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1.
杯芳烃衍生物的合成3   总被引:2,自引:0,他引:2  
通过杯[4]芳烃的酚羟基的烷基化和苯环上的乙酰化制备了一系列的新的对乙酰基杯[4]芳烃烷基醚,烷基分别是n-C~4H~9(4a)、n-C~8H~1~7(4b)、n-C~1~2H~2~5(4c)和n-C~1~6H~3~3(4d)。核磁共振研究表明这些新的杯芳烃都是锥形(cone)构象。  相似文献   

2.
The thallium derivative of a fluorinated, B-methylated, tris(pyrazolyl)borate ligand, [MeB(3-(CF3)Pz)3]-, has been synthesized via a two-step process using the corresponding pyrazole, Li[MeBH3], and thallium(I) acetate. Reaction of [MeB(3-(CF3)Pz)3]Tl with CuBr in the presence of ethylene leads to [MeB(3-(CF3)Pz)3]Cu(C2H4). It is a thermally stable solid. [MeB(3-(CF3)Pz)3]Cu(C2H4) reacts with [(Bn)2ATI]SnCl to yield [MeB(3-(CF3)Pz)3]Cu<--Sn(Cl)[(Bn)2ATI], featuring an unsupported Cu(I)-Sn(II) bond [2.4540(4) A].  相似文献   

3.
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   

4.
The fluoride ion acceptor properties of OsO4 and OsO3F2 were investigated. The salts [N(CH3)4][OsO4F] and [N(CH3)4]2[OsO4F2] were prepared by the reactions of OsO4 with stoichiometric amounts of [N(CH3)4][F] in CH3CN solvent. The salts [N(CH3)4][OsO3F3] and [NO][OsO3F3] were prepared by the reactions of OsO3F2 with a stoichiometric amount of [N(CH3)4][F] in CH3CN solvent and with excess NOF, respectively. The OsO4F- anion was fully structurally characterized in the solid state by vibrational spectroscopy and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO4F]: Abm2, a = 7.017(1) A, b = 11.401(2) A, c = 10.925(2) A, V = 874.1(3) A3, Z = 4, and R = 0.0282 at -50 degrees C. The cis-OsO4F2(2-) anion was characterized in the solid state by vibrational spectroscopy, and previous claims regarding the cis-OsO4F2(2-) anion are shown to be erroneous. The fac-OsO3F3- anion was fully structurally characterized in CH3CN solution by 19F NMR spectroscopy and in the solid state by vibrational spectroscopy of its N(CH3)4+ and NO+ salts and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO3F3]: C2/c, a = 16.347(4) A, b = 13.475(3) A, c = 11.436(3) A, beta = 134.128(4) degrees, V = 1808.1(7) A3, Z = 8, and R = 0.0614 at -117 degrees C. The geometrical parameters and vibrational frequencies of OsO4F-, cis-OsO4F2(2-), monomeric OsO3F2, and fac-OsO3F3- and the fluoride affinities of OsO4 and monomeric OsO3F2 were calculated using density functional theory methods.  相似文献   

5.
The compound [NH4(NH3)4][B(C6H5)4].NH3 (1) was prepared by the reaction of NaB(C(6)H(5))(4) with a proton-charged ion-exchange resin in liquid ammonia. [NH(4)(NH(3))(4)][Ca(NH(3))(7)]As(3)S(6).2NH(3) (2) and [NH4(NH3)4][Ba(NH3)8]As3S6.NH3 (3) were synthesized by reduction of As(4)S(4) with Ca and Ba in liquid ammonia. All ammoniates were characterized by low-temperature single-crystal X-ray structure analysis. They were found to contain the ammine-ammonium complex with the maximal possible number of coordinating ammonia molecules, the [NH4(NH3)4]+ ion. 1 contains a special dimer, the [(NH4(NH3)4)2(mu-NH3)2]2+ ion, which is formed by two[NH4(NH3)4]+ ions linked by two ammonia molecules. The H(3)N-H...N hydrogen bonds in all three compounds range from 1.82 to 2.20 A (DHA = Donor-H...Acceptor angles: 156-178 degrees). In 2 and 3, additional H(2)N-H...S bonds to the thioanions are observed, ranging between 2.49 and 3.00 A (DHA angles: 120-175 degrees). Two parallel phenyl rings of the [B(C(6)H(5))(4)](-) anion in 1 form a pi...pi hydrogen bond (C...C distance, 3.38 A; DHA angles, 82 degrees), leading to a dimeric [B(C6H5)4]2(2-) ion.  相似文献   

