Synthesis and nitration of calix[4] (aza)crowns

Calix[4] (aza) crowns containing amide groups 3a-d were synthesized by the reactions of calix[4]arene (1a) or p-tert-butylcalix[4]arene (1b) with N, N'-ethylenebis(2-chloroac-etamide) (2a) or N, N'-1,2-phenylenebis(2-chloroacetamide) (2b) by one step procedure in yields of 85-90% . Calix[4]-(aza) crowns 4a-b could be obtained by the reduction of 3a-b with LiAlH4 in yields of 51 and 67% , respectively. The nitration of 3a or 3c afforded new chromogenic calix[4]arenes 5a bearing two nitrophenol moieties and 5c bearing one nitro-phenol and one quinone moiety, respectively. The ipso-nitrations of 3b and 3d were also studied. Both gave the products containing one nitrophenol and one quinone moiety. Moreover, a very interesting calix[4]arene derivative 5d containing one cyclohexadienone moiety was also separated as the main product when 3d was ipso -nitrated.     

一对含有苯甲醛基修饰的杯芳烃异构体的晶体结构以及它们与铽离子配位的光物理性质

Two calix[4]arene isomers with benzaldehyde moieties, i.e., 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(o-formyl-phenoxy)ethoxy]-26,28-dihydroxycalix[4]arene (3) and 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(p-formylphenoxy)-ethoxy]-26,28-dihydroxycalix[4]arene (4), were synthesized according to a newly designed route in high yields, and their crystal structures have been determined by X-ray crystallographic study. The photophysical behavior on complexation of calix[4]arene derivatives 3 and 4 with terbium(Ⅲ) nitrate was investigated in anhydrous acetonitrile at 25℃ by UV-Vis and fluorescence spectroscopies. The crystallographic structure of 3 indicated that the eight oxygen atoms formed a preorganized ionophoric cavity due to intramolecular π-π stacking, which could encapsulate lanthanide ions tightly. In sharp contrast, the compound 4 formed a linear array by intermolecular π-π stacking, hence the oxygen atoms of pendant arms could not coordinate with metal ions, giving a poor binding ability to Tb^3 . The absorption spectra of 3 with Tb^3 showed clearly a new broad intense absorption at 385nm. Interestingly, the narrow emission line spectrum has also been observed for compound 3 with Tb^3 , and the results obtained were discussed from the viewpoint of energy transfer mechanism between host structures and the properties of lanthanide ions.     

Studies on Properties of p—Nitrophenylazo Calix[4]arene Derivatives

The p-nitrophenylazo calix[4] arene derivatives la-ld with nonlinear optical(NLO)properties were prepared by the diazo-coupling reaction of calix[4]arene with p-nitrophenyl diazonium.The diazotization reaction of p-nltroaniline was caried out with isoamyl nitrite as a source of nitrous acid in EtONa/EtOH under refluxing conditon.X-Ray crystallographic analysis and ^1H NMR sptectra reveal that they exist as cone conformation in crystal state or in soution.HRS measurements at 1064 nm in THF indicate that p-nitrophenylazo calix[4]arenes have higher hyperpolarizability βz values than the corresponding reference compound 4-(4-nitrophenylazo)-2,6-dimethyl-phenol,without red shift of the charge transfer band.The tetrakis p-nitropheylazo calix[4]arene(2)with longer alkyl chains can form monolayer aht the air/water interface.     

Synthesis and Structure of an Octopus-like Octapropargyl Tetra-iso-butyl-resorcin[4]arene

1 INTRODUCTION Resorcin[4]arene is a cyclic tetramer and can be easily obtained by acid-catalyzed condensation of resorcinol with a variety of aldehydes. The all-cis isomer with crown C4v symmetry is mostly isolated by means of alkyl aldehydes[1]. They have been used as starting materials for the synthesis of cavitands, velc-rands, and even more complex compounds like carce-rands, hemicarceracnds, and holands[2～4]. Of the ob-vious places for the chemical modification of reso-rcin[4]arene…     

Aminolysis reaction of calix [ 4 ] arene esters and crystal structures and conformational behaviors of calix[4]arene amides

