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1.
研究了氨基分别为1'-四氢吡咯,1'-六氢吡啶和4'-吗啉的1-苯基-3-氨基-2-丁烯-1-酮的晶体结构. 它们的构型.构象均为trans, S-cis.由于共轭体系的扩展,这些烯氨酮的氮原子都比相应的烯胺有程度更大的电子离域,其中又以扭式构象的四氢吡咯基的离域程度最高.四氢吡咯形成N-不饱和化合物的特殊活性与此有关.  相似文献   

2.
为合成某些芳香族有机化合物提供一种新途径,用色谱-质谱联用技术和质量色谱法研究了苯甲酸钐的热分解反应产物。其热分解产物溶入丙酮后有大量9,10-蒽醌析出,其丙酮溶液中还含有1,2-二苯甲酰基苯(256%)、苯甲酸(187%)、二苯酮(144%)、9-芴酮(82%)、9-苯基芴(49%)、联苯(36%)、二苯甲烷(23%)、3-甲酰苯基联苯(21%)、二苯基乙二酮(19%)、4-甲酰苯基联苯(18%)、芴(17%)、m-二苯甲酰基苯(11%)和p-二苯甲酰基苯(02%)等55种化合物。讨论了苯甲酸盐的热分解反应机理。  相似文献   

3.
几种新的4-酰代吡唑啉酮衍生物的合成与结构   总被引:7,自引:0,他引:7  
利用4-酰代吡唑啉酮与氨基硫脲类化合物反应制备了新的吡唑啉酮类衍生物,并用IR,NMR,MS和元素分析进行表征,最后用X射线四圆衍射对其中的2个化合物进行了晶体结构测定。  相似文献   

4.
1 INTRODUCTIONThe molecular structures of five-coordinated copper (II) complexes show an extensive variability ranging from trigonal bipyramidal to square pyramidal stereochemistry, with most complexes displaying a structure which is intermediate between these two extremes[1,2]. Most crystal structures of 1,10-phenanthroline with copper (II) complexes are known, [Cu (phen)2X]Y, where X = Cl, Br, I, CN, NCS, H2O or thiourea and Y = perchlorate, nitrate, tetrafluoroborate, chloride o…  相似文献   

5.
软段结构对聚氨酯性能影响的研究   总被引:3,自引:0,他引:3  
用熔融缩聚法俣成了己二酸系和己二酸/芳香二酸混合系两个系列的聚酯;同溶液一步法将部分聚酯与MDI反应,形成一系列聚酯型氨酯,以化学分析,VPO,IR,DSC,WAXD,力学拉伸等手段对聚酯和聚氨酯进行了表征;讨论了软段聚酯的结构对聚氨酯的结晶性,耐热性,粘结性等性能的影响。  相似文献   

6.
From the roots of Sophora koreensis (Fabaceae), three new oleanene-type triterpene glycosides, echinosophorosides A(1) (1) and B (2), and acetyl-subproside II (5), were isolated as their methyl esters, together with the four known ones sophoraflavoside I, kudzusaponin SA(3), subproside II, and azukisaponin V. The structures of the new saponins were elucidated to be 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl kudzusapogenol A 22-O-alpha-L-arabinopyranoside (1), 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-glucuronopyranosyl abrisapogenol C 22-O-alpha-L-arabinopyranoside (2), and 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl kudzusapogenol A 22-O-acetate (5), respectively. It is noteworthy that two arabinopyranosyl moieties in the same molecule, echinosophoroside B (2), have different conformations. The conformation of the arabinopyranosyl moiety existing in the trisaccharide moiety was determined to be (1)C(4), whereas that of the arabinopyranosyl unit at C-22 was identified as (4)C(1).  相似文献   

7.
One new limonoid of the phragmalin type (1) named Swietenine J with nine known compounds methyl-6-β-hydroxy angolensate (2), 1-O-acetylkhayanolide A(3), Khayanolide E (4), Khayalactone (5), Khayanone (6), 1-O-Acetylkhayanolide B (7), 1-O-Deacetylkhayanolide E (8), Khayanolide A (9), Khayanolide B (10) were isolated from Swietenia macrophylla. The structure of 1 was elucidated on the basis of 1D and 2D- NMR spectroscopic analysis.  相似文献   

