Structures and properties of solvated and unsolvated isopropyl functionalised calix[4]arenes

The tetra-isopropyl ethers of calix[4]arene and p-t-butylcalix[4]arene have been isolated in the cone conformation, and structurally characterised as chloroform solvates. Thermogravimetric analysis demonstrated that the parent isopropylcalix[4]arene solvate is significantly more stable than the p-t-butylcalix[4]arene analogue, retaining the solvent up to a temperature of 125°C. It was found that the calix[4]arene ether sublimes at atmospheric pressure, and solvent-free crystals appropriate for structure determination were produced at reduced pressure. The p-t-butylcalix[4]arene ether was also isolated without solvent in the lattice, but in this case the calixarene was crystallised from acetone, as sublimation did not produce crystals of sufficient quality.     

Stable Hydrogen-Bonded Spherical Capsules Formed from Self-Assembly of Pyrogallol[4]arenes

The self-assemblies of two pyrogallol[4]arenes held together by 48 intermolecular hydrogen bonds stably associate in the form of spherical hexameric capsules. The molecular structures of two hexameric capsules with large interior space were analyzed by single crystal X-ray crystallography.     

Hydrogen bonded co-crystallised layered isopropanol-pyrogallol[4]arenes

A novel isopropanol-pyrogallol[4]arene forms a layered structure via hydrogen bonding and C–H…π interactions. The layered structure results in encapsulation of one isopropanol molecule. The application of NMR methods to determine solution structures and crystal structures provides insight into host–guest properties and the molecular interactions between them.     

Crystal and molecular structure of two calix[6]arenes:p-Isopropylcalix[6]arene andp-tert-butylcalix[6]arene—benzene(1∶3) complex

The isopropyl derivative crystallizes from a mixture of carbon disulfide and benzene in the orthorhombic system: Space groupP2₁ nb, a=17.420(3),b=17.708(3),c=18.972(3) Å,V=5852(3) Å,Z=4. Thet-butyl derivative crystallizes from benzene, but the crystal is a complex (13), space groupP,a=15,065(5),b=19.103(3),c=13.878(3) Å, =106.95(2), =102.72(2), =80.61(2),V=3703(2) ų,Z=2. Refinement led toR=0.185 for 1512 reflections for the isopropyl derivative, a sufficiently high number to establish the conformation of the molecule; for thet-butyl complexR=0.12 for 7340 reflections. Intramolecular hydrogen bonds are given as well as comparison of the conformation of both compounds. Thet-butyl groups and the benzene molecules are disordered but the isopropyl groups are not. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82071 (57 pages).     

1,3-Alternate and C-1,2-Alternate Tetrahomodioxacalix[4]crowns. Crystal Structures and Metal Ion Complexation

Two novel tetrahomodioxacalix[4]crowns with crown-5 and crown-6 rings weresynthesized. From X-ray crystal structures, homooxacalix[4]crown-5 (3) andhomooxacalix[4]crown-6 (2) were found to be in the 1,3-alternate and theC-1,2-alternate conformations, respectively. Homooxacalix[4]crown-5 (1)shows a marked selectivity for cesium ion over other metal ions tested.     

Synthesis,Crystal Structure and Complexing Properties of Calix[4]arene Schiff Bases

Four p‐tert‐butylcalix[4]arene derivatives with different Schiff base groups at the lower rim were efficiently prepared in three steps. p‐tert‐Butylcalix[4]arene was firstly O‐peralkylated with ω‐haloalkylphthalimide in the system of NaH/DMF to give calixarene tetraalkylphthalimides, which were in turn hydrazinolyzed to give tetraaminoalkylcalixarenes. Then by condensation of the latter with salicylaldehyde and 2‐hydroxy‐1‐naphthaldehyde, a series of calixarene Schiff bases were obtained in satisfying yields. The complexing properties of these Schiff bases for transition metal ions were investigated with UV spectroscopy.     

