Syntheses,structures, and magnetism of two coordination compounds with 3,3′,4,4′-biphenyltetracarboxylic acid and 1,10-phenanthroline

Two coordination polymers, {[Mn(1,10-phen)₂(3,4-H₂bptc)]?·?(H₂O)}_{2 n} (1) and {[Co₂(1,10-phen)(3,4-bptc)(H₂O)₂]?·?H₂O} _n (2) (3,4-H₄bptc = 3,3′,4,4′-biphenyltetracarboxylic acid, 1,10-phen?=?1,10-phenanthroline), have been prepared and structurally characterized. In both compounds, 3,4-H₂bptc^2– and 3,4-bptc^4? exhibit different coordination modes and lead to various architectures. Compound 1 displays 1-D zigzag chains constructed with hydrogen bonds. Compound 2 exhibits a 2-D layer constructed from bpta^4? between the dinuclear Co(II) units. The thermal stabilities and magnetic properties are also reported. In addition, 1 was explored as a luminescent material. The carboxylic oxygen atoms act as H-bond acceptors and donors forming a 1-D ladder-like arrangement.     

Synthesis and structural characterization of three supramolecular coordination polymers constructed from different metal ions and 2,2′-bipyridyl-3,3′-dicarboxylic acid

Three new supramolecular coordination polymers based on 2,2′-bipyridyl-3,3′-dicarboxylic acid (H₂BPDC) and Mn(II), Fe(II), and Zn(II) were synthesized under hydrothermal conditions and characterized with single-crystallographic X-ray analysis and IR spectrum. Complex 1 exhibits a 1-D, chain-like structure, which is further connected to 2-D supramolecular layer structure through hydrogen bonds. Complex 2 exhibits a 3-D supramolecular structure constructed from 1-D chains through hydrogen bonds and π–π interactions. Like 1, 3 also shows 2-D supramolecular layer structure based on 1-D chains. Furthermore, the fluorescence of 3 was studied.     

Syntheses,crystal structures,and characterization of three metal–organic complexes with 2,2′-biphenyldicarboxylic acid and phenanthroline ligands

Three complexes constructed with 2,2′-biphenyldicarboxylic acid, multidentate nitrogen donors, and metal salts, {[Cd(2,2′-dpdc)(tppp)(H₂O)]₂?·?2H₂O} _n (1), {[Pb(2,2′-dpdc)(pyphen)]₂} _n (2), and {[Pb(2,2′-dpdc)(dppz)]} _n (3) (H₂dpdc = 2,2′-diphenyldicarboxylic acid; tppp = 4-(1H-1,3,7,8-tetraazacyclopenta[l]phenanthren-2-yl)phenol; pyphen?=?pyrazino[2,3-f]-[1,10]phenanthroline; and dppz = dipyrido[3,2-a:2′,3′-c]phenazine), are synthesized under hydrothermal conditions. These complexes are characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA, and photoluminescence. In 1, two 2,2′-dpdc ions bridge two Cd(II) ions to form an isolated cluster with Cd?···?Cd distance of 5.023(4)?Å. These clusters are further linked by intermolecular hydrogen bonds, yielding a 2-D supramolecular structure. Complex 2 contains two crystallographically independent Pb(II) ions in the asymmetric unit. Pb1 ions are bridged by 2,2′-dpdc anions to form a chain along the x-axis. Two Pb2 ions are coordinated by two 2,2′-dpdc anions and two pyphen ligands to form a cluster. These clusters are linked by π–π interactions to yield a 1-D supramolecular chain along the y-axis. In 3, neighboring Pb(II) atoms are bridged by 2,2′-dpdc anions to form a 1-D chain structure. Further, the chains are linked into a 3-D supramolecular network through aromatic π–π interactions.     

A novel efficient synthetic method for 2,2′,3,3′-biphenyltetracarboxylic dianhydride

A novel approach to the synthesis of 2,2′,3,3′-biphenyltetracarboxylic dianhydride is described.The target compound was prepared by a nickel-catalyzed coupling reaction of dimethy 3-chlorophthalate(3-DMCP) for 4 h at 70-80℃,followed by subsequent hydrolysis of tetra-ester in acid solution and dehydration of tetra-acid,with overall yield of 68%.The structures of the products were characterized by IR,~1H NMR and ~(13)C NMR respectively.     

