共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Vijay Luxami 《Tetrahedron letters》2008,49(27):4265-4268
Chemosensors 5-7 possessing a quaternary ammonium cation (for electrostatic interactions) and an N-H group(s) (for H-bonding) as recognition sites and an anthracene-9,10-dione as both a chromogenic and fluorescent moiety exhibit absorption and emission changes with fluoride ions only. No significant response to other anions such as Cl−, Br−, I−, , CH3COO−, , and is observed. The dual emission at λmax 580 nm (free 5/6) and λmax 510 and 540 nm (5/6 + F−) in chemosensors 5 and 6 enables ratiometric analysis of fluoride ions. 相似文献
3.
4.
Mônica M. Linn 《Tetrahedron letters》2007,48(26):4547-4551
The interaction of Brooker’s merocyanine (BM), a merocyanine dye, with calix[4]pyrrole (CP) was studied in acetonitrile. BM is violet in solution, but its interaction with CP changes the color of the solution due to the formation of CP-BM species associated through hydrogen bonding. A displacement assay was then carried out in the presence of different anions (F−, Cl−, Br−, I−, , , and ). It was verified that F−, and to a lesser extent Cl− and , displace BM through the formation of a complex with CP, coloring the solution. Addition of makes the solution almost colorless because it is sufficiently acidic to transfer a proton to BM, removing it from the receptor site in CP and protonating the dye, thereby allowing the visual detection of the anion in relation to the other anions. 相似文献
5.
6.
Hao-Hong Li Jun-Qian Li Hong-Bing Zhan Chang-Cang Huang Bin Zhao 《Journal of solid state chemistry》2006,179(5):1415-1420
In this paper, treatment of N-ethyl-benzo[f]quinolium (ebq) iodide and CuI with excess KI afforded an unusual coordination polymer [(ebq)2(Cu3I4)(CuI2)]n (1). 1 crystallizes in tetragonal system, space group P4(2)bc with cell parameters of , , , Z=8, , R1=0.0447 and wR2=0.0974. A highly interesting feature of 1 is its presence of mixed types of chains [ and chain] in one crystal lattice based on supramolecular self-assembly directed by cations. The infinite chains and in 1 could be described as the edge-sharing arrangement of CuI4 tetrahedron. Furthermore, IR, EA, UV-Vis, thermal analysis and optical limiting measurements were adopted to characterize polymer 1. The optical limiting experiment shows that the present polymer exhibits a large optical limiting capacity. 相似文献
7.
Feng-Tong Xie Hai-Ying Bie Guang-Hua Li Ji-Qing Xu 《Journal of solid state chemistry》2005,178(9):2858-2866
Two interesting coordination polymers, [Ag8(IN)6(NO3)2] 1 and [Ag(IN)(HIN)]1/2 [Ag(IN)] 2 (HIN=isonicotinic acid) have been synthesized hydrothermally at different pH values. 1 crystallizes in the triclinic space group P-1, with , , , α=75.87(3)°, β=80.87(3)°, γ=76.50(3)°, and Z=2. Compound 1 is the first example of a bilayer framework, in which both single layers are connected by the bond interactions (Ag-O) between Ag from two two-dimensional (2D) single layers generated by the A building block and O atoms from one-dimensional (1D) chain constructed by the B building block, in which coordination modes of IN were reported for the first time. 2 crystallizes in the monoclinic space group P2(1)/c, with , , , β=92.90(3)°, V=1185.0(4) and Z=4. Compound 2 exhibits a 2D plywood-like structure assembled by hydrogen bonds and weak Ag-O interactions. 相似文献
8.
Two new anhydrous sodium borophosphates with one-dimensional structure, Na3B6PO13(1) and Na3BP2O8(2), were synthesized by low-temperature molten salts techniques using boric acid and sodium dihydrogen phosphate as flux, respectively. The crystal structures were solved by means of single-crystal X-ray diffraction (1, orthorhombic, Pnma (no. 62), , , , Z=4; 2 , monoclinic, C2/c (no. 15), , , , β=92.492(5)°, Z=8). Compound 1 is characterized by an infinite chain of containing eight-membered rings in which all vertexes of borate groups contribute to interconnection. Compound 2 reveals an infinite straight chain built of vertex-sharing four-membered rings, and chains in neighboring layers arranged along different orientations. The relations between structures and the synthetic conditions with only traced water are discussed. 相似文献
9.
