High‐Pressure Synthesis and Single‐Crystal Structure Elucidation of the Indium Oxide‐Borate In4O2B2O7

The indium oxide‐borate In₄O₂B₂O₇ was synthesized under high‐pressure/high‐temperature conditions at 12.5 GPa/1420 K using a Walker‐type multianvil apparatus. Single‐crystal X‐ray structure elucidation showed edge‐sharing OIn₄ tetrahedra and B₂O₇ units building up the oxide‐borate. It crystallizes with Z = 8 in the monoclinic space group P2₁/n (no. 14) with a = 1016.54(3), b = 964.55(3), c = 1382.66(4) pm, and β = 109.7(1)°. The compound was also characterized by powder X‐ray diffraction and vibrational spectroscopy.     

Biflavonoids,Lignans, and Related Compounds from the Roots of Diplomorpha canescens

Two new biflavonoids, 14″‐O‐methyldihydrodaphnodorin B ( 1 ) and 14″‐O‐methyldaphnodorin J ( 2 ), along with 16 known compounds, i.e., dihydrodaphnodorin B ( 3 ), daphnodorin J ( 4 ), 3″‐epidihydrodaphnodorin B ( 5 ), daphnodorin B ( 6 ), neochamaejasmin B ( 7 ), sikokianin B ( 8 ), (?)‐syringaresinol ( 9 ), (?)‐syringaresinol 4‐O‐β‐D ‐glucopyranoside ( 10 ), (+)‐nortrachelogenin ( 11 ), (?)‐lariciresinol ( 12 ), (?)‐pinoresinol ( 13 ), syringin ( 14 ), syringinoside ( 15 ), daphnoretin ( 16 ), phorbol 13‐acetate ( 17 ), and methyl paraben ( 18 ) were isolated from the roots of Diplomorpha canescens (Meisn.) C.A. Meyer . The structures were determined on the basis of spectroscopic data.     

Three New C19‐Diterpenoid Alkaloids from Aconitum forrestii

A further study of the alkaloid constituents of Aconitum forrestii led to the isolation of three new C₁₉‐diterpenoid alkaloids, named 14‐acetoxy‐8‐O‐methylsachaconitine ( 1 ), 14‐acetoxyscaconine ( 2 ), and 8‐O‐ethylcammaconine ( 3 ). Their structures were determined by UV, IR, and MS, 1D‐ and 2D‐NMR analyses.     

保护的几丁寡糖及结构类似物的合成：复杂氨基寡糖合成的通用方法

建立了逐步合成具有重要生物活性的2-脱氧-2-氨基葡萄糖寡糖链的通用方法。采用邻苯二甲酰基保护氨基、硫代苯基为还原末端的离去基团,以氨基葡萄糖为起始原料,几种保护的几丁寡糖及结构类似物被合成：3-O-乙酰基-4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基-b-D-吡喃葡萄糖-（1→4）-（3-O-乙酰基-6-O-苄基-2-脱氧-2-邻苯二甲酰亚氨基）-b-D-吡喃葡萄糖甲苷（4）、3-O-乙酰基-4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基-b-D-吡喃葡萄糖-（1→4）-（3-O-乙酰基-6-O-苄基-2-脱氧-2-邻苯二甲酰亚氨基-b-D-吡喃葡萄糖）-（1→4）-（3-O-乙酰基-6-O-苄基-2-脱氧-2-邻苯二甲酰亚氨基）-b-D-吡喃葡萄糖甲苷（6）、3-O-乙酰基-4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基-b-D-吡喃葡萄糖-（1→3）-（4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基）-b-D-吡喃葡萄糖甲苷（8）、3-O-乙酰基-4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基-b-D-吡喃葡萄糖-（1→3）-（4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基-b-D-吡喃葡萄糖）- （1→3）-（4,6-O-亚苄基-2-脱氧-2-邻苯二甲酰亚氨基）- b-D-吡喃葡萄糖甲苷（10）。所合成化合物通过核磁共振和质谱分析确证了其化学结构。     

