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1.
新喜树碱衍生物的核磁共振谱分析与结构鉴定   总被引:1,自引:1,他引:0  
以20(S)-喜树碱(CPT)为起始原料,对其进行结构修饰,合成了一种新的喜树碱衍生物CPT-A.并利用1D(~1H、~(13)C和DEPT135)和2D(异核单量子相关谱和异核多碳相关谱)核磁共振(NMR)技术对该化合物进行了结构确定,详细归属了CPT-A~1H和~(13)C NMR谱的化学位移,喜树碱骨架的指认结果与文献报道基本一致,并发现喜树碱骨架6位碳与取代基苯环3’位碳的化学位移相同,谱峰完全重叠,这在~(13)C谱中是不常见的.研究结果可为喜树碱类天然产物的发现和结构鉴定提供NMR数据支持和方法指引.  相似文献   

2.
测定和解析了氧哌嗪青霉素酸等六种抗菌素的~1H NMR 谱和~(13)C NMR 谱的宽带去偶谱、偏共振谱和全偶合谱以及偶合常数~3J_(HH)和~1J_(CH).除氧哌嗪青霉素酸和羟哌唑头孢菌素酸的~1H NMR 已有报道外,其余尚未见报道.实验用 FX-60Q 脉冲 Fourier 变换核磁共振仪测定(磁场强度14093G,观察频率:~1H NMR谱59.80MHz;~(13)C NMR 谱15.04MHz).样品皆由太原制药厂研究所合成,以氘代二甲基亚  相似文献   

3.
本文测定了具有抗癌活性的含氮配体铂配合物——宁辛铂Pt(C_8H_(18)N_2)(CICH_2COO)_2的~1H,~(13)C及~(195)Pt NMR谱,用DEPT及选择去偶等技术对~1H,~(13)C谱线进行了归属,并用位移理论和经验规律对~(195)Pt NMR化学位移进行了初步探讨,从而进一步确证了该化合物双齿配位的平面正方形结构。  相似文献   

4.
本文测定并研究了氮杂菲和它的10-羟基,7,9-二溴-10-羟基,7,9-二氯-10-羟基,10-乙酰基,10-甲氧基衍生物的~1H及~(13)C NMR谱。在XL-200型仪器上使用标准的FT技术、分辨率增强和自旋模拟法,识别了~1H和~(13)C谱峰,测得J_(HH)。氮杂菲的10-H显著去屏蔽。当忽略10-H时,δ_O和δ_H相关很好。还测得氮杂菲~(13)C的T_1值。  相似文献   

5.
本文报导了六个二氢十氟环己烷异构体的~(13)C NMR的化学位移和偶合常数,指定了谱峰的归属,并对数据进行了讨论。含氟化合物~(13)C NMR谱中谱峰的归属主要通过预先确定~(19)F谱的谱峰归属,然后通过作~(19)F的选择性去偶的~(13)C NMR谱来定出~(13)C谱谱峰的归属。  相似文献   

6.
对辛伐他汀的红外(IR)、紫外(UV)、质谱(MS)、氢-氢相关谱(^1H-^1HCOSY)、碳谱(^13C NMR,DEPT)、碳氢相关谱(HMQC)、碳氢远程相关谱(HMBC)予以解析并进行了报道,对所有的^1H NMR和^13C NMR谱信号进行了归属;讨论了红外特征吸收峰所对应的官能团的振动形式,并且对样品进行热差和热重分析,显示该样品为单一晶型,不含结晶水。  相似文献   

7.
室温下SO_4~(2-)/ZrO_2催化剂(SZ)上~(13)C标记的丁烷异构化反应的原位 ~(13)C MAS NMR谱研究结果表明:其反应动力学符合Langmuir-Hinshelwood一级可 逆表面反应动力学公式,由该动力学公式计算得到的反应速率常数可以用于衡量固 体催化剂的表面超强酸性。这种新的表征方法显示采用一步-醇热-超临界干燥综合 技术合成的SZ催化剂不仅比表面和硫酸根含量高,而且其超强酸性和异构化反应活 性均明显优于常规法合成的催化剂,具有良好的应用前景。  相似文献   

