Biodegradable hyperbranched polyesters derived from 1,1,1‐tris(hydroxymethyl)ethane

Low molar mass hyperbranched polyesters were prepared by polycondensation of 1,1,1‐tris(hydroxymethyl)ethane and various dimethyl esters of aliphatic dicarboxylic acids in bulk. The usefulness of nontoxic bismuth salts as transesterification catalysts for these polycondensations was studied. The maximum conversion increased, and the reaction time decreased in the following sequence of increasing reactivity: dimethyl sebacate < adipate < glutarate < succinate. Regardless of the monomer combination, gelation occurred at conversions > 91.5%. The hyperbranched structure was proven by ¹H NMR spectroscopy and the absence of cyclic elements by MALDI‐TOF mass spectrometry. Quantitative acylation of all CH₂OH groups was achieved with an excess of acetic anhydride or methycrylic anhydride. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 231–238, 2009     

Multicyclic polyethers derived from 1,1,1‐tris(4‐hydroxyphenyl)ethane and 2,6‐dihalopyridines

Poly(pyridine ether)s were prepared in two ways: the polycondensation of silylated 1,1,1‐tris(4‐hydroxyphenyl)ethane (THPE) with 2,6‐difluoropyridine (method A) and the polycondensation of free THPE with 2,6‐dichloropyridine (method B). With method A, the THPE/difluoropyridine feed ratio was varied from 1.0:1.0 to 1.0:1.6. Cycles, bicycles, and multicycles were the main reaction products, and crosslinking was never observed. When ideal stoichiometry was used exclusively, multicycles free of functional groups were obtained. These multicycles were detectable in matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectra up to B₃₈C₇₆ with a mass of approximately 32,000 Da. With method B, the reaction conditions were varied at a fixed feed ratio to achieve an optimum for the preparation of multicyclic polyethers, but because of the lower reactivity of 2,6‐dichloropyridine, a quantitative conversion was not achieved. The reaction products were characterized with MALDI‐TOF mass spectrometry, viscosity measurements, and size exclusion chromatography. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5725–5735, 2004     

Multicyclic polyethers with pendant keto groups by polycondensation of silylated 1,1,1‐tris(4‐hydroxyphenyl)ethane

1,1,1‐Tris(4‐trimethylsiloxyphenyl)ethane, (silylated THPE), was polycondensed with 2,4‐difluoroacetophenone and 2,4‐difluorobenzophenone. All polycondensations were performed in N‐methylpyrrolidone with K₂CO₃ as promotor. The feed ratio THPE/difluoroaromat was varied from 1.0:1.3 to 1.0:1.5. Instead of hyperbranched polymers or gels, soluble multicyclic oligo‐ and polyethers were identified as main reaction products by MALDI‐TOF mass spectrometry in all experiments. At feed ratios around 1.0:1.5 multicycles free of functional group were the main products. However, when isomeric a₂‐monomers such as 2,6‐difluoroacetophenone, 2,6‐difluorobenzophenone (or 2,6‐difluorodiphenylsulfone) were used, gelation occurred at feed ratios as low as 1.0:1.1. An explanation of the different cyclization tendencies on the basis of different conformations is discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6233–6246, 2005     

Synthesis and functionalization of poly(ether sulfone)s based on 1,1,1‐tris(4‐hydroxyphenyl)ethane

Branched poly(ether sulfone)s were prepared from 1,1,1‐tris(4‐hydroxyphenyl) ethane and 4,4′‐difluorodiphenyl sulfone (DFDPS) either by polycondensation in dimethyl sulfoxide with the elimination of water or via the silyl method in N‐methylpyrrolidone. With an exact 1/1 stoichiometry, crosslinking was avoidable, but significant fractions of cyclic oligomers and polymers were detected by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Furthermore, bridged cycles (bicycles) were detected. For the silyl method, even an excess of DFDPS of 10 mol % did not result in crosslinking. The pendant OH groups were modified by acylation with acetic anhydride, methacrylic anhydride, undecylenoyl chloride, or cinnamoyl chloride. Alkylation was only successful in a one‐pot procedure via the silyl method. Alkylbromide, ethyl bromoacetate, 3‐chloropropionitrile, 4‐nitrobenzyl bromide, and 3,4‐dichlorobenzyl chloride served as alkylating agents. With 1,3‐propane and 1,4‐butane sultone, poly(ether sulfone)s with pendant sulfonate groups were obtained. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2967–2978, 2002     