Covalent‐assisted supramolecular synthesis: the effect of hydrogen bonding in cocrystals of 4‐tert‐butylbenzoic acid with isoniazid and its derivatized forms

A series of cocrystals of isoniazid and four of its derivatives have been produced with the cocrystal former 4‐tert‐butylbenzoic acid via a one‐pot covalent and supramolecular synthesis, namely 4‐tert‐butylbenzoic acid–isoniazid, C₆H₇N₃O·C₁₁H₁₄O₂, 4‐tert‐butylbenzoic acid–N′‐(propan‐2‐ylidene)isonicotinohydrazide, C₉H₁₁N₃O·C₁₁H₁₄O₂, 4‐tert‐butylbenzoic acid–N′‐(butan‐2‐ylidene)isonicotinohydrazide, C₁₀H₁₃N₃O·C₁₁H₁₄O₂, 4‐tert‐butylbenzoic acid–N′‐(diphenylmethylidene)isonicotinohydrazide, C₁₉H₁₅N₃O·C₁₁H₁₄O₂, and 4‐tert‐butylbenzoic acid–N′‐(4‐hydroxy‐4‐methylpentan‐2‐ylidene)isonicotinohydrazide, C₁₂H₁₇N₃O₂·C₁₁H₁₄O₂. The co‐former falls under the classification of a `generally regarded as safe' compound. The four derivatizing ketones used are propan‐2‐one, butan‐2‐one, benzophenone and 3‐hydroxy‐3‐methylbutan‐2‐one. Hydrogen bonds involving the carboxylic acid occur consistently with the pyridine ring N atom of the isoniazid and all of its derivatives. The remaining hydrogen‐bonding sites on the isoniazid backbone vary based on the steric influences of the derivative group. These are contrasted in each of the molecular systems.     

Synthesis and Conformational Analysis of 1′‐ and 3′‐Substituted 2‐Deoxy‐2‐fluoro‐D‐ribofuranosyl Nucleosides

Convergent syntheses of the 9‐(3‐X‐2,3‐dideoxy‐2‐fluoro‐β‐D ‐ribofuranosyl)adenines 5 (X=N₃) and 7 (X=NH₂), as well as of their respective α‐anomers 6 and 8 , are described, using methyl 2‐azido‐5‐O‐benzoyl‐2,3‐dideoxy‐2‐fluoro‐β‐D ‐ribofuranoside ( 4 ) as glycosylating agent. Methyl 5‐O‐benzoyl‐2,3‐dideoxy‐2,3‐difluoro‐β‐D ‐ribofuranoside ( 12 ) was prepared starting from two precursors, and coupled with silylated N⁶‐benzoyladenine to afford, after deprotection, 2′,3′‐dideoxy‐2′,3′‐difluoroadenosine ( 13 ). Condensation of 1‐O‐acetyl‐3,5‐di‐O‐benzoyl‐2‐deoxy‐2‐fluoro‐β‐D ‐ribofuranose ( 14 ) with silylated N²‐palmitoylguanine gave, after chromatographic separation and deacylation, the N⁷‐β‐anomer 17 as the main product, along with 2′‐deoxy‐2′‐fluoroguanosine ( 15 ) and its N⁹‐α‐anomer 16 in a ratio of ca. 42 : 24 : 10. An in‐depth conformational analysis of a number of 2,3‐dideoxy‐2‐fluoro‐3‐X‐D ‐ribofuranosides (X=F, N₃, NH₂, H) as well as of purine and pyrimidine 2‐deoxy‐2‐fluoro‐D ‐ribofuranosyl nucleosides was performed using the PSEUROT (version 6.3) software in combination with NMR studies.     

