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1.
The possible mechanisms for the chiral recognition of 2-(R)-N-[1-(6-aminopyridin-2-ylmethyl)piperidin-4-yl]-2-[(1R)-3,3-difluorocyclopentyl]-2-hydroxy-2-phenylacetamide (RR-M3), and its enantiomer (SS-M3) with octakis(2,3-di-O-acetyl-6-sulfo)-gamma-cyclodextrin (ODAS-gamma-CD) and octakis(6-sulfo)-gamma-cyc?pdextrom enantiomer; (OS-gamma-CD), were investigated using capillary electrophoresis (CE), proton ((1)H), fluorine ((19)F) and carbon ((13)C) nuclear magnetic resonance spectroscopy (NMR), and infrared (IR) spectroscopy. Clear evidence for the formation of diastereomeric complexes between the enantiomers and the two CDs was observed. NMR spectra suggest that the phenyl and difluorocyclopentyl rings are involved in the complexation. The phenyl ring on the guest molecule is deeply penetrated into the cavity of OS-gamma-CD, but it is not included into the cavity of ODAS-gamma-CD. The continuous variation plots built based on the (1)H NMR and IR spectra indicate a 1:1 complex stoichiometric ratio of the M3 enantiomers for both CDs. The affinity of the enantiomers for the two CDs is opposite.  相似文献   

2.
CpCr(NO)(CO)_2与Fe(C_5H_4S)_2S反应,形成氧化-还原产物CpCr(NO)(SC_5H_4)_2Fe(1)。双杂核二茂铁化合物CpM(NO)(EC_5H_4)_2Fe[M=Mo,E=S(2a),Se(2b);M=W,E=S(4a),Se(4b)]、CpMo(NO)(SC_5H_4)_2Fe(3)、Cp_2Mo(SeC_5H_4)_2Fe(6)和Cp_2W(SC_5H_4)_2Fe(7)可通过Fe(C_5H_4ELi)_2·2THF(E=S,Se)与CpM(NO)I_2(M=Mo,W)、[CpMo(NO)I_2]_2或Cp_2MCl_2(M=Mo,W)反应制得。三核杂原子二茂铁化合物[CpCr(NO)_2]_2(EC_5H_4)_2Fe[E=S(8a),Se(8b)],由Fe(C_5H_4ELi)_2·2THF(E=S,Se)与二倍摩尔量的CpCr(NO)_2I反应制备。通过AgBF_4氧化2a得到二茂铁离子型化合物[CpMo(NO)(SC_5H_4)_2Fe]~ BF_4~-(5)。采用元素分析、红外光谱、~1H和~(13)C NMR谱以及EI-MS表征了所合成的新型化合物。  相似文献   

3.
设计合成了2种新型的含不同氟原子数的8-羟基喹啉衍生物配体:(E)-2-[2-(2-氟代苯基)乙烯基]-8-羟基喹啉(4a)和(E)-2-[2-(五氟苯基)乙烯基]-8-羟基喹啉(4b)及其相应的锌配合物5a和5b,利用1H NMR、IR、MS、元素分析确认了产物结构。通过紫外滴定模拟了金属锌与配体4a和4b的配位过程,测定了其在二甲基甲酰胺(DMF)溶液中的荧光性质。荧光光谱显示:配体4a和4b在DMF溶液中的λmax分别为505 nm(蓝绿色)和517 nm(绿色),配合物5a和5b的λmax分别为559 nm(青绿色)和599 nm(黄色),配位后体系共轭程度增大,荧光光谱发生明显的红移。而且随着取代氟原子的增加,配体和配合物的荧光光谱也发生明显的红移。荧光光谱显示氟原子取代数量的改变可以调控8-羟基喹啉锌配合物的发光性质。  相似文献   

