Tetramethyl‐m‐benziporphodimethene and Isomeric α,β‐Unsaturated γ‐Lactam Embedded N‐Confused Tetramethyl‐m‐benziporphodimethenes

The condensation reaction of α,α′‐dihydroxy‐1,3‐diisopropylbenzene, pyrrole, and an aldehyde leads to the formation of tetramethyl‐m‐benziporphodimethene and outer α‐pyrrolic carbon oxygenated N‐confused tetramethyl‐m‐benziporphodimethenes containing a γ‐lactam ring in the macrocycle. Two isomers with the carbonyl group of the lactam ring either close to (O‐Up) or away from (O‐Down) the neighboring sp³ meso carbon were synthesized and characterized. The single crystal X‐ray diffraction analysis on the regular and γ‐lactam containing tetramethyl‐m‐benziporphodimethenes showed highly distorted macrocycles for all compounds. For O‐Up and O‐Down isomers, dimeric structures, assembling by intermolecular hydrogen‐bonding interactions through lactam rings, were observed in the solid state. Fitting the concentration dependent chemical shifts of the outer NH proton using the non‐linear regression method give a maximum association constant of 108.9 M ^?1 for the meso 4‐methylcarboxyphenyl substituted O‐Down isomer. The DFT calculations concluded that the O‐Up isomer is energetically more stable, and the keto form is more stable than the enol form.     

N‐substituted bis(tetrazol‐5‐yl)diazenes: Synthesis,spectra, X‐ray molecular and crystal structures,and quantum‐chemical DFT calculations

N‐Substituted bis(tetrazol‐5‐yl)diazenes (substituents are 1‐CH₃ ( 3a ), 1‐Ph ( 3b ), 2‐CH₃ ( 3c ), and 2‐^tBu ( 3d )) were synthesized by oxidative coupling of corresponding 5‐aminotetrazoles. All compounds were characterized with ¹H and ¹³C NMR, IR‐ and UV‐spectroscopy, and thermal analysis. Crystal and molecular structures of bis(1‐phenyltetra‐ zol‐5‐yl)diazene ( 3b ) and bis(2‐tert‐butyltetrazol‐5‐yl)diazene ( 3d ) were determined by single crystal X‐ray diffraction. Molecules of these compounds are trans‐isomers in solid. According to X‐Ray data, 3b molecule is S‐trans‐S‐trans conformer, however 3d is S‐cis‐S‐cis one. Quantum‐chemical investigation of geometry and relative stability of cis‐ and trans‐isomers and stable conformations of compounds 3a–d was carried out. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:24–35, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20574     

Synthesis and Self‐Assembly of NCN‐Pincer Pd‐Complex‐Bound Norvalines

The NCN‐pincer Pd‐complex‐bound norvalines Boc‐D /L ‐[PdCl(dpb)]Nva‐OMe ( 1 ) were synthesized in multigram quantities. The molecular structure and absolute configuration of 1 were unequivocally determined by single‐crystal X‐ray structure analysis. The robustness of 1 under acidic/basic conditions provides a wide range of N‐/C‐terminus convertibility based on the related synthetic transformations. Installation of a variety of functional groups into the N‐/C‐terminus of 1 was readily carried out through N‐Boc‐ or C‐methyl ester deprotection and subsequent condensations with carboxylic acids, R¹COOH, or amines, R²NH₂, to give the corresponding N‐/C‐functionalized norvalines R¹‐D /L ‐[PdCl(dpb)]Nva‐R² 2 – 9 . The dipeptide bearing two Pd units 10 was successfully synthesized through the condensation of C‐free 1 with N‐free 1 . The robustness of these Pd‐bound norvalines was adequately demonstrated by the preservation of the optical purity and Pd unit during the synthetic transformations. The lipophilic Pd‐bound norvalines L ‐ 2 , Boc‐L ‐[PdCl(dpb)]Nva‐NH‐n‐C₁₁H₂₃, and L ‐ 4 , n‐C₄H₉CO‐L ‐[PdCl(dpb)]Nva‐NH‐n‐C₁₁H₂₃, self‐assembled in aromatic solvents to afford supramolecular gels. The assembled structures in a thermodynamically stable single crystal of L ‐ 2 and kinetically stable supramolecular aggregates of L ‐ 2 were precisely elucidated by cryo‐TEM, WAX, SAXS, UV/Vis, IR analyses, and single‐crystal X‐ray crystallography. An antiparallel β‐sheet‐type aggregate consisting of an infinite one‐dimensional hydrogen‐bonding network of amide groups and π‐stacking of PdCl(dpb) moieties was observed in the supramolecular gel fiber of L ‐ 2 , even though discrete dimers are assembled through hydrogen bonding in the thermodynamically stable single crystal of L ‐ 2 . The disparate DSC profiles of the single crystal and xerogel of L ‐ 2 indicate different thermodynamics of the molecular assembly process.     