Topological identification of the first uninodal 8‐connected lsz MOF built from 2,2′‐difluorobiphenyl‐4,4′‐dicarboxylate pillars and cadmium(II)–triazolate layers

Using polynuclear metal clusters as nodes, many high‐symmetry high‐connectivity nets, like 8‐connnected bcu and 12‐connected fcu , have been attained in metal–organic frameworks (MOFs). However, construction of low‐symmetry high‐connected MOFs with a novel topology still remains a big challenge. For example, a uninodal 8‐connected lsz network, observed in inorganic ZrSiO₄, has not been topologically identified in MOFs. Using 2,2′‐difluorobiphenyl‐4,4′‐dicarboxylic acid (H₂L) as a new linker and 1,2,4‐triazole (Htrz) as a coligand, a novel three‐dimensional Cd^II–MOF, namely poly[tetrakis(μ₄‐2,2′‐difluorobiphenyl‐4,4′‐dicarboxylato‐κ⁵O¹,O^1′:O^1′:O⁴:O^4′)tetrakis(N,N‐dimethylformamide‐κO)tetrakis(μ₃‐1,2,4‐triazolato‐κ³N¹:N²:N⁴)hexacadmium(II)], [Cd₆(C₁₄H₆F₂O₄)₄(C₂H₂N₃)₄(C₃H₇NO)₄]_n, (I), has been prepared. Single‐crystal structure analysis indicates that six different Cd^II ions co‐exist in (I) and each Cd^II ion displays a distorted [CdO₄N₂] octahedral geometry with four equatorial O atoms and two axial N atoms. Three Cd^II ions are connected by four carboxylate groups and four trz⁻ ligands to form a linear trinuclear [Cd₃(COO)₄(trz)₄] cluster, as do the other three Cd^II ions. Two Cd₃ clusters are linked by trz⁻ ligands in a μ_1,2,4‐bridging mode to produce a two‐dimensional Cd^II–triazolate layer with (6,3) topology in the ab plane. These two‐dimensional layers are further pillared by the L²⁻ ligands along the c axis to generate a complicated three‐dimensional framework. Topologically, regarding the Cd₃ cluster as an 8‐connected node, the whole architecture of (I) is a uninodal 8‐connected lsz framework with the Schläfli symbol (4²²·6⁶). Complex (I) was further characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction, thermogravimetric analysis and a photoluminescence study. MOF (I) has a high thermal and water stability.     

Synthesis of magnetic,reactive, and thermoresponsive Fe3O4 nanoparticles via surface‐initiated RAFT copolymerization of N‐isopropylacrylamide and acrolein

A reversible addition‐fragmentation chain transfer (RAFT) agent was directly anchored onto Fe₃O₄ nanoparticles in a simple procedure using a ligand exchange reaction of S‐1‐dodecyl‐S′‐(α,α′‐dimethyl‐α″‐acetic acid)trithiocarbonate with oleic acid initially present on the surface of pristine Fe₃O₄ nanoparticles. The RAFT agent‐functionalized Fe₃O₄ nanoparticles were then used for the surface‐initiated RAFT copolymerization of N‐isopropylacrylamide and acrolein to fabricate structurally well‐defined hybrid nanoparticles with reactive and thermoresponsive poly(N‐isopropylacrylamide‐co‐acrolein) shell and magnetic Fe₃O₄ core. Evidence of a well‐controlled surface‐initiated RAFT copolymerization was gained from a linear increase of number‐average molecular weight with overall monomer conversions and relatively narrow molecular weight distributions of the copolymers grown from the nanoparticles. The resulting novel magnetic, reactive, and thermoresponsive core‐shell nanoparticles exhibited temperature‐trigged magnetic separation behavior and high ability to immobilize model protein BSA. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 542–550, 2010     

