Complexation properties of macrocyclic polyether-diester compounds containing furan and benzene subcyclic units

A new series of macrocyclic polyether-diester ligands containing a furan subcyclic unit is reported. In contrast to other macrocyclic ligands, the twenty-four membered ring diester compounds containing either a furan or benzene subcyclic unit complex more strongly with benzylammonium perchlorate than do the eighteen membered ring compounds.     

A simple crab-like cyclization procedure to prepare polyaza-crowns and cyclams with one or two unsubstituted macroring nitrogen atoms or with a hydroxy group

A simple and convenient method to prepare polyaza-crowns and cyclams containing one or two unsubstituted macroring nitrogen atoms or a hydroxy group is described. The process involves the reaction of a bis- chloroamide with a bis-secondary amine followed by reduction of the cyclic diamide. The bis-chloroamide resembles a crab with two reactive organochloride groups poised and ready to react, hence the term “crab-like” cyclization. Nine new polyaza-crowns and cyclams were prepared.     

Synthesis of mixed‐donor azaoxathia macrocyclic tetraamides,acyclic polyether di/and tetraamides and their C‐pivot lariat derivatives

The macrocyclic tetraamides 11a‐e and 15‐hydroxy macrocyclic tetraamides 23a‐c were prepared in good yields by the nucleophilic reaction of the potassium salts of the bis‐phenoles 10a‐c with the appropriate dihalo compounds 5a‐d and 15. Moreover, the acyclic diamides 7, 9, 17‐21 and bis‐acyclic tetraamide 22 were obtained in high yields by the reaction of the appropriate dichloro compounds with different phenoxides and secondary amines. Acylation of 23a‐c with different acid chlorides gave the corresponding esters 24a‐c. Compounds 24a‐c reacted with different secondary amines to afford the corresponding novel lariat macrocycles 25a‐d in high yields.     

Proton-ionizable crown compounds. 11. Synthesis of macrocyclic ligands containing two sulfonamide groups and chloro substituents or pyridine subcyclic units and a preliminary study of cation transport by three of these ligands

Five new macrocyclic ligands each containing two sulfonamide groups have been prepared. Three of these compounds contain one or two chloro substituents and the other two have one or two pyridine subcyclic units. A seventeen-membered ring ligand (4) was found to be an excellent transport agent for all alkali metal cations in a water-methylene chloride-water bulk liquid membrane system when the pH of the source phase was 13 or higher. The chlorine-substituted analog (5) was a poor transport agent for the alkali metal cations possibly because the chlorine atom blocked entry to the macrocycle cavity. An open-chain analog containing two sulfonamide groups was particularly effective in transporting cesium ions.     

Relative stability of linear and cyclic configurations of systems containing four atoms of nitrogen,carbon, or oxygen

Conclusions The present article has been devoted to an investigation of the relative stability of various conceivable structures of systems X₄ (where X=C, CH, N, or O). We regard the comparative regularities which we have discovered as reliable, in spite of the use of MHM, in which no account is taken in any explicit way of the interelectronic interaction. We have considered homoatomic systems, where, on the qualitative side many conclusions are essentially of a theoretical-group character, while from a quantitative point of view the accuracy of the results obtained is increased because of the justifiable similarities assumed in the approximations of the matrix elements (both diagonal and nondiagonal). We have also investigated the geometry of the molecules, a problem of the solution of which the MHM method (as shown by comparing this with the SSP-MO [26] method) is remarkably effective.The main results of the present work are in our view to be found in the great similarity discovered in the structures of the systems C₄H₄ and N₄ (and their appreciable difference from the structure of the O₄ molecule). Therefore, returning to the over-all problem formulated at the beginning of this article, we are able to emphasize that the hypothesis of the possible formation of the N₄ system by combination of molecular nitrogen in certain complexes of the transition metals [1] is still further confirmed.N. S. Kurnakov Institute of General and Inorganic Chemistry of the Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 10, No. 4, July–August, 1969.     

