首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
0IntroductionThemetalphosphonatechemistryhasbeenofin-creasinginterestinthepastdecadeduetotheirpoten-tialapplicationsinionexchanges,adsorptionsandsensors犤1~4犦.Anumberofphosphonatecompoundshavebeenprepared,amongwhichthecoppercompoundsareuniquebecauseoftheversatilecoordinationcapabilitiesofCuions犤5~7犦.Basedon1-hydroxyethylidenediphosp-honate犤hedp,CH3C(OH)(PO3)2犦,severalcopperph-osphonateshavebeenobtainedinourlaboratoryin-cluding犤NH3(CH2)2NH3犦Cu2(he…  相似文献   

2.
0IntroductionRecently,severalresearchgroupshaveemployedahybridapproach,inwhich犤M(CN)6犦n-buildingblockhavebeencombinedwithtransitionmetalionsorlanthanideionscomplexesinordertoexploitthefea-turesoftheligandsintheformationofdifferentstruc-tures犤1~8犦.Cyano-bridgedcomplexesaregenerallyob-tainedbyreactinghexacyanometalatewithmononuclearassemblercomplexinwhichsomeofthecoordinationsitescanbeoccupiedbysomeassistantligands(ortermsasthethirdligands).Severalcyano-bridgeddin-uclear…  相似文献   

3.
0IntroductionWhiskerswithhighaspectratiohavebeenexten-sivelyusedascompositematerialsinalloys,ceramics,cementandplastic犤1~5犦,sincetheyhavespecificdesirepropertiessuchashighmeltingpoint,lowdensityandhighmodulus犤6犦.Magnesiumoxysulfate(MOS)com-poundshowsthehighcrystallinityandaspectratiotomakeitapotentialreinforcingmaterialforplastics,resinandrubber犤7,8犦.Inpastyears,MgSO4·5Mg(OH)2·3H2Ohasbeensynthesizedbyhydrothermalreactionusingmagnesiumhydroxideandmagnesium…  相似文献   

4.
0IntroductionRareearthsarenowappliedwidelyinChina,whichcanimprovecropsyieldsandthetheirqualit-ies犤1犦.Thebeneficialeffectsmaybeduetothestimu-latoryeffectsoftheseelementsonthenutrientuptakebyplantsorontheincreasingofchlorophyllsynthesisintheplants犤2犦.Whilealotofresearcheshavebeendoneontheimprovednutritionofcropsafterapplica-tionofrareearths,muchlessattentionhasbeenpaidtothedeteriorationofsoilqualityduetotheapplicationofrareearthsforyears犤3犦.Scientistshavediscoveredthataccumula…  相似文献   

5.
正丁基黄原酸根合镉(Ⅱ)的合成和晶体结构   总被引:1,自引:0,他引:1  
黄原酸配合物以及它们与各种路易斯碱反应的产物得到广泛的研究犤1~4犦。可溶性的黄原酸碱金属盐广泛用于汞、银、镉等金属的萃取分离犤5~7犦,并且这类盐对于汞中毒具有解毒作用犤8犦。E.D.Zelmon等犤9犦对过渡金属黄原酸配合物的非线性光学性质进行了研究。但迄今为止,对黄原酸镉配合物与路易斯碱的反应与结构研究较少。我们首先合成了一种配位聚合物犤Cd(S2CO-n-C4H9)2犦n晶体,然后利用吡啶与犤Cd(S2CO-n-C4H9)2犦n反应破坏其原有配位聚合物的结构,得到了犤Cd(C5H5N)2(S2CO-n-C4H9)…  相似文献   

