含吡啶-2,6-二酰亚胺单元的大环化合物合成及性质

在硫酸催化作用下,用前体二醛1[1,3-二(2'-甲酰苯氧基)丙烷]和前体二胺2[N,N'-(2-胺基苯基)-2,6-二甲酰亚胺吡啶]合成了[1+1]席夫碱大环化合物3,进一步还原得到饱和大环4。 用¹H NMR、IR、元素分析和质谱等技术手段对大环3和4的组成进行了表征。 采用X射线衍射仪测定了大环3 和4的晶体结构。 用UV-Vis光谱仪对大环3和4与系列阴离子的作用分别进行了考察,结果表明,饱和大环4仅对F^-有明显的选择性作用,并测定了该配位反应的配位比和平衡常数,进一步考察了大环3和4对甲醇的吸附性能。     

6 + 6 Macrocycles derived from 2,6-diformylpyridine and trans-1,2-diaminocyclohexane

While the non-templated reaction of racemic trans-1,2-diaminocyclohexane with 2,6-diformylpyridine leads to a mixture of 2?+?2 and 4?+?4 macrocyclic imines, the reaction of the isolated 2?+?2 macrocycle with cadmium(II) chloride results in the fusion of three smaller macrocyclic units into a large 6?+?6 macrocycle. The X-ray molecular structures of the hexanuclear cadmium complex of this macrocycle as well as the derived 6?+?6 protonated amine reveal multiply folded macrocycles that adopt container-type conformations.     

Synthesis, crystal structure and thermal analysis of tetraiodo-4, 4’-bi-1, 2, 4-triazole

Tetraiodo-4,4’-bi-1,2,4-triazole(1)was synthesized from a reaction of iodine monochloride with 4,4’-bi-1,2,4-triazole(2),which was prepared by a transamination reaction between 4-amine-1,2,4-triazole and N,N-dimethylformamide azine dihydrochloride(3)obtained via a Vilsmeier reaction.The title compound was extensively characterized by melting point,elemental analysis,IR,HRMS and single crystal X-ray diffraction.The single crystal X-ray structural analysis reveals that compound 1 exhibits a stable conformation with the two triazole rings being perpendicular to minimize three-dimensional steric hindrance and stacking through aromatic π...π packing interactions between molecules.The thermal analysis from TGA and DSC indicates that compound 1 decomposes at 275.40℃ and 338.35℃,respectively.     

New polydentate macrocyclic ligands of hybrid amine-imine and amide-imine types as artificial anion receptors. Synthesis and study of anion binding

Three new macrocyclic Schiff bases containing an amine or amide structural fragment along with imine groups were synthesized by condensation of 2,6-bis(2-aminophenyliminomethyl)pyridine (1) and N, N’-bis(2-aminophenyl)pyridine-2,6-dicarboxamide (2) with 2,5-diformylpyrrole (₃) and 2,2-bis(5-formylpyrrol-2-yl)propane (4). The reaction of compound 1 with 3 proceeds abnormally and is accompanied by redox disproportionation of compound 1 in the first step. The structure of the macrocyclic product of this reaction was established by X-ray diffraction analysis. Spectrophotometric titration showed that hybrid macrocycle 10, which was prepared by condensation of compound 2 with 4, possesses the properties of an anion receptor and selectively binds hydrosulfate and dihydrophosphate anions in the presence of bromide and nitrate anions. The structures of 10 and its adduct with the hydrosulfate anion were calculated by density functional theory.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 161–168, January, 2005.     

Mannich reaction of pyrrole and dimethylpyrrole with monoamines and diamines

The Mannich reaction of pyrrole with ethylenediamine dihydrochloride and formaldehyde gave two compounds: N¹,N¹,N²,N²-tetrakis(pyrrol-2-ylmethyl)ethane-1,2-diamine 1 and 1,3-bis(pyrrol-2-ylmethyl)imidazolidine 2 in poor yields. Conversely, the reaction of pyrrole with propylenediamine dihydrochloride afforded macrocyclic compound 3 containing two pyrrole rings bridged by two dimethylenehexahydropyrimidine moieties in 50% yield. The reaction of 2,5-dimethylpyrrole with methylamine hydrochloride and formaldehyde gave novel bicycle 4 consisting of a dimethyltetrahydro-1,3-diazepine ring fused with a 2,5-dimethylpyrrole ring. The reaction of 2,5-dimethylpyrrole with ammonium chloride gave the tripodal ligand tris(2,5-dimethylpyrrol-3-yl)methylamine 5 in 62% yield. The structures of 2–4 were determined by single crystal X-ray diffraction studies.     