Morphologies of branched-chain pyrogallol[4]arenes in the solid state

A suite of branched-chain pyrogallol[4]arene (Pg) macrocycles, most of which show activity in bilayer membranes, has been prepared and studied by X-ray crystallography. The little-known branched side-chain Pgs include 2-propyl, 2-butyl, 2-pentyl, 3-pentyl, 3-heptyl, 4-heptyl, 5-nonyl and cyclohexyl. The Pgs form self-assembled structures having bilayer, capsule or, in one case, a nanotube morphology. The nanotube structure observed for C-(di-n-ethyl)pyrogallol[4]arene was confirmed by X-ray structure analysis and by transmission and scanning electron microscopies.     

Synthesis, crystal structure and configuration of acetylated aryl Pyrogallol[4]arenes

A series of aryl and ferrocenyl pyrogallol[4]arenes have been synthesized by the HCl-catalyzed condensation reactions of pyrogallol with aromatic aldehydes and ferrocenecarbaldehyde. The fully acetyl and ethoxycarbonylmethoxy derivatives were also prepared and fully characterized. The crystal structures show that acylated phenyl pyrogallol[4]arene exists in rctt (cis-trans-trans) configuration, while the corresponding ferrocenyl pyrogallol[4]arene in rccc (all cis) configuration.     

Homodiselenacalix[4]arenes: Molecules with Unique Channelled Crystal Structures

A synthetic route towards homodiselenacalix[4]arene macrocycles is presented, based on the dynamic covalent chemistry of diselenides. The calixarene inner rim is decorated with either alkoxy or tert‐butyl ester groups. Single‐crystal X‐ray analysis of two THF solvates with methoxy and ethoxy substituents reveals the high similarity of their molecular structures and alterations on the supramolecular level. In both crystal structures, solvent channels are present and differ in both shape and capacity. Furthermore, the methoxy‐substituted macrocycle undergoes a single‐crystal‐to‐single‐crystal transformation during which the molecular structure changes its conformation from 1,3‐alternate (loaded with THF/water) to 1,2‐alternate (apohost form). Molecular modelling techniques were applied to explore the conformational and energetic behaviour of the macrocycles.     

Synthesis of new calix[4]arenes containing nucleoside bases

A family of novel calix[4]arene derivatives containing nucleoside bases were designed and synthesized. Coupling reaction between para mono- or bis-amino calix[4]arenes 5, 6 or 7 and thymin-1-ylacetic acid in the presence of DCC afforded mono- or bis-thymine-substituted calix[4]arenes 8, 9 or 10 in over 70% yield. Owing to the low solubility of adenine-N⁹-ylacetic acid in DMF and DMSO and the weak nucleophilicity of aminocalix[4]arene derivatives, alternatively, the substitution reaction of bromoacetylated aminocalix[4]arenes derivatives 11, 12, 13 with adenine in the presence of sodium hydride was carried out to synthesize mono- or bis-adenine-substituted calix[4]arenes. Two kinds of isomers 15 and 16 or 17 and 18 were obtained due to the non-regiospecific alkylation of adenine, and their structures have been confirmed by ¹³C NMR and ¹H NMR spectra.     

Crystal and molecular structure of the (1 : 1) clathrate between a calix[4]arene containing onep-nitrophenol unit and toluene

p-(Methyl,tert-butyl, nitro,tert-butyl) calix[4]arene: toluene, C₃₇H₄₁NO₆. C₇H₈,M _r = 687.87, triclinic, ,a = 13.668(2),b = 12.187(2),c = 13.231(1) Å, = 106.78(8), = 77.88(1), = 114.00(1)°,V = 1916.8(8) ų,Z = 2,D _x = 1.19 g cm^–3, (CuK ) = 1.54178 Å, = 5.90 cm^–1,F(000) = 736,T = 293 K, finalR = 0.068 for 6309 observed reflections. This macrocycle, having different substituents at the positionspara to the hydroxyl groups, is the first one of its type to be studied. The general conformation of this calix[4]arene is compared to similar symmetrical ones. Thetert-butyl groups are not disordered as is usual and toluene is retained between the macrocycles. Two calixarene molecules are positioned to permit atert-butyl group of one to be inside the cavity of the second to establish CH₃- interactions.     