Flavonoid Glycosides from the Leaves of Machilus philippinensis

Thirteen flavonoid glycosides ( 1‐7 , 11‐13 , 15 , 17 , and 18 ) were isolated from the EtOH extract of the leaves of Machilus philippinensis. Of these, kaempferol 3‐O‐(2‐O‐β‐D ‐apiofuranosyl)‐α‐L ‐rhamnopyranoside ( 1 ) and kaempferol 3‐O‐(2‐O‐β‐D ‐apiofuranosyl)‐a‐L ‐arabinofuranoside ( 2 ) are new natural products. By application of HPLC‐SPE‐NMR hyphenated technique, five additional flavonol glycosides were characterized ( 8‐10 , 14 , and 16 ). Their structures were elucidated based on spectroscopic analysis. Of these, quercetin 3‐O‐(6‐O‐α‐L ‐rhamnopyranosyl)‐β‐D ‐galactopyranoside ( 5 ) and kaempferol 3‐O‐α‐L ‐arabinopyranoside ( 15 ) showed moderate inhibitory activity against α‐glucosidase type IV from Bacillus stearothermophilus with the IC₅₀ values of 19.5 and 19.0 μM, respectively.     

Synthesis of Ganglioside Mimics for Binding Studies with Myelin‐Associated Glycoprotein (MAG)*

Glycosylation of 3‐O‐unprotected 2‐azido‐2‐deoxy‐galactopyranoside (compound 5) with O‐(2,3‐di‐O‐acyl‐4,6‐O‐benzylidene‐D‐galactopyranosyl) trichloroacetimidates (compounds 4A, B) as glycosyl donors afforded β (1–3)‐linked disaccharides (9A, B) in high yield. Removal of the 2,3‐O‐acyl groups and selective 3‐O‐alkylation with α‐benzyloxycarbonyl‐alkyl triflates furnished the protected target molecules, which could be readily transformed into the desired ganglioside mimics.     

Separation and purification of four flavonol diglucosides from the flower of Meconopsis integrifolia by high‐speed counter‐current chromatography

Flavonoids are the main components of Meconopsis integrifolia (Maxim.) Franch, which is a traditional Tibetan medicine. However, traditional chromatography separation requires a large quantity of raw M. integrifolia and is very time consuming. Herein, we applied high‐speed counter‐current chromatography in the separation and purification of flavonoids from the ethanol extracts of M. integrifolia flower. Ethyl acetate/n‐butanol/water (2:3:5, v/v/v) was selected as the optimum solvent system to purify the four components, namely quercetin‐3‐O‐β‐d‐ glucopyrannosy‐(1→6)‐β‐d‐ glucopyranoside (compound 1 , 60 mg), quercetin 3‐O‐[2’’’‐O‐acetyl‐β‐d‐ glucopyranosyl‐(1→6)‐β‐d‐ glucopyranoside (compound 2 , 40 mg), quercetin 3‐O‐[3’’’‐O‐acetyl‐β‐d‐ glucopyranosyl‐(1→6)‐β‐d‐ glucopyranoside (compound 3 , 11 mg), and quercetin 3‐O‐[6’’’‐O‐acetyl‐β‐d‐ glucopyranosyl‐(1→6)‐β‐d‐ glucopyranoside (compound 4 , 16 mg). Among the four compounds, 3 and 4 were new acetylated flavonol diglucosides. After the high‐speed counter‐current chromatography separation, the purities of the four flavonol diglucosides were 98, 95, 90, and 92%, respectively. The structures of these compounds were identified by mass spectrometry and NMR spectroscopy.     

Synthesis and bioanalytical evaluation of morphine-3-O-sulfate and morphine-6-O-sulfate in human urine and plasma using LC-MS/MS

The aim of this work was to synthesize morphine‐3‐O‐sulfate and morphine‐6‐O‐sulfate for use as reference substances, and to determine the sulfate conjugates as possible heroin and morphine metabolites in plasma and urine by a validated LC‐MS/MS method. Morphine‐6‐O‐sulfate and morphine‐3‐O‐sulfate were prepared as dihydrates from morphine hydrochloride, in overall yields of 41 and 39% with product purities of >99.5% and >98%, respectively. For bioanalysis, the chromatographic system consisted of a reversed‐phase column and gradient elution. The tandem mass spectrometer was operated in the positive electrospray mode using selected reaction monitoring, of transition m/z 366.15 to 286.40. The measuring range was 5–500 ng/mL for morphine‐3‐O‐sulfate and 4.5–454 ng/mL for morphine‐6‐O‐sulfate in plasma. In urine, the measuring range was 50–5000 ng/mL for morphine‐3‐O‐sulfate and 45.4–4544 ng/mL for morphine‐6‐O‐sulfate. The intra‐assay and total imprecision (coefficient of variation) was below 11% for both analytes in urine and plasma. Quantifiable levels of morphine‐3‐O‐sulfate in authentic urine and plasma samples were found. Only one authentic urine sample contained a detectable level of morphine‐6‐O‐sulfate, while no detectable morphine‐6‐O‐sulfate was found in plasma samples.     