Synthesis and characterization of two zinc(II) macrocyclic Schiff-base complexes containing piperazine moiety, crystal structure of one complex

Two symmetrical and asymmetrical Zn(II) complexes of a pentadentate (N₅) macrocyclic Schiff-base ligands, were prepared via templated [1 + 1] cyclocondensation of 2,6-diacetylpyridine with two different amines containing piperazine moiety. The complexes have been characterized by a variety of methods including, IR, FAB mass spectrometry, elemental analysis and conductivity measurements. The crystal structure of the asymmetric complex, [ZnL¹Br]ClO₄ was determined by X-ray diffraction. It is shown that in the solid state the complex adopts a distorted pentagonal–pyramidal geometry, with the macrocycle in the pentagonal plane and the bromide ion in the axial position.     

Synthesis of new proton-ionizable and neutral macrocyclic,macrobicyclic and macrotricyclic crown compounds containing dibenzo-16-crown-5 units

Fifteen new macrocyclic, macrobicyclic and macrotricyclic crown ether compounds with sym-dibenzo-16-crown-5 units have been prepared. The series includes macrocyclic polyether and bis(crown ether) compounds with proton-ionizable carboxylic or phosphonic acid monoethyl ester groups and bis(crown ether) and macrotricyclic polyether compounds with two sym-dibenzo-16-crown-5 units linked by amide, diamide, or diester functions.     

Syntheses,characterizations and crystal structures of monomeric or macrocyclic compounds of di- or triorganotin (IV) moieties with 4,4′-thiodibenzenethiol

Six organotin compounds with 4,4′-thiodibenzenethiol (LH₂) of the type R_nSnL_4−nSnR_n (n = 3: R = Me 1, Ph 2, PhCH₂3, n = 2: R = Me 4, Ph 5, PhCH₂6) have been synthesized. All compounds were characterized by elemental analysis, IR and NMR (¹H, ¹³C, and ¹¹⁹Sn) spectra. The structures of compounds 1, 2, 4, 5 and 6 were also determined by X-ray diffraction analysis, which revealed that compounds 1 and 2 were monomeric structures, compounds 4, 5 and 6 were centrosymmetric dinuclear macrocyclic structures, and all the tin(IV) atoms are four-coordinated. Furthermore, supramolecular structures were also found in compounds 1, 2, 4, 5 and 6, which exhibit one-dimensional chains, two-dimensional networks or three-dimensional structures through intermolecular C–H?S weak hydrogen bonds (WHBs), non-bonded Sn?S interactions or C–H?π interactions.     

Preparation, spectral and biological investigation of formaldehyde-based ligand containing piperazine moiety and its various polymer metal complexes

A novel tetradentate salicylic acid-formaldehyde ligand containing piperazine moiety (SFP) was synthesized by condensation of salicylic acid, formaldehyde and piperazine in presence of base catalyst, which was subjected for the preparation of coordination polymers with metal ions like manganese(II), cobalt(II), copper(II), nickel(II) and zinc(II). All the synthesized polymeric compounds were characterized by elemental analysis, IR, (1)H NMR and electronic spectral studies. The thermal stability was determined by thermogravimetric analysis and thermal data revealed that all the polymer metal complexes show good thermal stability than their parent ligand. Electronic spectral data and magnetic moment values revealed that polymer metal complexes of Mn(II), Co(II) and Ni(II) show an octahedral geometry while Cu(II) and Zn(II) show distorted octahedral and tetrahedral geometry respectively. The antimicrobial screening of the ligand and coordination polymers was done by using Agar well diffusion method against various bacteria and fungi. It was evident from the data that antibacterial and antifungal activity increased on chelation and all the polymer metal complexes show excellent antimicrobial activity than their parent ligand.     