Fluorescent detection of phosphate anion by a highly selective chemosensor in water

A macrocyclic dinuclear copper complex, [Cu₂^II(1)Br₄]·2H₂O has been synthesized and characterized by X-ray crystallography, in which each metal ion is pentacoordinated in a square pyramidal environment and the macrocycle is folded to form a boat-shaped empty cavity. As studied by an indicator displacement assay, the dinuclear complex shows strong selectivity for phosphate over sulfate, nitrate, perchlorate and halides in water at physiological pH.     

Nitro derivatives of <Emphasis Type="Italic">N</Emphasis>-alkylbenzoaza-15-crown-5: synthesis,structures, and complexation with metal and ammonium cations

A number of N-alkylnitrobenzoaza-15-crown-5 with the macrocycle N atom conjugated with the benzene ring were obtained. The structural and complexing properties of these compounds were compared with those of model nitrobenzo- and N-(4-nitrophenyl)aza-15-crown-5 using X-ray diffraction, ¹H NMR spectroscopy, and DFT calculations. The macrocyclic N atom of benzoazacrown ethers are characterized by a considerable contribution of the sp3-hybridized state and a pronounced pyramidal geometry; the crownlike conformation of the macrocycle is preorganized for cation binding, which facilitates complexation. The stability constants of the complexes of crown ethers with the NH₄ ⁺, EtNH₃ ⁺, Na⁺, K⁺, Ca²⁺, and Ba²⁺ ions were determined by 1H NMR titration in MeCN-d₃. The most stable complexes were obtained with alkaline-earth metal cations, which is due to the higher charge density at these cations. The characteristics of the complexing ability of N-alkylnitrobenzoaza-15-crown-5 toward alkaline earth metal cations are comparable with analogous characteristics of nitrobenzo-15-crown-5 and are much better than those of N-(4-nitrophenyl)aza-15-crown-5.     

Synthesis and cation binding properties of new arylazo- and heteroarylazotetrathiacalix[4]arenes

New macrocyclic tetrathiacalix[4]arenes have been synthesized by incorporating arylazo-, thiazoleazo- and β-naphthylazo- units in the tetrathiacalix[4]arene molecular architecture through diazotization and coupling reactions. The new compounds have been characterized by ¹H NMR, ¹³C NMR and FAB-MS spectroscopic analysis. X-ray crystallography for one of the new dyes (4a) reveals that the compound is present in the cone conformation. The synthesized macrocycles have been examined for their binding with alkali (Li⁺, Na⁺, K⁺, Cs⁺ and Rb⁺), alkaline earth (Ca²⁺, Mg²⁺ and Ba²⁺) and transition metal cations (Cr³⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Hg⁺, Hg²⁺, Pd²⁺ and Pt²⁺) by UV-visible spectroscopy to reveal selective bathochromic shifts for heavier alkali metal ions (cesium and rubidium) and palladium in a 1:1 and 2:1 stoichiometry respectively. The study has a significant bearing on the development of useful ionic filters and sensor materials.     

Barbatusin and cyclobutatusin,two novel diterpenoids from coleus barbatus bentham

The structure of three diterpenoids from Coleus barbatus, Bentham (Labiatae) having a spirocyclopropyl side chain have been determined: they are barbatusin (1a), 3β-hydroxy-3-deoxybarbatusin (2) and cyclobutatusin (3a). The structures of 1a and 3a were established by X-ray diffraction analysis, and the latter compound has been shown to have an unusual 4-membered ring produced by a bond across C(1) to C(11). Chemical transformations and interconversions are presented, together with spectroscopic studies.     