Preparation and molecular structures of N,N-2,2′-dipicolyl- and N,N-3,3′-dipicolyldithiocarbamato metal complexes

New iron(III) and cobalt(III) complexes, [Fe(2,2′-dpdtc)₃], [Fe(3,3′-dpdtc)₃], [Co(2,2′-dpdtc)₃], and [Co(3,3′-dpdtc)₃] (dpdtc?=?dipicolyldithiocarbamate) have been synthesized and their molecular structures and spectroscopic properties determined. The 2,2′- and 3,3′-dpdtc ligands have four donors, S, S′, N, and N′. These complexes are insoluble in water, but soluble in acidic solution. Crystal structures of these metal complexes reveal that the central metal ions have MS₆ (M?=?Fe and Co) octahedral structures and all dipicolyl groups do not coordinate.     

Syntheses,crystal structures,and optical properties of a series of transition metal coordination polymers with chelidamic acid and 4,4′-bipyridine

A series of transition metal (Zn, Cu, Mn) complexes with chelidamic acid (2,6-dicarboxy-4-hydroxypyridine, H₃CAM) and 4,4′-bipyridine (bipy), [Zn₂(bipy)Cl₂] _n (1), {[Zn₂(HCAM)(H₂CAM)₂]?·?(bipy)?·?3.5H₂O} _n (2), [Mn₃(HCAM)₃(H₂O)₇]?·?(bipy)?·?3H₂O (3), [Mn₂(HCAM)₂(bipy)?·?(H₂O)₂]?·?4H₂O (4), [Cu₂(HCAM)₂(bipy)?·?(H₂O)₂]?·?4H₂O (5), and Cu₂(HCAM)₂(bipy)?·?(H₂O)₂ (6), have been synthesized by hydrothermal or solution methods and characterized by single-crystal X-ray diffraction. The structural analyses reveal that 1 exhibits a zigzag chain of Zn(II), Cl^?, and 4,4′-bipyridine. In 2, a 1-D polymeric [Zn₂(HCAM)(H₂CAM)₂] _n chain and a discrete 4,4′-bipyridine assemble into a 2-D supramolecular network via H-bonds. Complex 3 consists of asymmetric units of Mn₃(HCAM)₃(H₂O)₇ that are linked by hydrogen bonds to form a 2-D H-bonded network. Complexes 4–6 are isomorphous and possess discrete structures. The photoluminescent properties of 1–6 at room temperature were studied.     

Two supramolecular structures constructed from Keggin-type polyoxometalates and 4,4′-bipyridine

Two supramolecular compounds based on Keggin-type polyoxometalates (POMs), (4,4′-H₂bpy)(4,4′-Hbpy)[PMo₁₂O₄₀] (1) and (4,4′-H₂bpy)(4,4′-Hbpy)₂[SiW₁₂O₄₀]?·?4H₂O (2), have been synthesized hydrothermally and characterized by elemental analyses, IR, UV-Vis, XPS spectra, thermogravimetric analyses, and single-crystal X-ray diffraction analyses. The two compounds consist of 4,4′-bipyridine (4,4′-bpy) ligands and different Keggin-type POMs which are [PMo₁₂O₄₀]^3? for 1 and [SiW₁₂O₄₀]^4? for 2. There are hydrogen-bonding interactions between the POMs, 4,4′-bipyridine, and/or water in 1 and 2. In addition, 2 contains an uncommon (H₂O)₂ water cluster.     

Synthesis and characterization of phenylethynyl-terminated polyimide oligomers derived from 2,3,3′,4′-diphenyl ether tetracarboxylic acid dianhydride and 3,4′-oxydianiline

With the goal of improving processability of imide oligomers and achieving high toughness of thermosetting polyimides, a series of 4-phenylethynylphthalic anhydride(PEPA)-terminated imide oligomers prepared by the reaction of 2,3,3',4'-diphenyl ether tetracarboxylic acid dianhydride(a-ODPA) and 3,4'-oxydianiline(3,4'-ODA) with different molecular weights(degree of polymerization: n = 1?9) were formed. The resultant oligomers with different molecular weights were characterized for their chemical architecture, cure behavior, thermal properties, solubility in organic solvents and rheological characteristics. Besides, the thermal properties and tensile test of cured polyimide films were also evaluated. The imide oligomer(degree of polymerization: n = 1) has some somewhat crystalline phase, and imide oligomers(degree of polymerization: n = 2?9) showed excellent solubility(40 wt%) in N-methyl-2-pyrrolidone(NMP) and N,Ndimethylacetamide(DMAc) at room temperature. Furthermore, the rheological properties of imide oligomers showed very low melt viscosity and wider processing window. The cured films exhibited good thermal properties with the glass transition temperatures of 282?373 ?C and 5 wt% thermal decomposition temperatures higher than 551 ?C in nitrogen atmosphere. The elongation at break of the prepared films was found to be high(almost 9.3%).     

