequivocal proof exists that metal clusters themselves serve as the true catalysts among the catalytic process. In many cases it is known that fragments of the original clusters are the actual catalytic species. The unambiguous proof would be the use of a rigid chiral cluster to catalyze an asy…  相似文献   

3.
1INTRoDUCTIoNIntenseinterestintransition-metalclusterscontinuesbecausetheyrepresentpos-sibleconceptualbridgesbetweenhomogeneousandheterogeneouscatalystsmoreoveralsobecausetheyrepresentsyntheticchallenges.TheuseofelementsofGroup16ofthePeriodicTableassingleatomligandsforclustergrowthandstabilizationofthemetalcorearenowwellestablished[1i.ThereisanincreasinginterestintheuseofSe-bridgrdclusters,manyofthereactionsofSe2Fe2(CO),andSe2Fe,(CO),havebeenreported"';however,therehasbeenverylittlewor…  相似文献   

4.
trans—(η~5—C_5Me_5)_2Mo_2(μ_2—S)_2(t—O)_2[Ⅰ]和cis—(η~5—C_5Me_5)Mo_2(μ_2—O)_2(t—O)_2(Ⅱ]是由Mo(CO)_6和C_5(CH_3)_5H的反应产物(η~5—C_5Me_5)_2Mo_2(CO)_4与(CH_2)_3S反应中同时得到的。晶体[Ⅰ]属四方晶系,空间群为P4_2/n,单胞参数;a=b=16.317,c=8.463,V=2253.16,Z=4。晶体[Ⅱ]亦属四方晶系,空间群为P42_1c,单胞参数:a=b=12.101,c=15.425,V=2258.54,Z=4 [Ⅰ]和[Ⅱ]分子分别具有C_1—T和C_2—2对称性。如把C_5Me_5-看成具有理想的园柱体对称性,则它们分别具有C_(2h)—2/m和C_(2v)—mm2对称性。在[Ⅰ]中Mo_2(μ_2—S)_2为菱形平面结构,而[Ⅱ]中则畸变成“蝶式”结构。由两个钼原子之间的距离(2.902和2.808)可以看出钼一钼间作用属于单键的范围内。所以它们是具有金属单键的双钼金属簇的两个立体异构体。  相似文献   

5.
Mechanochemical reaction of cluster coordination polymers 1infinity[M3Q7Br4] (M = Mo, W; Q = S, Se) with solid K2C2O4 leads to cluster core excision with the formation of anionic complexes [M3Q7(C2O4)3]2-. Extraction of the reaction mixture with water followed by crystallization gives crystalline K2[M3Q7(C2O4)3].0.5KBr.nH2O (M = Mo, Q = S, n = 3 (1); M = Mo, Q = Se, n = 4 (2); M = W, Q = S, n = 5 (3)). Cs2[Mo3S7(C2O4)3].0.5CsCl.3.5H2O (4) and (Et4N)1.5H0.5K{[Mo3S7(C2O4)3]Br}.2H2O (5) were also prepared. Close Q...Br contacts result in the formation of ionic triples {[M3Q7(C2O4)3](2)Br}5- in 1-4 and the 1:1 adduct {[Mo3S7(C2O4)3]Br}3- in 5. Treatment of 1 or 2 with PPh(3) leads to chalcogen abstraction with the formation of [Mo3(mu3-Q)(mu2-Q)3(C2O4)3(H2O)3]2-, isolated as (Ph4P)2[Mo3(mu3-S)(mu2-S)3(C2O4)3(H2O)3].11H2O (6) and (Ph4P2[Mo3(mu3-Se)(mu2-Se)3(C2O4)3(H2O)3].8.5H2O.0.5C2H5OH (7). All compounds were characterized by X-ray structure analysis. IR, Raman, electronic, and 77Se NMR spectra are also reported. Thermal decomposition of 1-3 was studied by thermogravimetry.  相似文献   

