Macrocyclic Diamides Research Articles

In2Q2: A New Entry of 16-Membered Tetraazamacrocycle Concatenating Indole and Quinoline Units.

A new family of 16-membered macrocycles comprising two indole (In) and two quinoline (Q) units, coined In2Q2, was synthesized. Each unit is diagonally located and concatenated in a head-to-tail fashion, furnishing a non-flat saddle-shaped architecture with C2 symmetry. The synthetic protocol utilizing macrocyclic diamide as a pivotal precursor allowed us to access a series of In2Q2 derivatives bearing various substituents on the periphery. The In2Q2 derivatives and their Zn2+ complexes were emissive in both solution phase and solid state. While the entire architecture of In2Q2 is similar to that of quinoline tetramer TEtraQuinoline, a couple of contrasting physicochemical properties were revealed.

Synthesis and Characterization of Some Novel 18‐Membered‐Ring Tri‐Aza Macrocyclic Diamides Containing Appended Coumarin and their Derived Podands

AbstractIn this research, some new eighteen‐membered‐ring nitrogen‐pivot lariat ethers were synthesized from a tri‐aza macrocyclic diamide containing dibenzosulfide and a coumarin fragment as the sidearm. The aza‐macrocyclic compound used in the synthesis of lariat ethers was obtained from the reaction of dibenzosulfide diester and diethylenetriamine. The corresponding 3‐amidocoumarins were synthesized from the reaction of 3‐aminocoumarins and chloroacetyl chloride in good yields. Moreover, symmetrical bis coumarin podands were prepared by reacting a sulfide or sulfoxide monomer with 3‐amidocoumarin. The structures of the products were identified by IR, 1H NMR, 13C NMR, and mass spectroscopies.

Three 18-membered macrocyclic diamides with differing donor atoms and backbone substituents

Three 18-membered macrocyclic diamides with differing donor atoms and backbone substituents

Static Combinatorial Chemistry: A High-Pressure Approach to the Synthesis of Macrocyclic Benzoamide Libraries.

We investigated the yield and distribution of macrocyclic products formed in combinatorial libraries (CLs) obtained via double-amidation reactions of methyl diesters with α,ω-diamines. The application of the static combinatorial chemistry (SCC) approach allowed us to generate a large number of macrocyclic diamides and tetraamides in single experiments. We show that high-pressure conditions accelerate the macrocyclization process but also have a great impact on the distribution of macrocyclic products in the presented libraries, promoting the formation of macrocyclic compounds and eliminating the linear ones. The distribution of macrocyclic products was also found to be strongly dependent on the structural features of the substrates employed. Furthermore, in three- and four-substrate CLs we observed the formation of a new type of hybrid tetraamides consisting of three different components.

A review on nanomaterial-based electrochemical, optical, photoacoustic and magnetoelastic methods for determination of uranyl cation.

This review (with 177 refs) gives an overview on nanomaterial-based methods for the determination of uranyl ion (UO22+) by different types of transducers. Following an introduction into the field, a first large section covers the fundamentals of selective recognition of uranyl ion by receptors such as antibodies, aptamers, DNAzymes, peptides, microorganisms, organic ionophores (such as salophens, catechols, phenanthrolines, annulenes, benzo-substituted macrocyclic diamides, organophosphorus receptors, calixarenes, crown ethers, cryptands and β-diketones), by ion imprinted polymers, and by functionalized nanomaterials. A second large section covers the various kinds of nanomaterials (NMs) used, specifically on NMs for electrochemical signal amplification, on NMs acting as signal tags or carriers for signal tags, on fluorescent NMs, on NMs for colorimetric assays, on light scattering NMs, on NMs for surface enhanced Raman scattering (SERS)-based assays and wireless magnetoelastic detection systems. We then discuss detection strategies, with subsections on electrochemical methods (including ion-selective and potentiometric systems, voltammetric systems and impedimetric systems). Further sections treat colorimetric, fluorometric, resonance light scattering-based, SERS-based and photoacoustic methods, and wireless magnetoelastic detection. The current state of the art is summarized, and current challenges are discussed at the end. Graphical abstract An overview is given on nanomaterial-based methods for the detection of uranyl ionby different types of transducers (such as electrochemical, optical, photoacoustic, magnetoelastic, etc) along with a critical discussion of their limitations, benefits and application to real samples.