8.
王鹏  袁艺  景晓燕  朱果逸 《分析化学》1999,27(11):1337-1340
用1H NMR和13C NMR谱研究了新型电化学发光探针六氟磷酸二(4,4'-二甲基-2,2'-联吡啶)·(4,4'-二羧酸-2,2'-联吡啶)合钌(Ⅱ)的立体结构,通过1H-1H COSY、13C-1H HETCOR谱对其氢谱和碳谱中的各谱峰进行了归属,并给出了氢谱和碳谱峰的化学位移值.  相似文献   

9.
本文合成并分离提纯了1位和4位单取代的苯并咪唑萘酰亚胺(NBI)类化合物1~4,对化合物1的紫外-可见光谱、红外光谱、质谱、核磁共振谱(包括1H NMR、13C NMR、DEPT、1H-13C HSQC、1H-13C HMBC、1H-1HCOSY多种NMR技术)进行了详细解析,对其所有的1H和13C NMR信号进行了归属,并使用了GIAO和CSGT两种方法量化计算核磁位移,通过多种波谱学技术确证了化合物的结构。  相似文献   

10.
EVAc共聚物的序列结构和它的~(13)C NMR谱的关系   总被引:2,自引:0,他引:2  
本文以EVAc共聚物为例,阐述了EV共聚物序列结构的符号表示与Bovey关系(Ⅰ)的一致性。在此基础上,选择了EV共聚物序列结构的Sung表示并赋予它以化学位移的意义,在二元组和三元组序列水平上分析了EV共聚物的13种序列结构与Sung表示,与取代基参数,与其~(13)C NMR谱13个谱峰之间的一一对应关系。其主要内容由Sung表示与取代基参数之间的α~S_1,β~S_2,γ~S_3,δ~S_4,δ~+~0ppm对应关系表征,从而构架了由EV共聚物的~(13)C NMR谱通向其序列结构的桥梁,建立起研究EV共聚物序列结构的普适方法。  相似文献   

11.
Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of four Linkage Isomeric Trichlorotrirhodanoosmates(IV) By treatment of fac-[OsCl3I3]2? with (SCN)2 in dichloromethane the linkage isomers fac-[OsCl3(NCS)3]2? ( 1 ), mer-[OsCl3(NCS)2c(SCN)]2? ( 2 ), mer-[OsCl3(NCS)(SCN)2t]2? ( 3 ), and mer-[OsCl3(NCS)(SCN)2c]2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. X-Ray structure determinations have been performed on single crystals of fac-(Ph4As)2[OsCl3(NCS)3] (triclinic, space group P1 , a = 12.142(5), b = 13.233(5), c = 19.300(5) Å, α = 98.642(5)º, β = 100.509(5)º, γ = 112.514(5)º, Z = 2), mer-(Ph4As)2[OsCl3(NCS)2c (SCN)] · acetone (triclinic, space group P1 , a = 11.707(5), b = 13.238(5), c = 19.048(5) Å, α = 75.960(5)º, β = 88.981(5)º, γ = 69.999(5)º, Z = 2), mer-(Ph4As)2[OsCl3(NCS)(SCN)2 t] (triclinic, space group P1, a = 10.6861(12), b = 11.6587(5), c = 12.5232(5) Å, α = 112.069(8)º, β = 95.052(8)º, γ = 92.559(7)º, Z = 1) and mer-(Ph4As)2[OsCl3(NCS)(SCN)2 c] · 2acetone (triclinic, space group P1 , a = 11.444(5), b = 14.661(5), c = 15.830(5) Å, α = 75.790(5)º, β = 80.273(5)º, γ = 75.205(5)º, Z = 2). The complex anions are completely ordered. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 169.1º, 171.5º, 175.7º ( 1 ), 175.6º, 178.6º ( 2 ), 172º ( 3 ), and 173.1º ( 4 ) and Os? S? C angles of 106.2º ( 2 ), 106.1º, 106.6º ( 3 ), 105.1º, and 108.2º ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts of all four linkage isomers have been assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are fd(OsN) = 1.71 ( 1 ), 1.46 and 1.62 ( 2 ), 1.69 ( 3 ), and 1.61 ( 4 ), fd(OsS) = 1.27 ( 2 ), 1.36 ( 3 ), 1.32, and 1.49 mdyn/Å ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.  相似文献   