The crystal and molecular structure of the dimethylplatinum(II) complex of 1,1,1-tris(diphenylphosphinomethyl)ethane

A new crystal X-ray study, as well as proton and phosphorus-31 NMR studies, show that the structure of Pt(CH₃)₂(tripod) [tripod = 1,1,1-tris(diphenylphosphinomethyl)ethane] consists of a four-coordinate, nearly planar platinum with the triphosphine functioning as a bidentate ligand.     

Adducts of 1,1,1‐tris(4‐hydroxy­phenyl)­ethane with 1,2‐bis(4‐pyridyl)­ethane and 1,2‐bis(4‐pyridyl)­ethene: continuously interwoven structures in three dimensions

In the adduct 1,2‐bis(4‐pyridyl)­ethane–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2), C₁₂H₁₂N₂·2C₂₀H₁₈O₃, the bipyridyl component lies across an inversion centre in P. The tris‐phenol mol­ecules [systematic name: 4,4′,4′′‐(ethane‐1,1,1‐triyl)­triphenol] are linked by O—H?O hydrogen bonds to form sheets built from R(38) rings, and symmetry‐related pairs of sheets are linked by the bipyridyl mol­ecules via O—H?N hydrogen bonds to form open bilayers. Each bilayer is interwoven with two adjacent bilayers, forming a continuous three‐dimensional structure. In the adduct 1,2‐bis(4‐pyridyl)­ethene–1,1,1‐tris(4‐hydroxy­phenyl)­ethane–methanol (1/1/1), C₁₂H₁₀N₂·C₂₀H₁₈O₃·CH₄O, the mol­ecules are linked by O—H?O and O—H?N hydrogen bonds into three interwoven three‐dimensional frameworks, generated by single spiral chains along [010] and [001] and a triple‐helical spiral along [100].     

Adducts of 1,1,1‐tris(4‐hydroxyphenyl)ethane with diamines: three‐dimensional hydrogen‐bonded frameworks formed with 1,6‐diaminohexane and 2,2′‐bipyridyl

The adduct 1,6‐di­amino­hexane–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2) is a salt {hexane‐1,6‐diyldiammonium–4‐[1,1‐bis(4‐hydroxyphenyl)ethyl]phenolate (1/2)}, C₆H₁₈N₂²⁺·2C₂₀H₁₇O₃^?, in which the cation lies across a centre of inversion in space group P. The anions are linked by two short O—H?O hydrogen bonds [H?O 1.74 and 1.76 Å, O?O 2.5702 (12) and 2.5855 (12) Å, and O—H?O 168 and 169°] into a chain containing two types of R(24) ring. Each cation is linked to four different anion chains by three N—H?O hydrogen bonds [H?O 1.76–2.06 Å, N?O 2.6749 (14)–2.9159 (14) Å and N—H?O 156–172°]. In the adduct 2,2′‐bipyridyl–1,1,1‐tris(4‐hydroxy­phenyl)­ethane (1/2), C₁₀H₈N₂·2C₂₀H₁₈O₃, the neutral di­amine lies across a centre of inversion in space group P2₁/n. The tris­(phenol) mol­ecules are linked by two O—H?O hydrogen bonds [H?O both 1.90 Å, O?O 2.7303 (14) and 2.7415 (15) Å, and O—H?O 173 and 176°] into sheets built from R(38) rings. Pairs of tris­(phenol) sheets are linked via the di­amine by means of a single O—H?N hydrogen bond [H?N 1.97 Å, O?N 2.7833 (16) Å and O—H?N 163°].     