4.
Metal selenocarboxylate salts (PPh4)[M(SeC[O]Tol)3] (M = Zn (1), Cd (2) and Hg (3); Tol = C6H4-p-CH3) have been synthesized by reacting Zn(NO3)2 .6H2O, Cd(NO3)2 .4H2O or HgCl2 with (Na+)TolC[O]Se- and PPh4Cl in the ratio of 1 : 4 : 1. The structures of these compounds were determined by single-crystal X-ray diffraction methods. The crystal structures contain discrete cations and anions. In the each anion, the metal center is bound to three TolC[O]Se ligands, primarily through Se, though some long M...O interactions also occur. NMR spectra (113Cd, 199Hg and 77Se, as appropriate) are reported for solutions of [M(SeC[O]Tol)3]-, and of [M(SeC[O]Tol)3](-) - [M(SC[O]Ph)3]- mixtures (M = Zn-Hg), in CH2Cl2 at reduced temperatures. In addition, ESI-MS data have been obtained for [M(SeC[O]Tol)(3)](-) - [M(SC[O]Ph)3]- mixtures (M = Zn-Hg) in acetone and in CH2Cl2. The NMR and ESI-MS studies show that the complexes [M(SeC[O]Tol)n(SC[O]Ph)(3-n)]- (n= 3-0) persist in solution.  相似文献   

5.
A reinvestigation of the NMR spectra of the complexes (NBu4)2[M2(mu-LL)2R4] (M = Pd, Ni, Pt, LL = pyrazolate (pz), 3,5-dimethylpyrazolate (dmpz), 3-methylpyrazolate (mpz), indazolate (indz), R = C6F5; M = Pd, LL = pz, dmpz, mpz, indz, R = 2,4,6-C6F3H2) shows that the boat-shaped dimeric structures of their anions are quite stable in solution, and the previously proposed fast equilibria or dissociations to give species such as [R2M(N-N)(acetone)]-, [R2M(acetone)2] + 2dmpz-, or [R2M(N1-N2)(acetone)]- + [R2M(N2-N1)(acetone)]- in no case occur. A mixture of the two diastereoisomers (head-to-head, HH, and head-to-tail, HT) is present for the asymmetrically substituted azolates (mpz and indz), in a ratio ranging from 1:7 to 1:30 for the different complexes. Strong through-space coupling between the endo ortho fluorine nuclei of different MR2 fragments is observed in the 19F NMR spectra of these diastereoisomers whose boatlike structures place these atoms at short distances.  相似文献   

6.
Borate complexes formed in the ternary system at pH 9.2 containing borate, (S)-3-amino-1,2-propanediol (SAP), and DL-pantothenic acid (DL-PTA) were identified by 13C and 11B NMR, and it is confirmed that the binary complexes, [B(OH)2(SAP)], [B(SAP)2]+ [B(OH)2(D- or L-PTA)]2-, and [B(D- or L-PTA)2]3- (including [B(D-PTA)(L-PTA)]3-), and the ternary complexes, [B(SAP)(D- or L-PTA)]-, coexist at equilibrium in the ternary system. Thermodynamic experiments by variable-temperature 11B NMR revealed that the ternary complex, [B(SAP)(D-PTA)]-, is entropically more stable than [B(SAP)(L-PTA)]-. Because two geometrical isomers are possible for the respective ternary complexes, semi-empirical molecular orbital calculations were performed by PM5, PM3, and AM1 methods in order to obtain the optimized structures. It is indicated from the calculated heats of formation and experimentally obtained thermodynamic parameters that the (S)-isomer is more probable for the respective ternary complexes with D- and L-PTA. In the optimized structure of (S)-[B(SAP)(D-PTA)]- in water, the SAP and D-PTA ligands were oppositely oriented to form a rather linear structure, while the diastereomer, (S)-[B(SAP)(L-PTA)]-, had a folded structure. Because such a difference in the solvated structure of the ternary complexes can give a different electrophoretic velocity in CE, the enantioseparation of DL-PTA in CE is reasonably attributed to a difference in the observed electrophoretic mobility for the equilibrated ternary systems containing the respective ternary complexes.  相似文献   

7.
[reaction: see text] Further oxidation of the common DNA lesion 8-oxo-7,8-dihydroguanosine by one-electron oxidants such as IrCl6(2-), Fe(CN)6(3-), or SO4-* leads to two major products, depending upon reaction conditions. In nucleosides at pH 7, 22 degrees C, the principal product is shown herein to be a spiroiminodihydantoin nucleoside, as a diastereomeric mixture, that can be characterized by NMR, ESI-MS/MS, and independent synthesis.  相似文献   