12.
Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of Four Linkage Isomeric Tetrachlorodirhodanoosmates(IV) By treatment of cis- or trans-[OsCl4I2]2? with (SCN)2 in dichloromethane the linkage isomers cis-[OsCl4(NCS)2]2? ( 1 ), trans-[OsCl4(NCS)(SCN)]2? ( 2 ), cis-[OsCl4(NCS)(SCN)]2? ( 3 ) and trans-[OsCl4(SCN)2]2? ( 4 ) are formed which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determinations on single crystals of cis-(Ph4As)2[OsCl4(NCS)2] (triclinic, space group P1 , a = 10.019(5), b = 11.702(5), c = 21.922(5) Å, α = 83.602(5)°, β = 85.718(5)°, γ = 73.300(5)°, Z = 2), trans-(Ph4As)2[OsCl4 · (NCS)(SCN)] (monoclinic, space group P21/c, a = 18.025(5), b = 11.445(5), c = 23.437(5) Å, β = 94.208(5)°, Z = 4), cis-(Ph4As)2[OsCl4(NCS)(SCN)] (triclinic, space group P1 , a = 10.579(5), b = 11.682(5), c = 22.557(5) Å, α = 81.073(5)°, β = 85.807(5)°, γ = 87.677(5)°, Z = 2) and trans-(Ph4As)2 · [OsCl4(SCN)2] (triclinic, space group P1 , a = 10.615(5), b = 11.691(5), c = 11.907(5) Å, α = 111.314(5)°, β = 96.718(5)°, γ = 91.446(5)°, Z = 1) reveal the complete ordering of the complex anions. The via N or S coordinated thiocyanate groups are located nearly direct above one of the cis-positioned Cl ligands with Os? N? C angles of 171.2° and 174.3° ( 1 ), 162.3° ( 2 ), 172° ( 3 ) and Os? S? C angles of 108.3° ( 2 ), 105.7° ( 3 ) and 105.5° ( 4 ). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu4N) salts of all four linkage isomers are assigned by normal coordinate analyses based on a modified valence force field. The valence force constants are fd(OsN) = 1.59 ( 1 ), 1.67 ( 2 ), 1.60 ( 3 ) and fd(OsS) = 1.27 ( 2 ), 1.31 ( 3 ) and 1.32 mdyn Å?1 ( 4 ). Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved.  相似文献   

13.
Preparation and Crystal Structure of (n-Bu4N)3[Ir(NCS)(SCN)5] The evaporated ethanolic extrakt of the reaction product of K3[IrCl6] and HNO3, refluxed with an aqueous KSCN solution yields a mixture of the linkage isomers [Ir(NCS)n(SCN)6?-n]3?, n = 0? 2, and small amounts of linkage isomeric chloropentarhodanoiridates(III), from which [Ir(NCS)(SCN)5]3? has been isolated by ion exchange chromatography on DEAE-cellulose. The X-Ray structure determination on a single crystal of (n-Bu4N)3[Ir(NCS)(SCN)5] (monoclinic, space group P 21/a, a = 17.513(5), b = 32.607(5), c = 23.661(5) Å, β = 94.757(5)°, Z = 8) confirms the existance of a heteroleptic hexakis(thiocyanato(N)-thiocyanato(S))iridate(III) with an Ir? N distance of 2.03 Å and Ir? S bond lengths between 2.29 and 2.38 Å. The SCN groups with angles between 166 and 175° are nearly linear with Ir? S? C angles from 99.9 to 109.4°. The Ir? N? C angles of the two crystallographic independent anions are 166 and 174°.  相似文献   

14.
Thermogravimetry (TG) was employed to study the thermal degradation kinetics of poly(etherketone/sulfone)ethylimide (PEK-IE and PES-IE). The corresponding decomposition activation energies and reaction orders were obtained and the comparison was made with their parent polymerspoly(ether-ketone/sulfone) with Cardo group (PEK-C and PES-C). The results show that the degradation activation energies of PEK-IE and PES-IE were lower than that of PEK-C and PES-C; and two stages of the degradation process were found for all the four polymers. For PEK-IE and PES-IE, the activation energies in the first decomposition stage are much lower than that in the second stage and the two stages can be taken as slow induction and fast degradation, whereas for PEK-C and PES-C the activation energies in the first decomposition stage are larger than that in the second stage, and the two stages can both be taken as two fast degradation stages. The decomposition mechanism of the two stages was also speculated.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