CEC with tris(2,2′‐bipyridyl) ruthenium(II) electrochemiluminescent detection

For the first time, CEC was coupled with tris(2,2‐bipyridyl) ruthenium(II) ( Ru(bpy) electrochemiluminescence detection. Efficient CEC separations of proline, putrescine, spermidine and spermine were achieved when the pH of the mobile phase is in the range of 3.5–7.0. The optimum mobile phase for CEC separation is much less acidic than that for CZE separation, which matches better with the optimum pH for Ru(bpy) electrochemiluminescence detection and dramatically shortens the analysis time because of larger EOF at higher pH. The time for CEC separation of the polyamines is less than 12.5 min, which is about half as much as the time needed for CZE. The detection limits were 1.7, 0.2, and 0.2 μM for putrescine, spermidine, and spermine, respectively. The RSD of retention time and peak height of these polyamines were less than 0.85 and 6.1%, respectively. The column showed good long‐term stability, and the RSD of retention time is below 5% for 150 runs over one‐month use. The method was successfully used for the determination of polyamines in urine samples.     

Aryl-diamide bridged binuclear ruthenium (II) tris(bipyridine) complexes: Synthesis, photophysical, electrochemical and electrochemiluminescence properties

Several new symmetrical aromatic hydrocarbon bridged bipyridine ligands and their binuclear Ru (II) complexes have been designed, synthesized and characterized on the basis of ¹H NMR, MS and HRMS. Their absorption and emission properties, electrochemical behaviors and electrochemical luminescence were investigated. All ruthenium complexes show characteristic MLCT absorption and similar redox potential. Among the three complexes reported, 4c has the best electrochemical luminescence property.     

Preparation of phosphinated bisphenol from acid‐fragmentation of 1,1,1‐tris(4‐hydroxyphenyl)ethane and its application in high‐performance cyanate esters

We reveal a route for the preparation of phosphinated bisphenol, 1,1‐bis(4‐hydroxyphenyl)‐1‐(6‐oxido‐6H‐dibenz <c,e> <1,2> oxaphosphorin‐6‐yl)ethane (2) , via a one‐pot reaction of 1,1,1‐tris(4‐hydroxyphenyl)ethane and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene 10‐oxide (DOPO) in the catalysis of p‐toluenesulfonic acid. A two‐step reaction mechanism, acid‐fragmentation of 1,1,1‐tris(4‐hydroxyphenyl)ethane followed by nucleophilic addition of DOPO, is proposed for the synthesis. Based on (2) , a dicyanate ester derivative, 1,1‐bis(4‐cyanatophenyl)‐1‐(6‐oxido‐6H‐dibenz <c,e> <1,2> oxaphosphorin‐6‐yl)ethane (3) was prepared and co‐cured with a commercially available dicyanate ester, the dicyanate ester of bisphenol A (BACY). Experimental data show that incorporating (3) into BACY enhances the flame retardancy and dielectric properties with little penalty to the thermal properties. A thermoset with T_g 274 °C, coefficient of thermal expansion (CTE) 49 ppm/°C, D_k 3.04 (1 GHz), T_d (5%,) N₂: 435 °C, air: 424 °C, and UL‐94 V‐0 rating can be achieved via this approach. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

A three‐dimensional net of Δ‐tris(1,10‐phenanthroline)ruthenium(II) in the dual‐metal self‐assembly of bis[tris(1,10‐phenanthroline)ruthenium(II)] tetraisothiocyanatoiron(II) bis(perchlorate)

The title compound, [Ru(C₁₂H₈N₂)₃]₂[Fe(NCS)₄](ClO₄)₂, crystallizes in a tetragonal chiral space group (P4₁2₁2) and the assigned absolute configuration of the optically active molecules was unequivocally confirmed. The Δ‐[Ru^II(phen)₃]²⁺ complex cations (phen is 1,10‐phenanthroline) interact along the 4₁ screw axis parallel to the c axis, with an Ru...Ru distance of 10.4170 (6) Å, and in the ab plane, with Ru...Ru distances of 10.0920 (6) and 10.0938 (6) Å, defining a primitive cubic lattice. The Fe atom is situated on the twofold axis diagonal in the ab plane. The supramolecular architecture is supported by C—H...O interactions between the [Ru^II(phen)₃]²⁺ cation and the disordered perchlorate anion. This study adds to the relatively scarce knowledge about intermolecular interactions between [Ru(phen)₃]²⁺ ions in the solid state, knowledge that eventually may also lead to a better understanding of the solution state interactions of this species; these are of immense interest because of the photochemical properties of these ions and their interactions with DNA.     