8.
[structure: see text] Two flexible receptors for carboxylic acids, based on 1-amino-3-fluoro-2-alcohol functional arrays and built on aminomethylpyridine platforms, are described. The C(2)-symmetric one [from 2,6-bis(aminomethyl)pyridine] has been shown to be an efficient CSA due to its ability to form geometrically different diastereomeric complexes enabling the discrimination between the enantiomers of a series of carboxylic acid in the (1)H NMR spectra.  相似文献   

9.
A series of complexes, [M(bpy)(SAr)2] (M = platinum(II) or palladium(II), bpy = 2,2'-bipyridine, SAr = 2- or 4-(acylamino)benzenethiolate, or 2-(alkylcarbamoyl)benzenethiolate), were synthesized and characterized on the basis of 1H NMR, IR, and electrochemical properties. The structures of [Pt(bpy)(S-2-Ph3CCONHC6H4)2] (1) and [Pt(bpy)(S-2-t-BuNHCOC6H4)2] (3) were determined by X-ray analysis. The complexes have intramolecular NH...S hydrogen bonds between the amide NH group and the sulfur atom. A weak NH...S hydrogen bond in these complexes and [Pd(bpy)(S-2-Ph3CCONHC6H4)2] (4) is detected from the 1H NMR spectra and the IR spectra in chloroform and in the solid state. [Pt(bpy)(S-2-Ph3CCONHC6H4)2] (1) exhibits a remarkably high-energy-shifted lowest-energy band in UV-visible spectra and has a positively shifted oxidation potential. The blue-shift of 42 nm and the positive shift of +0.24 V, as compared to those of [Pt(bpy)(SC6H5)2), are due to the effect of the NH...S hydrogen bond.  相似文献   

10.
Zhou L  Lin Z  Reamer RA  Mao B  Ge Z 《Electrophoresis》2007,28(15):2658-2666
Optical pure (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid, a chiral crown ether, was successfully used as a chiral selector for the stereoisomeric separation of numerous real pharmaceutical compounds. Both practical and mechanistic aspects were described. Effects of chiral selector concentration under different pH values of BGE were discussed. Chiral recognition for the enantiomeric compounds with (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was investigated through model compounds using CE and infrared spectroscopic techniques. Relations between the enantioselectivity of the chiral crown ether and the structural features of the studied compounds were also investigated. Unusual resolutions of compound-p and its enantiomer as well as compound-o and its 2b epimer were described. These compounds contained only tertiary amine, believed to be nonbinding with crown ethers in general. The possible mechanisms for the interaction between compound-o and the chiral crown ether were investigated using CE, electrospray MS (ESI-MS), and proton ((1)H) NMR spectroscopy. All experiments provided clear evidence that binding between compound-o and the chiral crown ether had occurred. ESI-MS spectra indicated that the complexes had a 1:1 stoichiometric ratio. The advantages and disadvantages of using chiral crown ether for stereoisomeric separations were compared with those using sulfated CDs.  相似文献   

11.
The addition reactions of the 16e half-sandwich complexes [M(eta5-Cp*)[E2C2(B10H10)]] (Cp*=pentamethylcyclopentadienyl: 1S: E=S, M=Rh; 2S: E=S; M=Ir; 2Se: E=Se, M=Ir) and [M(eta6-p-cymene)[S2C2(B10H10)]] (p-cymene=4-isopropyltoluene; 3S: M=Ru; 4S: M=Os), with acetylene, propyne, and 3-methoxypropyne lead to the 18e complexes 5-19 with a metal-boron bond in each case. The reactions start with an insertion of the alkyne into one of the metal-chalcogen bonds, followed by B-H activation, transfer of one hydrogen atom from the carborane via the metal to the terminal carbon of the alkyne, and concomitant ortho-metalation of the carborane. The E-eta2-CC and the C(1)B units are arranged either cisoid or transoid at the metal. X-ray structural analyses are reported for one of the starting 16e complexes (4S), the cisoid complex 12S (from 2S and HC[triple bond]C-CH3), and the transoid complexes 9S and 14S (from 1S and HC[triple bond]C-CH2OMe, and from 3S and HC[triple bond]CH, respectively). All new complexes 5-19 were characterized by NMR spectroscopy (1H, 11B, 13C, and 77Se and 103Rh NMR spectroscopy when appropriate).  相似文献   