Zhi-En Lin 《Journal of solid state chemistry》2007,180(3):981-987
A new zinc phosphite cluster, Zn2(4,4′-dmbpy)2(H2PO3)41, and a new chainlike zinc phosphate, Zn2(5,5′-dmbpy)2(HPO4)(H2PO4)22, have been synthesized under hydrothermal conditions (4,4′-dmbpy=4,4′-dimethyl-2,2′-dipyridy, 5,5′-dmbpy=5,5′-dimethyl-2,2′-dipyridy). Compound 1 is a molecular zinc phosphite constructed from ZnO3N2 trigonal bipyramids, H2PO3 pseudo-pyramids and 4,4′-dmbpy ligands. Compound 2 possesses a 1D chainlike framework constructed from ZnO3N2 trigonal bipyramids, HPO4 tetrahedra, H2PO4 tetrahedra and 5,5′-dmbpy ligands. Both compounds 1 and 2 exhibit intensive photoluminescence originated from the intraligand π-π* transitions. Crystal data: 1, monoclinic, P21/n, , , , β=110.857(3)°, , Z=2, R1=0.0297, wR1=0.0801; 2, triclinic, P-1, , , , α=64.995(9)°, β=65.952(9)°, γ=65.296(8)°, , Z=2, R1=0.0418, wR1=0.1010. 相似文献
10.
Use of the interaction of a boronic acid with a merocyanine to develop an anionic colorimetric assay
Jaqueline Nicolini 《Tetrahedron letters》2007,48(19):3467-3470
A displacement assay based on the interaction of Brooker’s merocyanine (BM), a merocyanine dye, with an excess of phenylboronic acid (BA) was studied in acetonitrile. BM is colored in solution, but its reaction with BA yields a colorless covalently linked BA-BM species. This strategy was studied in the presence of different anions (F−, Cl−, Br−, I−, , , CH3COO−, and ), but only fluoride, a strongly nucleophilic anion, and to a much lesser extent acetate, reacted with BA-BM, displacing BM through a bimolecular nucleophilic substitution mechanism, and coloring the solution. Experimental data were collected and are shown here in order to gain a better understanding of this chromogenic sensor. 相似文献
11.
Guang-Ao Yu 《Journal of organometallic chemistry》2007,692(18):3914-3921
Six novel ionic phosphine ligands with a cobaltocenium backbone, 1,1′-bis(dicyclohexylphosphino) cobaltocenium hexafluorophosphate () (1a), 1,1′-bis(di-iso-propylphosphino) cobaltocenium hexafluorophosphate () (2a), 1,1′-bis(di-tert-butylphosphino) cobaltocenium hexafluorophosphate () (3a), and the monophosphine ligand (Cc+ = cobaltocenium; R = Cy, 1b; R = i-Pr, 2b; R = t-Bu, 3b) were synthesized and characterized by elemental analysis, spectroscopy, and X-ray diffraction techniques. These ligands are air-stable and useful for Suzuki coupling reactions in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (), enabling high catalytic activity. 相似文献
12.
The Ni6Se5−xTex, 0<x<∼1.7, system has been carefully investigated via electron diffraction and TEM imaging. They reveal a somewhat disordered modulated superstructure phase arising from Ni ion ordering within an essentially well-defined chalcogen sub-structure. As x, and the underlying parent substructure cell dimensions increase, the incommensurate primary modulation wave-vector q characteristic of this Ni ion ordering quickly swings from close to for x=0 towards for x?0.5. A lock-in to would formally transform the underlying parent Bmmb (ap, bp, cp) structure into a P1a1 (as=2ap, bs=bp, cs=ap+cp) superstructure phase. 相似文献
13.
14.
Li Liu 《Journal of solid state chemistry》2006,179(5):1312-1317
Two new zinc phosphites [Zn2(HPO3)2(H2PO3)][C3H5N2] 1 and [Zn2(HPO3)3][C4H7N2]2·2H2O 2 have been hydrothermally synthesized templated by imidazole and 2-methylimidazole. Single-crystal X-ray diffraction analysis reveals that the two compounds have the similar inorganic framework structures, which both exhibit 2D double layer structures with double 12-membered rings. Due to the different space-filling effect of the guest molecules, the stacking mode of adjacent layers and the arrangement mode of the organic amines are distinct. In 1, the adjacent layers are stacked in an -ABAB- sequence and monoprotonated imidazole molecules sit in the middle of 12MR windows, while in 2, the layers are stacked in an -AAAA- pattern. Monoprotonated 2-methylimidazole molecules occupy two different sites, one inserts into 12MR and the other resides in the interlayer region. Crystal data for 1: triclinic, P-1, , , , α=114.71(3)°, β=92.78(3)°, γ=113.04(3)°, , Z=2; for 2: triclinic, P-1, , , , α=68.244(7)°, β=76.143(7)°, γ=63.113(6)°, , Z=2. 相似文献
15.