Structural Features of Certain p‐substituted Phenyl 2‐nitrovinyl Sulfones

The structure of p‐substituted phenyl 2‐nitrovinyl sulfones was studied through different spectral methods. It has been found that the nucleophilic substitution reactions of sodium phenylsulfinates with 1‐chloro‐2‐nitroethene occur stereospecifically. The formation of E‐isomers of this type of substituted phenyl vinyl sulfones was confirmed by FTIR and NMR spectroscopy. It was suggested that the E‐isomers formation was determined by the more stable conformation of the carbanionic intermediate as a result of intramolecular rotation around single Cα‐Cβ bond. This appears to be the product‐determining pathway during the interaction of sodium phenyl sulfinates with the highly activated substrate 1‐chloro‐2‐nitroethene.     

Synthesis of Davankov‐type hypercrosslinked resins using different isomer compositions of vinylbenzyl chloride monomer,and application in the solid‐phase extraction of polar compounds

Two different gel‐type resins have been prepared by suspension polymerization using 2 wt % divinylbenzene (DVB) with either p‐vinylbenzyl chloride (pVBC) or a mixture of VBC isomers (～ 70% m‐; ～ 30% p‐). Significant difference in the chlorine content was observed, which was attributed to a more favored hydrolysis process when p‐VBC was used. The presence of hydroxyl groups has been confirmed by elemental microanalytical data and solid‐state ¹³C cross‐polarization/magic angle spinning (CP‐MAS) nuclear magnetic resonance (NMR) spectra. Hypercrosslinked resins were prepared from both gel‐type precursors by treatment with FeCl₃ in 1,2‐dichloroethane (DCE) at 80 °C. The resultant resins showed differences in specific surface area and degree of hydrophilicity. The performance of the hypercrosslinked resins was evaluated in solid‐phase extraction (SPE) of polar compounds, and better results were obtained for the hypercrosslinked resin prepared from p‐VBC that combines a relatively high specific surface area (908 m² g^?1) and somewhat higher oxygen content (3.96 wt % O). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1718–1728, 2005     

3-烷基/对烷氧基苯基-3-羟基-联茚满烯二酮衍生物的合成，晶体结构与固态光致变色及光致自由基性质研究

本文合成了一系列3-烷基/对烷氧基苯基-3-羟基-联茚满烯二酮新化合物,并通过¹H NMR, IR, MS 和元素分析数据进行了结构表征,其中化合物1,5,6的结构通过单晶X-Ray衍射进行了确证。分别用固体紫外光谱和电子自旋共振光谱研究了化合物的光致变色性能和光致自由基性质,结果表明：该类化合物在200W高压水银灯光源照射下产生光致变色现象,同时具有光致自由基性质。本文还根据分子结构和及分子内的作用力讨论了性质与结构之间的关系。     

Selective Sensing of Fe3+ and Al3+ Ions and Detection of 2,4,6‐Trinitrophenol by a Water‐Stable Terbium‐Based Metal–Organic Framework

A water‐stable luminescent terbium‐based metal–organic framework (MOF), {[Tb(L₁)_1.5(H₂O)] ? 3 H₂O}_n (Tb‐MOF), with rod‐shaped secondary building units (SBUs) and honeycomb‐type tubular channels has been synthesized and structurally characterized by single‐crystal X‐ray diffraction. The high green emission intensity and the microporous nature of the Tb‐MOF indicate that it can potentially be used as a luminescent sensor. In this work, we show that Tb‐MOF can selectively sense Fe³⁺ and Al³⁺ ions from mixed metal ions in water through different detection mechanisms. In addition, it also exhibits high sensitivity for 2,4,6‐trinitrophenol (TNP) in the presence of other nitro aromatic compounds in aqueous solution by luminescence quenching experiments.     