6.
Alkylation of (ArNHCH2CH2){(2-C5H4N)CH2}NH with RX [RX = MeI, 4-CH2=CH(C6H4)CH2Cl) and (2-C5H5N)CH2Cl] in the presence of base has allowed access to the sterically demanding multidentate nitrogen donor ligands, {(2,4,6-Me3C6H2)NHCH2CH2}{(2-C5H4N)CH2}NMe (L1), {(2,6-Me3C6H3)NHCH2CH2}{(2-C5H4N)CH2}NCH2(C6H4)-4-CH=CH2 (L2) and (ArNHCH2CH2){(2-C5H4N)CH2}2N (Ar = 2,4-Me2C6H3 L3a, 2,6-Me2C6H3 L3b) in moderate yield. L3 can also be prepared in higher yield by the reaction of (NH2CH2CH2){(2-C5H4N)CH2}2N with the corresponding aryl bromide in the presence of base and a palladium(0) catalyst. Treatment of L1 or L2 with MCl2 [MCl2 = CoCl2.6H2O or FeCl2(THF)1.5] in THF affords the high spin complexes [(L1)MCl2](M = Co 1a, Fe 1b) and [(L2)MCl2](M = Co 2a, Fe 2b) in good yield, respectively; the molecular structure of reveals a five-coordinate metal centre with bound in a facial fashion. The six-coordinate complexes, [(L3a)MCl2](M = Co 3a, Fe 3b, Mn 3c) are accessible on treatment of tripodal L3a with MCl2. In contrast, the reaction with the more sterically encumbered leads to the pseudo-five-coordinate species [(L3b)MCl2](M = Co 4a, Fe 4b) and, in the case of manganese, dimeric [(L3b)MnCl(mu-Cl)]2 (4c); in 4a and 4b the aryl-substituted amine arm forms a partial interaction with the metal centre while in 4c the arm is pendant. The single crystal X-ray structures of , 1a, 3b.MeCN, 3c.MeCN, 4b.MeCN and 4c are described as are the solution state properties of 3b and 4b.  相似文献   

7.
The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a = 15.359(2), b = 18.378(3), c = 24.952(2), β = 102.268(4)°, V = 6882.3(16) 3, Mr = 1348.34, Z = 4, Dc = 1.301 g/cm3, F(000) = 2832 and μ = 0.424 mm-1. The final R = 0.0606 and wR = 0.1552 for 9396 observed reflections (I > 2σ(I)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) , indicating no metal- metal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.  相似文献   

8.
The chiral clusters (μ3-S)MCoW(CO)8[η^5-C5H4C(O)OCH3] [M=Ru(2), Fe(3)] were synthesized by asymmetric induction of N-benzylcinchonium chloride as phase-transfer catalyst (PTC). The most suitable amount of PTC is 70 mol%. Cluster 3 was determined by single crystal X-ray diffraction analysis. The best ee of the chiral cluster is over 20%.  相似文献   

9.
Unimolecular metastable decomposition of diethoxymethane (CH(2)(OCH(2)CH(3))(2), 1) upon electron impact has been investigated by means of mass-analyzed ion kinetic energy (MIKE) spectrometry and theD-labeling technique in conjunction with thermochemistry. The m/z 103 ion ([M - H](+) : CH(OCH(2)CH(3)) = O(+)CH(2)CH(3)) decomposes into the m/z 47 ion (protonated formic acid, CH(OH) = O(+)H) by consecutive losses of two C(2)H(4) molecules via an m/z 75 ion. The resulting product ion at m/z 47 further decomposes into the m/z 29 and 19 ions by losses of H(2)O and CO, respectively, via an 1,3-hydroxyl hydrogen transfer, accompanied by small kinetic energy release (KER) values of 1.3 and 18.8 meV, respectively. When these two elimination reactions are suppressed by a large isotope effect, however, another 1,1-H(2)O elimination with a large KER value (518 meV) is revealed. The m/z 89 ion ([M - CH(3)](+) : CH(2)(OCH(2)CH(3))O(+) = CH(2)) decomposes into the m/z 59 ion (CH(3)CH(2)O(+) = CH(2)) by losing CH(2)O in the metastable time window. The source-generated m/z 59 ion ([M - OCH(2)CH(3)](+) : CH(2) = O(+)CH(2)CH(3)) decomposes into the m/z 41 (CH(2) = CH(+)CH(2)) and m/z 31 (CH(2) = O(+)H) ions by losses of H(2)O and C(2)H(4), respectively, with considerable hydrogen scrambling prior to decomposition. Copyright 2000 John Wiley & Sons, Ltd.  相似文献   

10.
1 INTRODUCTION Constructing higher nuclearity clusters with well-defined dimensions and structures provide a rather active field of chemistry with potential applications in areas including nanotechnology, molecular recognition and catalysis[1~4]. A continuing effort has been directed toward developing a better methodology for systematic synthesis of supracluster compounds through molecular design [5,6]. On the basis of extensive investigation on the metal exchange reaction in cluster com…  相似文献   

11.
The polyoxoanion incorporated {Mn(CO)3+} complex, (n-Bu4N)2[Mo6O16(OCH3)2{HOCH2C(CH2O)3}2· {Mn(CO)3}2](1), has been synthesized by the reaction of (n-Bu4N)4[Mo8O26] with Mn(CO)5Br in methanol, in the presence of C(CH2OH)4. The complex 1 has been characterized by IR, UV-Vis, X-ray single crystal diffraction, and TG. Crystal data for the complex 1: C25H48MnMo3NO16 (1), Triclinic P1, a=0.9405(3) nm, b=1.3351(4) nm, c=1.5455(4) nm, α=103.206(5)o, β=102.165(5)o, γ=100.784(5)o, V=1.7896(9) nm3, Z=2, R1=0.0703, wR...  相似文献   