A two‐dimensional cadmium(II) coordination polymer constructed from 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate and 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate ligands

Crystals of poly[[aqua[μ₃‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylato‐κ⁵O¹O^1′:N³,O⁴:O⁵][μ₄‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ⁷N³,O⁴:O⁴,O^4′:O¹,O^1′:O¹]cadmium(II)] monohydrate], {[Cd₂(C₁₅H₁₄N₂O₄)(C₁₆H₁₄N₂O₆)(H₂O)]·H₂O}_n or {[Cd₂(Hcpimda)(cpima)(H₂O)]·H₂O}_n, (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H₃cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H₃cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd²⁺ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate (Hcpimda²⁻) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate (cpima²⁻) anion, one coordinated water molecule and one lattice water molecule. One Cd²⁺ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN₂O₄ geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda²⁻ ligand and three cpima²⁻ ligands. This Cd²⁺ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima²⁻ ligands bridge between Cd2 centres to generate [Cd₂O₂] units, which are further linked by two cpima²⁻ ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda²⁻ ligands to generate 1D zigzag chains. The two types of chains are linked through a μ₂‐η² bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima²⁻ to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (4³)₂(4⁶.6⁶.8³) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated.     

Highly Efficient and Versatile Synthesis of Some Important Precursors from 1,6-Anhydrous-β-D-glucopyranose as a Green Starting Material

Some important precursors (1,6-anhydrous-2-deoxy-2-azido-β-D-glucopyranose (3), 1,6-anhydrous-2-deoxy-2- azido-3,4-di-O-benzyl-β-D-mannopyranose (5), 1,6:2,3-dianhydrous-β-D-glucopyranose (6), 1,6-anhydrous-3- deoxy-3-azido-β-D-glucopyranose (10) and 1,6-anhydrous-2,4-di-O-benzoyl-β-D-glucopyranose (11)) for complex oligosaccharide synthesis were readily prepared from a green starting material 1,6-anhydrous-β-D-glucopyranose in one or two steps with moderate to high yields. These improved methods established herein will greatly facilitate the assembly of some complex oligosaccharides for the biological study.     

A new linear bismuth coordination polymer based on 1,10‐phenanthroline‐2,9‐dicarboxylic acid: ionothermal synthesis,crystal structure and fluorescence properties

A new linear bismuth(III) coordination polymer, catena‐poly[[chloridobismuth(III)]‐μ₃‐1,10‐phenanthroline‐2,9‐dicarboxylato‐κ⁶O²:O²,N¹,N¹⁰,O⁹:O⁹], [Bi(C₁₄H₆N₂O₄)Cl]_n, has been obtained by an ionothermal method and characterized by elemental analysis, energy‐dispersive X‐ray spectroscopy, IR spectroscopy, thermal stability studies and single‐crystal X‐ray diffraction. The structure is constructed by Bi(C₁₄H₆N₂O₄)Cl fragments in which each Bi^III centre is seven‐coordinated by one Cl atom, four O atoms and two N atoms. The coordination geometry of the Bi^III cation is distorted pentagonal–bipyramidal (BiO₄N₂Cl), with one bridging carboxylate O atom and one Cl atom located in the axial positions. The Bi(C₁₄H₆N₂O₄)Cl fragments are further extended into a one‐dimensional linear polymeric structure via subsequent but different centres of symmetry (bridging carboxylate O atoms). Neighbouring linear chains are assembled via weak C—H...O and C—H...Cl hydrogen bonds, forming a three‐dimensional supramolecular architecture. Intermolecular π–π stacking interactions are observed, with centroid‐to‐centroid distances of 3.678 (4) Å, which further stabilize the structure. In addition, the solid‐state fluorescence properties of the title coordination polymer were investigated.     