15.
Abstract

The reaction, in water, of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with sodium ampicillinate at room temperature has allowed isolation of dimers with the following general formula [M(amp)Cl]2 × nH2O (n = 1.5?3.2). The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibilities and spectroscopic methods (IR, Raman, EPR and UV-Visible). A dinuclear structure based on octahedrally coordinated metal ions is proposed.  相似文献   

16.
高原  张茂根  王昉  王炳祥  沈健 《应用化学》2005,22(10):1096-1099
PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性  相似文献   

17.
Summary: The thermal degradation behavior of poly(ε-caprolactone) (PCL) and poly(L-lactic acid) (PLA) have been studied in different environment. It was found that these polymers undergo completely different degradation processes in nitrogen and oxygen atmosphere. In oxygen environment PCL and PLA mainly decompose to CO2, CO, water and short-chain acids. In nitrogen atmosphere PCL releases 5-hexenioc acid, CO2, CO and ε-caprolactone, whereas PLA decomposes to acetaldehyde, CO2, CO and lactide. The polymer blends of poly(3-hydroxybutyrate) (PHB) with PCL and PLA decompose similar to the individual homopolymers with crotonic acid as the initial decomposition product of PHB.  相似文献   

18.
In this paper, we carry out the calculation on the system (X@C60)(X=Li, Na, K, Kb, Cs; F, Cl, Br, I), where the position of X changes along 5 typical symmetry directions. For the calculation of quantum chemistry we use EHMO/ASED method, for the calculation of molecular mechanics we use Buckingham potential (exp-6-1) function, and for the calculation of thermo-chemical cycle we use individually isolating the processes such as the structure variation, charge transfer and charge distribution, and their interactions etc. The calculation results show that (1) In the region of radius r≈0.2 nm of the Ceo cage, the potential field is nearly spherical; (2) Except for Li and Na, the systems are the most stable with minimum energies at the center of C60 cage. For Li and Na, the systems are the most stable with minimum energies at r≈0.16 nm and r≈0.13 nm, respectively. In view of the interactive region of chemical bonds, the interactions between X and the C60 cage do not belong to the classical chemical bonds; (  相似文献   

19.
Cu以其优异的导电性、导热性和易加工性广泛用于工农业生产中.自然Cu的腐蚀和防腐成为人们很关注的问题.人们已经注意到,Cl-对Cu的腐蚀有影响,并进行过一些研究.但目前使用光电化学方法研究这一问题的文章尚不多见,特别是利用测量开路光电压及其瞬态波形这一现场的、无损的、灵敏的监测方法研究户对Cu电极腐蚀全过程的文章尚未见到.本文正是利用如上方法及XPS,AES方法,研究了Cl-对Cu电极腐蚀的全过程,取得了一些有意义的结果.1实验方法Cu电极用99.99%(质量分数)的Cu制成,面积约为39mm2;电极底部由Cu导线焊接引出,…  相似文献   

20.
Fundamental understanding of microphase separation in ABC miktoarm copolymers is vital to access a plethora of nonconventional morphologies. Miktoarm stars based on poly(cis 1,4-isoprene) (I), poly(styrene) (S), and poly(2-vinylpyridine) (V) are model systems, which allow systematic studies of the effects of composition, chemical microstructure, and temperature on the thermodynamics of microphase separation. Eleven ISV-x (I:S:V = 1:1:x, v:v:v) miktoarm copolymers were synthesized by anionic polymerization affording well-defined copolymers with a variable V arm. Equilibrium bulk morphologies of all samples, as evidenced by small-angle X-ray scattering, transmission electron microscopy (TEM), and self-consistent field theory, showed a systematic transition from lamellae (x ≈ 0–0.2) to [8.8.4] tiling (x ≈ 0.6–0.9) to cylinders in undulating lamellae (x ≈ 2–4) and, finally, to hexagonally packed core–shell cylinders (x ≈ 5–8). Chemical microstructure of the I arm [poly(cis 1,4-isoprene)] versus poly(3,4-isoprene) is shown to play important role in affecting morphological behavior. To reconcile differences between ISV-x star morphologies reported in the literature and those reported herein, even for the same composition, effects of the microstructure of I arm on the Flory–Huggins parameter between I and V arms were taken into account in a qualitative manner. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1491–1504  相似文献   

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