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1.
Wetherby AE Goeller LR DiPasquale AG Rheingold AL Weinert CS 《Inorganic chemistry》2007,46(18):7579-7586
The protonolysis reaction of the germanium(II) amide Ge[N(SiMe3)2]2 with calix[4]arene and calix[8]arene furnishes the two germanium(II) calixarene complexes {calix[4]}Ge2 and {calix[8]}Ge4, respectively, which have been crystallographically characterized. The calix[4]arene complex contains a Ge2O2 rhombus at the center of the molecule and is one of the only four germanium(II) calix[4]arenes that have been structurally characterized. The calix[8]arene species is the first reported germanium calix[8]arene complex, and it exhibits an overall bowl-shaped structure which contains two Ge2O2 fragments. The latter complex reacts with Fe2(CO)9 to yield an octairon compound, which has also been structurally characterized and contains four GeFe2 triangles arranged around the macrocyclic ring. The germanium(II) centers are oxidized to germanium(IV) in this process, with concomitant reduction of the neutral diiron species to Fe2(CO)(8)2- anions. 相似文献
2.
New calix[5]arene trivalent phosphorus derivatives have been synthesized which should be excellent ligands with which to study and control the interaction of a ligand atom with a metal. The larger cavity of the calix[5]arene (compared to calix[4]arene) provides a good balance between constraint and flexibility. Treatment of p-tert-butylcalix[5]arene with 2 equiv of either tris(dimethylamino)phosphine or dichlorophenylphosphine inserts two RP moieties into the calix[5]arene framework to give calix[5](PR)2(OH) (1, R = Me2N; 2, R = Ph). Further treatment of 1 with 4 equiv of HCl gives calix[5](PCl)2(OH) (3). Heating a solution of the monophosphorus compound calix[5](PNMe2)(OH)3 (4) releases dimethylamine to yield both monomeric calix[5](P)(OH)2 (6) and dimeric [calix[5](P)(OH)2](2) (7), the latter having a tubelike geometry. X-ray crystallographic studies confirm the structures and show that 1 and 2 have approximate cone conformations while 3 has an approximate 1,2-alternate conformation. The orientations of the phosphorus lone pairs and oxygen atoms in all derivatives provide a framework for both soft and hard ligand interactions within the calix[5]arene. 相似文献
3.
Salmon L Thuéry P Ephritikhine M 《Dalton transactions (Cambridge, England : 2003)》2006,(30):3629-3637
Reactions of UCl4 with calix[n]arenes (n = 4, 6) in THF gave the mononuclear [UCl2(calix[4]arene - 2H)(THF)2].2THF (.2THF) and the bis-dinuclear [U2Cl2(calix[6]arene - 6H)(THF)3]2.6THF (.6THF) complexes, respectively, while the mono-, di- and trinuclear compounds [Hpy]2[UCl3(calix[4]arene - 3H)].py (.py), [Hpy](4)[U2Cl6(calix[6]arene - 6H)].3py (.3py), [Hpy]3[U2Cl5(calix[6]arene - 6H)(py)].py (.py) and [Hpy]6[U3Cl11(calix[8]arene - 7H)].3py (.3py) were obtained by treatment of UCl4 with calix[n]arenes (n = 4, 6, 8) in pyridine. The sodium salt of calix[8]arene reacted with UCl4 to give the pentanuclear complex [U{U2Cl3(calix[8]arene - 7H)(py)5}2].8py (.8py). Reaction of U(acac)4 (acac = MeCOCHCOMe) with calix[4]arene in pyridine afforded the mononuclear complex [U(acac)2(calix[4]arene - 2H)].4py (.4py) and its treatment with the sodium salt of calix[8]arene led to the formation of the 1D polymer [U2(acac)6(calix[8]arene - 6H)(py)4Na4]n. The sandwich complex [Hpy]2[U(calix[4]arene - 3H)2][OTf].4py (.4py) was obtained by treatment of U(OTf)4 (OTf = OSO2CF3) with calix[4]arene in pyridine. All the complexes have been characterized by X-ray diffraction analysis. 相似文献
4.
Hasalettin Deligöz 《Journal of inclusion phenomena and macrocyclic chemistry》2002,43(3-4):285-289
In this study, seven new compounds p-(4-butyl-phenylazo)calix[6]arene(1), p-(4-(phenylazo)phenylazo)calix[6]arene (2),p-(4-hydroxyphenylazo)calix[6]arene (3),p-{4-[N-(thiazol-2-yl)sulfamoyl]phenylazo\}calix[6]arene(4), p-(4-acetamidophenylazo)calix[6]arene (5),p-(thiazol-2-ylazo)calix[6]arene (6) andp-(2-sulfanylphenylazo)calix[6]arene (7) have been synthesizedfrom calix[6]arene by diazo coupling with the corresponding aromaticamines. UV-Vis, IR, 1H and 13C NMR spectral data have been used to elucidate the structures of the compounds elemental analyses 相似文献
5.