Me‐BIPAM for the Synthesis of Optically Active 3‐Aryl‐3‐hydroxy‐2‐oxindoles by Ruthenium‐catalyzed Addition of Arylboronic Acids to Isatins

A chiral O‐linked C₂‐symmetric bidentate phosphoramidite (Me‐BIPAM) was found to be efficient for the ruthenium‐catalyzed addition of arylboronic acids to isatins. Asymmetric synthesis of 3‐aryl‐3‐hydroxy‐2‐oxindoles by 1,2‐addition of arylboronic acids to isatins was carried out in the presence of [RuCl₂(PPh₃)₃]/(R,R)‐Me‐BIPAM and KF, resulting in an enantioselectivity as high as 90 % ee. It was found that the reaction with N‐protected isatins proceeds with high yields and good enantioselectivities. The best protective groups on the nitrogen atom were different depending on the substituents on the aromatic ring. The use of a N‐benzyl group resulted in excellent enantioselectivities in many substrates compared with other groups.     

A new two‐dimensional CoII coordination polymer based on bis[4‐(2‐methyl‐1H‐imidazol‐1‐yl)phenyl] ether and biphenyl‐4,4′‐diyldicarboxylic acid: synthesis,crystal structure and photocatalytic degradation activity

A novel two‐dimensional Co^II coordination framework, namely poly[(μ₂‐biphenyl‐4,4′‐diyldicarboxylato‐κ²O⁴:O^4′){μ₂‐bis[4‐(2‐methyl‐1H‐imidazol‐1‐yl)phenyl] ether‐κ²N³:N^3′}cobalt(II)], [Co(C₁₄H₈O₄)(C₂₀H₁₈N₄O)]_n, has been prepared and characterized by IR, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. The crystal structure reveals that the compound has an achiral two‐dimensional layered structure based on opposite‐handed helical chains. In addition, it exhibits significant photocatalytic degradation activity for the degradation of methylene blue.     

One‐pot concomitant preparation of two copper(II) coordination polymers with different configurations of bridging bithiophene ligands

By employing the conjugated bithiophene ligand 5,5′‐bis(1H‐imidazol‐1‐yl)‐2,2′‐bithiophene (bibp), which can exhibit trans and cis conformations, two different Cu^II coordination polymers, namely, poly[[μ‐5,5′‐bis(1H‐imidazol‐1‐yl)‐2,2′‐bithiophene‐κ²N:N′](μ₂‐4,4′‐oxydibenzoato‐κ²O:O′)copper(II)], [Cu(C₁₄H₈O₅)(C₁₄H₁₀N₄S₂)]_n or [Cu(bibp)(oba)]_n, (I), and catena‐poly[μ‐aqua‐bis[μ‐5,5′‐bis(1H‐imidazol‐1‐yl)‐2,2′‐bithiophene‐κ²N:N′]bis(μ₃‐4,4′‐oxydibenzoato)‐κ³O:O′:O′′;κ⁴O:O′,O′′:O′‐dicopper(II)], [Cu₂(C₁₄H₈O₅)₂(C₁₄H₁₀N₄S₂)(H₂O)]_n or [Cu₂(bibp)(oba)₂(H₂O)]_n, (II), have been prepared through one‐pot concomitant crystallization and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, elemental analysis, powder X‐ray diffraction (PXRD) and thermogravimetric (TG) analysis. Single‐crystal X‐ray diffraction indicates that the most interesting aspect of the structure is the existence of sole trans and cis conformations of the bibp ligand in a single net of (I) and (II), respectively. Compound (I) displays a threefold interpenetrating three‐dimensional framework with a 4‐connected {6⁵.8} cds topology, whereas (II) features a one‐dimensional chain structure. In the crystal of (II), the polymeric chains are further extended through C—H…O hydrogen bonds and C—H…π interactions into a three‐dimensional supramolecular architecture. In addition, strong intramolecular O—H…O hydrogen bonds formed between the bridging water molecules and the carboxylate O atoms improve the stability of the framework of (II). Furthermore, solid‐state UV–Vis spectroscopy experiments show that compounds (I) and (II) exhibit optical band gaps which are characteristic for optical semiconductors, with values of 2.70 and 2.26 eV, respectively.     

