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1.
IntroductionSincethepioneerworksofClearfieldandcoworkersinthe 196 0s ,1,2 layeredmetalphosphateshaveattractedmuchattentionduetotheirapplicationsonionex change ,intercalation ,heterogeneouscatalysisandsorp tion .3 7Amongthenumerouslamellarphases ,theproto typical…  相似文献   

2.
李宝龙  徐艳  刘琦  王化勤  徐正 《中国化学》2002,20(2):187-190
IntroductionCrystalengineeringofsupramoleculararchitecturessustainedbycoordinatecovalentbondsorhydrogenbondsrepresentsarapidlyexpandingfieldthatofferspo tentialfordevelopmentofnewclassesoffunctionalsolids .1,2 Thearchitecturesofcoordinationpolymerscanbe…  相似文献   

3.
1 INTRODUCTIONOneofourcurrentinterestsfocusesonthedesignandsynthesesofpolyazamacrocyclicligands,andthestabilitiesofcorrespondingmetalcomplexes.Twopolyazadiphenolmacrocycles,R(babp) 2 (dfc) 2 andR (bac) 2 (dfp) 2 ;[1 ]oneoctaaza macrocycle,BPBD ;[2 ,3]andseveralhexaazama…  相似文献   

4.
Polyoxometalates (POMs)containingKegginmoi etieshavebeenreceivingextensiveattentioninrecentyearsowingtotheirgreatfundamentalandpracticalinter est .1Especiallytheunusualelectronicproperty (highnegativecharges) ,oneofthemostimportantpropertiesofPOMs ,haspoten…  相似文献   

5.
IntroductionThesupramolecularcomplexeformedbytheweakinteractions (electrostaticinteraction ,hydrogenbonds ,vanderWaalsforce ,short rangeexclusionforce ,etc .)ofmorethantwosortsofspeciesisanorganizingentitythatusuallypossessesspecialstructureandfunction .1Sup…  相似文献   

6.
王瑞虎  洪茂椿  翁家宝  曹荣  罗军华 《中国化学》2002,20(10):1124-1128
IntroductionDesignandsynthesesofnovelsupramolecularcom plexeswithunusualandtailorablestructuresarefunda mentalstepsindiscoveryandfabricationofvarioustech nologicallyusefulfunctionalsupramoleculardevices .1 3Recently ,considerableeffortshavebeendevotedtocr…  相似文献   

7.
IntroductionResss[1,2]recentstudyresultsshowthattheFeMo-cofactorconsistsoftwocubanefrag-ments[Fe4S3]and[Fe3MoS3]boundbythree...  相似文献   

8.
1 INTRODUCTIONCertaincoppercomplexeshavebeenshowntohaveunusualchemicalpropertiessuchasoxygentransfer,oxidativeadditionandhomogenouscatalytichydrogenation[1].Oxidativeadditionreactionsarekeystepsintheactivationofσbondsinagreatnumberofcatalyticprocess.Cop…  相似文献   

9.
刘志宏  高世扬  胡满成  夏树屏 《中国化学》2002,20(12):1519-1522
IntroductionTherearemanykindsofmagnesiumborates ,bothnaturalandsynthetic .Aboratedoublesalt (2MgO·2B2 O3 ·MgCl2 · 14H2 O)namedchloropinnoitewasob tainedfromthenaturalconcentratedsaltlakebrine .1Inordertofindtheformingrelationbetweenthedoublesaltandmagnesium bora…  相似文献   

10.
Recentprogressinsurfacespectroscopyandmolecularbeamscatteringanddetectiontechniquesmakesitnowpossibleatthemicroscopicleveltoaccuratelymeasuresuchthingsasdissociationrates,adsorbatebindingandgeometry,andmobilitiesofadsorbedspeciesonsurfaces.Thiskindofe…  相似文献   

11.
The reaction of 1H‐tetrazole‐1‐acetic acid (Htza) and perchloric acid with cuprous chloride with slow evaporation at room temperature gave a novel 3D porous CuII coordination polymer, [Cu2(tza)4] · ClO4 · 4H2O ( 1 ), (tza = tetrazole‐1‐acetate). The structure exhibits an unusual 3D microporous coordination framework built up by four coordinated CuII nodes and bidentate bridging tza ligands with lvt‐type topology. Furthermore, the magnetic properties of complex 1 were also investigated.  相似文献   