We first make use of aminolysis of calix[4]arene esters to synthesize calix[4]arene amides. When the two ethyl esters of the calix[4]arene esters are aminolysized, the 1, 3-amide derivative is formed selectively. The crystal structures of the calix-[4]arene with two butyl amide (3b) and four butyl amide moieties (4b) were determined. The intermolecular hydrogen bonds make 4b form two-dimensional net work insolid state. The 1H NMR spectra prove that 3b is of a pinched cone conformation, while 4b and tetraheptylamide-calix[4]arene (6b) take fast interconversion between two C2v isomers in solution and appear an apparent cone conformation at room temperature. As decreasing temperature, the interconversion rate decreases gradually and, finally, the interconversion process is frozen at Tc = -10℃, which makes both conformations of 4b and 6b the pinched cone structures. The hydrogen bond improves the interconversion barrier, and the large different values of the potential barrier between 6b and 4b (or 6b) may     

Metal-organic supramolecular nanoarchitectures by Ru(Ⅱ)bis-(terpyridine)-bridged pillar[5]arene dimers with triphenylamine

A metal-organic photoinduced electron transfer(PET) supramolecular nanoarchitecture comprised of Ru(Ⅱ) bis(terpyridine)-modified pillar[5]arene(electron acceptor) and triazole triphenylamine amyl cyanide(electron donor) has been designed and constructed.Through the comparison of diverse solvents and acceptors,the two conditions,i.e.,modification of pillar[5]arene to donor and weak polar solvent are benefit for the occurrence of "efficient PET" because of shorter D-A distance in the presence of pillar[5]arene.Crucially,the fluorescence and PET process of the supramolecular assembly could be further modulated by solvent conversion and another competitive guest.The study provides a supramolecular method to design and construct tunable PET systems and PET-based smart materials.     

Synthesis of Schiff Base Calix [4] arene Crowns

This letter reports the synthesis of Schiff base calix [4] arene crowns containing m-xylylene phenol subunit, in which calix [4] arene Schiff base crowns 2a,2b and 2c were formed by 1:1 condensation of calix [4] arene diamine 1 with dialdehydes (2,6-diformyl-4-chlorophenol 3a,2,6-diformyl-4-methylphenol 3b,2,6-diformyl-4-tert-butylphenol 3c)under high dilute condition in refluxing anhydrous ethanol in 65-70% yield.     

Interaction and Interfacial Molecular Recognition of Calix[4] arene Derivatives Bearing Nucleobases for Complementary Nucleoside

The p-tert-butyl calix[4] arene derivatives la with uracils and 1b with adenines at the lower rim were synthesized.The Interaction between 1a and 1b in CDCl3 solution was demonstrated by ^1H NMR spectra.The interfacial molecular recognitions of la and 1b for the complementary nucleosides in aqueous subphases were investigated by Langmuir-Blodgett technique.     

An Interesting Approach to Bis-calix[5]arene Analogue from Calix[6]arene

Calix [n] arenas {n = 4, 6 or 8} are easily prepared from formaldehyde and para-substituted phenols via cyclic condensation under alkaline conditions in one step. It is not surprising that the calyx [n] arene (n = 4, 6, 8) chemistry has been developing very rapidly during the latest 20 years1. However, it is not the case for calixarenes with odd benzene rings (for example, n = 5). The yield of p-tert-butylcalix [5] arene synthesized in one-step from p-tert-butylphenol and formaldehyde was a…     

Synthesis and Conformational Properties of Bis（calix [4] arene）

The bis(calix [4] arene)3 was synthesized in moderate yield by the reaction of p-tert-butylcalix [4] arene (1) with 1,4-bis(chloromethyl) benzene (2). The conformation of all alkylated product 4 was investigated by the variable-temperature ^1H-NMR.     