Out-cage metal ion coordination by novel benzoazacrown bisamides with carboxyl, pyridyl and picolinate pendant arms

A new series of macrocyclic diamides with carboxyl, pyridyl and picolinate pendant arms have been synthesized and the stability constants of their complexes with Ni2+, Cu2+, Zn2+, Cd2+, Pb2+ in water were determined. Complexes with a stoichiometry of 1 : 1 (M: L) were found for all ligands with the exception of 15-membered crown ethers with one pendant carboxyl or pyridine group. The ligand containing two picolinate backbone groups exhibits the highest values of the stability constants for all studied cations (logβML = 12.5–15.7). X-ray study of free ligands showed that the introduction of benzene and amide fragments into the macrocyclic moiety provides a flatten open structure of the ligand. The crystallographic analysis of Cu2+ and Zn2+ complexes revealed the external coordination of the metal atom by amine N atoms of the macrocycle and heteroatoms of the pendant groups.

1H-NMR study of the stoichiometry and stability of the Ba2+, Sr2+, Hg2+, Pb2+, K+, Ag+, and Tl+ complexes with a new macrocyclic diamide in acetonitrile–nitrobenzene solvent mixture

Proton NMR technique was utilized to study the complexation reactions of a new macrocycle diamide with Ba2+, Sr2+, Hg2+, Pb2+, K+, Ag+, and Tl+ ions in % 50 (w/w) acetonitrile–nitrobenzene binary mixture. In all the cases, the chemical shifts of the single NMR signals due to the –O–CH2–CH2–O– and Ph–O–CH2– groups of the ligand were determined at 300 K. The exchange between free form of the macrocycle (I) and its complexes was fast on the NMR time scale and just a single population average 1H signal was observed. Formation constants of the resulting 1:1 complexes were determined by computer fitting of the chemical shift–mole ratio data. The stabilities of the resulting 1:1 complexes varying in the order Ba2+ > Sr2+ > Hg2+ > Pb2+ > Ag+ > K+ > Tl+ were determined. For two singlet groups of ligand (I) (Ph–O–CH2– and –O–CH2–CH2–O–), the values of the formation constants which were obtained from data fitting were found to be similar, but shift of the signal for Ph–O–CH2– group was larger than for –O–CH2–CH2–O– group. The theoretical studies on the structures and the energetic data of the five conformers of ligand macrocycle (I) and the complexes with Ba2+, Sr2+, Hg2+, Pb2+, Ag+, K+, and Tl+ have been performed by DFT-B3LYP/6-31G* method for ligand (I) and QM-PM6 method for the complexes. The comparison of the experimental and theoretical data with respect to the formation constants and the structures of the complexes have shown good agreement.

Preparation and characterization of organic–inorganic adduct of dinaphtosulfide macrocyclic diamide and silicotungstic acid: study of interaction in solid and solution phase

An adduct compound containing dinaphtosulfide macrocyclic diamide and silicotungstic acid was prepared and characterized by elemental analyses, IR, UV–VIS spectrophotometry and diffuse reflectance spectrometry. The stoichiometry and stability of adduct were studied by conductometry in nitrobenzene (NB) solvent. This is the first report of the interaction of crown ether containing sulfur heteroatom and heteropoly acid. The interaction of the adduct compound with Hg2+ was studied by spectrophotometric and pH-metric methods in NB solvent. The formation constant of the Hg2+-adduct complex was calculated from the computer fitting of the obtained data. The extraction of Hg2+ and Pb2+ was studied from aqueous solution using this adduct compound.

A new potentiometric sensor based on a high-performance composite for nanomolar determination of mercury (II) in environmental samples

A new potentiometric sensor for the rapid determination of Hg2+ based on modified carbon paste electrode consisting of room temperature ionic liquid, 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6), multi-walled carbon nanotubes (MWCNTs), alumina nanoparticles and a synthetic macrocyclic diamide ‘7,10,13-triaza-1-thia-4,16-dioxa-6,14-dioxo-2,3;17,18-dinaphtho-cyclooctadecane’ as an efficient ionophore was constructed. Prepared composite is an ideal paste because it has low drift of potential, high selectivity and fast response time (10 s), which leads to a more stable potential signal. The morphology and properties of electrodes surface were characterised by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy. A linear dynamic range of 2.01–2.01 × 107 µg L−1 with detection limit of 1.40 µg L−1 Hg2+ was obtained at pH range of 2.5 to 4.5. The prepared modified electrode shows several advantages such as simple preparation method, high stability of the composite paste, high sensitivity, long-term life time (at least 13 weeks) and remarkable potentiometric reproducibility. The modified electrode was successfully applied for the accurate determination of trace amounts of Hg 2+ in environmental samples.