Synthesis and Crystal Structure of 1-Phenyl-3-methyl-4-（4-bromophenyl）-6-（2-chlorophenyl）-pyrazolo[3,4-b] Pyridine under Microwave Irradiation

1INTRODUCTIONThepyrazolo[3,4-b]pyridineclassofcompoundspossessmanybiologicalandpharmacologicalactivi-ties[1],suchasactiveanti-concretionmedicaments[2]aswellasactiveanti-gramnegativeandpositivebacteriaagents[3].Thereforethesynthesesofsuchcompoundshavearousedgreatattentionofalargenumberofchemists.Themostimportantsyntheticrouteisthecondensationreaction[4～11]ofamino-pyrazoleandα,β-unsaturatedcompounds.Theorganicreactionundermicrowaveirradia-tionhastheadvantagesoffastreactionspeed,shorttime…     

Synthesis and Properties of Upper Rim Schiff Base Calix[4]arenes

The synthesis and properties of upperrim Schiff base calix[4]arenes are described in thisarticle. Tetrakis-p-bromomethylcalix[4]arene(1) reacts with hexamethylenetetramine to givetetrakis-p-formylcalix[4]arene (2) in highyield. Then upper rim Schiff base calix[4]arenes 3 can be easily synthesized by 2 reacting withappropriate alkylamines. The complexation ability of3 toward transition metals Pb²⁺, Cu²⁺and Co²⁺ was studied by UV-VIS spectrophotometry.     

Synthesis of New Calix[4]arenes Functionalizated by Acetylhydrazide Groups

A series of new calix[4]phenols, calix[4]resorcinols and calix[4]pyrogallols with acetylhydrazide substitutes has been␣synthesized with high yields by hydrazinolysis of ester group containing calix[4]arenes. The synthesized calix[4]phenols adopt the cone conformation while the calix[4]resorcinol and calix[4]pyrogallol derivatives prefer the boat conformation. The amide fragment of the hydrazide groups predominantly exists in the trans-conformation. The binding ability of synthesized calix[4]arenes toward transition and alkali metals by solvent extraction has been investigated.     

Crystal Structures of Two Calix[10]arenes Complexed with Neutral Molecules

Two calix[10]arenes were synthesized: the tert-butylcalix[10]arene (t-Bu-C10) and the detertbutylated analogue (H-C10). Both were crystallized from saturated solutions: t-Bu-C10 from a mixture of toluene and tetrahydrofuran (THF), H-C10 from acetone. In each case, complexes were obtained: H-C10, acetone 1:2 and t-Bu-C10, toluene, THF 1:2.5:0.5. The crystal structures of these twocomplexes and the different conformations of the macrocycles are presented here.For the first, the crystals are triclinic, space group Pmacr{1}, a = 9.037(2)Å, b = 11.447(2)Å, c = 15.197(3)Å, = 80.79(3)Å, = 84.96(3)°, = 88.60(3)°, V = 1545.7(5)ų, Z = 1; the complex with t-Bu-C10 is orthorhombic, space group Fmm2, a = 32.211(6)Å, b = 32.289(7)Å, c = 12.179(2)Å, V = 12667(4)ų, Z = 4. The complex from H-C10 shows a pleated loop conformation with H-bonds between acetone and hydroxylgroups. The complex from t-Bu-C10 shows several cavities, in the conesshaped by the phenol moieties and near the hydroxyl groups. The packingsare given for both crystals.     