6.
由[Mo~3(μ~3-O)(μ-S)~3(dtp)~4(H~2O)和PbI~3^-在咪唑存在下反应获得异四核混合簇[Mo~3(PbI~3)S~4(dtp)~3(C~3H~4N~2)~3][(CH~3)~2CO]~2(2)[dtp=S~2P(OC~2H~5)~2^-]。簇合物属斜方晶系,空间群P~b~c~a(No.61),晶胞参数为a=2.3590(3),b=1.9161(5),c=2.6458(9)nm,V=11.959(6)nm^3,Z=8。结构最终偏离因子R=0.067。此四核簇分子具有[Mo~3PbS~4]类立方烷簇芯,簇分子整体对称性接近C~3~v。在同一不对称单元中,簇分子的咪唑环以(NH)和溶剂丙酮分子的氧原子形成O---H---N氢键。  相似文献   

7.
The crystalline dimeric 1-azaallyllithium complex [Li{mu,eta(3-N(SiMe3)C(Ad)C(H)SiMe3}]2 (1) was prepared from equivalent portions of Li[CH(SiMe3)2] and 1-cyanoadamantane (AdCN). Complex was used as precursor to each of the crystalline complexes 2-8 which were obtained in good yield. By 1-azaallyl ligand transfer, 1 afforded (i) [Al{eta3-N(SiMe3)C(Ad)C(H)SiMe3}{kappa1-N(SiMe3)C(Ad)=C(H)SiMe3-E}Me] (5) with [AlCl2Me](2), (ii) [Sn{eta3-N(SiMe3)C(Ad)C(H)SiMe3}2] (7) with Sn[N(SiMe3)2]2, and (iii) [Li(N{C(Ad)=C(H)SiMe3-E}{Si(NN)SiMe3})(thf)2] (8) with the silylene Si[(NCH(2)Bu(t))2C6H(4)-1,2] [= Si(NN)]. By insertion into the C[triple bond, length as m-dash]N bond of the appropriate cyanoarene RCN, gave the beta-diketiminate [Li{mu-N(SiMe3)C(Ad)C(H)C(R)NSiMe3}]2 [R = Ph (2), C(6)H(4)Me-4 (3)], and yielded [Al{kappa2-N(SiMe3)C(Ad)C(H)C(Ph)NSiMe3}{kappa1-N(SiMe3)C(Ad)=C(H)SiMe3-E}Me] (6). The beta-diketiminate [Al{kappa2-N(SiMe3)C(Ad)C(H)C(Ph)NSiMe3}Me2] (4) was prepared from 2 and [AlClMe2]2. The X-ray structures of 1 and 3-8 are presented. Multinuclear NMR spectra in C6D6 or C6D5CD3 have been recorded for each of 1-8; such data on 8 revealed that in solution two minor isomers were also present.  相似文献   