Bis(benzo)triazinethionoaza-14-crown-4 ether and its complex with CoBr<Subscript>2</Subscript>: Synthesis and crystal structures

8,11,14-Trioxa-22,24,25-triazatetracyclo[19.3.1.0^2,7.0^15,20]pentacosa-2,4,6,15(20),16,18-hexaene-23-thione (L) containing a symmetric triazinethione subunit in its macrocycle and its complex with cobalt(II) bromide of the formula [CoL₂Br₂] · 0.5CHCl₃ (I) were obtained and examined by X-ray diffraction, IR and NMR spectroscopy, and mass spectrometry. It was found that the thiourea fragment in compound L is attached to the nitrogen macrocycle through the C(2) and C(19) atoms, thus forming a substantially nonplanar six-membered triazine ring in a slightly distorted sofa conformation. Its mean-square plane is nearly perpendicular to the mean-square plane of the macrocycle (the dihedral angle between them is 83.3°). Structure L is stabilized by two bifurcate endocyclic hydrogen bonds between the N(1) atom of the triazine ring and the O(1) and O(3) atoms. The size of the macrocyclic cavity is 4.07 Å. The coordination polyhedron of the Co atom is a distorted tetrahedron made up of the sulfur atoms of two monodentate terminal molecules L and two bromine atoms.     

Tubular structures bearing channels in organic crystals composed of adamantane-based macrocycles

Five macrocyclic molecules (1–5) were efficiently synthesized from the dimerization and trimerization of di-substituted adamantane derivatives, which were composed of three different aromatic units and two different linker groups. Three single-crystals were obtained from these macrocyclic molecules, including a set of pseudopolymorphs (3a and 3b) of macrocycle 3 and another macrocycle 5 (5a). Single crystal X-ray analysis revealed that the three monocyclic compounds were rectangular or square in shape with solvent molecules in the cavity. Macrocycle 3 in 3a formed stacks to produce tubular structures with channels that assembled into three-dimensional networks through CH/π interactions.     

Synthesis,crystal structure,and photoluminescence of a zinc metalloporphyrin

A zinc metalloporphyrin, ZnTCPP(acetone) (1) (TCPP = meso-tetra(4-carboxyphenyl)porphyrin), has been prepared via a solvothermal reaction and structurally characterized by single-crystal X-ray diffraction. Compound 1 features an isolated structure with a planar macrocycle and an embedded zinc ion binded to four pyrrole nitrogen atoms and one acetone oxygen atom. Photoluminescent investigation reveals that compound 1 displays an intensive emission in the red region.     

Xylyl derived oxacalixcrowns：Synthesis and crystal structure

Oxacalixcrowns 1, 2 and 3 were synthesized via reactions of dihydroxyoxacalix[2]arene[2]pyrazine 5 with ortho-, meta- and para-bis(bromomethyl)benzenes in a 1:1 fashion. The structures and conformations of 1, 2 and 3 were established by a combination of NMR, mass spectroscopies and single crystal X-ray diffraction analysis.     

Synthesis and structures of copper(II) and cadmium(II) compounds based on pyridazine derivative ligands

The two new compounds [Cu(HODA)₂(H₂O)₂] · 3H₂O (I) and [Cd(HODA)₂(H₂O)₃] (II) (HODA = 6-oxo-1,6-dihydropyridazine-4-carboxylic acid) based on pyridazine derivation ligands have been synthesized and characterized by elemental analysis, infrared spectrum and X-ray single crystal diffraction. X-ray analysis shows that in compound I, Cu²⁺ ion is four-coordinated with a plane square geometry while Cu²⁺ ion in compound II is seven-coordinated with a distorted pentagonal bipyramid geometry. Both of the two units are all connected as 3D supramolecular structures by the intermolecular hydrogen bonds. Moreover, thermal gravimetric analysis of two compounds has been also investigated.     

Synthesis and characterization of two new macrobicyclic salts containing hexahydropyrimidine moieties: experimental and density functional theory studies

Two macrocyclic Schiff base ligands (L¹, L²) and their related reduced forms (L³ and L⁴) have been prepared. In the presence of nickel(II) perchlorate in methanol, the reinforced macrobicyclic salts containing hexahydropyrimidine cation moiety have been developed. Here, it seems that Ni(II) perchlorate acts as oxidizing agent converting methanol to the formaldehyde which in turn bridges two nitrogen atoms of reduced forms of macrocycle producing final products. All Schiff base ligands and their reduced forms together with related salts were characterized by elemental analysis, IR spectroscopy, ¹H and ¹³C NMR, EI-Mass and in the case of [L^3′](ClO₄) salt by X-ray crystallography. The proposed mechanism for the formation of macrobicyclic ligand [L^3′] from the reaction of macrocyclic ligand L³ and formaldehyde has also been studied via density functional theory (DFT).     