Preparation, characterization, and application of a new stationary phase containing different kinds of amine groups

A new stationary phase containing primary amine and tertiary amine groups was synthesized and its structure was confirmed by infrared spectra, elemental analysis, and zeta potential. This new material was packed into a stainless steel column and the effect of acetonitrile (ACN) content in mobile phase on retention was evaluated using probes of nucleosides, sulfanilamides, and quinolone compounds. This showed hydrophilic interaction, ion interaction, or a mixed-mode retention mechanism for different kinds of solutes, respectively. The effects of the pH and ion strength of the mobile phase were investigated to further understand the retention mechanism of the new stationary phase. The interaction forces caused by the new phase included adsorption, electrostatic function, and ion exchange. The new material could be used as a stationary phase in different high-performance liquid chromatography modes.     

Proton-ionizable crown compounds. 10. Preparation and structural studies of macrocyclic ligands containing two sulfonamide units and with seventeen to twenty-six ring members

Eight new macrocylic ligands each containing two sulfonamide groups have been prepared. Six of these compounds have both the sulfur and nitrogen atoms of the sulfonamide units substituted with aromatic rings. The nitrogen atoms of the other two compounds have alkyl ring connections. X-ray crystal structure data were obtained for new macrocyclic compounds of 20 and 23 ring members. Each crystal structure showed two molecules in the asymmetric unit. Molecule A of 5 and both molecules of 7 exist in a compact conformation suggesting that they could wrap around a metal ion during complexation. Some of these compounds will be used as cation carriers in a bulk liquid membrane system.     

Behavior of a polypyrrole solid contact pH-selective electrode based on tertiary amine ionophores containing different alkyl chain lengths between nitrogen and a phenyl group.

We compared the slopes of the EMF responses and the response range of a solid contact electrode based on a tribenzylamine ionophore with those based on a tris(2-phenylethyl)amine ionophore and a tris(3-phenylpropyl)amine ionophore. Their slopes of the EMF responses showed, respectively, 57.7, 58.1, 59.0 mV pH(-1) (at 20 +/- 0.2 degrees C). Also, the linear pH response dynamic ranges were 2.74-10.63 for tribenzylamine-based SCEs, pH 4.47-12.59 for tris(2-phenylethyl)amine, and pH 4.60-13.24 for tris(3-phenylpropyl)amine. When the slopes of the EMF responses and the response range were considered, as the length of the replaced alkyl chain increased between the nitrogen atom and the phenyl group in the ionophore, though the dynamic range and the slopes of the EMF responses of these electrodes did not show any particularly different results, their response ranges moved toward the alkali range (shifted to pH 14). When it was directly applied to cow's milk (in pH range of 6.0-8.5), we could obtain the same satisfying results. This electrode continuously contacted a Tris 7.50 buffered solution as well as cow's milk for one month without any loss of performance. Also, especially, these electrodes showed very good results, such as stabilization of the base potential as well as the best reproducibility and response time (< 10 s).     

SINDO1 II. Application to ground states of molecules containing carbon,nitrogen and oxygen atoms

Molecular geometries, binding energies, ionization potentials and dipole moments are calculated by the SINDO1 method for a large number of molecules containing C, N and O atoms. Comparison is made with MINDO/3, MNDO and where possible with STO-3G results. The explicit data and an error statistics show the relative merits of SINDO1.     

Preparation of silica nanoparticles catalysed by small organic tertiary amine and applications in surface coating with antireflective/antifogging properties

Herein, a facile strategy which is based on Stöber method was presented in the preparation of sol–gel that contains silica nanoparticles with tunable diameter adopting small organic tertiary amine including trimethylamine, triethylamine and tri-n-propylamine (TPA) as the catalysts. The size of the resulting silica particles decreased sharply with extending the length of alkyl chain bonded on tertiary amine. The sub-10 nm silica nanoparticles were prepared while employing TPA as basic catalyst. Silica particles were characterized by transmittance electron microscopy, scanning electron microscopy and dynamic light scattering. Furthermore, after being coated by the as-prepared sol containing sub-10 nm silica particles, the glass substrate exhibited good antireflective property with the maximum transmittance as high as 96.2 % compared with that of the bare at about 91 %. Also, the coated glass showed good antifogging property. Finally, the underlying mechanism responsible for the formation of ultrasmall silica nanoparticles was proposed taking into account the steric barrier of protonated tertiary amine molecules anchored at silica nuclei surface by electrostatic interactions.     