Syntheses and structural characterization of trivalent lanthanide complexes of p-sulfonatothiacalix[4]arene

The X-ray crystallographic studies are reported for the water-soluble trivalent lanthanide complexes of the macrocyclic p-sulfonatothiacalix[4]arene [Gd(H₂O)₆((CH₃)₂SO)(p-sulfonatothiacalix[4]arene)]·H₃O⁺·5H₂O (1) and Na[Nd(H₂O)₆((CH₃)₂SO)(p-sulfonatothiacalix[4]arene)]·3H₂O (2). The complexes are isostructural and belong to monoclinic system, C2/m space group. The Ln³⁺ metal ion is coordinated by the thiacalixarene ligand via the sulfonato group, and also ligated by an oxygen atom of a dimethyl sulfoxide (DMSO) molecule that occupies the cavity of the thiacalixarene and six aqua ligands. The thiacalixarenes are linked by the coordinated water molecules through hydrogen bonding to form a 2D polymer. The p-sulfonatothiacalixarenes maintain the clay-like bi-layer structure in the coordination network.     

Second-sphere coordination in the complex [Mn(H2O)6]2[thiacalix[4]arene tetrasulfonate]

The title calixarene, dimanganese thiacalix[4]arene tetrasulfonate, was prepared and its crystal structure was determined. [Mn(H₂O)₆]₂[thiacalix[4]arene tetrasulfonate]·0.5H₂O crystallizes in the monoclinic system, P2(1)/m space group, with a=13.014 (6), b=14.146 (9), c=13.184 (7) Å, β=113.307 (10)°, V=2229 (2) Å³ and Dc=1.710 gcm⁻³, Z=2. The title calixarene exists in the solid state as bilayer structure. The hydrophobic organic layer consists of thiacalix[4]arene tetrasulfonate in an up-down fashion, whereas, the hydrophilic inorganic layer consists of hexaaquamanganese (II) which is linked to the former through a second-sphere coordination.     

Molecular, supramolecular structure and catalytic activity of transition metal complexes of phenoxy acetic acid derivatives

Six mononuclear complexes [M(L₁)₂(H₂O)₄] (M = Co(II), 1a and M = Mn(II), 1b), [Cu(L₁)₂(H₂O)₂] (1c), [Cu(L₁)₂(H₂O)(Py)₂] (1d), [Cu(L₃)(H₂O)Cl] · H₂O (3a) and [Co(Sal)(H₂O)(Py)₃] · 2ClO₄ · H₂O (3b) of phenoxyacetic acid derivatives and Schiff base were determined by single crystal X-ray diffraction. The Co(II) (1a) and Mn(II) (1b) complexes are isomorphous. X-ray crystal structural analyses reveal that these coordination complexes form polymeric structure via formation of different types of hydrogen bonding and π-stacking interactions in solid. Thermal analysis along with the powder X-ray diffraction data of these complexes shows the importance of the coordinated and/or crystal water molecules in stabilizing the MOF structure. Complexes 1a, 1c, 3a show marginal catalytic activity in the oxidation of olefins to epoxides in the presence of i-butyraldehyde and molecular oxygen.     

Characterization and crystal structures of copper(II), cobalt(II), and nickel(II) complexes with two kinds of piperidine carboxylic acids

Copper(II) complex with -piperidine-3-carboxylic acid ( -Hpipe-3):[Cu( -pipe-3)₂(H₂O)] and cobalt(II) and nickel(II) complexes with piperidine-4-carboxylic acid (Hpipe-4):[M(Hpipe-4)₂(H₂O)₄]Cl₂ (M: Co, Ni) have been prepared and characterized by means of IR and powder diffuse reflection spectra, thermal analysis, and magnetic susceptibility. The crystal structures of these complexes have been determined by X-ray diffraction. The crystal of [Cu( -pipe-3)₂(H₂O)] is orthorhombic with the space group Pbcn. The copper atom is in a square pyramidal geometry, ligated by two carboxylato oxygen atoms, two nitrogen atoms, and a water molecule. One molecule of this complex consists of either -piperidine-3-carboxylic acid or -piperidine-3-carboxylic acid. The crystals of [M(Hpipe-4)₂(H₂O)₄]Cl₂ are monoclinic with space group P2₁/n. In these complexes the metal atom is in an octahedral geometry ligated by two carboxylato oxygen atoms and four water molecules.     