Ho(III)希夫碱大环配合物的合成、晶体结构及对DNA的切割活性

本文合成一个新的希夫碱大环配体硝酸Ho(III)配合物 [Ho(H2L)(NO3)2](NO3) (H2L表示大环配体Fig. 1),并进行了系统的物理表征. 晶体结构研究表明: 配合物晶体结构属六方晶系,P 3(1)21空间群,晶胞参数a=1.47213(7) nm,c=2.8998(3) nm,α=90°,γ=120°,V=5.4424(7) nm 3,Z=6,R＝0.0331, wR＝0.0928。中心离子Ho3+位于隔室大环配体的一侧并于希夫碱大环上的两个酚基氧原子和三个氮原子配位,两个双齿配位硝酸根分别从希夫碱大环平面的两侧与中心离子配位使中心离子形成扭曲的九配位三冠三棱柱配位构型。并通过凝胶电泳实验初步研究了该配合物对pBR322质粒DNA的切割作用。     

“S”-shaped isopolyoxotungstate cluster decorated by calcium ions

One novel "S"-shaped isopolyoxotungstate Ca2(H2O)12{Ca4(H2O)18[H2W11O37]2}·20H2O (1) has been successfully synthesized by the conventional aqueous solution method. Single-crystal X-ray diffraction analysis revealed that compound 1 crystallized in triclinic system, space group P-1, with lattice constants a=12.591(3)Å, b=12.738(3)Å, c=17.961(4)Å, α=98.97(3)8, β=99.85(3)8, γ=93.42(3)8. The "S"-shaped cluster was built from two {W11} subunits, four Ca2+linking units and two {Ca(H2O)6}2+ decorating fragments. The electrochemical properties of 1 have been investigated in details.     

Molecular and crystal structures of two β-bend forming monothiated analogues of melanostatin

The molecular and crystal structures of two monothiated analogues of melanostatin, namely t-Boc-L-Proψ(CSNH)-L-Leu-Gly-NH₂ (1)^C and L--Top-L-Leu-Gly-NHEt (2), determined by X-ray diffraction analyses, are reported. In compound (1) the tertiary urethane bond adopts the cis conformation. Both tripeptide amides are folded in a type-II β-bend conformation at the -L-Leu-Gly-sequence. A weak intramolecular H bond, involving the thioamide sulfur atom as the acceptor, is a significant characteristic of compound 1. The two structures are discussed, in particular, in comparison to those of H-L-Pro-L-Leu-Gly-NH₂, and t-Boc-L-Pro-L-Leu-Gly-NH₂, the latter recently solve in the Padova laboratory.     

Selective crown ether based macrocyclization: a model case study from N,N-bis(2-hydroxyalkylbenzyl)alkylamine

A model case of selective crown ether based macrocycles, i.e., [1+1] or [2+2] macrocycles, obtained from a simple reaction of N,N-bis(2-hydroxyalkylbenzyl)alkylamine, HBA, and ditosylated compounds is proposed. For HBA with the methyl group at ortho and para positions, and at N atom, 1, the reaction between this derivative and the ditosylated compound with three, four, five, or eight atom chain length gives only a [1+1] macrocycle. For HBA with the methyl group at ortho and para positions, but a cyclohexyl group at N atom, 2, the reaction gives both [1+1] and [2+2] macrocyclic types when reacting with the ditosylated compound. The present work indicates that the structure of HBA induces selective macrocyclization to provide both [1+1] and [2+2] macrocycles.     

Efficient macrocyclization of U-turn preorganized peptidomimetics: the role of intramolecular H-bond and solvophobic effects

Simple peptidomimetic molecules derived from amino acids were reacted with meta- and para-bis(bromomethyl)benzene in acetonitrile to very efficiently yield macrocyclic structures. The cyclization reaction does not require high dilution techniques and seems to be insensitive to the size of the formed macrocycle. The analysis of data obtained by (1)H NMR, single-crystal X-ray diffraction, fluorescence measurements, and molecular mechanics indicate that folded conformations can preorganize the system for an efficient cyclization. The role played by intramolecular hydrogen-bonding and solvophobic effects in the presence of folded conformations is analyzed.