选择性合成三取代乙氧羰基甲氧基硫杂杯[4]芳烃

对叔丁基硫杂杯[4]芳烃与氯乙酸乙酯在K2CO3/丙酮体系中反应,选择性地合成了三取代乙氧羰基甲氧基硫杂杯[4]芳烃,产率78%,其结构经1H NMR,MS和元素分析表征.     

Self-assembly of [2]pseudorotaxanes based on pillar[5]arene and bis(imidazolium) cations

A simple bis(imidazolium) dication, 1,4-bis[N-(N'-hydroimidazolium)]butane, can act as a new template for formation of [2]pseudorotaxane with pillar[5]arene, in which the dethreading/rethreading process can be controlled by addition of base and acid. The effect on the association constant of both the solvent and counterion is also described.     

(1+1) or (2+2) Coupling for bis(tosyloxyethoxy)benzenes with calix[4]arene and thiacalix[4]arene

As bifunctional reagents, bis(tosyloxyethoxy)benzenes can react with p-tert-butylcalix[4]arene or p-tert-butylthiacalix[4]arene to afford intramolecularly bridged (1+1) or intermolecularly bridged (2+2) products. It was found that the bridging pattern strongly depended on the structure of bis(tosyloxyethoxy)benzene and the kind of calixarene. For the ortho-isomer of bis(tosyloxyethoxy)benzene, intramolecularly bridged calix[4]arene and thiacalix[4]arene were the main products. For the para-isomer, the bridging reaction was in a (2+2) fashion. As for the meta-isomer, double thiacalix[4]arene and intramolecularly bridged calix[4]crown were synthesized.     

Nitrogen heteroaromatic cations by [2+2+2] cycloaddition

A modular approach to the construction of monocationic quaternary N-heteroaromatic frameworks was developed capitalizing on a direct pyridine-type nitrogen quaternization followed by metal-catalyzed [2+2+2] cycloaddition with gaseous acetylene. The flexibility of the route is demonstrated on 12 diverse scaffolds based on pyridinium, quinolinium, thiazolium, benzothiazolium, imidazolium, and pyrimidinium. Electrochemical study revealed a quinolinium redox system with two electrochemically distinct forms that are interconverted by a homogeneous chemical reaction triggered by fast electron transfers (reduction at -0.7 V and oxidation at -0.05 V).     

Formal [(2+2)+2] and [(2+2)+(2+2)] nonconjugated dienediyne cascade cycloadditions

[reaction: see text] Fluoranthene 2 and heptacycle 3 are easily accessible from the reaction of diyne 1 and norbornadiene (NBD) in the presence of the rhodium catalyst. The unusual [(2+2)+(2+2)] adduct 3 was confirmed by the X-ray crystal structure analysis.     

Nanometer Channels and Cages within the Extended Basic Mercurous Cations [(Hg2)3(OH)2]4+ and [(Hg2)2O]2+

The two‐ and three‐dimensional mercurous cations [(Hg₂)₃(OH)₂]⁴⁺ and [(Hg₂)₂O]²⁺ crystallize with channels and cages of roughly 1 nm diameter from aqueous solutions dependent upon the acidity of the solution. Crystal structures were determined, for example, for [Zn(H₂O)₆][(Hg₂)₃(OH)₂](NO₃)₆ (trigonal, space group P321, a = 1183.5(2) pm, c = 534.8(1) pm, Z = 1, R1 = 0.0351 for I₀ > 2σ(I₀)) and for [(Hg₂)₂O][Pb(NO₃)₃]₂ (cubic, space group , a = 1543.1(2) pm, Z = 8, R1 = 0.0534 I₀ > 2σ(I₀)).     

Selective extraction of Fe3+ by a polymeric calix[4]arene

A polymeric compound containing more than one calixarene molecule was synthesized by reacting the oligomer ( 2 ) with 25,26,27-tribenzoyloxy-28-hydroxy calix[4]arene. After basic hydrolysis of 3a , the polymeric calixarene ( 3b ) was utilized for selective extraction of some metal cations from aqueous phase to organic phase. It was found that the compound ( 3b ) was selective toward Fe³⁺ from an aqueous solution containing Cu²⁺, Ni²⁺, Co²⁺ and Fe³⁺ cations. The mechanism of the extraction process was discussed. © 1994 John Wiley & Sons, Inc.     