Formation of lithium,sodium and potassium complexes with 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol (taci)

Single crystals of (1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol‐κ³O²,O⁴,O⁶)(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ³O²,O⁴,O⁶)lithium(I) diiodide dihydrate, [Li(C₆H₁₆N₃O₃)(C₆H₁₅N₃O₃)]I₂·2H₂O or [Li(Htaci)(taci)]I₂·2H₂O (taci is 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol), (I), bis(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ³O²,O⁴,O⁶)sodium(I) iodide, [Na(C₆H₁₅N₃O₃)₂]I or [Na(taci)₂]I, (II), and bis(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ³O²,O⁴,O⁶)potassium(I) iodide, [K(C₆H₁₅N₃O₃)₂]I or [K(taci)₂]I, (III), were grown by diffusion of MeOH into aqueous solutions of the complexes. The structures of the Na and K complexes are isotypic. In all three complexes, the taci ligands adopt a chair conformation with axial hydroxy groups, and the metal cations exhibit exclusive O‐atom coordination. The six O atoms of the resulting MO₆ unit define a centrosymmetric trigonal antiprism with approximate D_3d symmetry. The interligand O...O distances increase significantly in the order Li < Na < K. The structure of (I) exhibits a complex three‐dimensional network of R—NH₂—H...NH₂—R, R—O—H...NH₂—R and R—O—H...O(H)—H...NH₂—R hydrogen bonds. The structures of the Na and K complexes consist of a stack of layers, in which each taci ligand is bonded to three neighbours via pairwise O—H...NH₂ interactions between vicinal HO—CH—CH—NH₂ groups.     

An investigation into synergistic effects of rare earth oxides on intumescent flame retardancy of polypropylene/poly (octylene‐co‐ethylene) blends

Synergistic effects of two kinds of rare earth oxides (REOs), neodymium oxide (Nd₂O₃) or lanthanum oxide (La₂O₃) on the intumescent flame retardancy of thermoplastic polyolefin (TPO) made by polypropylene/poly (octylene‐co‐ethylene) blends were investigated systemically by various methods. The limiting oxygen index (LOI) of flame retardant TPO (FRTPO) filled by 30 wt% intumescent flame retardants (IFR) composed of ammonium polyphosphate (APP) and pentaerythritol (PER) has been increased from 30 to 32.5 and 33.5 when 0.5 wt% of IFR was substituted by La₂O₃ and Nd₂O₃, respectively. Cone calorimetry tests also reveal the existence of synergistic effects. Thermalgravimetric analyses (TGA) demonstrate that the presence of REOs promotes the esterification and carbonization process in low‐temperature range while enhances the thermal stability of IFR and FRTPO in high‐temperature range. X‐ray diffraction (XRD) reveals that the interaction of Nd₂O₃ with IFR results in the formation of neodymium phosphate (NdP₅O₁₄) with high‐thermal stability. Thermal scanning rheological tests show that the presence of REOs increases complex viscosity of FRTPO in the temperature range of 190～300°C so as to suppress melt dripping but decreases the complex viscosity and increases the loss factors tan δ in temperature range of 300～400°C to make the carbonaceous strucuture more flexible and viscous to resist stress, expand better and keep intact. Copyright © 2009 John Wiley & Sons, Ltd.