8.
The present study investigates structural and functional aspects of the redox chemistry of rhenium(III) chloride [Re3Cl9] (1) in aqueous and organic solvents, with emphasis on the dioxygen-activating capabilities of reduced rhenium clusters bearing the Re3(8+) core. Dissolution of 1 in HCl (6 M) generates [Re3(mu-Cl)3Cl9]3- (2a), which can be isolated as the tetraphenylphosphonium salt (2b). Anaerobic one-electron reduction of 1 by Hg in HCl (6-12 M) produces [(C6H5)4P]2[Re3(mu-Cl)3Cl7(H2O)2].H2O (3), the structure of which features a planar [Re3(mu-Cl)3Cl3] framework (Re3(8+) core), involving two water ligands that occupy out-of-plane positions in a trans arrangement. Compound 3 dissociates in the presence of CO, yielding [(C6H5)4P]2[ReIII2Cl8] (4) and an unidentified red carbonyl species. In situ oxidation (O2) of the reduced Re3(8+)-containing cluster in HCl (6 M) produces quantitatively 2a, whereas oxidation of 3 in organic media results in the formation of [(C6H5)4P]4[(Re3(mu-Cl)3Cl7(mu-OH))2].2CH2Cl2 (5). The structure of 5 reveals that two oxygen ligands (hydroxo units) bridge asymmetrically two Re3(9+) triangular clusters. The origin of these hydroxo units derives from the aquo ligands, rather than O2, as shown by 18O2 labeling studies. The hydroxo bridges of 5 can be replaced by chlorides upon treatment with Me3SiCl to afford the analogous [(C6H5)4P]4[(Re3(mu-Cl)3Cl7(mu-Cl))2].10CH2Cl2 (6). The reaction of 5 with Hg in HCl (6 M)/tetrahydrofuran regenerates compound 3. Complexes 1-3 exhibit nitrile hydratase type activity, inducing hydrolysis of CH3CN to acetamide. The reaction of 3 with CH3CN yields [(C6H5)4P]2[Re3(mu-Cl)3Cl6.5(CH3CN)1.5(CH3C(O)NH)0.5] (7), the structure of which is composed of [Re3(mu-Cl)3Cl7(CH3CN)2]2- (7a) and [Re3(mu-Cl)3Cl6(CH3CN)(CH3C(O)NH)]2- (7b) (Re3(8+) cores) as a disordered mixture (1:1). Oxidation of 7 with O2 in CH3CN affords [(C6H5)4P]2[Re3(mu-Cl)3Cl7(CH3C(O)NH)].CH3CN (8) and small amounts of [(C6H5)4P][ReO4] (9). Compound 8 is also independently isolated from the reaction of 2b with wet CH3CN, or by dissolving 5 in CH3CN. In MeOH, 5 dissociates to afford [(C6H5)4P]2[Re3(mu-Cl)3Cl8(MeOH)].MeOH (10).  相似文献   

9.
Oxacalix[3]arenes p-methyloxacalix[3]arene (L(1)), p-isopropyloxacalix[3]arene (L2), and p-ethoxycarbonyloxacalix[3]arene (L3) are able to bind the Re(I)(CO)3 moiety with two of their three phenol-O atoms and one of their ether-O atoms. The monoanionic complexes were isolated in the salts (DBUH)[Re(CO)3(L1H-2)].L1 (1) and (NEt4)[Re(CO)3(L2H-2)].L2.0.5 MeCN (2) (DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene). Over the course of its reaction with (NEt4)(2)[Re(CO)3Br(3)] and DBU, p-ethoxycarbonyloxacalix[3]arene decomposes to form [{Re(CO)3(L4H-2)}2] (3) {L4 = 1-(5-ethoxycarbonyl-2-hydroxy-3-hydroxymethyl-benzyl)-2,3,4,6,7,8,9,10-octahydro-pyrimido[1,2-a]azepin-1-ium. The expected monoanion [Re(CO)3(L3H-2)]- (4) was identified by 13C NMR and mass spectra.  相似文献   