12.
An efficient synthesis of 2‐substituted benzoxazoles through RuCl3·3H2O catalyzed, air oxidized tandem reactions of 2‐aminophenols and aldehydes in [bmim]BF4 was developed. This synthetic strategy has such advantages as mild reaction conditions, cost‐free oxidant, readily available starting materials, and recyclable catalyst and solvent. As an application, it was successfully used in the synthesis of the unreported 5‐(benzoxazol‐2‐yl)‐2′‐deoxyuridines with potential biological activities.  相似文献   

13.
Water‐rich aluminium halide hydrate structures are not known in the literature. The highest known water content per Al atom is nine for the perchlorate and fluoride. The nonahydrate of aluminium bromide, stable pentadecahydrates of aluminium chloride, bromide and iodide, and a metastable heptadecahydrate of the iodide have now been crystallized from low‐temperature solutions. The structures of these hydrates were determined and are discussed in terms of the development of cation hydration spheres. The pentadecahydrate of the chloride and bromide are isostructural. In AlI3·15H2O, half of the Al3+ cations are surrounded by two complete hydration spheres, with six H2O in the primary and 12 in the secondary. For the heptadecahydrate of aluminium iodide, this hydration was found for every Al3+.  相似文献   

14.
In the title coordination polymer, catena‐poly[[dichloridomanganese(II)]‐μ‐1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azaniumylylidene)]dibut‐1‐en‐1‐olate‐κ2O:O′], [MnCl2(C26H30N2)]n, synthesized by the reaction of the chiral Schiff base ligand 1,1‐diphenyl‐3,3′‐[(1R,2R)‐cyclohexane‐1,2‐diylbis(azanediyl)]dibut‐2‐en‐1‐one (L) with MnCl2·4H2O, the asymmetric unit contains one crystallographically unique MnII ion, one unique spacer ligand, L, and two chloride ions. Each MnII ion is four‐coordinated in a distorted tetrahedral coordination environment by two O atoms from two L ligands and by two chloride ligands. The MnII ions are bridged by L ligands to form a one‐dimensional chain structure along the a axis. The chloride ligands are monodentate (terminal). The ligand is in the zwitterionic enol form and displays intramolecular ionic N+—H...O hydrogen bonding and π–π interactions between pairs of phenyl rings which strengthen the chains.  相似文献   

15.
The title compound, lithium magnesium chloride heptahydrate, LiCl·MgCl2·7H2O, was analyzed in 1988 by powder X‐ray diffraction [Emons, Brand, Pohl & Köhnke (1988). Z. Anorg. Allg. Chem. 563 , 180–184] and a monoclinic crystal lattice was determined. In the present work, the structure was solved from single‐crystal diffraction data. A trigonal structure was found, exhibiting a network structure of Mg(H2O)6 octahedra and Li(H2O)Cl3 tetrahedra connected by H...Cl hydrogen bonds. The [Li(H2O)]+ unit is coordinated by distorted edge‐connected Cl octahedra.  相似文献   

16.
杨颙  张为俊  高晓明 《中国化学》2006,24(7):887-893
A theoretical study on the blue-shifted H-bond N-H…O and red-shifted H-bond O-H…O in the complexHNO…H_2O_2 was conducted by employment of both standard and counterpoise-corrected methods to calculate thegeometric structures and vibrational frequencies at the MP2/6-31G(d),MP2/6-31 G(d,p),MP2/6-311 q G(d,p),B3LYP/6-31G(d),B3LYP/6-31 G(d,p) and B3LYP/6-311 G(d,p) levels.In the H-bond N-H…O,the calcu-lated blue shift of N-H stretching frequency is in the vicinity of 120 cm~(-1) and this is indeed the largest theoreticalestimate of a blue shift in the X-H…Y H-bond ever reported in the literature.From the natural bond orbital analy-sis,the red-shifted H-bond O-H…O can be explained on the basis of the dominant role of the hyperconjugation.For the blue-shifted H-bond N-H…O,the hyperconjugation was inhibited due to the existence of significant elec-tron density redistribution effect,and the large blue shift of the N-H stretching frequency was prominently due tothe rehybridization of sp~n N-H hybrid orbital.  相似文献   