6.
钴是生物学上重要的微量元素,它能在一些酶中代替锌,而不改变原来酶的活性犤1犦,钴的光谱和磁性是酶活性部位的有效探针犤2犦。钴催化剂是单活性中心催化剂犤3犦,同时又是很好的乙烯齐聚催化剂犤4,5犦。β-二酮是重要的催化剂原料,徐德民等犤6犦报道了含有β-二酮金属配合物催化剂制备间规聚苯乙烯与聚丙烯共混复合物。宓霞等犤7犦报道了含β-二酮钛非茂催化剂催化降冰片烯聚合。近年来,已报道了一些β-二酮的Co?配合物犤8~10犦的晶体结构,本文报道两个β-二酮的Co?配合物的合成和晶体结构。1实验部分1.1配合…  相似文献   

7.
Awell-groundmixtureof犤NH4犦2犤MoS2O2犦,CuI,andEt4NBr,wasputintoareactiontubeandheatedat80℃for4hunderanitrogenatmosphere.AfterextractingtheresultantblacksolidwithCH3CN,theextractwasfilteredtoaffordadeepredfiltratewhichcontainsatwin-nestshapeinter-mediate犤NEt4犦4犤Mo2O2S6Cu6I4Br2犦1犤1犦.Twin-nestshapeproductsareinterestingbecausetheirbridgegroupscleavagecanincorporatedifferentligandsintotheclusterspecieswithinterestingskeletalstructures.Takingadvantageo…  相似文献   

8.
0IntroductionThereiscurrentlyintenseresearchinterestinde-velopingnewnonlinearmaterialswithhighthird-ordernonlinearopticaleffectsduetotheirpotentialapplica-tionsinanumberofimportanttechnologiesincludingopticalpowerlimitingforsensorprotection,opticalswitches,allopticalsignalprocessingandopticalcom-puting犤1~3犦.Metalcomplexeswithplanar,π-conjugatedtetradentateorbidentateligandareofparticularinterestbecausetheycontainbothelectronsthatarefreetomovewithintheπextendedsystemoftheligand…  相似文献   

9.
Zincisanecessarylifeelementinhumanbody.L-α-aminoacidisthebasicunitofproteinrelatedwithlife.L-α-Thr(Threonine),L-α-Phe(Phenylalanine),L-α-Val(Valine)andL-α-Met(Methionine)arein-dispensabletolifewhichhavetobeabsorbedfromfoodbecausetheycannotbesynthesizedinhumanbody.Thecomplexesofzincsaltswithα-aminoacidasad-ditivehaveawideapplicationinmedicine,foodstuffandcosmetics犤1~3犦.Thesynthesismethodsofthecom-plexesofzincsaltswithα-aminoacidhavebeenre-viewed犤…  相似文献   

10.
硒作为一种生命体所必须的微量营养元素,近年来由于其在防癌犤1,2犦和抗氧化,增强免疫力等方面的作用而越来越受到广泛的关注。其中L-硒代蛋氨酸(L-Se-MetH)作为一种有效的防癌剂正处在临床试验阶段犤2犦。对于硒代蛋氨酸在抑制癌细胞生长和在体内的抗氧化作用的机理已有很多报导犤3~5犦,但作为生物体的主要含硒氨基酸之一,与L-蛋氨酸(L-MetH)相比,它与金属离子的作用却少见报导犤6,7犦。本文利用电喷雾质谱(ESMS)和2D犤1H-15N犦HSQCNMR的手段研究了第二代铂类抗癌药物卡铂(犤Pt(NH3)2(CB…  相似文献   

11.
随着倍半锗氧类化合物的合成及应用研究的日益广泛,含Ge_O键的烃基锗衍生物的合成及应用也逐渐引起了人们的关注.1984年,Lukevics等[1]合成了具有抗癌活性的介吗川类化合物,1990年Kakimoto等[2]报道了具有杀菌活性的环状烃基羧酸的合成与应用.  相似文献   