Tuning Cadmium Coordination Architectures by Phenylenediacetate Position Isomers and 1,4‐Bis(benzimidazol‐1‐ylmethyl)benzene

Three position isomers 1,2‐, 1,3‐, 1,4‐phenylenediacetate and 1,4‐bis(benzimidazol‐1‐ylmethyl)benzene (bmb) were used to assembly cadmium(II) coordination polymers, [Cd(bmb)(1,2‐phda)]_n ( 1 ), {Cd(bmb)(1,3‐phda)] · 0.5(bmb)}_n ( 2 ), and [Cd(bmb)_0.5(1,4‐phda)]_n ( 3 ), which are characterized by elemental analyses, infrared spectra (IR), thermogravimetric analysis (TGA) and single‐crystal X‐ray diffraction. Single crystal structure analysis shows that complex 1 is a two‐dimensional wave‐like layer network. Complex 2 features a (3,5)‐connected three‐dimensional frameworks with (4².6)(4².6⁵.8³) topology, whereas complex 3 shows a (4,4)‐connected three‐dimensional (4.6⁴.7)(4².6².8²) topology. The structural versatility reveals that a significant structure‐directing effect of the position of the acetate groups during self‐assembly of these coordination polymers. Moreover, luminescent properties and thermal stabilities of three complexes were discussed in detail.     

Ring opening of pyridines: the pseudo‐cis and pseudo‐trans isomers of tetra‐n‐butylammonium 4‐nitro‐5‐oxo‐2‐pentenenitrilate

The reaction of 2‐chloro‐5‐nitropyridine with two equivalents of base produces the title carbanion as an intermediate in a ring‐opening/ring‐closing reaction. The crystal structures of the tetra‐n‐butylammonium salts of the intermediates, C₁₆H₃₆N⁺·C₅H₃N₂O₃⁻, revealed that pseudo‐cis and pseudo‐trans isomers are possible. One crystal structure displayed a mixture of the two isomers with approximately 90% pseudo‐cis geometry and confirms the structure predicted by the S_N(ANRORC) mechanism. The pseudo‐cis intermediate undergoes a slow isomerization over a period of months to the pseudo‐trans isomer, which does not have the appropriate geometry for the subsequent ring‐closing reaction. The structure of the pure pseudo‐trans isomer is also reported. In both isomers, the negative charge is highly delocalized, but relatively small differences in C—C bond distances indicate a system of conjugated double bonds with the nitro group bearing the negative charge. The packing of the two unit cells is very similar and largely determined by the interactions between the planar carbanion and the bulky tetrahedral cation.     

Microwave‐assisted nucleophilic cleavage of 5,7‐dimethyl‐2‐phenyl‐1‐oxo‐lH‐pyrazolo[ 1,2‐a]pyrazol‐4‐ylium‐3‐olate to α‐phenylmalonamides

Three α‐phenylmalonamides have been prepared by the selective nucleophilic cleavage of 5,7‐dimethyl‐2‐phenyl‐1‐oxo‐1H‐pyrazolo[1,2‐a]pyrazol‐4‐ylium‐3‐olate in solventless microwave syntheses. The three weak nucleophiles employed were aniline, p‐chloroaniline and m‐toluidine. The α‐phenylmalonamides of these three aniline derivatives could not be prepared using the previously reported solvent syntheses via 3‐oxopyrazolo[1,2‐a]pyrazol‐8‐ylium‐1‐olates. All products were characterised using, infrared spectroscopy, ¹H nmr and electrospray mass spectrometry. The single crystal X‐ray structures of the starting pyrazolo‐[1,2‐a]pyrazole and α‐phenylmalon‐m‐toluidide are also reported.     