Big macrocyclic assemblies of carboranes (big MACs): synthesis and crystal structure of a macrocyclic assembly of four carboranes containing alternate ortho- and meta-carborane icosahedra linked by para-phenylene units

The macrocyclic compound, [1,2-C₂B₁₀H₁₀-1,4-C₆H₄-1,7-C₂B₁₀H₁₀-1,4-C₆H₄]₂ (5)—a novel cyclooctaphane, was prepared by condensation of the C,C′-dicopper(I) derivative of meta-carborane with 1,2-bis(4-iodophenyl)-ortho-carborane. The X-ray crystal structure of 5·C₆H₆·6C₆H₁₂ was determined at 150 K, revealing an extremely loose packing mode. Molecule 5 has a crystallographic C_s and local C_2v symmetry; the macrocycle adopts a butterfly (dihedral angle 143°) conformation with the ortho-carborane units at the wingtips and the phenylene ring planes roughly perpendicular to the wing planes. Multinuclear NMR spectra suggest that molecule 5 in solution inverts rapidly via the planar D_2h geometry, which (from ab initio HF/6-31G* calculations) is only 1 kcal mol⁻¹ higher in energy than the C_2v one. An attempt to prepare an even larger macrocycle, comprising three para-carborane and three ortho-carborane units linked by six para-phenylene units, was unsuccessful.     

Synthesis of proton‐ionizable acyclic,macrocyclic and macrobicyclic compounds containing one or two triazole groups

New acyclic, macrocyclic and macrobicyclic compounds containing one or two proton‐ionizable triazole groups are prepared and characterized. The series includes six podands, a macrocycle with one triazole and one pyridine unit in the ring, a bis‐triazolo macrocycle with four pentafluorobenzyl substitutents, and two bis(crown ethers) with a triazolo group connecting the two polyether rings. The solid‐state structure and solubility in supercritical carbon dioxide are determined for the bis‐triazolo macrocycle with pendant pentafluorobenzyl groups.     

Electronic structure and spectra of fused n/m ring systems with one or two bridgehead nitrogen atoms

Electronic structures and absorption spectra of the quinolizinium cation, all its monoaza-derivatives and the pyridazo(1.2-a)pyridazinium dication, have been computed by using the Pariser-Parr-Pople method, including all singlet mono-excited electronic configurations. The assignment of the observed bands of the quinolizinium cation has been made by comparing its observed transition energies and intensities with those of naphthalene, quinoline and isoquinoline. Discussion is given on reactivity and band interpretation.

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Zusammenfassung Die Elektronenstrukturen und Absorptionsspektren des Quinolizinium Kations und aller seiner Monoazaderivate und des Pyridazo(1,2-a)-pyridazinium Dikations, werden nach der Pariser-Parr-Pople Methode berechnet, wobei alle einzeln angeregten Konfigurationen berücksichtigt werden. Die Banden des Quinolizinium Kations werden durch einen Vergleich der beobachteten Übergangsenergien und Intensitäten mit denen des Naphthalins, Quinolins und Isoquinolins zugeordnet. Reaktivität und Bandeninterpretation werden diskutiert.

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Résumé La structure électronique et les spectres d'absorption du cation quinolizinium, de tous ses monoazadérivés et du dication pyridazo(1,2-a)pyridazinium ont été calculés par la méthode de Pariser-Parr-Pople, avec intéraction de toutes les configurations singulets mono-excitées. L'attribution des bandes d'absorption du cation quinolizinium a été faite en comparant ses énergies de transition et intensités observées avec celles du naphthaléne, quinoléine et isoquinoléine. On a aussi discuté la reactivité et l'interprétation des bandes.