12.
三苯基锗不饱和烃基酸衍生物的合成和性质   总被引:3,自引:0,他引:3  
随着倍半锗氧类化合物的合成及应用研究的日益广泛 ,含 Ge_ O键的烃基锗衍生物的合成及应用也逐渐引起了人们的关注 .1 984年 ,L ukevics等 [1]合成了具有抗癌活性的介吗川类化合物 ,1 990年Kakimoto等 [2 ] 报道了具有杀菌活性的环状烃基羧酸的合成与应用 .但是三烃基锗的膦酸类衍生物的合成及生物活性研究均未见文献报道 .为了研究该类化合物的生理活性 [3~ 5] ,本文以三苯基氯化锗和炔基 (烯基 )膦酸钠为原料 ,在苯中反应 ,合成了一系列双 - O- (三苯基锗 )炔基 (烯基 )膦酸酯和单 - O-三苯基锗炔基 (烯基 )膦酸 ,部分化合物初步生理…  相似文献   

13.
尹汉东  马春林 《合成化学》1999,7(3):235-237
由三苯基氯化猪与烯或炔基膦酸盐反应,合成了8种新的三苯基锗烯基或炔基膦酸衍生物,利用元素分析,IR和HNMR表征了这些化合物的结构  相似文献   

14.
Ten triphenylgermanium heteroaromatic carboxylates Ph3GeO2CR (where R=2‐furanyl, 2‐furanvinyl, 2‐(5‐tertbutyl) furanyl, 2‐thiophenyl, 2‐pyridinyl, 3‐pyridinyl, 4‐pyridinyl, 3‐indolyl, 3‐indolylmethyl, 3‐indolylpropyl) were synthesized by the reaction of sodium heteroaromatic carboxylates with the triphenylgermanium chloride. All compounds were characterized by elemental analysis, 1H NMR and MS spectra. The compounds were tested against two human tumour cell lines: MCF‐7 and WiDr. The results showed that they had high activities. The crystal structure of triphenylgermanium 2‐furoate was determined by X‐ray single crystal diffraction. The crystal belongs to monoclinic with space group P21/c, a = 1.1545(4), b=0.9934(3), c = 1.6284(5) nm, β= 91.59(5), Z = 4. In this crystal, the structure consists of discrete molecule containing four‐coordinate germanium atom in a distored tetrahedron.  相似文献   

15.
The triphenyl oxinates of the group 14 elements (M = Si, Ge, Sn, and Pb) contain the 8-hydroxyquinoline ligand (HOx), which can function in either a bidentate or monodentate fashion. The compounds Ph3MOx were prepared by reaction of the triphenylmetal chloride with HOx in the presence of an HCl scavenger triethylamine or, sodium acetate, and in the case of lead, with the sodium salt of 8-hydroxyquinoline. The interaction of the nitrogen with the central atom was studied through the use of the NMR chemical shifts of the central metal atom and the 15N atom of the ligand. The chemical shifts of the central metal provided evidence that the triphenylgermanium and silicon oxinates are uncoordinated while the triphenyltin and lead oxinates are five-coordinate. These conclusions are confirmed by molecular modeling, 15N chemical shifts and the metal-13C one bond coupling constants at the ipso carbon. The NMR data provides evidence that the strength of the interaction of the nitrogen with the metal increases from silicon and germanium to lead. Two peaks in the 5-coordinate region of the 207Pb NMR spectra can be rationalized with the postulate that strong interaction with lead produces two geometrical isomers. Two peaks were also present in the 5-coordinate region of the 119Sn NMR spectra at low temperatures indicating a rapid exchange between the two geometrical isomers at room temperature.  相似文献   