Synthesis of Novel Benzo‐substituted Macrocyclic Ligands Containing Thienothiophene Subunits

A facile synthetic approach was adopted toward the synthesis of benzo‐fused macrocyclic ligands with thienothiophene group incorporated into the ring system. Thus, treatment of bis(bromomethyl) compound 2 with the K salt of the appropriate bis(phenol)s 3a, 3b, 3c, 3d in boiling DMF led to the formation of the novel macrocyclic diamides 4a, 4b, 4c, 4d in 39–58% yield. Reaction of 2 with the potassium salt (obtained upon treatment of salicylaldehyde 5 with ethanolic potassium hydroxide) in refluxing DMF afforded the novel bis(aldehyde) 6 in 73% yield. Cyclocondensation of 6 with the appropriate bis(N‐substituted) cyanoacetamide derivatives 7a and 7b afforded the target macrocycles 8a and 8b in 48 and 55% yields, respectively. Reaction of the bis(aldehyde) 6 with 1,3‐ and 1,4‐diaminopropane 9a and 9b in refluxing ethanol under high‐dilution conditions afforded the corresponding macrocyclic Schiff bases 10a and 10b in 41 and 37% yields, respectively. Cyclocondensation of 6 with 1,3‐bis(4‐amino‐5‐phenyl‐3‐ylsulfanylmethyl)propane (15) in glacial acetic acid under high‐dilution conditions gave the macrocyclic Schiff base 14 in 46% yield. On the other hand, cyclocondensation of bis(aldehydes) 17 and 20 with 3,4‐bis(4‐amino‐5‐phenyl‐3‐ylsulfanylmethyl)thienothiophene 16 in refluxing acetic acid under high‐dilution conditions afforded unexpectedly the novel condensed heteromacrocycles 18 and 21 in 33 and 28%, respectively. The novel bis(amine) 16 was obtained in 50% yield upon treatment of 2 with 4‐amino‐1,2,4‐triazol‐3‐thione 11 in ethanol/water mixture containing potassium hydroxide.

Synthesis, metal ion complexation and first use of a thia-aza substituted macrocyclic diamide as a novel sensing material for preparation of selective and sensitive poly(vinyl chloride)-membrane potentiometric sensors for Ag+ ion

A novel thia-aza substituted macrocyclic diamide 7,10,13-triaza-1-thia-4,16-dioxa-20,24-dimethyl-2,3;17,18-dibenzo-cyclooctadecane-6,14-dione (L) was synthesized and stability of its complexes with several alkaline earth, transition and heavy metal ions were studied conductometrically in methanol solution. The resulting 1:1 Ag+–L complex found to be the most stable one among all cation complexes studied. The optimized structures of the ligand and its Ag+ complex were also investigated. Based on the preliminary results thus obtained, L was used as an excellent sensing material to prepare polymeric membrane (PME) and coated graphite (CGE) silver-selective electrodes. The electrodes revealed a Nernstian behavior over wide Ag+ ion concentration ranges (i.e., 2.0 × 10−6–1.0 × 10−2 M for PME and 5.0 × 10−7–1.0 × 10−2 M for CGE). The potentiometric responses were independent of pH of the test solution in the range 2.9–6.8. The electrodes possessed advantages of low resistance, relatively fast response time, long lifetimes and, especially, good selectivity relative to a wide variety of other cations. The electrodes were used, as indicator electrodes, in the potentiometric titration of silver ion and in the determination of Ag+ ion in waste water, photographic emulsion, radiographic and photographic films and dental amalgams.