Crystal structure of 1,1′-biphenyl-2,2′,3,3′-tetracarboxylic and 1,1′-biphenyl-2,2′,3,3′,5,5′,6,6′-octacarboxylic acids: solid-state chiralization and dissociation

X-ray diffraction analysis revealed unexpected stereochemical features accompanying crystal self-assembly of the two title oligocarboxylic acids.     

Two new frameworks for biphenyl-3,3′,5,5′-tetracarboxylic acid and nitrogen-containing organics

Two complexes, {Zn(bptc)_0.5(bib)} _n (I) and {Mn₂(bptc)(pip)(H₂O)} _n (II) (H₄bptc = biphenyl-3,3′,5,5′-tetracarboxylic acid; bib = 1,4-bis(2-methylimidazol-1-yl)butane; pip = 2-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline) were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA and solid fluorescence spectra. The results show that I and II both have 3D network architectures. I has porous architecture with a 16² topology structure. Effective porosity calculated by Platon is 5.5 %. Moreover, it has a two-fold interpenetrating structure allowed by a 70.73° torsion between the benzene rings of the bptc^4? ligand and the flexibility of bib. II has a tetranuclear structure composed of binuclear architecture units with the torsion of 43.44° between the benzene rings of the bptc^4? ligand. TGA shows that the skeletons of I and II are stable up to 372°C and 553°C, respectively. I exhibits fluorescence.     

Solvent extraction of metal ions from aqueous solutions containing N,N,N′,N′-ethylenediaminetetraacetic and related acids—II. La(III) and diethylenetriaminepentaacetic acid

In the absence of a competing anion, [La(DTPA)]²⁻ was extracted from aqueous phases in the pH ranges 1–3 by the perchlorate salt of the primary amine Primene JM-T. The addition of small amounts of SO²⁻₄ to the aqueous phases depressed the extraction of La to near zero. As the SO²⁻₄ concentration was increased further, D_La increased to values greater than that found in the absence of SO²⁻₄; this was caused by a change in the mechanism of extraction and [La(SO₄)₂]⁻ became the extracted species.     

Polymeric and sandwich Schiff’s bases complexes derived from 4,4′-methylenedianiline

Cobalt(II), nickel(II) and copper(II) complexes of Schiff’s bases derived from 4,4′-methylenedianiline and pyridine-2-carboxaldehyde(L¹), furan-2-carboxaldehyde(L²) or thiophene-2-carboxaldehyde(L³), were prepared and characterized by different analytical and spectral methods. The Schiff bases behave as neutral tetradentate ligands. The chloro-complexes of (L²) with (2:3) mole ratio have a polymeric nature. However, that of L¹ and L³ with (1:1) mole ratio showed a sandwich structure. All complexes display an octahedral geometry, except complex (2) which has a tetrahedral one. O _h/T _d equilibrium for chloro-complexes of cobalt with ligand L¹ was established in the solid state. ESR spectra of solid copper(II) complexes showed isotropic and axial type with dx ²-y ² ground state. The thermal study showed that the complexes with different solvents of crystallization exercise different types of interaction. The observed thermochromic phenomenon for cobalt complex was explained along with its thermal behaviour.     

Three silver coordination polymers constructed from 4,4′-bipyridine-like ligands and 2,5-thiophenedicarboxylic acid: crystal structures and photocatalytic performances

Transition Metal Chemistry - Three coordination polymers (CPs), formulated as [Ag(bpy)]2(tdc)·4H2O (BUC-78), [Ag(bpe)]2(tdc)·6H2O (BUC-79) and [Ag(bpp)]2(tdc)·8H2O (BUC-80) have been...     

Resolution and determination of the absolute configuration of 3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxaldehyde

Racemic 3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxaldehyde 1 was resolved via the formation of diastereomeric dioxolanes with (S)-(+)-1-phenyl-1,2-ethanediol. Four stereoisomers were separated by column chromatography. The absolute configuration of one of them (2′′R, 4′′S,1R) was established by X-ray diffraction. Acid hydrolysis of the dioxolanes afforded quantitatively (R)- and (S)-enantiomers of 1. Optical rotatory dispersion (ORD) spectra of both enantiomers are also reported.     