Indium-sulfur supertetrahedral polymers integrated with [M(phen)3]2+ cations (M = Ni and Fe)

A series of supertetrahedral polymers of chalcogenometalates (T3 cluster compounds) integrated with M-phen complexes (phen =1,10-phenanthroline; M = Ni, Fe) was prepared by a similar solvothermal technique. Compound [Fe(phen)(3)](4)[H(4)In(20)S(38)]·Hphen·3HDMA·8H(2)O (Mp-InS-4) (DMA = dimethylamine) is a 1-D straight chain. Compounds [M(phen)(3)](4)[In(20)S(37)]·6Hphen·4H(2)O (M = Ni, Mp-InS-5; Fe, Mp-InS-6) are the first reported 2-D Tn polymers integrated with complex cations of [M(phen)(3)](2+). Compound [Ni(phen)(3)](4)[H(4)In(20)S(38)]·2Hphen·2HDMA·3H(2)O (Mp-InS-7) shows a zigzag 1-D structure. We find that the reaction time is an important factor in assembling of the T3 clusters. Prolonging the reaction time seems favorable to the higher condensed phases (from 0-D to 2-D). However, a longer reaction time resulted in the crack of 2-D structure. Integrating M-phen complex cations with the chalcogenido anions can improve absorption of the materials in the visible range due to the charge transfers within the cations or between cations and anions.     

Charge density studies on [(NO)Fe(S2C6H4)2][PPN] and [(NO)3Fe(S2C6H4)3] complexes

Charge density studies of chemical bonds for two iron complexes, [(NO)Fe(S,S-C₆H₄)₂] [PPN] (1), where PPN = N(Pph₃)₂ and Fe₃(NO)₃(S,S-C₆H₄)₃ (2) are investigated in terms of the topological properties at bond critical points based on the ‘atoms in molecule’ theory. The one electron reduction form (1R) of complex 1 and the one electron oxidation form (2O) of complex 2 are also included for comparison. The X-ray absorption spectroscopy of Fe K- and L_III,II-edges, as well as the N/S K-edge are applied to verify the illustration in the variation of the electronic structures. Based on the ρ_c, ?²ρ_c, and H_b values among the compound studied, Fe-S/N can be regarded as polarized covalent bond, and Fe-N bonds show stronger covalent character than that of the Fe–S bond, which is believed to be a highly polarized covalent bond.     

A novel rhodamine-based thiacalix[4]arene fluorescent sensor for Fe3+ and Cr3+

The novel fluorescent sensor 1, which is comprised of two rhodamine B lactams as fluorophores that are 1,3-alternately linked to a thiacalix[4]arene, behaves as a highly sensitive ion-induced fluorescent sensor for Fe³⁺ and Cr³⁺. This compound was synthesized, and its recognition of metal ions was evaluated by fluorescence and absorption spectroscopy. The possible mechanism of Fe³⁺- and Cr³⁺-induced spirocycle opening of 1 leads to fluorescent and colorimetric enhancement, and these properties were investigated by spectroscopy, ¹H NMR and IR. The stoichiometric ratios and association constants of the complexes between 1 and these ions have been measured and calculated, and showed that the presence of Fe³⁺ or Cr³⁺ induced sensor 1 to form a stable 1:1 complex.     

The First New Hydrogen-Bonded Heterohexanuclear Complex [(salen)Cu]4[(salen)Fe(H2O)2]2(ClO4)2: Molecular and Crystal Structure and Magnetic Properties

The preparation, magnetic properties, and crystal structure of [(salen)Cu]₄[(salen)Fe(H₂O)₂]₂(ClO₄)₂ via hydrogen bonding are described [salen=N,N-ethylenebis (salicylideneiminate)]. Crystals are triclinic, of space group , with cell constants a=12.853(3), b=13.921(3), c=14.251(3) Å, =68.68(3)°, =87.86(3)°, =86.82(3)°, and Z=1. The structure was solved and refined to R=0.064 and R=0.068. The structure comprises the hexanuclear units which result from the linking of four mononuclear fragments [(salen)Cu] and two mononuclear fragment [(salen)Fe(H₂O)]⁺, through Cu -O H -O -Fe -O -H O -Cu hydrogen bonds of coordinating H₂O. In this complex, Fe^III ions are in almost square-planar surroundings. The temperature dependences of the magnetic susceptibilities of the complex have been studied in the 4.2–300 K range, indicating the presence of an antiferromagnetic interactions between metal ions.     