10.
Novel crystallographic D3-symmetric binuclear triple molecular helices [Co2L(1)3][BF4]4 (1), [Zn2L(1)3][BF4]4 (2), [Mn2L(1)3][BF4]4 (3), [Co2L(2)3][BF4]4 (4), [Zn2L(2)3][BF4]4 (5), and [Mn2L(2)3][BF4]4 (6) have been achieved to establish the side chain effect on molecular packing, where L1 is [(C5H4N)C(CH3)=N-(C6H4)-]2CH2 and L2 is [(C5H4N)C(CH3)=N-(C6H4)-]2O, respectively. Crystal structure analyses show that each helix crystallizes in a hexagonal crystal system with space group Pc1 and the general axis of the helix occupies the crystallographic 3-fold axial position with the other three crystallographic 2-fold symmetries perpendicular to it. Each metal center is bound to three pyridylimine units to attain C3 pseudooctahedral coordination geometry with respective equivalent metal-N (CH=N) and metal-N (pyridyl) bonds. It is speculated that the existence of the methyl group might minimize the potential intermolecular interactions, which would be the essential factor controlling the helices formed in idealized crystallographic D3 symmetry. Moreover, crystallographic idealized C3-symmetric helicates [Co2L(3)3][BF4]4 (7), [Zn2L(3)3][BF4]4 (8), [Ni2L(3)3][BF4]4 (9), and [Cu2L(3)3][BF4]4 (10) were also structurally characterized for comparison, where L3 is [(C5H4N)C(CH3)=N-]2. All the results indicate that the existence of the methyl group in the side chain of aromatic ligands could effectively reduce the potential - intermolecular interactions and the side chain effect of the methyl group in crystal packing is robust enough to be exchanged from one network structure to another, which ensures the generality and predictability of the crystallographic idealized symmetry formation to a certain extent.  相似文献   

11.
A series of luminescent branched platinum(II) alkynyl complexes, [1,3,5-{RC[triple bond]C(PEt3)2PtC[triple bond]C-C6H4C[triple bond]C}3C6H3] (R=C6H5, C6H4OMe, C6H4Me, C6H4CF3, C5H4N, C6H4SAc, 1-napthyl (Np), 1-pyrenyl (Pyr), 1-anthryl-8-ethynyl (HC[triple bond]CAn)), [1,3-{PyrC[triple chemical bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}2-5-{(iPr)3SiC[triple bond]C}C6H3], and [1,3-{PyrC[triple bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}2-5-(HC[triple bond]C)C6H3], was successfully synthesized by using the precursors [1,3,5-{Cl(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}3C6H3] or [1,3-{Cl(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}2-5-{(iPr)3SiC[triple bond]C}C6H3]. The X-ray crystal structures of [1,3,5-{MeOC6H4C[triple bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}3C6H3] and [1,8-{Cl(PEt3)2PtC[triple bond]C}2An] have been determined. These complexes were found to show long-lived emission in both solution and solid-state phases at room temperature. The emission origin of the branched complexes [1,3,5-{RC[triple bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}3C6H3] with R=C6H5, C6H4OMe, C6H4Me, C6H4CF3, C5H4N, and C6H4SAc was tentatively assigned to be derived from triplet states of predominantly intraligand (IL) character with some mixing of metal-to-ligand charge-transfer (MLCT) (dpi(Pt)-->pi*(C[triple bond]CR)) character, while the emission origin of the branched complexes with polyaromatic alkynyl ligands, [1,3,5-{RC[triple bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}3C6H3] with R=Np, Pyr, or HC[triple bond]CAn, [1,3-{PyrC[triple bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}2-5-{(iPr)3SiC[triple bond]C}C6H3], [1,3-{PyrC[triple bond]C(PEt3)2PtC[triple bond]CC6H4C[triple bond]C}2-5-(HC[triple bond]C)C6H3], and [1,8-{Cl(PEt3)2PtC[triple bond]C}2An], was tentatively assigned to be derived from the predominantly 3IL states of the respective polyaromatic alkynyl ligands, mixed with some 3MLCT (d(pi)(Pt)-->pi*(C[triple bond]CR)) character. By incorporating different alkynyl ligands into the periphery of these branched complexes, one could readily tune the nature of the lowest energy emissive state and the direction of the excitation energy transfer.  相似文献   