8.
The time-resolved emission properties of selected anthracene derivatives, namely anthracene (1a), 2-methylanthracene (1b), 2-chloroanthracene (1c), 2-methoxyanthracene (1d), 2-methoxy-6-methylanthracene (1e), 2-(N,N'-dicyclohexylureidocarbonyl)-6-methoxyanthrace ne (1f), 2-(6-methoxyanthr-2-yl)-4,4-dimethyl-2-oxazoline (1g), 2-(6-methoxyanthr-2-yl)-pyridine (1h), and N-cyclohexylanthracene-2-carboxamide (1i) were investigated. In contrast to anthracene (1a), 1b, and 1c, the 2-methoxy-substituted anthracene derivatives 1d-1h exhibit two emission lifetimes. The determination of the lifetimes at different emission wavelengths and additional time-resolved emission spectroscopy (TRES) reveal that the dual emission originates from two different, interconvertible emissive species, with the s-cis and s-trans conformation relative to the exocyclic C2-O bond. The energy difference between the two emissive species is very small (<0.1 eV) both in the ground and in the excited state. The larger energy difference between the conformers in the excited-state is responsible for the interconversion within the singlet excited-state lifetimes of the s-cis into the s-trans conformations leading to coupled decay kinetics. The proposed mechanism for the dual emission was qualitatively supported by theoretical studies on CASSCF and DFT level. In addition, the emission lifetimes of the fluoride- and pH-sensitive fluorescent probes 1f and 1g change upon addition of fluoride or acid, respectively, so that in these cases the detection of the fluorescence lifetime may be used complementary to the steady-state fluorimetric detection of these analytes.  相似文献   

9.
合成了5种氨基酸席夫碱Sal-Gly(甘氨酸席夫碱)、Sal-Glu(谷氨酸席夫碱)、Sal-Met(甲硫氨酸席夫碱)、Sal-Tyr(酪氨酸席夫碱)、Sal-Arg(精氨酸席夫碱)及其金属锌离子配合物共10种化合物.用元素分析、核磁共振、红外光谱、紫外-可见光谱等手段对其组成的结构进行表征.以Sal-Tyr-Zn为主体,咪唑(1),1-甲基-咪唑(2),2-乙基-4-甲基咪唑(3),吡唑(4),4-碘苯胺(5),DABCO(1,4-重氮双环[2,2,2]辛烷)(6),邻苯二胺(7)和1,2-环己二胺(8)为客体,进行配位相互作用研究.选取大肠杆菌作为抑菌菌种,研究了氨基酸席夫碱的抑菌能力.结果表明,氨基酸席夫碱配体及金属锌配合物对大肠杆菌均有抑菌活性,配体的抗菌活性随氨基酸残基的增大而减小.金属锌配合物的抑菌活性大于其所对应的氨基酸席夫碱配体的抑菌活性,活性最大的则为Sal-Arg-Zn.  相似文献   

10.
王志林  沈孟长  罗勤慧 《化学学报》1992,50(10):1000-1004
本文报道以2,3-苯并-11-甲基-18-冠-6,2,3-苯并-8,15-二甲基-18-冠-6和2,3-苯并-8-11,15-三甲基-18-冠-6为液膜载体,研究其对碱金属离子的传输,发现当水相金属盐浓度和膜相配体相近时,金属离子的传输为串联一级反应,求得了串级速率常数,并讨论了传输速率和配位作用的关系及载体结构的影响.  相似文献   

11.
Thirty-two new bakkenolides, bakkenolides-Db (1)--Dh(7), -Fa(8), -Fb(9), -I(10)--M(14), -Na(15), -Nb(16), -O(17)--T(22), -Ua (23), -Ub(24), -V(25)--X(27), -Ya(28), -Yb(29), -Za(30), -Zb(31) and -III(32), from the roots of Petasites formosanus together with thirty known compounds were isolated. The structures were characterized by spectral analysis. The locations, C-1 and/or C-9 of bakkenolide skeleton, of the substituents, such as acetoxy, isobutyroyloxy and isovaleroyloxy groups, can be determined by the chemical shifts of their signals and the H-1 and/H-9 in the 1H-NMR spectra. The cytotoxicity was also discussed.  相似文献   

