Triazole-containing terpyridines with terminal aurophilic groups and their complexes with RhIII for adsorption on the surface of gold

We synthesized substituted phenylterpyridines containing one or two terminal disulfide groups and triazole-containing fragments in the linker between the terpyridine and sulfur-containing functional groups, as well as coordination compounds of the obtained terpyridines with Rh^III. The possibility of the ligands and complexes under study to be chemisorbed on the surface of gold electrodes with the formation of an Au-S bond was shown.

     

Effect of the composition and structure of carbofunctional oligodimethylsiloxanes on their colloidal-chemical properties

The effect of the composition and structure of oligodimethylsiloxanes containing carboxy- and amino-functional substituents at the silicon atom on their colloidal-chemical properties was studied. It was established that their colloidal-chemical properties are affected not only by the nature and concentration of functional groups, but also by the molecular weight of the organosilicon compound.

     

Synthesis of spacered derivatives of β-lactosylamine with an amino function at the terminal position of an aglycon

A set of N-acyllactosylamine derivatives containing a terminal amino group in aglycons of various lengths (up to 16 atoms) and various hydrophilicities were synthesized. The aglycons were represented by di-, tri-, and pentapeptides containing glycine and serine residues and by aglycons containing fragments of tartaric acid or a tertiary amine. Dedicated to the memory of Full Member of the Russian Academy of Sciences N. K. Kochetkov. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1214–1219, July, 2006.     

Synthesis and properties of hyperbranched polyester polyacrylic acids and their metal complexes

New polydentate ligands based on the hyperbranched third generation polyesters containing terminal acrylic acid fragments were synthesized. The ionization and complexation parameters of new compounds in solution were estimated by spectrophotometry and pH-metric titration followed by experimental data processing using mathematical simulation by the CPESSP program. The procedure for the synthesis was proposed. The polynuclear cobalt(II), nickel(II), and copper(II) complexes with polyester polycarboxylates were synthesized.     

Synthesis and Complexing Ability of Hyperbranched Polyester Polyols Containing Carboxylic Acid Fragments

New hyperbranched polyester polycarboxylic acids containing terminal propanoic and acrylic acid fragments have been synthesized. According to the IR spectral data, the complexation of polydentate hyperbranched polyester polycarboxylic acids with Co(II), Ni(II), and Cu(II) ions involves chelation and bidentate bridging coordination by the terminal carboxy groups. All Co(II), Ni(II), and Cu(II) complexes with the obtained polyester polypropanoic acids are characterized by octahedral geometry of the coordination entity (MO₆). The Co(II), Ni(II), and Cu(II) complexes with polyester polyacrylic acids have tetrahedral configuration of the coordination entity (MO₄).     

Rhodium(I) carbonyl complexes based on naphthophosphacyclophanes

Naphthphosphacyclophanes based on symmetrical dihydroxynaphthalenes linked by diethylamidophospite groups were used to synthesize rhodium(I) complexes containing carb-onyl and acetylacetonato fragments. The physicochemical and spectral characteristics of the synthesized coordination systems were studied.

     

Polycyclic Phosphorus-Containing Oxaboracyclanes

Abstract

The olygomers consisting of regularly repeating heterocyclic fragments were synthesized by the reaction of polycondensation of the ether of p-phenylenediboric acid and tetraoxymethyloldphosphioes obtained from the different diphosphines and aldehydes. The compounds with endocyclic phosphorus atom (I) were obtained in case of using the aliphatic aldehydes, and the compounds with exocyclic phosphoruscontaining group (II) were obtained when using the hydroxyaldehydes.     

Conjugates of polyhedral boron compounds with carbohydrates

Conjugates of β-lactosylamine derivatives bearing terminal amino groups in aglycon with ortho-carboranylacetic acid were synthesized. Five glycoconjugates with spacers of different length (from 9 to 18 atoms) and hydrophilicity containing di-, tri-, and pentapeptide fragments constructed of glycine and serine residues and spacers incorporating ethylenediamine and tartaric acid or tertiary amine residues were prepared Dedicated to the memory of outstanding chemist and biochemist V. N. Shibaev. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2033–2036, October, 2007.     