12.
New examples of [C6F5Xe]+ salts of the weakly coordinating [BY4]- (Y = CN, CF3, or C6F5) anions were synthesized by metathesis of [C6F5Xe][BF4] with MI[BY4] (MI = K or Cs; Y = CN, CF3, or C6F5) in CH3CN at -40 degrees C, and were crystallized from CH2Cl2 or from a CH2Cl2/CH3CN solvent mixture. The low-temperature (-173 degrees C) X-ray crystal structures of the [C6F5Xe]+ cation and of the [C6F5XeNCCH3]+ adduct-cation are reported for [C6F5Xe][B(CF3)4], [C6F5XeNCCH3][B(CF3)4], [C6F5Xe][B(CN)4], and [C6F5XeNCCH3][B(C6F5)4]. The [C6F5Xe]+ cation, in each structure, interacts with either the anion or the solvent, with the weakest cation-anion interactions occurring for the [B(CF3)4]- anion. The solid-state Raman spectra of the [C6F5Xe]+ and [C6F5XeNCCH3]+ salts have been assigned with the aid of electronic structure calculations. Gas-phase thermodynamic calculations show that the donor-acceptor bond dissociation energy of [C6F5XeNCCH3]+ is approximately half that of [FXeNCCH3]+. Coordination of CH3CN to [C6F5Xe]+ is correlated with changes in the partial charges on mainly Xe, the ipso-C, and N, that is, the partial charge on Xe increases and those on the ipso-C and N decrease upon coordination, typifying a transition from a 2c-2e to a 3c-4e bond.  相似文献   

13.
The crystalline compounds [Mg(Br)(L)(thf)].0.5Et2O [L = {N(R)C(C6H3Me2-2,6)}2SiR, R = SiMe3] (1), [Mg(L){N=C=C(C(Me)=CH)2CH2}(D)2] [D = NCC6H3Me2-2,6 (2), thf (3)] and [{Mg(L)}2{mu-OSO(CF3)O-[mu}2] (4) were prepared from (a) Si(Br)(R){C(C6H3Me2-2,6)=NR}2 and Mg for (1), (b) [Mg(SiR3)2(thf)2] and 2,6-Me2C6H3CN (5 mol for (2), 3 mol for (3)), and (c) (2) + Me3SiOS(O)2CF3 for (4); a coproduct from (c) is believed to have been the trimethylsilyl ketenimide Me3SiN=C=C{C(Me)=CH}2CH2 (5).  相似文献   

14.
Chiou TW  Liaw WF 《Inorganic chemistry》2008,47(17):7908-7913
The unprecedented nickel(III) thiolate [Ni (III)(OR)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) [R = Ph ( 1), Me ( 3)] containing the terminal Ni (III)-OR bond, characterized by UV-vis, electron paramagnetic resonance, cyclic voltammetry, and single-crystal X-ray diffraction, were isolated from the reaction of [Ni (III)(Cl)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) with 3 equiv of [Na][OPh] in tetrahydrofuran (THF)-CH 3CN and the reaction of complex 1 with 1 equiv of [Bu 4N][OMe] in THF-CH 3OH, respectively. Interestingly, the addition of complex 1 into the THF-CH 3OH solution of [Me 4N][OH] also yielded complex 3. In contrast to the inertness of complex [Ni (III)(Cl)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) toward 1 equiv of [Na][OPh], the addition of 1 equiv of [Na][OMe] into a THF-CH 3CN solution of [Ni (III)(Cl)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) yielded the known [Ni (III)(CH 2CN)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) ( 4). At 77 K, complexes 1 and 3 exhibit a rhombic signal with g values of 2.31, 2.09, and 2.00 and of 2.28, 2.04, and 2.00, respectively, the characteristic g values of the known trigonal-bipyramidal Ni (III) [Ni (III)(L)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) (L = SePh, SEt, Cl) complexes. Compared to complexes [Ni (III)(EPh)(P(C 6H 3-3-SiMe 3-2-S) 3)] (-) [E = S ( 2), Se] dominated by one intense absorption band at 592 and 590 nm, respectively, the electronic spectrum of complex 1 coordinated by the less electron-donating phenoxide ligand displays a red shift to 603 nm. In a comparison of the Ni (III)-OMe bond length of 1.885(2) A found in complex 3, the longer Ni (III)-OPh bond distance of 1.910(3) A found in complex 1 may be attributed to the absence of sigma and pi donation from the [OPh]-coordinated ligand to the Ni (III) center.  相似文献   