Resolution and determination of the absolute configuration of 3,3′4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxylic acid

(±)-3,3′4,4′-Tetramethyl-1,1′-diphosphaferrocene-2-carboxylic acid 1 was resolved via diastereomeric salts with brucine. The (R)-absolute configuration of (+)-1 was determined by X-ray crystallography.     

Two transition metal coordination polymers constructed from 3-aminobenzoate and 4,4′-bipyridine

Two new transition metal coordination polymers, [Zn(abz)(bipy)](ClO₄) (1) and [Mn(bipy)₅(H₂O)₆](ClO₄)_2?·?2(abz)?·?2(H₂O) (2) (bipy?=?4,4′-bipyridine, abz?=?3-aminobenzoate), were prepared and characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is a 2-D-layered network with a (4,4) net built up by bipy and 3-aminobenzoate ligands connecting two zinc nodes. Complex 2 is a 3-D supramolecular grid network constructed from close stacking bipy ligands of H-type cation units with large cavities hosting 3-aminobenzoate, perchlorate ions, and water. Solid state photoluminescence for 1 was also investigated.     

Two metastable high hydrates of energetic material 3,3′,5,5′-tetranitro-4,4′-bipyrazole

Poly-stoichiometry of hydrated phases is relatively uncommon for organic materials and extended libraries of such species adopting different aqua-to-substrate ratios are still rare. The kinetically controlled higher hydrates could be particularly interesting for their structural relationships, which presumably may imprint some features of the substrate/substrate and aqua/substrate bonding in solutions, and provide insights into the nucleation stage. Two metastable high hydrates are prepared by crash crystallization. The crystal structures of 3,3′,5,5′-tetranitro-4,4′-bipyrazole tetrahydrate, C₆H₂N₈O₈·4H₂O, (1), and 3,3′,5,5′-tetranitro-4,4′-bipyrazole pentahydrate, C₆H₂N₈O₈·5H₂O, (2), are intrinsically related to the previously reported anhydrate and monohydrate, while displaying natural evolution of the patterns upon progressive watering. The accumulation of the water molecules causes their clustering, with the generation of one-dimensional tapes and two-dimensional layers in the genuine channel hydrates (1) and (2), respectively, versus the pocket hydrate structure of C₆H₂N₈O₈·H₂O. The hydration primarily affects the pyrazole sites. It conditions the emergence of N—H…O and O—H…N hydrogen bonds, which is a destructive factor for pyrazole/pyrazole N—H…N hydrogen bonding. At the same time, extensive noncovalent interactions of the organic molecules, namely, lone pair–π-hole O…N interactions of the NO₂/NO₂ and NO₂/pyrazole types, are more competitive to the hydrogen bonding and the motifs of mutual organic/organic stacks remain intact with the increase in hydration. These trends agree with the results of Hirshfeld surface analysis. The contributions of the contacts involving H atoms are increased in line with the growing number of water molecules, while the fraction of O…N/N…O (NO₂) contacts is nearly invariant. One may postulate the significance of the lone pair–π-hole interactions to the aggregation of nitro species in solutions and their relevance for the sebsequent development of the solid-state patterns through nucleation.     

Syntheses,crystal structures,and luminescence of two new coordination polymers based on biphenyl-2,2′,4,4′-tetracarboxylate

Two new coordination polymers, [Zn(H₂btc)(4,4′-bpy)₂] _n (1) and {[Cd(H₂btc) (terpy)]?·?H₂O} _n (2) (H₄btc?=?biphenyl-2,2′,4,4′-tetracarboxylic acid, 4,4′-bpy?=?4,4′-bipyridine, terpy?=?terpyridine), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complexes 1 and 2 are 1-D chains linked through partially deprotonated H₄btc. The adjacent 1-D chains of 1 are further formed into 2-D supramolecular architecture through inter-chain N–H···O hydrogen bonds. In contrast, due to a different auxiliary ligand, the 1-D chains of 2 are further extended into 3-D supramolecular framework through inter-chain O–H···O hydrogen bonds. Thermal stabilities and luminescence of 1 and 2 were also studied.     

3,3′-二氨基-2,2′,4,4′,6,6′-六硝基二苯胺钾的合成

由间二氯苯合成了热安定性炸药3,3′-二氨基-2,2′,4,4′,6,6′-六硝基二苯胺钾,目标化合物和部分中间体经元素分析,HNMR和MS表征,总收率58％。