Study on the interaction between dinaphthosulfide-substituted macrocyclic diamides and some metal ions: experimental measurements vs. quantum mechanical calculations

Complexation properties of dinaphthosulfide-substituted macrocyclic diamides 1 and 2 with some metal cations that have been obtained by conductometric method are described with quantum mechanics calculations. To do this, the most stable structures of ligands, Hg2+-ligand complexes, ligand-MeOH and ClO4−–MeOH are optimized at HF/Lanl2dz level of theory and the most important interactions are analyzed by atoms in molecules (AIM) theory. These calculations predict the existence of strong interaction between Hg2+ cation and ligands 1 and 2, particularly, S–Hg2+ interaction. The different conductometric behaviors of complexation of ligands 1 and 2 with metal ions are interpreted on the basis of the calculated intramolecular hydrogen bonds in ligands and intermolecular hydrogen bonds between ligands and methanol as a solvent and perchlorate as a counter ion. In addition, binding energies between Hg2+ and ligands are also calculated by HF/Lanl2dz level of theory. Results show that all theoretical predictions are in line agreement with the experimental data.

Synthesis of Nano Machines Based on Catenanes and Rotaxanes

A nanomachine is an assembly of a discrete number of supramolecular components designed to perform mechanical like movements as a consequence of appropriate external stimuli. In this research work we wish report synthesis of a part of nanomachines are based on interlocked macrocycle named rotaxanes, catenanes, pseudorataxane and knots, that Bis aza thiacrown compound (5) was synthesized by macrocyclic diamide (4) and 2, 6-dicarbonyldicholoride pyridine in dry CH2Cl2 and was refluxed in presence of Et3N in good yield. The structures of these compounds were confirmed by IR, 1H NMR, 13C NMR and elemental analysis.

ChemInform Abstract: 3-Allylsalicylaldehyde and 3-Allylsalicylic Acid Derivatives: Synthesis and Conversion to Allyl-Crown Compounds as New Potential Precursors for Polymer Supported Crown Compounds.

3-Allylsalicylaldehyde and methyl 3-allylsalicylate are converted in moderate to good yields into the new diallyl substituted 14–16, 23–25-membered macrocyclic crown diamides 8a–h, 10a–c, 15a,b and the 21–23-membered dithiatetraaza-crown compounds 17a–g, 18a–c.

New heavy metal ion-selective macrocyclic ligands with mixed-donor atoms and their extractant properties

Synthetic procedures for new macrocyclic diamides with N2S4O3- and N2S5O3-donors were given. The corresponding macrocyclic ligands were prepared by reaction of NaBH4 with the macrocyclic diamides in the presence of boron triflouride ethyl etherate in dry tetrahydrofuran. The solvent extraction method was used to evaluate metal-ion binding properties of the new ligands. The values of the extraction constants (log K ex) and the complex compositions were determined for the extracted complexes. The solvent extraction experiments suggested that the reduced N2S5O3-donor macrocycle has Ag+ selectivity compared to Pb2+, Co2+, Ni2+, Mn2+, and Cd2+ for chloroform as organic solvent.

ChemInform Abstract: Synthesis of New Benzo-Substituted Macrocyclic Ligands Containing Quinoxaline Subunits.

Abstract The macrocyclic Schiff bases 20 – 25 were prepared by cyclocondensation of the bis aldehydes 12 – 15 with the appropriate diaminoalkanes 17 – 19 . Reduction of the latter with NaBH 4 afforded the corresponding azacrown ethers 27 – 30 . Heating of the aldehydes 12 – 16 in refluxing acetic acid afforded the corresponding 2,3-bis(benzofuranyl)quinoxalines 33 – 37 . Nucleophilic reaction of the bis phenols 45 – 48 , 54 , 56 , 57 with the appropriate dihalo compounds 1 , 38 afforded the corresponding macrocyclic diamides 49 – 52 and 1,ω-bis[quinoxalino(2,3- b )benzoxazepino-13-on-yl]alkanes 60 , 61 , respectively.

ChemInform Abstract: Macrocyclic Amides as Ionophores for Lead-Selective Membrane Electrodes.