15.
Wu Y  Bensch W 《Inorganic chemistry》2008,47(17):7523-7534
Four new quaternary alkali neodymium thiophosphates K 9Nd[PS 4] 4 ( 1), K 3Nd[PS 4] 2 ( 2), Cs 3Nd[PS 4] 2 ( 3), and K 3Nd 3[PS 4] 4 ( 4) were synthesized by reacting Nd with in situ formed fluxes of K 2S 3 or Cs 2S 3, P 2S 5 and S in appropriate molar ratios at 973 K. Their crystal structures are determined by single crystal X-ray diffraction. Crystal data: 1: space group C2/ c, a = 20.1894(16), b = 9.7679(5), c = 17.4930(15) A, beta = 115.66(1) degrees , and Z = 4; 2: space group P2 1/ c, a = 9.1799(7), b = 16.8797(12), c = 9.4828(7) A, beta = 90.20(1) degrees , and Z = 4; 3: space group P2 1/ n, a = 15.3641(13), b = 6.8865(4), c = 15.3902(13) A, beta = 99.19(1) degrees , and Z = 4; 4: space group C2/ c, a = 16.1496(14), b = 11.6357(7), c = 14.6784(11) A, beta = 90.40(1) degrees , and Z = 4. The structure of 1 is composed of one-dimensional (1) infinity{Nd[PS 4] 4} (9-) chains and charge balancing K (+) ions. Within the chains, eight-coordinated Nd (3+) ions, which are mixed with K (+) ions, are connected by [PS 4] (3-) tetrahedra. The crystal structures of 2 and 3 are characterized by anionic chains (1) infinity{Nd[PS 4] 2} (3-) being separated by K (+) or Cs (+) ions. Along each chain the Nd (3+) ions are bridged by [PS 4] (3-) anions. The difference between the structures of 2 and 3 is that in 2 the Nd (3+) ions are coordinated by four edge-sharing [PS 4] (3-) tetrahedra while in 3 each Nd (3+) ion is surrounded by one corner-sharing, one face-sharing, and two edge-sharing [PS 4] (3-) tetrahedra. The structure of 4 is a three-dimensional network with K (+) cations residing in tunnels running along [110] and [110]. The {Nd(1)S 8} polyhedra share common edges with four [PS 4] tetrahedra forming one-dimensional chains (1) infinity{Nd[PS 4] 2} (3-) running along [110] and [110]. The chains are linked by {Nd(2)S 8} polyhedra yielding the final three-dimensional network (3) infinity{Nd[PS 4] 2} (3-). The internal vibrations of both crystallographically independent [PS 4] (3-) anions of 2- 4 have been assigned in the range 200-650 cm (-1) by comparison of their corresponding far/mid infrared and Raman spectra (lambda exc = 488 nm) on account of locally imposed C 1 symmetry. In the Fourier-transform-Raman spectrum (lambda exc = 1064 nm) of 2- 4, very similar well-resolved electronic Raman (ER) transitions from the electronic Nd (3+) ground-state to two levels of the (4)I 9/2 ground manifold and to the six levels of the (4)I 11/2 manifold have been determined. Resonant Raman excitation via a B-term mechanism involving the (4)I 15/2 and (4)F 3/2 intermediate states may account for the significant intensity enhancement of the ER transitions with respect to the symmetric P-S stretching vibration nu 1. Broad absorptions in the UV/vis/NIR diffuse reflectance spectrum at 293 K in the range 5000-25000 cm (-1) of 2- 4 are attributed to spin-allowed excited quartet states [ (4)(I < F < S < G < D)] and spin-forbidden doublet states [ (2)(H < G < K < D < P)] of Nd (3+). A luminescense spectrum of 3 obtained at 15 K by excitation with 454.5 nm shows multiplets of narrow lines that reproduce the Nd (3+) absorptions. Sharp and intense luminescence lines are produced instead by excitation with 514.5 nm. Lines at 18681 ( (4)G 7/2), 16692 ( (4)G 5/2), 14489 ( (4)F 9/2), and 13186 cm (-1) ( (4)F 7/2) coincide with the corresponding absorptions. Hypersensitive (4)G 5/2 is split by 42 cm (-1). The most intense multiplet at about 16500 cm (-1) is assigned to the transition from (4)G 5/2 to the Stark levels of the ground manifold (4)I 9/2.  相似文献   

