Mild template synthesis of a copper(II)-containing macrocyclic compound with 4,4,6-trimethyl-2,3,7,8-tetraazanonen-6-dithiohydrazide-1,9 in a gelatin-immobilized matrix

The complexing processes in the triple copper(II)–thiocarbohydrazide–propanone system taking place in a copper(II) hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous-alkaline solutions (pH12), containing thiocarbohydrazide and propanone, have been studied. Template synthesis leading to a macrocyclic coordination compound with the tetradentate N,N,S,S-donor ligand, (4,4,6-trimethyl-2,3,7,8-tetraazanonen-6-dithiohydrazide-1,9), occurs under these specific conditions when thiocarbohydrazide and propanone are the ligand synthons.     

Template synthesis in the nickel(II)–thiocarbohydrazide–propanone triple system

The complexing process proceeding in the Ni^II–thiocarbohydrazide (H₂N–H–NC(=S)–NH–NH₂)–propanone triple system in EtOH solution and nickel(II)hexacyanoferrate(II) gelatin-immobilized matrix has been studied. It has been found that in the first case, template synthesis leading, as a minimum, to formation of three coordination compounds of Ni^II with (N,N,S,S)-donor tetradentate ligands having NiL¹, NiL² and NiL³compositions where L¹ is 4,6,6-trimethyl-2,3,7,8-tetraazanonen-3-di(thiohydrazide)-1,9, L² is 4,6,6,12-tetrametyl-1,9-dithio-2,3,7,8,10,11-hexaazatridekadien-3,11-hydrazide-1 and L³ is 2,8,10,10,16-pentamethyl-5,13-dithio-3,4,6,7,11,12,14,15-octaazaheptadekatrien-2,7,15 is observed, whereas in the gelatin-immobilized matrix, a complexing process in the system considered does not occur.     

Complexing processes in M(II)-dithiomalonamide-diacetyl triple systems (M= Ni,Cu) in ethanol solution and in a metal(II)hexacyanoferrate(II) gelatin-immobilized matrix materials

The complexing processes in the M ^II -dithiomalonamide-diacetyl triple system (M=Ni, Cu) occuring in the nickel(II)- and copper(II)hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous alkaline solutions (pH~12) containing dithiomalonamide and diacetyl at room temperature, and between MCl₂, dithiomalonamide and diacetyl in EtOH solutions upon heating to$80°C, have been studied. In the Ni ^II -dithiomalonamide-diacetyl system, template synthesis occurs in EtOH solution but does not occur in the gelatin-immobilized matrix, whereas in the Cu ^II -dithiomalonamide-diacetyl system, template synthesis occurs in the gelatin-immobilized matrix but not in EtOH solution. Dithiomalonamide and diacetyl are the ligand synthons in the processes indicated.     

Mild template synthesis of copper(II)-containing macrocyclic compounds in the CuII–1,2-diaminoethanedithione-1,2–ethanedione-1,2 and CuII–1,2-diamino-ethanedithione-1,2–butanedione-2,3 triple systems into Cu2[Fe(CN)6]-gelatin-immobilized matrix implantates

The complexing processes in the Cu^II–1,2-diaminoethanedithione-1,2–ethanedione-1,2 and Cu^II–1,2-diaminoethanedithione-1,2–butanedione-2,3 triple systems occuring in the copper(II)hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous alkaline solutions (pH~12) containing 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-1,2 under room temperature, and between MCl₂, 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-1,2 in the ethanol solutions, upon heating up to ~80 °C, have been studied. In both systems indicated, template synthesis occurs in the gelatin-immobililized matrix but does not occur in the ethanol solution. As a result of template synthesis, macrocyclic Cu^II chelates with 2,7-dithio-3,6-diazaoctadien-3,5-dithioamide-1,8 and its 4,5-dimethylsubstituted derivative are formed in the gelatin-immobililized matrix. 1,2-diaminoethanedithione-1,2 and ethanedione-1,2 or butanedione-2,3 are the ligand synthons in the processes indicated.     