12.
In this paper, the vertical excitation energies of total of 32 states of N(2)O(4) including the lowest two singlet states and two triplet states of each of the A(g), B(3u), B(2u), B(1g), B(1u), B(2g), B(3g), and A(u) symmetries were calculated at multiconfigurational self-consistent field (MCSCF) and the multireference internally contracted configuration interaction (MRCI) levels of theory on the active space (15o,16e) with aug-cc-pVDZ basis set. The potential energy curves of the eight singlet states(1 (1)A(g), 1 (1)B(3u), 1 (1)B(2u), 1 (1)B(1g), 1 (1)B(1u), 1 (1)B(2g), 1 (1)B(3g), and 1 (1)A(u)) and eight triplet states (1 (3)A(g), 1 (3)B(3u), 1 (3)B(2u), 1 (3)B(1g), 1 (3)B(1u), 1 (3)B(2g), 1 (3)B(3g), and 1 (3)A(u)) were calculated at MCSCF and MRCI levels of theory on the active space (15o,16e) with aug-cc-pVDZ basis set along the N-N distance. The vertical excitation energies of 1 (1)B(3u), 1 (1)B(2u), and 1 (1)B(1u) states with nonzero transition moment are 4.60 eV (269.6 nm), 6.06 eV (204.6 nm), and 7.71 eV (160.8 nm), respectively, at MRCI level of theory. The photodissociation asymptotics were assigned as NO(2)(X (2)A(1))+NO(2)(X (2)A(1)) for ground state 1 (1)A(g) and the 1 (3)B(1u) state, NO(2)(X (2)A(1))+NO(2)(1 (2)A(2)) for the 1 (1)B(1g), 1 (3)B(1g), 1 (1)A(u), and 1 (3)A(u) states, NO(2)(X (2)A(1))+NO(2)(1 (2)B(1)) for the 1 (1)B(3u), 1 (3)B(3u), 1 (1)B(2g), and 1 (3)B(2g) states, and NO(2)(X (2)A(1))+NO(2)(1 (2)B(2)) for the 1 (1)B(2u), 1 (3)B(2u), 1 (1)B(3g), and 1 (3)B(3g) states.  相似文献   

13.
The singlet ground ((approximate)X(1)Sigma1+) and excited (1Sigma-,1Delta) states of HCP and HPC have been systematically investigated using ab initio molecular electronic structure theory. For the ground state, geometries of the two linear stationary points have been optimized and physical properties have been predicted utilizing restricted self-consistent field theory, coupled cluster theory with single and double excitations (CCSD), CCSD with perturbative triple corrections [CCSD(T)], and CCSD with partial iterative triple excitations (CCSDT-3 and CC3). Physical properties computed for the global minimum ((approximate)X(1)Sigma+HCP) include harmonic vibrational frequencies with the cc-pV5Z CCSD(T) method of omega1=3344 cm(-1), omega2=689 cm(-1), and omega3=1298 cm(-1). Linear HPC, a stationary point of Hessian index 2, is predicted to lie 75.2 kcal mol(-1) above the global minimum HCP. The dissociation energy D0[HCP((approximate)X(1)Sigma+)-->H(2S)+CP(X2Sigma+)] of HCP is predicted to be 119.0 kcal mol(-1), which is very close to the experimental lower limit of 119.1 kcal mol(-1). Eight singlet excited states were examined and their physical properties were determined employing three equation-of-motion coupled cluster methods (EOM-CCSD, EOM-CCSDT-3, and EOM-CC3). Four stationary points were located on the lowest-lying excited state potential energy surface, 1Sigma- -->1A", with excitation energies Te of 101.4 kcal mol(-1) (1A"HCP), 104.6 kcal mol(-1)(1Sigma-HCP), 122.3 kcal mol(-1)(1A" HPC), and 171.6 kcal mol(-1)(1Sigma-HPC) at the cc-pVQZ EOM-CCSDT-3 level of theory. The physical properties of the 1A" state with a predicted bond angle of 129.5 degrees compare well with the experimentally reported first singlet state ((approximate)A1A"). The excitation energy predicted for this excitation is T0=99.4 kcal mol(-1) (34 800 cm(-1),4.31 eV), in essentially perfect agreement with the experimental value of T0=99.3 kcal mol(-1)(34 746 cm(-1),4.308 eV). For the second lowest-lying excited singlet surface, 1Delta-->1A', four stationary points were found with Te values of 111.2 kcal mol(-1) (2(1)A' HCP), 112.4 kcal mol(-1) (1Delta HPC), 125.6 kcal mol(-1)(2(1)A' HCP), and 177.8 kcal mol(-1)(1Delta HPC). The predicted CP bond length and frequencies of the 2(1)A' state with a bond angle of 89.8 degrees (1.707 A, 666 and 979 cm(-1)) compare reasonably well with those for the experimentally reported (approximate)C(1)A' state (1.69 A, 615 and 969 cm(-1)). However, the excitation energy and bond angle do not agree well: theoretical values of 108.7 kcal mol(-1) and 89.8 degrees versus experimental values of 115.1 kcal mol(-1) and 113 degrees. of 115.1 kcal mol(-1) and 113 degrees.  相似文献   