16.
The salt [CF3C[triple bond]CXe] [BF4] was prepared as neat compound by the reaction of the hitherto unknown alkynyldifluoroborane CF3C[triple bond]CBF2 with XeF2 in 1,1,1,3,3-pentafluoropropane (PFP) at -45 degrees C in 59% yield. [CF3C[triple bond]CXe] [BF4] was unambiguously characterised by multinuclear NMR spectroscopy in anhydrous HF (aHF) solution.  相似文献   

17.
The reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with 1,2-phenylenediamine resulted in the unexpected formation of 10a-aryl-1,2,10,10a-tetrahydrobenzo-[4,5]-imidazo[1,2-a]pyridin-3-yl(2-hydroxyphenyl)-1-methanones. Their structure elucidation and complete 1H and 13C assignments have been performed by a combination of various one- and two-dimensional NMR experiments.  相似文献   

18.
The first structurally authenticated example of a hexadentate chelating tertiary phosphine in which all six donors are bound to a single metal centre is described. The multidentate ligand (RP*,RP*,RP*)- and (RP*,RP*,SP*)-CH3C(CH2PPhC6H4NH2-2)3 has been prepared in 80% yield via the reaction of five equivalents of sodium (2-aminophenyl)phenylphosphide (generated in situ from (2-aminophenyl)phenylphosphine and sodium in thf) with 1,1,1-tri(bromomethyl)ethane in thf. The diastereomeric mixture has been complexed to cobalt(III) and the resulting pair of complexes, viz. [Co{(RP*,RP*,RP*)-CH3C(CH2PPhC6H4NH2-2)3}]Cl3 and [CoCl{(RP*,RP*,SP*)-CH3C(CH2PPhC6H4NH2-2)3}]Cl2, separated by ion exchange chromatography. The structure of the former (as the corresponding hexafluorophosphate salt) has been confirmed by X-ray crystallography and clearly shows all six donors of the P3N3 ligand coordinated to a single cobalt(III) centre. The related hexadentate ligand with internal N donors and terminal diphenylphosphino groups, viz. CH3C(CH2NHC6H4PPh2-2)3, has also been synthesised, albeit in low yield, via the reaction of [Li(tmeda)][2-NHC6H4PPh2] (generated in situ from (2-aminophenyl)diphenylphosphine, n-butyllithium and tmeda in diethyl ether) with 1,1,1-tri(iodomethyl)ethane in thf. No formation of a P3N3 ligand has been observed when either Na[2-PPhC6H4NH2] or [Li(tmeda)][2-NHC6H4PPh2] is reacted with the related tripodal substrate 1,1,1-tris(tolyl-4-sulfonyloxymethyl)ethane in thf. Rather the P-methyloxetane (+/-)-[3-{(2-aminophenyl)phenylphosphinomethyl}]-3-methyloxetane and the sulfonamide 2-(4-CH3C6H4SO2)NHC6H4PPh2 and the corresponding N-methyloxetane [3-{(2-diphenylphosphinophenyl)aminomethyl}]-3-methyloxetane have been isolated from the respective reactions. The structure of the sulfonamide has been confirmed by an X-ray analysis of the platinum(II) complex trans-[PtCl(CH3){2-PPh2C6H4NH(SO2C6H4CH(3-4)}2].  相似文献   