Four coordination polymers [Zn(bqdc)(phen)]n (1), [Zn(bqdc)(bpy)(H2O)]n (2), [Mn(bqdc)(bpy)(H2O)2]n (3) and [Mn(bqdc)(phen)(H2O)2]n (4) (H2bqdc=2,2′-biquinoline-4,4′-dicarboxylic acid, phen=1,10-phenanthroline and bpy=2,2′-bipyridyl) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. Crystal data for 1: monoclinic system, C2/c, , , , β=103.78(3)°, , Z=4. Crystal data for 2: monoclinic system, p21/n, , , , β=107.13(7)°, , Z=4. Crystal data for 3: monoclinic system, C2/c, , , , β=116.8010(11)°, , Z=4. Crystal data for 4: monoclinic system, C2/c, , , , β=117.04(3)°, , Z=4. Single helix-like chains exist in 1. The supramolecular structure of 1 exhibits extended two-dimensional network while 2-4 display extended three-dimensional architectures based on interchain hydrogen bonding and π-π interactions. Compounds 1 and 2 show blue photoluminescence under UV light suggesting that they may be employed to develop luminescent materials. Compounds 3 and 4 show interesting magnetic behaviors. 相似文献
16.
17.
Tyler A. Sullens Jessica A. Byrd Travis H. Bray 《Journal of solid state chemistry》2006,179(4):1192-1201
Three novel Th(IV) compounds containing heavy oxoanions, Th(SeO3)(SeO4) (1), Th(IO3)2(SeO4)(H2O)3·H2O (2), and Th(CrO4)(IO3)2 (3), have been synthesized under mild hydrothermal conditions. Each of these three distinct structures contain trigonal pyramidal and tetrahedral oxoanions. Compound 1 adopts a three-dimensional structure formed from ThO9 tricapped trigonal prisms, trigonal pyramidal selenite, SeO32-, anions containing Se(IV), and tetrahedral selenate, SeO42-, anions containing Se(VI). The structure of 2 contains two-dimensional porous sheets and occluded water molecules. The Th centers are found as isolated ThO9 tricapped trigonal prisms and are bound by four trigonal pyramidal iodate anions, two tetrahedral selenate anions, and three coordinating water molecules. In the structure of 3, the Th(IV) cations are found as ThO9 tricapped trigonal prisms. Each Th center is bound by six IO31- anions and three CrO42- anions forming a chiral three-dimensional structure. Second-harmonic generation of 532 nm light from 1064 nm radiation by a polycrystalline sample of 3 was observed. Crystallographic data (193 K, MoKα, λ=0.71073): 1; monoclinic, P21/c; , , , β=103.128(1), Z=4, R(F)=2.47% for 91 parameters with 1462 reflections with I>2σ(I); 2, monoclinic, P21/n, , , , β=100.142(2), Z=4, R(F)=4.71% for 158 parameters with 2934 reflections with I>2σ(I); 3, orthorhombic, P212121, , , , Z=4, R(F)=2.04% for 129 parameters with 2035 reflections with I>2σ(I). 相似文献
18.
ESR spectroelectrochemical measurements of 2-diphenylamino-substituted oligothiophenes 8m proved the existence of radical cations upon oxidation. Their stability and dimerization depend significantly on the number m of thiophene units. The radical cations and are very reactive and dimerize spontaneously to yield either 2,5-bis(diphenylamino)-2,2′-bithiophene 102 or 2,5-bis(diphenylamino)-5,5′-bis(2-thienyl)-3,3′-bithiopene 112, respectively. In contrast, the radical cations are highly stable and do not dimerize at all. 相似文献
19.
In a model study, , , - and - correlated NMR techniques confirm a Markovnikov type reaction intermediate for the major coupling products between a short, low MW perfluorinated iodide C2F5I (I) and a short, low MW fluorinated olefin CF3(CF2)7CHCH2 (II). The reaction is peroxide induced (di-t-butyl peroxide, DTBP) and is conducted at 140 °C for a 3 h reaction time in a sealed glass ampoule. Side reaction products due to the reaction of DTBP with radical reaction intermediates were also observed and identified. The study aimed to mimic as closely as possible the peroxide-initiated coupling reaction between an iodine terminated fluoropolymer (model compound I) and its fluorinated di-olefin coupling agent (model compound II). A mono-olefin was chosen to simplify the model reaction. 相似文献