Anthony E. Wetherby Jr. Arnold L. Rheingold Christa L. Feasley Charles S. Weinert 《Polyhedron》2008,27(7):1841-1847
The reaction of Ge[N(SiMe3)2]2 with calix[6]arene furnishes a novel macrocyclic product having two divalent germanium atoms incorporated into a Ge2NO rhombus which contains a μ2-oxygen atom and a μ2-NH2 group. The crystal structure of the product indicates the presence of a conformationally rigid molecule where three of the six oxygen atoms of the calix[6]arene are bound to the germanium atoms while the remaining three have been converted into –OSiMe3 or unusual –OSi(H)(NH2)2 groups. Spectral (1H, 13C, and 29Si NMR) data in solution are consistent with the solid-state structure and indicate the germanium calix[6]arene retains its structure in solution. 相似文献
6.
Si-Zhe Li Ke Yang Hong-Bing Liu Yu-Xiang Xia Rong-Xiu Zhu Jun Luo Qian Wan 《Tetrahedron letters》2013
Inherently chiral biscalixarenes with hetero-cavities were synthesized by a covalent assembly of p-tert-butylcalix[5]arene with a 1,3-substituted calix[4]arene via 1,3-alkylation reaction and subsequent desymmetrization. The racemates were resolved by chiral HPLC method. 1H NMR spectra, VT-NMR spectra, and theoretical calculations support that the calix[5]arene subunit of the inherently chiral calix[4][5]arene ester adopts a cone-in conformation, with the aromatic ring bearing the CH2CO2Et group tilting inward the calix[5]arene cavity. By contrast, such a cone-in structural feature of the calix[5]arene subunit disappears for the corresponding inherently chiral calix[4][5]arene carboxylic acid, due to the intramolecular hydrogen bonding between the carboxyl group and an ethereal oxygen of the glycolic chain. 相似文献
7.
8.
The electronic effects resulting from noncovalent host-guest interactions between calix[6]arene and a ruthenium dimer, [Ru3O(OAc)6(CO)(ppy)]2-mu-pz (ppy=4-phenyl pyridine, pz=pyrazine), are presented. The noncovalent interaction is between the calix[6]arene and the ppy ligands of the dimer. The dimer can bind 2 equiv of calix[6]arene. The complex [Ru3O(OAc)6(CO)(ppy)]2-mu-pz forms a highly stable mixed valence ion with strong electronic coupling between the two Ru3 clusters. The strength of the electronic interaction is found to be moderated by calix[6]arene binding. Addition of calix[6]arene to the mixed valence ion causes the electronic coupling to decrease. The binding of calix[6]arene is found to be cooperative. The origins of cooperative binding are developed in terms of the potential energy surfaces associated with the symmetric and asymmetric mixed valence ion. In particular, it is found that symmetry breaking (through the binding of a single calix[6]arene) destabilizes the mixed valence state. Restoration of symmetry (through the binding of a second calix[6]arene) increases the stability of the mixed valence ion and provides an additional driving force for the binding of the second calix[6]arene. 相似文献
9.
[reaction: see text] Two new calix[6]arene derivatives 3 and 4 in a 1,4-anti conformation and one calix[8]arene derivative 5 were synthesized. SAMs of calix[n]arene (n = 4, 6, 8) derivatives 1-5 were formed on gold bead electrodes. Cyclic voltammetry with Ru(NH3)6(3+/2+) as a redox probe, together with impedance spectroscopy and reductive desorption, indicates that SAMs of 5 have a higher coverage than those of 3 and 4 due to the presence of hydrogen bonding and possibly its conformation. Noncovalent immobilization of C60 on gold surfaces was achieved with SAMs of calix[8]arene derivative 5 but not with those of 1-4. 相似文献
10.
A series of novel N-chromogenic calix[4]arene azacrown ethers were synthesized as selective extractants of potassium ion. 1,3-Alternate calix[4]arene azacrown ethers were prepared by reacting 25,27-dipropyloxy-26,28-bis(5-chloro-3-oxapentyloxy) calix[4]arenes with p-toluenesulfonamide in the presence of potassium carbonate. The coupling reaction of calix[4]arene azacrown ether with 2-hydroxy-5-nitrobenzyl bromide in the presence of triethylamine in THF gave the chromogenic calix[4]arene azacrown ether in moderate yield. These compounds show high potassium selectivity over other metal ions as shown by two-phase extraction, bulk liquid membrane, and 1H NMR studies on a ligand-metal complex. It is assumed that the OH of the chromogenic group attached on nitrogen can assist the complexation by encapsulation of the metal. 相似文献
11.