12.
Reduction of [M(CO)2(eta-RC[triple bond]CR')Tp']X {Tp' = hydrotris(3,5-dimethylpyrazolyl)borate, M = Mo, X = [PF6]-, R = R' = Ph, C6H4OMe-4 or Me; R = Ph, R' = H; M = W, X = [BF4]-, R = R' = Ph or Me; R = Ph, R' = H} with [Co(eta-C5H5)2] gave paramagnetic [M(CO)2(eta-RC[triple bond]CR')Tp'], characterised by IR and ESR spectroscopy. X-Ray structural studies on the redox pair [Mo(CO)2(eta-PhC[triple bond]CPh)Tp'] and [Mo(CO)2(eta-PhC[triple bond]CPh)Tp'][PF6] showed that oxidation is accompanied by a lengthening of the C[triple bond]C bond and shortening of the Mo-C(alkyne) bonds, consistent with removal of an electron from an orbital antibonding with respect to the Mo-alkyne bond, and with conversion of the alkyne from a three- to a four-electron donor. Reduction of [Mo(CO)(NCMe)(eta-MeC[triple bond]CMe)Tp'][PF6] with [Co(eta-C5H5)2] in CH2Cl2 gives [MoCl(CO)(eta-MeC[triple bond]CMe)Tp'], via nitrile substitution in [Mo(CO)(NCMe)(eta-MeC[triple bond]CMe)Tp'], whereas a similar reaction with [M(CO){P(OCH2)3CEt}(eta-MeC[triple bond]CMe)Tp']+ (M = Mo or W) gives the phosphite-containing radicals [M(CO){P(OCH2)3CEt}(eta-MeC[triple bond]CMe)Tp']. ESR spectroscopic studies and DFT calculations on [M(CO)L(eta-MeC[triple bond]CMe)Tp'] {M = Mo or W, L = CO or P(OCH2)3CEt} show the SOMO of the neutral d5 species (the LUMO of the d4 cations) to be largely d(yz) in character although much more delocalised in the W complexes. Non-coincidence effects between the g and metal hyperfine matrices in the Mo spectra indicate hybridisation of the metal d-orbitals in the SOMO, consistent with a rotation of the coordinated alkyne about the M-C2 axis.  相似文献   

13.
Products of the gas-phase reactions of OH radicals with O,O-diethyl methylphosphonothioate [(C2H5O)2P(S)CH3, DEMPT] and O,O,O-triethyl phosphorothioate [(C2H5O)3PS, TEPT] have been investigated at room temperature and atmospheric pressure of air using in situ atmospheric pressure ionization mass spectrometry (API-MS) and, for the TEPT reaction, gas chromatography and in situ Fourier transform infrared (FT-IR) spectroscopy. Combined with products quantified previously by gas chromatography, the products observed were: from the DEMPT reaction, (C2H5O)2P(O)CH3 (21+/-4% yield) and C2H5OP(S)(CH3)OH or C2H5OP(O)(CH3)SH (presumed to be C2H5OP(O)(CH3)SH by analogy with the TEPT reaction); and from the TEPT reaction, (C2H5O)3PO (54-62% yield), SO2 (67+/-10% yield), CH3CHO (22-40% yield) and, tentatively, (C2H5O)2P(O)SH. The FT-IR analyses showed that the formation yields of HCHO, CO, CO2, peroxyacetyl nitrate [CH3C(O)OONO2], organic nitrates, and acetates from the TEPT reaction were <5%, 3+/-1%, <7%, <2%, 5+/-3%, and 3+/-2%, respectively. Possible reaction mechanisms are discussed.  相似文献   

14.
Solid-state decomposition of [V3O(O2CPh)6(H2O)3]Cl at 300 degrees C followed by alcoholysis of the product gives the new vanadium complexes [V6O6(PhCO2)6(CH3O)6(CH3OH)3] (1), [V6O6(PhCO2)6(C2H5O)6(C2H5OH)3] (2), [V6O6(PhCO2)6(C3H7O)6(C3H7OH)3] (3), [V6O6(PhCO2)6(C4H9O)6(C4H9OH)3] (4) and [V4O4(OCH3)6(O2CPh)2(HOCH3)2] (5). Complexes 2, 3 and 5 have been crystallographically characterised. DC magnetic susceptibility studies on complex shows antiferromagnetic coupling leading to a S = 0 spin ground state.  相似文献   

15.
1 INTRODUCTIONTransitionmetalclustercomplexeshavebeenreceivingconsiderableattentioninrecent yearslargelybecauseoftheir potentialapplicationsincatalysisaswellasthenoveltyandversatilityoftheirreactionsandstructures.[1~ 4] Ourinterestinmetalclustercatalysisp…  相似文献   