16.
Microwave chemistry is a green chemical method that improves reaction conditions and product yields while reducing solvent amounts and reaction times. This paper deals with the synthesis, spectral and biological studies of germanium(IV) complexes with chelating hydrazones derived from 1‐(pyridine‐2‐yl)ethanone (F1) and 1‐(furan‐2‐yl)ethanone (F2) with isonicotinohydrazide (INH). The complexes have been synthesized under a microwave–green chemical approach and investigated using a combination of microanalytical analysis, melting point, IR spectra, 1H NMR spectra and 13C NMR spectra. Trimethylgermanium(IV)chloride and triphenylgermanium(IV)chloride interact with the hydrazones in a 1:1 molar ratio (metal:ligand), resulting in the formation of coloured products. On the basis of conductance and spectral evidence, a pentacoordinated structure for germanium(IV) complexes has been assigned for these products. The ligand is coordinated to the germanium(IV) via the azomethine nitrogen atom and the enolic oxygen atom. The free ligands and their metal complexes have been tested in male rats in order to assess their antifertility properties. Ligands and their metal complexes have also been tested in vitro against a number of pathogenic microorganisms in order to assess their antimicrobial and pesticidal properties. Both the ligands and their complexes were found to possess appreciable antifertility activity and other activities, which have been discussed in brief. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

17.
Transition-metal-catalyzed asymmetric carbon−carbon bond formation to forge phosphonates with an α-chiral carbon center through C(sp3)−C(sp3) and C(sp2)−C(sp3) couplings has been successful. However, the enantioselective C(sp)−C(sp3) coupling has not yet been disclosed. Reported herein is an unprecedented enantioconvergent cross-coupling of alkynyl bromides and α-bromo phosphonates to deliver chiral α-alkynyl phosphonates.  相似文献   

18.
D(CH2CH2S)2MSNH(C6H4) (M = Ge, Sn; D = O, S) spirocycles were synthesized to analyze the influence of the decrease of the radius of the metal and the change of the hardness of donor atom on the strength of the transannular bond and the hypercoordination of group 14 elements. The compounds were characterized by IR, Raman and NMR (1H, 13C and 119Sn) spectroscopy, EI mass spectrometry and elemental analysis. Monocrystal X-ray diffraction analyses were made for the germanium compounds. The germaspirocycles were five-coordinated and had distorted trigonal bipyramid geometry. In contrast with most of the reported analogous germocanes, the transannular bond is stronger when the donor atom is oxygen, rather than sulfur. O(CH2CH2S)2GeSNH(C6H4) exhibits an intramolecular hydrogen bond formation between the amine group and the transannular oxygen. The presence of this hydrogen bond determines whether the sulfur (O?Ge–S) or the nitrogen (S?Ge–N) of the five-member ring is the axial atom. According to the 119Sn chemical shift, both stannospirocycles were five-coordinated and therefore the presence of the transannular interaction in solution could be suggested.  相似文献   

19.
Abstract

Direct addition of organolithium to 1-alkynylphosphonates (1) afforded vinylphosphonates and enamine phosphonates (2) in good to excellent yields. The reaction was carried out in dry THF at low temperature and proved to be completely stereoselective (syn addition). Alkyl, aryl, and haloalkyl groups were attached to the alkynyl entity, so the resulting vinylphosphonates contained various functional groups. The stereochemistry of the products as well as mechanism of the reaction were determined based on 1H and 13C NMR. The synthesis of enamine phosphonates in the absence of complicated, highly expensive organometallic catalysis has not been previously reported.  相似文献   

20.
RHF/6-31G(d) and MP2/6-31G(d) calculations were carried out to study the stereoelectronic structure of 1-(1-trichlorogermylethyl)pyrrolidin-2-one with a pentacoordinated germanium atom. These results were compared with the X-ray diffraction structural analysis data. Upon formation of the Ge ← O coordination bond in this molecule, the electron density of all the atoms of the coordination polyhedron of the germanium atom, including the oxygen atom, increases, especially the axial chlorine atom, while the electron density of the germanium, nitrogen, and carbonyl group carbon atoms decreases. Different polarization of all three valence p-orbitals of each Cl atom of this molecule was established. 35Cl nuclear quadrupole resonance spectrum parameters were evaluated. The molecule also has stable form, in which the germanium atom is tetracoordinated. The total energy of this form is 2.7 kcal/mol higher than for the structure with a pentacoordinated germanium atom.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号