12.
本文合成了9种含有由天然D( )鄄樟脑衍生的1R,3S鄄1,2,2鄄三甲基鄄1,3鄄环戊二胺(A)为配体的铂髤配合物[Pt髤AX]{其中,X=(CH2)3C(COO-)2(1,1鄄环丁烷二羧酸根),2CH3OCH2COO-,2CH3CH2OCH2COO-,2CH3(CH2)3OCH2COO-,[OCH(CH3)COO]2-(乳酸根),(OCH2COO)2-(乙醇酸根),2CH3OCH2CH2OCH2COO-,2CH3CH2OCH2CH2OCH2COO-和2CH3(CH2)3OCH2CH2OCH2COO-}。通过元素分析、热重分析、红外光谱、1H核磁共振谱和电喷雾质谱等对配合物进行了表征。体外生物活性测试表明,部分配合物对A549人肺癌细胞和HCT鄄116人结肠癌细胞具有较强的抗肿瘤活性。  相似文献   

13.
The ligation properties of three new upper-rim-substituted calix[4]arene ligands, 5,17-bis(hydroxymethyl)-tetra-n-butoxycalix[4]arene ((HOCH2)2-nBu4Clx, 7), 5,17-bis((diphenylphosphinito)methoxy)-tetra-n-butoxycalix[4]arene ((PPh2OCH2)2-nBu4Clx, 8), and 5,17-bis((diphenylphosphino)methyl)-tetra-n-butoxycalix[4]arene ((PPh2CH2)2-nBu4Clx, 10) are reported herein. The newly prepared compounds differ from previously reported diametrically substituted calix[4]arene derivatives in that the lower-rim substituent was n-butyl. The presence of this lower-rim substituent did not reduce the inherent crystallinity of these complexes as purification of all materials occurred via simple crystallizations. The key precursor for the syntheses of 8 and 10 was 7, acquisition of which occurred in six steps starting from tetra-tert-butylcalix[4]arene, 1. Calix[4]arene derivatives include, tetra-n-butoxycalix[4]arene (nBu4Clx, 3), 5,11,17,23-tetrabromo-tetra-n-butoxycalix[4]arene (Br4-nBu4Clx, 4), 5,17-dibromo-tetra-n-butoxycalix[4]arene (Br2-nBu4Clx, 5), 5,17-bis(formyl)-tetra-n-butoxycalix[4]arene ((CHO)2-nBu4Clx, 6), and 5,17-bis(chloromethyl)-tetra-n-butoxycalix[4]arene ((ClCH2)2-nBu4Clx, 9), all of which were synthesized using modifications of existing procedures. Characterization of all compounds occurred, when possible, using 1H, 13C, and 31P NMR, elemental analyses, FAB-MS, ESI-MS, FT-IR, and X-ray crystallography. The solid-state structures of all calix[4]arene intermediates and ligands showed that the annulus adopted the pinched-cone conformation in which the average C(5)...C(17) intraannular separation was 4.5 +/- 0.4 A. Reaction of 7 with CpTiMe3 yielded the cis-chelate, CpTi(Me)[(OCH2)2-nBu4Clx] (11), quantitatively. Data obtained using ESI-MS (positive-ion mode) confirmed the monomer formulation showed above, and 1H NMR spectra provided sufficient information to deduce the nature of the Ti coordination sphere. Reaction of 8 with cis-Cl2Pd(NCPh)2 in refluxing benzene afforded cis-Cl2Pd[(PPh2OCH2)2-nBu4Clx] (12) in good yields. The monomeric identity of this compound was verified by both X-ray crystallography and positive-ion ESI-MS. The cis-bidentate calix[4]arene ligand did not undergo any noticeable contortion upon chelation of the PdCl2 fragment. Acid-promoted decomposition of 12 occurred in the presence of adventitious HCl and gaseous HCl, and the products of this decomposition were 9 and [mu2-ClPd(PPh2OH)(PPh2O)]2. In addition, chelates of 8 that contained Mo(CO)3L (L = NCMe (14a), NCEt (14b), and CO (14c)) showed that the mode of coordination was relatively insensitive to the identity of the metal. X-ray crystallography afforded views of the solid-state structures of 14b,c and, like 12, showed that the Mo(CO)3L fragment resided above the pinched-cone of the calix[4]arene. 1H NMR revealed that C-H/pi interactions existed between L (14a,b) and a phenyl ring of the coordinated phosphinite. Finally, the bis(diphenylphosphine)calix[4]arene ligand (10) readily coordinated the Mo(CO)3L species, but the reaction did not go to completion, as evidenced by 1H NMR, even after a 5 day reaction time. Data suggest that the product is similar to that observed for 12 and 14, but the incomplete reaction complicated attempts to obtain pure material and prohibited definitive assignment of the coordination array.  相似文献   