16.
鲁晓明  刘顺诚  刘育  卜显和  洪少良 《化学学报》1997,55(10):1009-1018
为研究大环化合物对客体分子的选择性, 合成了通式为[NaL(Et2O)]2Na2Mo8O26的三种新型N-对R苯基氮杂15冠5八钼多酸钠超分子配合物(其中L分别为: N-苯基氮杂15冠5、N-对氯苯基氮杂15冠5和N-对甲苯基氮杂15冠5), 进行了元素分析, 红外光谱与核磁共振等结构参数的表征, 对R基为CH3的标题配合物作了X射线四圆衍射测定, 该晶体属单斜晶系, 空间群为P21/a,a=1.4590(4)nm, b=1.3817(3)nm, c=1.7639(5)nm, β=112.67(2)°, V=3.281(1)nm^3, Mr=2021.3, Dc=2.11g/cm^3,μ=2.37mm^-^1, F(000)=2048, R=0.045和Rw=0.057, 与[Na.(DB18C6)(CH3OH)M6O19和[Na(DB24C8)]2M6O19进行比较,结果表明: 大环化合物不仅对客体金属离子有分子识别性, 而且对与之抗衡的多酸阴离子也具有影响。  相似文献   

17.
The hydrothermal reaction of MoO3, [Ni(CH3CO2)2] x 4H2O, tpypyz, ethylenediphosphonic acid and water yields the 2D material [[Ni4(tpypyz)3][Mo5O15(O3PCH2CH2PO3)]2] x 23H2O (1 x 23H2O), constructed from [Mo5O15(O3PCH2CH2PO3)]4- clusters linked in one-dimension through the ethylene tethers of the diphosphonate component; these molybdodiphosphonate chains are in turn linked into a 2D network through the tetranuclear secondary metal-ligand subunit [Ni4(tpypyz)3]8+.  相似文献   

18.
手性金属簇合物的合成、结构表征及其反应   总被引:2,自引:0,他引:2  
用潜手性羰基簇合物 ( μ3 S)RuCo2 (CO) 9( 1 )与阴离子金属交换试剂Na[M (CO) 3C5 H4C(O)R][R =H ,CH3,C6 H5 ,C6 H4C(O)OCH3;M =Mo ,W ]在四氢呋喃中回流反应 ,生成一系列新的由四个不同原子组成的不对称四面体簇合物 ( μ3 S)RuCoM (CO ) 8CpCOR .研究了簇合物 ( μ3 S)RuCoMo(CO) 8CpCOCH3的还原反应 .对合成的所有化合物进行了IR、1HNMR、C/H元素分析 ,测定了簇合物( μ3 S)RuCoMo(CO) 8CpCOC6 H5 的单晶结构 .  相似文献   

19.
The ferrocenic ammonium (Rp)- and (Sp)-[1-CH2NR(3-)-2-CH3-C5H3Fe-C5H5] iodide salts with R=CH3, C2H5, n-C3H7, n-C4H9, were synthesized starting from the (Rp)- and (Sp)-[1-CH2N(CH3)2-2-CH3-C5H3Fe-C5H5] amines obtained in their optically active forms through asymmetric cyclopalladation of [C5H5Fe-C5H4CH2N(CH3)2]. 1H NMR studies of these planar chiral 1,2-disubstituted ferrocenic ammonium iodide salts in the presence of the (Delta)-(tris(tetrachlorobenzenediolato)phosphate(V) anion), [(Delta)-Trisphat] support the formation of specific diastereomeric ion pairs. Such intermolecular interactions can be related to the self-assembly of the two-dimensional optically active compounds [[(Sp)-1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5][Mn (Delta)-Cr(C2O4)3]] and [[(Rp)-1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5][Mn (Lambda)-Cr(C2O4)3]] starting from the resolved (Rp)- and (Sp)-[1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5]+ ion associated to the racemic anionic building block rac-[Cr(C2O4)3]3- and Mn2+. Both enantiomeric forms of the networks behave as ferromagnets with a Curie temperature of 5.7 K.  相似文献   

20.
1INTRODUCTIONBytreatingFeCo2(CO),(p,-S)withgroupVligands[L=PPh,,AsPh,,PBus",p(OEt),j,monosubstitutedderivativesFeCo2(CO),(p,-S)(L)havebeenobtained{1'2i.13C-NMRshowedthatthereplacementofCObyagroupVligandinFeCo,(CO),(p,-S)isatonecobaltatominthemonosubstitutedderivativet2).How-ever,thesubstitutedderivativeofFeCo,(CO),(p,-S)withP(OCH,Ph),hasnotbeenreportedanditscrystalstructurehasnotbeendetermined.WehavesynthesizedthetitlecompoundFeCo,(CO),(p,-S)[P(OCH,Ph),jandtestifiedth…  相似文献   

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