微波辐射下2-氨基-7,7-二甲基-3-乙氧羰基- 4-(2-呋喃)基-5-氧代-5,6,7,8-四氢-4H- 苯并吡喃的合成和晶体结构

标题化合物C18H21NO5是由2-呋喃亚甲叉氰乙酸酯和5,5-二甲基-1,3-环己酮在醋酸铵存在下用微波辐射反应得到,结构通过单晶X-射线衍射法确定,其晶体属三斜晶系,空间群P 睿琈r =332.36,a =11.232(2),b =13.048(2),c =13.274(3),α=105.7(1),β=95.68(2),g =109.56(1)? V=1752.4(6)3,Z=2,Dc=1.276Mg·m-1, =0.093mm-1,F(000)=704, 最终的偏离因子为R=0.0431,wR=0.0973,在分子结构中平面 1 (呋喃环) 与平面2 ((C(5)、 C(6)、C(9)、O(1))之间的二面角为 84.70°, 平面2 与平面 3 (C(1)、C(4)、C(5)、C(6)) 之间的二面角为 2.9°, 平面 1 与平面3 之间的二面角为 85.9°。吡喃环和与吡喃环合的六员环为信封式结构。     

Upper Rim Diester—bridged Calix[4] arenes and Oligocalix [4]—arenes：the Effects of the Length of Bridged Reagents on Their Distribution

A series of monobridged calix [4] arenes 3a-f,cyclic biscalix-[4] arenes 4a-f ,diametrically bridged at the upper rim with saturated aliphatic diester chians,have been synthesized,The results at diluted conditions show that the percentage of yields of mono-,bis- and oligo-calix[4] arenes are related to the legth of the chains ,With the shortening of the chains ,the percent-age of monocalix[4] arenes decreased ,All the calix [4] arene moieties are in a cone conformaiton according to the AB quar-tet pattern of the methylene protons between the phenolic rings in the ^1H NMR spectra.     

Solvation of Calix[4]arene-bis-crown-6 Molecules

Single crystal X-ray diffraction analyses of calix[4]arene-bis-crown-6 (1) and calix[4]arene-bis-benzocrown-61,2-dichloroethane (2) are reported. Thesestructures offer an opportunity to study the conformation of calix[4]arene-bis-crown-6 molecules in the absence of solvent, and when very weakly solvated. These structures exhibit different conformations of the crown ring, and limited flexibility of the calix[4]arene,but do not show solvent or crown inclusion in the calix[4]arene cavity. Comparisons to similar structures are made, and the implications for cesium binding are discussed.     

Process Development for Separation of Conformers from Derivatives of Resorcin[4]arenes and Pyrogallol[4]arenes

Macrocyclic compounds, such as resorcin[4]arenes and pyrogallol[4]arenes, have proven to be useful building blocks in the construction of supramolecular organic frameworks (SOFs) because of their unique bowl‐like shape and ability to interact through variety of intermolecular interactions. Herein, we report the synthesis and crystal structures of two functionalized resorcin[4]arenes and pyroagllol[4]arenes, 4‐hydroxyphenylresorcin[4]arenes, and 4‐hydroxyphenylpyrogallol[4]arenes. These phenyl‐functionalized macrocycles usually have different conformers, such as cone, boat, chair, saddle, and diamond. The successful separation of predominant conformers from the crude product was carried out with solvent‐extraction technique. The shape and molecular arrangement of these conformers in the individual crystal structure was verified with single‐crystal X‐ray diffraction studies.     

Synthesis and Crystal Structure of 4-（2-Chlorophenyl）-5-cyano-3-methyl-6-oxo-1-phenyl-4,5,6,7-tetrahydropyrazolo[3,4-b]Pyridine under Microwave Irradiation

1 INTRODUCTION The pyrazolo[3,4-b]pyridine system has many interesting biological and pharmacological proper- ties, such as active antitubercular agents[1, 2], active agents against gram positive and negative bacteria[3], ACTH(Adrenocorticotropic hormone…