Synthese und Kristallstruktur von [C(NMe2)3]2[(CO)4Fe(μ‐InCl2)2Fe(CO)4]

Synthesis and Crystal Structure of [C(NMe₂)₃]₂[(CO)₄Fe(μ‐InCl₂)₂Fe(CO)₄] Treatment of [C(NMe₂)₃]₂[(CO)₄FeInCl₃] ( 1 ) with hot water produces the dinuclear complex [C(NMe₂)₃]₂[(CO)₄Fe(μ‐InCl₂)₂Fe(CO)₄] ( 2 ) which could be crystallized from dichloromethane/pentane. 2 crystallizes in the monoclinic space group P2₁/n with a = 835.7(1), b = 1187.8(1), c = 1902.7(1) pm, β = 91.877(5)° and Z = 2. The anion contains a four‐membered Fe—In—Fe—In ring with octahedral environment at the iron atom and tetrahedral coordination at the In atom.     

A Bis(p-tert-butyloctahomotetraoxacalix[8]arene) Capsule with [(UO2)2(OH)2] Links and a Disordered [Rb4(H2O)4] Inner Core

p-tert-Butyloctahomotetraoxacalix[8]arene (LH⁸) reacts with uranyl nitrate hexahydrate in the presence of rubidium hydroxide to give a mixed complex that can be viewed as a tetrauranate dimer [(UO²)⁴(LH⁴)²(OH)⁴] containing four disordered rubidium ions and water molecules. Two uranyl ions are complexed in an “external” fashion by each macrocycle, each of them bound to two phenoxide groups and one ether group, as well as to two bridging hydroxide ions. The latter ensure the formation of a dimeric capsule that contains the disordered set of alkali metal ions. Apart from water molecules, the Rb⁺ ions are bound to the uranyl oxo groups directed towards the inner cavity, and to phenol and ether oxygen atoms from the macrocycle. The resulting octanuclear complex presents an unprecedented geometry evidencing the assembling potential of uranyl ions.

p-tert-Butyloctahomotetraoxacalix[8]arene (LH₈) reacts with uranyl nitrate hexahydrate in the presence of rubidium hydroxide to give a mixed complex that can be viewed as a tetrauranate dimer [(UO₂)₄(LH₄)₂(OH)₄] containing four disordered rubidium ions and water molecules. Two uranyl ions are complexed in an “external” fashion by each macrocycle, each of them bound to two phenoxide groups and one ether group, as well as to two bridging hydroxide ions. The latter ensure the formation of a dimeric capsule that contains the disordered set of alkali metal ions. Apart from water molecules, the Rb^+| ions are bound to the uranyl oxo groups directed towards the inner cavity, and to phenol and ether oxygen atoms from the macrocycle. The resulting octanuclear complex presents an unprecedented geometry evidencing the assembling potential of uranyl ions.     

Thiacalix[4]arene based fluorescent probe for sensing and imaging of Fe3+ ions

A thiacalix[4]arene based fluorescent chemosensor 3 in the cone conformation has been synthesized and its recognition behaviour is evaluated toward various metal ions in mixed aqueous media. The chemosensor 3 showed high selectivity towards Fe(3+) ions by fluorescence quenching of excimer emission. Further, evaluation of the 3·Fe(3+) complex prepared in situ demonstrated great promise for the detection of the Fe(3+) ion in the presence of amino acids, blood serum and bovine serum albumin (BSA) solution. The compound 3 has suitable permeability into the PC3 cells and can be utilized as a Fe(3+) selective sensor in living cells (PC3 cells).