Syntheses and crystal structures of binuclear ruthenium complexes bearing 1,8′-bis(diphenylphosphinomethyl)naphthalene

Treatment of [RuCl₂(η⁶-C₆H₆)]_x with bidentate phosphine ligand BDNA [1,8-bis(diphenylphosphinomethyl)naphthalene] in methanol at room temperature gave η⁶-benzene-ruthenium complexes Ru₂Cl₄(η⁶-C₆H₆)₂(μ-BDNA) (1). Complex 1 further reacted with AgBF₄ to form complex [Ru₂Cl₂(μ-Cl)(η⁶-C₆H₆)₂(μ-BDNA)](BF₄) (2). [RuCl₂(η⁶-C₆H₆)]_x reacted with BDNA in refluxing methanol and then the reaction solution was treated with AgBF₄ to generate complex [Ru₂Cl₂(η⁶-C₆H₆)₂(μ-BDNA)₂](BF₄)₂ (3). Their compositions and structures had been determined by elemental analyses, NMR spectra and single crystal X-ray diffractions. X-ray diffraction showed that complex 1 belonged to monoclinic crystal system, P2₁/c space group with Z = 4, a = 12.810 Å, b = 21.507 Å, c = 18.471 Å, β = 107.95°; complex 2 belonged monoclinic crystal system, P2₁/n space group with Z = 4, a = 14.498 Å, b = 15.644 Å, c = 20.788 Å, β = 103.404°, and complex 3 belonged to monoclinic crystal system, P2₁/n space group with Z = 2, a = 13.732 Å, b = 14.351 Å, c = 19.733 Å, β = 94.82°.     

A ruthenium(II) complex with p‐cymene and (S)‐2‐(anilinomethyl)pyrrolidine

The title compound, [(S)‐2‐(anilino­methyl)­pyrrolidine‐N,N′]‐chloro(η⁶‐para‐cymene)­ruthenium(II) chloride, [RuCl‐(C₁₀H₁₄)(C₁₁H₁₆N₂)]Cl, has been synthesized by the reaction of [RuCl₂(p‐cymene)]₂ (p‐cymene is para‐iso­propyl­toluene) with (S)‐2‐(anilinomethyl)­pyrrolidine in triethyl­amine/2‐propanol. The Ru atom is in a pseudo‐tetrahedral environment coordinated by a chloride ligand, the aromatic hydro­carbon is linked in a η⁶ manner and the amine is linked via its two N atoms. The chloride anion is involved in hydrogen bonding with the di­amine moieties through N—H?Cl interactions, with N?Cl distances of 3.273 (4) and 3.352 (4) Å.     

A non‐oxo methanolate‐bridged divanadium(IV) complex with tris(2‐sulfanidylphenyl)phosphane ligands: synthesis,structural characterization and magnetic investigation

Vanadium chemistry is of interest due its biological relevance and medical applications. In particular, the interactions of high‐valent vanadium ions with sulfur‐containing biologically important molecules, such as cysteine and glutathione, might be related to the redox conversion of vanadium in ascidians, the function of amavadin (a vanadium‐containing anion) and the antidiabetic behaviour of vanadium compounds. A mechanistic understanding of these aspects is important. In an effort to investigate high‐valent vanadium–sulfur chemistry, we have synthesized and characterized the non‐oxo divanadium(IV) complex salt tetraphenylphosphonium tri‐μ‐<!?tlsb=‐0.11pt>methanolato‐κ⁶O:O‐bis({tris[2‐sulfanidyl‐3‐(trimethylsilyl)phenyl]phosphane‐κ⁴P,S,S′,S′′}vanadium(IV)) methanol disolvate, (C₂₄H₂₀P)[V^IV₂(μ‐OCH₃)₃(C₂₇H₃₆PS₃)₂]·2CH₃OH. Two V^IV metal centres are bridged by three methanolate ligands, giving a C2‐symmetric V₂(μ‐OMe)₃ core structure. Each V^IV centre adopts a monocapped trigonal antiprismatic geometry, with the P atom situated in the capping position and the three S atoms and three O atoms forming two triangular faces of the trigonal antiprism. The magnetic data indicate a paramagnetic nature of the salt, with an S = 1 spin state.     