Polynuclear copper(II) complexes with polydentate nanoligands on the basis of aminoderivatives of the hyperbranched polyesters

Coordinationally active polydentate nanoplatforms on the basis of amino-modified hyperbranched polyesters containing 7 terminal amino fragments are synthesized. Synthetic procedure is developed and polynuclear Cu(II) complexes with polyesteropolyamines are prepared. Their composition and stability of the complex forms in DMSO-water solutions are evaluated. It is found that all the compounds obtained exhibit biological activity with respect to the induced asparagine proteinase of Candida albicans.     

Amphiphilic conjugates of β-cyclodextrin with acetylsalicylic and 2-(4-isobutylphenyl)propionic acids

New amphiphilic β-cyclodextrin derivatives containing pharmacologically important aromatic and aliphatic monocarboxylic acid fragments at both primary and secondary hydroxy groups were synthesized with the use of palmitic, acetylsalicylic, and 2-(4-isobutylphenyl)propionic acid chlorides. The position of the acyl groups in the carbohydrate fragments of β-cyclodextrin was determined by ¹³C NMR spectroscopy.     

Synthesis and copolymerization of new methacrylic monomers for the creation of nonlinear optical polymer materials

A new methacrylic monomer, 3,5-bis[2-(N-ethylanilino)ethoxy]benzyl methacrylate (MBA), has been synthesized. Methacrylic copolymers with different content of bi-chromophore fragments in the side chain were obtained by radical copolymerization of methyl methacrylate and MBA, followed by azo-functionalization reaction. The composition of the obtained copolymers was established, and their thermal properties were determined. Thin films of synthesized copolymers were prepared by spin-coating and the nonlinear optical characteristics of the obtained materials were investigated.

     

Liquid-crystalline carbosilane dendrimers of different molecular architecture with photochromic mesogenic and aliphatic terminal groups

Second-generation (G-2) liquid-crystalline carbosilane block and statistical dendrimers with aliphatic (decyl) and photochromic (azobenzene-containing) mesogenic terminal groups and a G-2 homo-dendrimer containing the same mesogenic terminal groups were synthesized for the first time. The influence of dendritic architecture on the phase behavior of the dendrimers and on photoinduced Z-E-isomerization of the azobenzene fragments in mesogenic terminal groups in dendrimer solutions are discussed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2325–2331, December, 2007.     

Synthesis and Properties of Water-Soluble Branched Polyester Poly{3-[3-(morpholin-4-yl)propyl]amino}propionate and Its Copper(II) Complex

A new water-soluble multidentate ligand based on a second-generation hyperbranched polyester containing 3-(morpholin-4-yl)propionate fragments in the terminal position has been synthesized, and its complex with copper(II) has been obtained. The degree of polyester functionalization with aminopropylmorpholine is 56%.     

Synthesis of lupane triterpenoids with triphenylphosphonium substituents and studies of their antitumor activity

New derivatives of lupane triterpenoids, viz., 20,29-dihydrobetulinic and 3-epi-20,29-dihydrobetulinic acid derivatives containing triphenylphosphonium fragments as substituents were synthesized. These compound considerably exceed betulinic acid in antitumor activity.     

Synthesis,properties, and interaction with paraquat of new fluorenonocrownophanes containing a hydroquinone fragment

New crownophane family was synthesized containing fragments of 2,7-dioxyfluorenone and hydroquinone connected with residues of tri- and tetraethylene glycols. The formation of inclusion complexes of these ligands with paraquat was established by means of mass spectrometry (fast-atom bombardment), ¹H NMR and electronic spectroscopy. The crownophane with a larger ring formed the more stable complex.