基于磺酰基杯[4]芳烃的Co16笼簇的合成、结构及电化学性质

以氯化钴、 对叔丁基磺酰杯[4]芳烃(H₄TC4A-SO₂)和非对称性3-(1H-四唑-5-基)苯甲酸(H₂L)为原料, 通过溶剂热法合成了一个具有四面体配位笼结构的16核化合物[Co₁₆(TC4A-SO₂)₄(OH)₄(L)₈]·[(C₈H₂₀N)(C₄H₁₂N)₂(C₂H₈N)]·solvent(Co₁₆-TC4A-SO₂). 采用X射线单晶衍射、 X射线粉末衍射、 热重分析、 红外光谱方法对配合物进行了表征. 将Co₁₆-TC4A-SO₂笼簇直接负载到碳纸上(Co₁₆-TC4A-SO₂/CP)用作工作电极, 其对析氧反应(OER)展现出较好的催化性能. 在1 mol/L KOH中, Co₁₆-TC4A-SO₂/CP在343.8 mV的过电位下达到10.0 mA/cm ²电流密度, Tafel斜率为79.31 mV/dec, 并且在20.0 mA/cm ²电流密度下表现出长达48 h的催化稳定性.     

新型磷-钒-氧层状化合物[H2en]2[H3O]6[Co(H2O)2(VO)8(OH)4(PO4)8]的水热合成与晶体结构

金属磷酸盐材料在吸附、离子交换、离子传导和催化剂方面有潜在的应用前景[1～5]. 近年来, 通过水热反应合成了一些A-V-P-O化合物. 在这些化合物中, A一般为碱金属或有机阳离子, 如层状结构的[H2N(C4H8)2NH2][(VO)4(OH)4(PO4)2][6] 和[H2N(C2H4)3NH2][(VO)8(HPO4)3(PO4)4*(OH)2]*2H2O[6], 一维链状结构的 [H2NCH2CH2NH3(VO)(PO4)][7], 手性双螺旋结构的 [(CH3)2NH2]K4[(VO)10(H2O)2(OH)4(PO4)7]*H2O[8]以及具有三维骨架结构的化合物 [H3N(CH2)3NH3K(VO)3(PO4)3][9], [H3N(CH2)3NH3]2[V(H2O)2(VO)6(OH)2(HPO4)3(PO4)5]*3H2O[10]和[H3N(CH2)2NH3][(VO)3(H2O)2(PO4)2(HPO4)4][11].     

Rhodium complexes with dioximes as catalysts of hydroformylation and hydrogenation of 1-hexene

Rhodium(II) complexes with dioximes [Rh(Hdmg)₂(PPh₃)]₂ [I] (Hdmg=monoanion of dimethylglyoxime) and [Rh(Hdmg)(ClZndmg)(PPh₃)]₂ [II] catalyse hydroformylation and hydrogenation reactions of 1-hexene at 1 MPa CO/H₂ and 0.5 MPa H₂ at 353 K, respectively. Hydroformylation with complex [I] produces 94% of aldehydes (n/iso=2.2) and 6% 2-hexene whereas the second catalyst [II] gives ca. 40% of aldehydes (n/iso=2.1) and 60% of 2-hexene. Corresponding Rh(III) complexes are inactive in hydroformylation except of RhH(Hdmg)₂(PPh₃) [III], which shows activity similar to [I]. Complexes [Rh(Hdmg)₂(PPh₃)]₂ [I], [Rh(Hdmg)(ClZndmg)(PPh₃)]₂ [II], RhH(Hdmg)₂(PPh₃) [III] and [Rh(Hdmg)₂(PPh₃)₂]ClO₄ [V] catalyse 1-hexene hydrogenation with an average TON ca. 18 cycles/mol [Rh]×min. Complex [II] has also been found to catalyse hydrogenation of cyclohexene, 1,3-cyclohexadiene and styrene.     