Bhattacharya S Nayak SK Semwal A Banerjee M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(4):595-606
Equilibria for the formation of supramolecular complexes of [60]fullerene with a series of mono O-substituted calix[6]arenes, namely: (i) 37-methoxy-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (1), (ii) 37-allyl-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (2), (iii) 37-phenacyl-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (3), (iv) 37-ethylester-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (4) and (v) 37-benzyl-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert-butyl)calix[6]arene (5) have been studied in CCl4 medium by absorption spectroscopic technique. The stoichiometry has been found to be 1:1 ([60]fullerene:calix[6]arene) in each case. An absorption band due to charge transfer (CT) transition is observed in each case in the visible region. The vertical ionisation potentials (I(D)(v)) of all the calix[6]arenes under study have been estimated utilising CT transition energy. The experimental I(D)(v) values also yield a good estimate of the electron affinity of [60]fullerene. The degrees of CT in the ground state of the complexes have been found to be very low (about 0.15%). Resonance energy of the complexes have been estimated. Thermodynamic parameters for the supramolecular complex formation of [60]fullerene with mono O-substituted calix[6]arene receptors are reported. It is observed that among the calix[6]arenes under the present study, only 1 and 4 form inclusion complexes with [60]fullerene. This has also been substantiated by theoretical calculation using PM3 method. Thus presence of one substituent group (of different types) on the lower rim of the calix[6]arene molecule has been shown to govern the host-guest complexation process. 相似文献
12.
Summary Two new kinds of calix[4]arene derivatives, 5, 11, 17, 23-tetra-tert-butyl-25,27-bis(isopropylcarbamoyl-methoxy)-26,28-diundecenyloxy
calix[4]arene (C[4]A) and 25,27-dibutoxy-5, 11, 17, 23-tetra-tert-butyl-26,28-diundecenyloxy calix[4]arene (C[4]B0, are prepared
and then are polymized by two different processes. Three calix[4]arene polysiloxane stationary phases for capillary gas chromatography
are obtained. Their chromatographic characteristics, including column efficiency, polarity, selectivity, glass-transition
temperature and thermal stability are studied. Retention mechanisms are also discussed. 相似文献
13.
14.
Arisa Jaiyu 《Tetrahedron letters》2007,48(10):1817-1821
A series of stilbene-bridged calix[4]arenes was synthesized through an intramolecular reductive McMurry coupling of bisbenzaldehyde calix[4]arene in high yields. Tetra- and pentaethylene glycol chains were tethered to the phenolic groups of calix[4]arene to form stilbene-bridged calix[4]arene crown-5 and crown-6, respectively. The presence of stilbene bridge over the calix[4]arene rim effectively prevented the connection of the polyether chains in the cone conformation resulting in the exclusive formation of 1,3-alternate stilbene-bridged calix[4]arene crown product. Compared to the cone analogues, the 1,3-alternate calix[4]arene crown ethers showed a greater extraction ability and selectivity toward Cs+. 相似文献
15.
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. 相似文献
16.
Corbellini F Mulder A Sartori A Ludden MJ Casnati A Ungaro R Huskens J Crego-Calama M Reinhoudt DN 《Journal of the American Chemical Society》2004,126(51):17050-17058
A molecular capsule based on ionic interactions between two oppositely charged calix[4]arenes, 1 and 2, was assembled both in solution and on a surface. In solution, the formation of the equimolar assembly 1.2 was studied by (1)H NMR, ESI-MS, and isothermal titration calorimetry, giving an association constant (K(a)) of 7.5 x 10(5) M(-1). A beta-cyclodextrin self-assembled monolayer (beta-CD SAM) on gold was used as a molecular printboard to anchor the tetraguanidinium calix[4]arene (2). The binding of tetrasulfonate calix[4]arene 1 was monitored by surface plasmon resonance spectroscopy. Rinsing of the surface with a high ionic strength aqueous solution allows the removal of the tetrasulfonate calix[4]arene (1), while by rinsing with 2-propanol it is possible to achieve the complete desorption of the tetraguanidinium calix[4]arene (2) from the beta-CD SAM. The K(a) for the capsule formation on a surface is 3.5 x 10(6) M(-1), thus comparing well with the K(a) determined in solution. 相似文献
17.