14.
A novel series of bis(carbamoylthiophenolato)mercury(II) complexes, [Hg(S-RNHCOC6H4)2] (1, R = 2-t-Bu; 2, R = 2-CH3; 3, R = 2-C6H5CH2; 4, R = 4-t-Bu), and a tetrakis(carbamoylthiophenolato)mercury(II) complex, (NEt4)2[Hg-(S-2-CH3NHCOC6H4)4] (5), were synthesized and characterized by 1H NMR, IR, 199Hg NMR, and crystallographic analyses. The bis(carbamoylthiophenolato)mercury complexes 1-3 do not have intramolecular NH...S hydrogen bonds between the amide NH group and the sulfur atom coordinated to mercury, whereas the tetrakis(thiophenolato)mercury complex 5 does have an intramolecular NH...S hydrogen bond. A relatively weak NH...S hydrogen bond in 5 can be seen in the 1H NMR spectra and the IR spectra in chloroform and in the solid state. The 199Hg NMR spectra in bis(carbamoylthiophenolato)mercury complexes 1-4 show a downfield shift, with an increase in the flow of electrons to mercury(II) from the oxygen atom due to the intramolecular Hg...O bonding interaction. Conversely, the 199Hg NMR spectra in 5 show a high-field shift with a decrease in the flow of electrons to mercury(II) from the sulfur atom due to the intramolecular NH...S hydrogen bond.  相似文献   

15.
以3,5-二甲基苯胺和2-莰酮为起始原料,在微波促进下,经缩合反应制得N-(3,5-二甲基苯基)-1-(1S,4S)-1,7,7-三甲基二环[2.2.1]庚烷-2-亚胺(1);1经硼氢化钠还原后再与羟胺-O-磺酸经胺化反应合成了1-(3,5-二甲基苯基)-1-[(1S,4S)-1,7,7-三甲基双环[2.2.1]庚烷-2-基]肼,总收率70.4%,其结构经1H NMR和ESI-MS确证。  相似文献   

16.
合成了2个新配体4-(4-硫代乙酸)甲苯基-6-苯基-2,2'-联吡啶HC^N^N(PhCH2SCOCH3)(L3)和6-(4-硫代乙酸)甲苯基-2,2'-联吡啶 HC^N^N (CH2SCOCH3)(L5)及其发光的铂(Ⅱ)配合物ClPtC^N^N(PhCH2SCOCH3)(C3)和ClPtC^N^N(CH2SCOCH3)(C5). 通过1H NMR谱和质谱对它们的结构进行了表征, 采用X射线单晶衍射分析确定了C3的晶体结构. 利用紫外-可见吸收光谱、 发射光谱及激发态寿命测定研究了它们的光物理性质和电化学性质, 以及配合物作为光敏剂在光催化制氢中的应用. 通过系列配合物产氢效率的比较, 揭示了它们的产氢效率和激发态寿命的关系.  相似文献   

17.
Various noncovalent complexes between native and derivatized cyclodextrins (CDs) and barbiturates were studied using capillary electrophoresis (CE) and electrospray ionization mass spectrometry (ESI-MS). This paper involves the study of four aspects of CD-barbiturate noncovalent inclusion complexes. The first study focused on determining the formation of CD-barbiturate inclusion complexes in ESI-MS. This determination was accomplished by the comparison of migration data from CE with ESI-MS inclusion complex peak abundances, which were found to be complementary. The second study found the possibility of predicting native beta-CD mediated CE elution orders for barbiturates using data from ESI-MS. A third study focused on the formation of barbiturate inclusion complexes with derivatized beta-CD and gamma-CD. As part of this study, the effect of the extent of side chain substitution on native CD complexation behavior was investigated. The results indicated that the number of side chains on the CD does not affect the formation of barbiturate complexes with the hydrophobic CD cavity. Finally, a comparison of the hydroxypropyl-beta-CD-barbiturate and hydroxypropyl-gamma-CD-barbiturate complexes in CE and ESI-MS was made to study the relationship between strength of drug-CD binding and enantioresolution. The results from the above studies indicated that the gas phase and the solution state complexes showed comparable behavior indicating that similar interactions played a role in stabilizing these complexes. While it was possible to use the ESI-MS data to determine drug binding to the CDs, it was not possible to predict whether a separation of the enantiomers of a chiral barbiturate would occur. However, the ESI-MS data could be used to eliminate certain CDs from consideration as chiral selectors.  相似文献   