Towards stabilization of the potential response of Mn(III) tetraphenylporphyrin-based solid-state electrodes with selectivity for salicylate ions

Journal of Solid State Electrochemistry - We report a new type of solid-state electrode (type I) of a simple design with polyvinyl chloride membranes based on Mn(III) tetraphenylporphyrin and with...     

Spectrum of one-dimensional oscillations in the combined stratified medium consisting of a viscoelasticmaterial and a viscous compressible fluid

Two averaged (effective) models corresponding to transverse and longitudinal oscillations in a periodic combined stratified medium are constructed. The medium considered consists of alternating layers of an isotropic viscoelastic material and a viscous compressible fluid. The dependence of the qualitative characteristics of the spectra of the averaged models on the linear dimensions of the stratified medium specimen is investigated.     

The spectrum of natural vibrations in a medium composed of layers of elastic material and viscous fluid

In this study, we investigated the spectral properties of two homogenized models corresponding to transverse and longitudinal vibrations in a microinhomogeneous layered combined medium. It is established that investigation of the spectrum of each model is reduced to finding the roots of the corresponding cubic equations, and the qualitative difference between the spectra of these models is also revealed.     

Ratiometric Detection of ATP by Fluorescent Cyclophanes with Bellows-Type Sensing Mechanism

Pyrene-based cyclophanes have been synthesized with the aim to realize a bellows-type sensing mechanism for the ratiometric detection of nucleotide concentrations in a buffered aqueous solution. The sensing mechanism involves the encapsulation of a nucleobase between two pyrene rings, which affects the monomer-excimer equilibrium of the receptor in the excited state. The nature of the spacer and its connection pattern to pyrene rings have been varied to achieve high selectivity for ATP. The 1,8-substituted pyrene-based cyclophane with the 2,2’-diaminodiethylamine spacer demonstrates the best selectivity for ATP showing a 50-fold increase in the monomer-excimer emission ratio upon saturation with the nucleotide. The receptor can detect ATP within the biological concentrations range over a wide pH range. NMR and spectroscopic studies have revealed the importance of hydrogen bonding and stacking interactions for achieving a required receptor selectivity. The probe has been successfully applied for the real-time monitoring of creatine kinase activity.     

Homogenizing the viscoelasticity problem with long-term memory

The system of integro-differential equations describing the small oscillations of an ?-periodic viscoelastic material with long-term memory is considered. Using the two-scale convergencemethod, we construct the systemof homogenized equations and prove the strong convergence as ? → 0 of the solutions of prelimit problems to the solution of the homogenized problem in the norm of the space L ².     

Crystal Structure of Tetra- and Pentasodium Salts of Nitrilotris(methylenephosphonic Acid)

Tetra- and pentasodium salts of nitrilotris(methylenephosphonic acid) N(CH₂PO₃)₃H₆ (NTP) have been studied by single-crystal X-ray diffraction and spectroscopy. [Na₈(H₂O)₁₂{NH(CH₂PO₃)₃H}₂] · H₂O crystallizes in triclinic system, space group P1?, Z = 1, a = 7.1515(2) Å, b = 11.1590(3) Å, c = 12.0583(3) Å; α = 92.077(2)°, β = 106.145(2)°, γ = 5.628(2)°, CCDC No. 1432091. The crystal structure comprises two-dimensional layers lying along planes (011?), where dimeric molecules are linked by bridges each comprising four Na hydration octahedra. The [Na₅(H₂O)₁₁{NH(CH₂PO₃)₃}] · 2H₂O crystals are monoclinic, space group P2₁/n, Z = 4, a = 6.3024(2) Å, b = 21.5639(7) Å, c = 18.1608(6) Å; β = 91.261(3)°, CCDC No. 1497161. The crystal packing comprises alternating layers in planes [020] made of two-dimensional nets of Na hydration polyhedra, and columns of Na hydration octahedra lying in planes [040], with acid moieties in between.