Synthesis and molecular structure of hydrido(tetrahydroborato)(1,1,1-tris(diphenylphosphinomethyl)ethane)-iron(II)

Sodium tetrahydroborate reacts with iron(II) tetrafluoroborate and 1,1,1-tris(diphenylphosphinomethyl)ethane (triphos) to give the complex (triphos)-FeH(BH₄) whose molecular structure, determined from X-ray data consists of monomolecular units in which the iron atom is six-coordinated by the three phosphorus atoms of the ligand, two hydrogen atoms of the BH₄ group, and a hydridic hydrogen atom. Variable temperature ³¹P NMR spectra reveal stereochemical non-rigidity of the complex in solution.     

A novel bridged asymmetric binuclear manganese(II) complex with DTPB [DTPB is 1,1,4,7,7‐pentakis(1H‐benz­imidazol‐2‐yl­methyl)‐1,4,7‐tri­aza­heptane]

The crystal structure of the title compound, tetra­chloro­[μ‐1,1,4,7,7‐pentakis(1H‐benzimidazol‐2‐yl­methyl)‐1,4,7‐tri­azaheptane]­dimanganese(II) methanol pentasolvate tetrahydrate, [Mn₂Cl₄(C₄₄H₄₃N₁₃)]·5CH₄O·4H₂O, contains an ­asymmetric dinuclear Mn^II–DTPB [DTPB is 1,1,4,7,7‐pentakis(1H‐benzimidazol‐2‐yl­methyl)‐1,4,7‐tri­aza­heptane] complex with an intra‐ligand bridging group (–NCH₂CH₂N–), as well as several solvate mol­ecules (methanol and water). Both Mn^II cations have similar distorted octahedral coordination geometries. One Mn^II cation is coordinated by a Cl⁻ anion and five N atoms from the ligand, and the other is coordinated by three Cl⁻ anions and three N atoms of the same ligand. The Mn⋯Mn distance is 7.94 Å. A Cl⋯H—O⋯H—O⋯H—N hydrogen‐bond chain is also observed, connecting the two parts of the complex.     

A mixed bridged trinuclear copper(II)–1,10‐phenanthroline complex with a linear structure

The title compound, diaqua‐1κO,3κO‐di‐μ‐hydroxido‐1:2κ²O:O,2:3κ²O:O‐di‐μ‐methacrylato‐1:2κ²O:O′,2:3κ²O:O′‐bis(1,10‐phenanthroline)‐1κ²N,N′;3κ²N,N′‐tricopper(II) dinitrate dihydrate, [Cu₃(C₄H₅O₂)₂(OH)₂(C₁₂H₈N₂)₂(H₂O)₂](NO₃)₂·2H₂O, has the central Cu atom on an inversion centre. The three Cu^II atoms are in a linear arrangement linked by methacrylate and hydroxide groups. The coordination environments of the Cu^II ions are five‐coordinated distorted square‐pyramidal for the outer Cu atoms and four‐coordinated square‐planar for the central Cu atom. All nitrate ions, hydroxide groups and water molecules are linked by hydrogen bonds, forming a linear structure. The complex exhibits ferromagnetic exchange coupling, which is helpful in elucidating magnetic interactions between copper ions and other metallic ions in heteronuclear complexes.     

mer‐Tri­chloro­tris(1,3‐thia­zole‐N)­ruthenium(III)

The potentially cytostatic title compound, mer‐[RuCl₃(C₃H₃NS)₃], is the first Ru^III–thz (thz is 1,3‐thia­zole) complex characterized via X‐ray diffraction and consists of discrete complex mol­ecules with an octahedral coordination sphere in which the metal centre is linked to three chloride ions and to three thz ligands through the N atoms. The Ru—Cl and Ru—N bond distances average 2.3462 (6) and 2.0851 (19) Å, respectively.