19.
The alkali dicyanamides M[N(CN)2] (M=K, Rb) were synthesized through ion exchange, and the corresponding tricyanomelaminates M3[C6N9] were obtained by heating the respective dicyanamides. The thermal behavior of the dicyanamides and their reaction to form the tricyanomelaminates were investigated by temperature-dependent X-ray powder diffractometry and thermoanalytical measurements. Potassium dicyanamide K[N(CN)2] was found to undergo four phase transitions: At 136 degrees C the low-temperature modification alpha-K[N(CN)2] transforms to beta-K[N(CN)2], and at 187degrees C the latter transforms to the high-temperature modification gamma-K[N(CN)2], which melts at 232 degrees C. Above 310 degrees C the dicyanamide ions [N(CN)2]- trimerize and the resulting tricyanomelaminate K3[C6N9] solidifies. Two modifications of rubidium dicyanamide have been identified: Even at -25 degrees C, the a form slowly transforms to beta-Rb[N(CN)2] within weeks. Rb[N(CN)2] has a melting point of 190 degrees C. Above 260 degrees C the dicyanamide ions [N(CN)2]- of the rubidium salt trimerize in the melt and the tricyanomelaminate Rb3[C6N9] solidifies. The crystal structures of all phases were determined by powder diffraction methods and were refined by the Rietveld method. alpha-K[N(CN)2] (Pbcm, a = 836.52(1), b = 46.90(1), c =7 21.27(1) pm, Z = 4), gamma-K[N(CN)2] (Pnma, a = 855.40(3), b = 387.80(1), 1252.73(4) pm, Z = 4), and Rb[N(CN)2] (C2/c, a = 1381.56(2), b = 1000.02(1), c = 1443.28(2) pm, 116.8963(6) degrees, Z = 16) represent new structure types. The crystal structure of beta-K[N(CN)2] (P2(1/n), a = -726.92(1), b 1596.34(2), c = 387.037(5) pm, 111.8782(6) degrees, Z = 4) is similar but not isotypic to the structure of alpha Na[N(CN)2]. alpha-Rb[N(CN)2] (Pbcm, a = 856.09(1), b = 661.711(7), c = 765.067(9) pm, Z = 4) is isotypic with alpha-K[N(CN)2]. The alkali dicyanamides contain the bent planar anion [N(CN)2]- of approximate symmetry C2, (average bond lengths: C-N(bridge) 133, C-N(term) 113 pm; average angles N-C-N 170 degrees, C-N-C 120 degrees). K3[C6N9] (P2(1/c), a = 373.82(1), b = 1192.48(5), c = 2500.4(1) pm, beta = 101.406(3) degrees, Z = 4) and Rb,[C6N9] (P2(1/c), a = 389.93(2), b = 1226.06(6), c = 2547.5(1) pm, 98.741(5) degrees, Z=4) are isotypic and they contain the planar cyclic anion [C6N9]3-. Although structurally related, Na3[C6N9] is not isotypic with the tricyanomelaminates M3[C6N9] (M = K, Rb).  相似文献   

20.
Kumar K  Kapoor R  Kapur A  Ishar MP 《Organic letters》2000,2(14):2023-2025
All-carbon dipole derived by the interaction of triphenylphosphine with allenic ester is able to locate the polarized 2pi-component in 3-formylchromones through a regioselective [2 + 3] addition to the C2-C3 pi-bond, which is followed by deformylation leading to novel 3a,9a-dihydro-1-ethoxycarbonyl-1-cyclopenteno[5, 4-b]benzopyran-4-ones. On the contrary, the dipole recognizes azadiene in 3-(N-aryliminomethyl)chromones through [4 + 3] annulation and initially formed adducts undergo tandem rearrangements to afford novel N-aryl-2, 3-dihydro-4-ethoxycarbonylchromano[2,3-b]azepine-6-ones in good yield.  相似文献   

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