     

Synthesis of rccc- and rctt-diastereoisomers of novel triazole-containing calix[4]resorcinols

Novel calix[4]resorcinols containing four triazole fragments on the aromatic substituents of the calixarene framework were synthesized via a one-step condensation of resorcinol and its derivatives with 4-(1-benzyl-1H-[1,2,3]triazol-4-ylmethoxy)benzaldehyde. The macrocyclic products are rctt- and/or rccc-isomers, which were isolated and characterized by NMR and single crystal X-ray diffraction studies. The same products were also prepared via the click-reaction of benzyl azide with previously synthesized calix[4]resorcinols containing four alkyne terminal groups on the aromatic substituents. In this case, only rctt-diastereomers of the corresponding calixarenes were isolated, which is governed by conformational features of the starting macrocycles.     

A Simple Efficient Click Synthesis of Novel Crown Ethers Containing 1,2,3-Triazole Moieties

Novel crown ether derivative containing 1,4-disubstituted-1,2,3-triazole moieties were synthesized. At the first step of the synthesis 4,13-diaza-18-crown-6 and 4-aminobenzo-15-crown-5 were converted into terminal alkynes, which were then subjected to copper(I)-catalyzed alkyne-azide coupling (CuAAC) in methylene chloride. This coupling reaction was performed according to the concept of click chemistry, using an Amberlyst A-21-supported copper(I) iodide catalyst.

     

Effect of N-terminal glutamic acid and glutamine on fragmentation of peptide ions

A prominent dissociation path for electrospray generated tryptic peptide ions is the dissociation of the peptide bond linking the second and third residues from the ammo-terminus. The formation of the resulting b₂ and y _n−2 fragments has been rationalized by specific facile mechanisms. An examination of spectral libraries shows that this path predominates in diprotonated peptides composed of 12 or fewer residues, with the notable exception of peptides containing glutamine or glutamic acid at the N-terminus. To elucidate the mechanism by which these amino acids affect peptide fragmentation, we synthesized peptides of varying size and composition and examined their MS/MS spectra as a function of collision voltage in a triple quadrupole mass spectrometer. Loss of water from N-terminal glutamic acid and glutamine is observed at a lower voltage than any other fragmentation, leading to cyclization of the terminal residue. This cyclization results in the conversion of the terminal amine group to an imide, which has a lower proton affinity. As a result, the second proton is not localized at the N-terminus but is readily transferred to other sites, leading to fragmentation near the center of the peptide. Further confirmation was obtained by examining peptides with N-terminal pyroglutamic acid and N-acetyl peptides. Peptides with N-terminal proline maintain the trend of forming b₂ and y _n−2 because their ring contains an imine rather than imide and has sufficient proton affinity to retain the proton at the N-terminus.     

Synthesis and liquid crystalline properties of novel compounds containing a 3‐fluoro‐4‐cyanophenoxy group

A series of novel compounds containing a 3‐fluoro‐4‐cyanophenoxy group were synthesized and fully characterized by IR and ¹H NMR, and their mesomorphic properties were studied. Seven compounds exhibited enantiotropic nematic phases and three compounds exhibited monotropic nematic phases, as confirmed by differential scanning calorimetry and polarizing optical microscopy. Selected properties of the liquid crystalline compounds synthesized were calculated by ab initio methods at a HF/6‐31G level. The bond lengths, bond angles and dihedral angles of the fragments with the same structure change little between the compounds. All the compounds with a terminal alkoxy chain approached a planar structure.     

MULTIFUNCTIONAL HYDROPHILIC POLYMERS

ABSTRACT

Different types of multifunctional hydrophilic polymers were synthesized and characterized in view of their possible biomedical application. Several poly(amide)s and poly(ester-amide)s containing oligo(oxyethylene) segments and tartaric or succinic acid residues were prepared by activated polycondensation methods. New functional derivatives of β-cyclodextrin were obtained by reaction with glycidyl ether of protected polyols. The mechanism of β-cyclodextrin polymerization with epichlorohydrine was investigated by ¹³C-NMR spectroscopy.