A series of ionophores based on diaza 18-crown-6 units possessing amide and sulfonamide functions were prepared. Their complexing properties were investigated in solvent polymeric membrane electrodes. The influence of the structure of ligands, prepared on the selectivity of complexation, was examined with special respect to lead ions. Substantial changes were observed, when methyl substituent in benzene rings was replaced with hydrogen, bromomethyl or nitro group. All results were rationalized on basis of steric and electronic effects. The synthesis and complexation studies of supramolecular compounds is of continuous interest [1]. Several types of ionophores were designed for medicine, biochemistry and environmental pollution monitoring [2]. For pollution monitoring some of ionophores, selective towards heavy metal cations, are of general interest. Previously, we have shown that macrocyclic polyether diamides can be readily prepared [3] and successfully applied in ion-selective electrodes [4], showing high selectivity towards Pb 2+ over other divalent cations. This result prompted us to the conclusion that the introduction of external amide function into the macrocyclic ring can increase the stability of electrodes and improve the complexing properties of ionophores towards divalent cations. This paper deals with the preparation of a series of external macrocyclic diamides derived from diaza-18-crown-6. Complexing properties of prepared compounds were investigated in ion-selective polymeric membranes system with a special respect to lead cation.

A novel PVC-membrane optical sensor for highly sensitive and selective determination of UO 22+ ion based on a recently synthesized benzo-substituted macrocyclic diamide and dibenzoylmethane

A highly sensitive ion-selective bulk optode membrane for sensing UO 2 2+ ion based on plasticized poly(vinyl chloride) containing 6,7,9,10,12,13,15,16,23,24,25,26-dodecahydrodibenzo[n,v][1,4,7,10,13,17,20]pentaoxa-diazacyclotricosine-22,27-dione as ionophore, dibenzodylmethane as chromoionophore and sodium tetraphenylborate as an ionic additive was prepared. In addition to its high stability, reproducibility and relatively long lifetime, the proposed optical sensor revealed good selectivity for uranyl ion over a large number of alkali, alkaline earth, transition, and heavy metal ions. The proposed sensor displays a calibration response for UO 2 2+ over a concentration range of 4.3 × 10 −6 to 2.5 × 10 −8 M with a limit of detection of 8.0 × 10 −9 M and a response time of less than 12 min. The proposed optical sensor was applied successfully to the determination of UO 2 2+ ion in tap water and Khoshumi mine concentrated solution samples.

Selective homogeneous liquid-liquid extraction and preconcentration of copper(II) into a micro droplet using a benzo-substituted macrocyclic diamide, and its determination by electrothermal atomic absorption spectrometry

A fast and reliable method was developed for the selective separation and preconcentration of Cu2+ ions using homogeneous liquid-liquid extraction using a novel benzo-substituted macrocyclic diamide, 5,6,7,8,9,10-hexahydro-2H-1,13,4,7,10-benzodioatriazacyclo-pentadecine-3,11(4 H,12 H)-dione, as a selective complexing agent. An aqueous solution of Zonyl FSA (FSA) was used as a phase-separation agent at pH 4.5. Electrothermal atomic absorption spectrometry was used for Cu2+ determination after preconcentration. The influences of pH, type and volume of the water-miscible organic solvent, concentration of FSA, concentration of the ligand and the effect of diverse ions were investigated. Factorial design and response surface methods were used for the optimization purposes. Under the optimum experimental conditions, 50 ng of Cu2+ in 5 mL aqueous sample could be extracted quantitatively into 76 µL of the sediment phase. The maximum preconcentration factor was 65. The calibration curve was linear in the concentration range 0.2 to 4.0 µg L−1. The detection limit and relative standard deviation were 4 ng L−1 and 4.6%, respectively. The method was successfully applied to the extraction and determination of Cu2+ in natural water samples.

Synthesis of macrocyclic compounds with steric barriers in macroheterocycle proceeding from (Z)-1,2,3,6-tetrahydrophthalic and phthalic acids

Using 1,2-dibromoethane, (E)-1,4-dibromo-2-butene, (Z)-1,2,3,6-tetrahydrophthalic and phthalic acids we obtained along [1+1] scheme uncommon macrocyclic compounds containing ester groups, multiple bonds, and amide moieties in the macroheterocycle. The neutralization of bis-acids with ethylenediamine gave the corresponding macrocyclic diammonium salts that on heating to the melting point were converted into the corresponding macrocyclic diamides. The structure of compounds obtained was established from the elemental analyses, IR and NMR spectra.