Serkan Erdemir Ozlem Sahin Arzu Uyanik Mustafa Yilmaz 《Journal of inclusion phenomena and macrocyclic chemistry》2009,64(3-4):273-282
Synthesis of the glutaraldehyde derivatives calix[n]arene (n = 4,6,8) (Calix[n]-GA) and using as cross-linkers for immobilization of Candida rugosa lipase (CRL) have been discussed in this paper. The amino functional calix[n]arene derivatives (Calix[n]-NH 2) were synthesized via reduction of dinitrile, hexanitrile and octanitrile derivatives of calix[n]arenes. These amino functional calix[n]arene derivatives (Calix[n]-NH 2) were converted to their aldehyde derivativatives with glutaraldehyde. The calix[n]arene derivatives were used in lipase immobilization in order to see the role of calix[n]arene binding site on the lipase activitiy and stability. The activity recovery of calix[n]arene-supported lipases (Calix[n]-CRL) based on the Calix[4]-CRL, Calix[6]-CRL and Calix[8]-CRL reaches to 53.5, 66.1 and 76.4%, respectively. 相似文献
18.
A. N. Novikov V. A. Bacherikov Yu. E. Shapiro A. I. Gren 《Journal of Structural Chemistry》2006,47(6):1003-1015
The cone conformation of C 4 symmetry is shown by the Hartree-Fock method (3-21G basis) to be the predominant conformer of calix[4]arene; the compressed cone of C 2 symmetry is the major conformer of calix[6]arene. Using quantum chemical methods we calculated hydrogen bond cleavage energies for calix[4]-(ab initio and density functional methods) and calix[6]arene (ab initio), and also for the complex of calix[4]arene with carbon disulfide. These energies along with structural data point to the cooperative effect of hydrogen bonds. The results of these studies provided an explanation to the greater conformational lability of calix[6]arene compared with calix[4]arene molecules. It is also predicted that the nucleophilic substitution reaction involving calix[6]arene in the presence of weak bases and in aprotic solvents, as well as in the gas phase, will occur via diastereomeric transition states. 相似文献
19.
Rajca A Mukherjee S Pink M Rajca S 《Journal of the American Chemical Society》2006,128(41):13497-13507
Calix[4]arenes constrained to the 1,3-alternate conformation and functionalized at the upper rim with four and two tert-butylnitroxides have been synthesized and characterized by X-ray crystallography, magnetic resonance (EPR and (1)H NMR) spectroscopy, and magnetic studies. The 1,3-alternate nitroxide tetraradical and diradical provide unique polyradical scaffolds for dissection of the through-bond and through-space intramolecular exchange couplings. In addition, detailed magnetic studies of the previously reported calix[4]arene nitroxide tetraradical, which possesses cone conformation in solution, reveal conformational dependence of exchange coupling. Through-bond coupling between the adjacent nitroxide radicals is mediated by the nitroxide-m-phenylene-CH(2)-m-phenylene-nitroxide coupling pathway, and through-space coupling is found between the diagonal nitroxide radicals at the conformationally constrained N...N distance of 5-6 A. Magnetic studies of the calix[4]arene polyradical scaffolds in frozen solutions show that the through-bond exchange coupling in the 1,3-alternate calix[4]arene tetraradical is antiferromagnetic, while that in cone calix[4]arene tetraradical is ferromagnetic. The through-space exchange couplings are antiferromagnetic in both cone and 1,3-alternate calix[4]arene tetraradical, as well as in the 1,3-alternate calix[4]arene diradical. The exchange coupling constants (|J/k|) are of the order of 1 K. 相似文献
20.
Cavalleri O Vignolo M Strano G Natale C Rolandi R Thea S Prato M Gonella G Canepa M Gliozzi A 《Bioelectrochemistry (Amsterdam, Netherlands)》2004,63(1-2):3-7
We investigate the self-assembly of modified calix[4]arene on gold surfaces. Calix[4]arene was modified through a reaction sequence which led to assembling of the crown-5 moiety and to the insertion of two thioether groups into the starting molecule. The so-obtained calix[4]arene-crown-5 bis(7-thiatridecyloxy) (hereafter called calix[4]arene) was in the stable 1,3-alternate conformation. The calix[4]arene/gold interface was investigated by means of spectroscopic ellipsometry (SE), scanning tunneling microscopy (STM) and cyclic voltammetry (CV). SE data indicate a layer thickness compatible with the formation of a monomolecular layer. This result is confirmed by STM imaging which shows the formation of a high density of small pits, one gold layer deep, a typical feature of self-assembled organosulphur monolayers on gold. CV measurements performed in presence of the [Ru(NH(3))(6)(2+/3+)] redox couple indicate a passivation of the metal electrode, resulting in a reduction of the redox current, after the layer deposition. CV has also been used to investigate the selectivity properties of calix[4]arene-covered gold electrodes by measuring the redox current decrease in the presence of different salt solutions. It is found that calix[4]arene-covered electrodes are able to complex K(+) and Ba(2+), while no complexation is observed in the case of Li(+), Na(+), Cs(+), Mg(2+) and Ca(2+). 相似文献