17.
The reaction of 3, 4‐dihydro‐6‐methyl‐3‐thioxo‐1, 2, 4‐triazin‐5(2H)‐one (6‐aza‐2‐thiothymine, AAT, 1 ) with copper(I) chloride in presence of hydrochloric acid in methanol gives the complex [{CuCl2(H2O)2(AT)}2] · 2H2O, 2 , AT = 6‐azathymine) in excellent yield. 2 was characterized by IR spectroscopy and elemental analyses as well as mass spectrometry. Also single‐crystal X‐ray diffraction studies on compound 2 revealed that AT acts as a monodentate ligand in the centrosymmetric binuclear complex via its oxygen atom. Crystal data for 2 at —80 °C: space group P21/c with a = 550.1(1), b = 2712.5(1), c = 729.7(1) pm, β = 95.99(1)°, Z = 2, R1 = 0.0213.  相似文献   

18.
Syntheses and Crystal Structures of the Rhenium(VII) Nitride Chlorides ReNCl4 and ReNCl4·H2O Rhenium(VII) nitride chloride, ReNCl4 ( 1 ) is obtained in form of brown needles with metallic luster by the reaction of ReCl5 with Cl3VNCl at 140 °C under vacuum in a sealed glass ampoule. It crystallizes in the tetragonal space group I4 with the lattice parameters a = 826.7(4), c = 405.1(2) pm, and Z = 2. The square pyramidal molecules are connected by asymmetric nitrido bridges to form chains along the crystallographic c axis. The shorter Re‐N distance of 163.0(5) pm corresponds to a triple bond, while the pronounced longer distance of 242.0(5) pm can be interpreted with a weak donor bond. The reaction of ReCl5 with VN at 170 °C under vacuum in a sealed glass ampoule yields red needles of ReNCl4·H2O ( 2 ). It crystallizes in the orthorhombic space group Pnma with a = 1075.4(2), b = 1108.5(2), c = 547.7(5) pm and Z = 4. The Re atoms exhibit a distorted octahedral coordination with the aqua ligand in trans position to the nitrido ligand. The Re‐N triple bond has a bond distance of 166.1(11) pm. The complexes are connected by hydrogen bridges O‐H···N to form chains.  相似文献   

19.
Novel method for the synthesis of 3‐acyl‐1,6‐dialkyl‐7‐methyl‐1,6‐naphthyridine‐2,5(1H,6H)‐diones (2) was developed. The reaction of 2‐acyl‐1‐alkylamino‐1‐ethoxyethylenes (1) with acetyl chloride or β‐keto amide 3 with acetyl chloride in the presence of p‐toluenesulfonic acid gave 2 in moderate yield (14‐59% yield).  相似文献   

20.
In the course of investigations relating to magnesia oxysulfate cement the basic magnesium salt hydrate 3Mg(OH)2 · MgSO4 · 8H2O (3–1–8 phase) was found as a metastable phase in the system Mg(OH)2‐MgSO4‐H2O at room temperature (the 5–1–2 phase is the stable phase) and was characterized by thermal analysis, Raman spectroscopy, and X‐ray powder diffraction. The complex crystal structure of the 3–1–8 phase was determined from high resolution laboratory X‐ray powder diffraction data [space group C2/c, Z = 4, a = 7.8956(1) Å, b = 9.8302(2) Å, c = 20.1769(2) Å, β = 96.2147(16)°, and V = 1556.84(4) Å3]. In the crystal structure of the 3–1–8 phase, parallel double chains of edge‐linked distorted Mg(OH2)2(OH)4 octahedra run along [–110] and [110] direction forming a pattern of crossed rods. Isolated SO4 tetrahedra and interstitial water molecules separate the stacks of parallel double chains.  相似文献   

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