14.
Seven rings A,B-seco limonoids 1-7 were isolated from the EtOH extract of the seed of Aphanamixis polystachya. Their structures were identified as rohituka-7 (1), dregeana-1 (2), rohituka-15 (3), Tr-B (4), rohituka-3 (5), rohituka-5 (6), and rohituka-14 (7) by MS and NMR spectroscopy. The complete assignment of proton and carbon signals was achieved by 1D and 2D NMR experiments including DEPT, HSQC, 1H--1H COSY, HMBC, and NOESY.  相似文献   

15.
The mass spectral fragmentations of 3-indazolone (I), 1-acetyl-3-acetoxyindazol (II), 1,2-diacetyl-3-indazolone (III), 1-methyl-3-indazolone (IV), 2-methyl-3-indazolone (V), 2-methyl-3-indazolone-N-d-1 (VI), 3-methoxy-indazole (VII), 1-ethyl-3-indazolone (VIII), 1-carbethoxy-3-indazolone (IX), 1-carbethoxy-2-methyl-3-indazolone (X), 2′-carboxyethyl-3-indazolone (XI), 1-oxo-2,3-dihydropyrazolo-(1,2-α)-3-indazolone (XII) and 1-ethyl-3-indazolone-N-d-2 (XIII) are reported. The loss of an ·N2R radical from the parent radical ion in indazolone and the alkyl indazolones occurs more readily than the loss of a formyl radical, and no loss of HCN is observed from the parent radical ion. Mass spectral data can be used to distinguish between N-methyl and O-methyl derivatives of 3-indazolone.  相似文献   

16.
From the hexane extractive of the nutmeg of Myristica fragrans Houtt, glyceryl trimyristate (1), myristicin (11), methyleugenol (12), elemicin (13), dehydrodiisoeugenol (9), 1-(3,4,5-trimethoxyphenyl)-2-(4-allyl-2,6-dimethoxyphenoxy)-propan-1-ol (4), 1-(3,4-methylenedioxyphenyl)-2-(4-allyl-2,6-dimethoxyphenoxy)-propan-1-ol (6), and a new compound 1-(3,4-dimethoxyphenyl)-2-(4-allyl-2,6-dimethoxyphenoxy) propan-1-ol (14) were isolated. The structure of compound (14) was determined to be an analogue of the β-0-4 ether type of dilignols.  相似文献   

17.
The enthalpies of formation [Delta(g)] of tricyclo[8.2.2.2(4,7)]hexadeca-1(13),2,4(16),5,7(15),10(14),11-heptaene (2, 1,2-dehydro[2.2]paracyclophane or [2.2]paracyclophane-1-ene) and tricyclo[8.2.2.2(4,7)]hexadeca-1(13),2,4(16),5,7(15),8,10(14),11-octaene (3, 1,2,9,10-dehydro[2.2]paracyclophane or [2.2]paracyclophane-1,9-diene) have been determined by measuring their heats of combustion in a microcalorimeter and their heats of sublimation by the transpiration method. Values of the strain energies (SE) [SE(2) = 34.7 kcal mol(-)(1), SE(3) = 42.0 kcal mol(-)(1)] have been derived from the gas-phase heats of formation and are compared with those from MM3 and PM3 calculations and with the corresponding value SE(1) = 30.1 kcal mol(-)(1) for the parent tricyclo[8.2.2.2(4,7)]hexadeca-1(13),4(16),5,7(15),10(14),11-hexaene (1, [2.2]paracyclophane). The higher strain energies of 2 and 3 (by 4.6 and 11.9 kcal mol(-)(1)) are in accord with the well-known increased reactivities of their aromatic rings as a consequence of their increased bending. As revealed by an X-ray crystal structure analysis, the bending in the monoene 2 corresponds to that of 1 and 3 at one of two bridging corners.  相似文献   

18.
19.
1 INTRODUCTIONNeonicotinoids[1~2]areanovelanddistinctclassofinsecticides.Theycombineselectiveactivityagainstinsectswithafavourablesafetyprofile.Neonicotinoidsactatthenicotinicacetylcholinereceptor(nAChR)[3~4].Sincethefirstneonicotinoid,imi-dacloprid(IMI)1wasintroducedtothemarketbyBayerin1991,alotofitsanalogswerereported.Thesecompoundshavethesamestructuralunit,asshowedindashedlineareainIMI.AccordingtothemodelproposedbyYamamotoetal[5],thedistancebetweenthetwonitrogenatomsofIMIisthe…  相似文献   

20.
合成了5种新型镧系四元混合阴离子配合物,用X射线四圆衍射仪测定了[Pr(CH3COO)2(NO3)(bipy)]2的晶体结构,四个醋酸根呈两种配位方式,测定了铕和钆配合物的荧光和ESR谱.  相似文献   

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