Neutral pyridylmethylamide ligands and their mononuclear copper(II) complexes

Mononuclear copper(II) complexes of a family of pyridylmethylamide ligands HL, HL^Me, HL^Ph, HL^Me3 and HL^Ph3, [HL = N-(2-pyridylmethyl)acetamide; HL^Me = N-(2-pyridylmethyl)propionamide; HL^Ph = 2-phenyl-N-(2-pyridylmethyl)acetamide; HL^Me3 = 2,2-dimethyl-N-(2-pyridylmethyl)propionamide; HL^Ph3 = 2,2,2-triphenyl-N-(2-pyridylmethyl)acetamide], were synthesized and characterized. The reaction of copper(II) salts with the pyridylmethylamide ligands yields complexes [Cu(HL)₂(OTf)₂] (1), [Cu(HL^Me)₂](ClO₄)₂ (2), [Cu(HL)₂Cl]₂[CuCl₄] (3), [Cu(HL^Me3)₂(THF)](OTf)₂ (4), [Cu(HL^Me3)₂(H₂O)](ClO₄)₂ (5a and 5b), [Cu(HL^Ph3)₂(H₂O)](ClO₄)₂ (6), [Cu(HL)(2,2′-bipy)(H₂O)](ClO₄)₂ (7), and [Cu(HL^Ph)(2,2′-bipy)(H₂O)](ClO₄)₂ (8). All complexes were fully characterized, and the X-ray structures vary from four-coordinate square-planar, to five-coordinate square-pyramidal or trigonal-bipyramidal. The neutral ligands coordinate via the pyridyl N atom and carbonyl O atom in a bidentate fashion. The spectroscopic properties are typical of mononuclear copper(II) species with similar ligand sets, and are consistent their X-ray structures.     

Solvothermal syntheses and crystal structures of two metal coordination polymers with double-chain structures

Two polymeric complexes, [Cu₂(btec)(phen)₂]_n·(H₂O)_n (1) and [Cd₄(btec)₂(phen)₄(H₂O)₄]_n (2) (H₄btec=1,2,4,5-benzenetetracarboxylic acid; PHEN=1,10-phenanthroline), were synthesized by solvothermal reactions at 140 °C. Both complex 1 and 2 possess infinite double-chain structures, in which each Cu(II) center has a tetrahedral configuration and the Cd(II) centers adopt triangular prismatic and square-based pyramidal configurations simultaneously. The inter-chain face to face π–π interactions among the aromatic rings of phen and the hydrogen bond interactions between aqua molecules and carboxyl O atoms result in 3-D networks in the two complexes. The ESR spectra study of complex 1 shows that there is negligibly small long-range super-exchange interactions between the Cu(II) atoms via benzenecarboxylate bridging.     

Coordination geometry of tetradentate Schiff’s base nickel complexes: the effects of donors, backbone length and hydrogenation

The X-ray crystal structures of (N,N′-bis-(o-amidobenzilidene)-1,3-diaminopropane)nickel (Niambpr), (N,N′-bis-(o-amidobenzilidene)-1,4-diaminobutane)nickel (Niambut), (N,N′-bis-(o-thiobenzilidene)-1,4-diaminobutane)nickel(II) (Nitsalbut), bis-acetonitrile-(N,N′-bis-(o-aminobenzyl)-1,2-diaminoethane) nickel(II) tetrafluoroborate [Ni(H₄amben)(MeCN)₂] [BF₄]₂, bis-O-acetato-(N,N′-bis-(o-aminobenzyl)-1,2-diaminoethane) nickel(II) [Ni(H₄amben)(OAc)₂ · H₂O] and bis-O-acetato-(N,N′-bis-(o-aminobenzyl)-1,3-diaminopropane) nickel(II) [Ni(H₄ambpr)(OAc)₂] are presented. These structures complete the structural characterisation of the simple unsubstituted Schiff’s base complexes with N₄ and N₂S₂ donor sets and allow us to assess the effects of donor groups and polymethylene chain length on the coordination geometries of nickel(II). The hydrogenated N₄ complexes offer an insight into the effects of increased flexibility and character of the internal nitrogen donors. Unlike the parent N₄ imine species the hydrogenated amine species do not deprotonate at the peripheral nitrogen donors and do not seem to be restricted to the meridial plane of the nickel.