18.
本文讨论了样品浓度对苯并氮杂冠醚化合物-氘代氯仿溶液~1H NMR镨及~1H纵向弛豫时间的影响(稀释位移效应)。在实验基础上提出了苯并氮杂冠醚化合物在氯仿中的叔胺-叔铵盐交换作用机制。以此馐土讼∈臀灰菩в? 并得到巳止诿鸦衔锎邮灏返绞屣а蔚姆从ζ胶獬J齂_2和交换速率常数k, 另外, 本文还讨论了冠醚环中氮原子上取代基对稀释位移效应的影响,  相似文献   

19.
王鹏鹏  李亮  付明伟  葛敏 《合成化学》2016,24(8):735-740
以7-羟甲基-1-四氢萘酮和1-溴-4-氯-苯甲醛为起始原料,经14步反应合成了抗丙肝新药维拉帕维--甲基(2S)-1-【(2S,5S)-2-【9{2[(2S,4S)-1-(2R)-2-[(甲氧基羰基)氨基]-2-苯乙酰基-4-(甲氧基甲基)吡咯烷-2-基]-1H-咪唑 5 基} 1,11-二氢异色烯[4′,3′ :6,7]萘并[1,2-d]咪唑-2-基-5-甲基吡咯烷-1-基】-3-甲基-1-氧丁烷-2-基】氨基甲酸酯,总产率10.14%,其结构经1H NMR和ESI-MS确证。  相似文献   

20.
To provide precedents for the possible interactions of platinum DNA adducts with zinc finger proteins, the complexes [Pt(dien)Cl]Cl (dien = diethylenetriamine) and [Pt(terpy)Cl]Cl (terpy = 2,2':6',2'-terpyridine) were exposed to the N,N'-bis(2-mercaptoethyl)-1,4-diazacycloheptanezinc(II) dimer, [Zn(bme-dach)]2, and the products defined by electrospray ionization mass spectrometry (ESI-MS), X-ray crystallography and (195)Pt NMR spectroscopy. The presence of a leaving chloride in both platinum(II) complexes facilitates electrophilic substitution involving sulfur-containing zinc finger synthetic models or, as in previous studies, zinc finger peptidic sequences. Monitored via ESI-MS, both reactants yielded evidence for Zn-(mu-SR)-Pt bridges followed by zinc ejection from the N2S2 coordination sphere and subsequent formation of a trimetallic Zn-(mu-SR)2-Pt-(mu-SR)2-Zn-bridged species. The isolation of Zn-(mu-SR)-Pt-bridged species [(Zn(bme-dach)Cl)(Pt(dien))]Cl is, to our knowledge, the first Zn-Pt bimetallic thiolate-bridged model demonstrating the interaction between Zn-bound thiolates and Pt(2+). In the case of the [Pt(terpy)Cl]Cl reaction with the [Zn(bme-dach)]2, ESI-MS analysis further suggests metal exchange by formation of [Zn(terpy)Cl](+), whereas the [Pt(dien)Cl]Cl reaction does not yield the corresponding [Zn(dien)Cl](+) ion. Direct synthesis of the Zn-Pt thiolate-bridged species and the Pt(N2S2) chelate, where Pt has displaced the Zn from the chelate core, permitted the isolation of X-ray-quality crystals to confirm the bridging and metal-exchanged structures. The ESI-MS, (195)Pt NMR spectroscopy, and molecular structures of the di- and trinuclear complexes will be discussed, as they provide insight into the metal-exchange mechanism.  相似文献   

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