The Convenient Synthesis of 11‐Methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione Derivatives

The 2‐arylidene‐3‐oxobutanenitrile derivatives 2 were prepared by the Knoevenagel condensation between aldehydes and 3‐oxobutanenitrile 1 , which was obtained by acid hydrolysis of β‐aminocrotononitrile. 3‐Acetyl‐2‐amino‐4H‐chromen‐5(6H)‐one derivatives 3 were synthesized by reaction of 2‐arylidene‐3‐oxobutanenitrile 2 and 5‐substituted‐1,3‐cyclohexanedione in ethylene glycol. The 11‐methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione derivatives 4 were obtained by Friedländer reaction of compounds 3 with 5‐substituted‐1,3‐cyclohexanedione, using p‐toluenesulfonic acid monohydrate as catalyst. The structures of all novel compounds were characterized by elemental analysis, IR, MS, and ¹H NMR spectra. The crystal and molecular structure of compound 4f has been determined by single crystal XRD analysis.     

Synthesis and Characterization of 11‐Amino‐3‐methoxy‐8‐substituted‐12‐aryl‐8,9‐dihydro‐7H‐chromeno[2,3‐b]quinolin‐10(12H)‐one Derivatives

A series of 2‐amino‐7‐methoxy‐4‐aryl‐4H‐chromene‐3‐carbonitrile compounds 2 were obtained by condensation of 3‐methoxyphenol with β‐dicyanostyrenes 1 in absolute ethanol containing piperidine. The intermediate enamines 3 were prepared by compounds 2 with 5‐substituted‐1,3‐cyclohexanedione using p‐toluenesuflonic acid (TsOH) as catalyst. The title compounds 11‐amino‐3‐methoxy‐8‐substituted‐12‐aryl‐8,9‐dihydro‐7H‐chromeno[2,3‐b]quinolin‐10(12H)‐one 4 were synthesized by cyclization of the intermediate enamines 3 in THF with K₂CO₃ /Cu₂Cl₂ as catalyst. The structures of all compounds were characterized by elemental analysis, IR, MS, and ¹H NMR spectra. The crystal structure of compound 4i was determined by single‐crystal X‐ray diffraction analysis.     

Synthesis,X‐ray Diffraction Study,and Cytotoxicity of a ­Cationic p‐Cymene Ruthenium Chloro Complex Containing a Chelating Semicarbazone Ligand

An organometallic salt composed of a new cationic p‐cymene ruthenium chloro complex containing a chelating benzaldehyde semicarbazone ligand and of the known anionic p‐cymene ruthenium trichloro complex, [(η⁶‐p‐cymene)Ru(bzsc)Cl]⁺[(η⁶‐p‐cymene)RuCl₃]^– ( 1 ) (bzsc = benzaldehyde semicarbazone) was synthesized and further characterized by IR, ¹H NMR, and UV/Vis spectroscopy HR‐ESI mass spectrometry, and elemental analysis. The single‐crystal structure of 1 was also determined. The in vitro anticancer activities of the complex was evaluated against three human cancer cell lines (SGC‐7901, BEL‐7404 and CNE‐1), and the IC₅₀ values were 20.7, 71.1 and 42.6 μM, respectively.     

Divergent Chemoenzymatic Synthesis of Asymmetrical‐Core‐Fucosylated and Core‐Unmodified N‐Glycans

A divergent chemoenzymaytic approach for the preparation of core‐fucosylated and core‐unmodified asymmetrical N‐glycans from a common advances precursor is described. An undecasaccharide was synthesized by sequential chemical glycosylations of an orthogonally protected core fucosylated hexasaccharide that is common to all mammalian core fucosylated N‐glycans. Antennae‐selective enzymatic extension of the undecasaccharide using a panel of glycosyl transferases afforded core fucosylated asymmetrical triantennary N‐glycan isomers, which are potential biomarkers for breast cancer. A unique aspect of our approach is that a fucosidase (FucA1) has been identified that selectively can cleave a core‐fucoside without affecting the fucoside of a sialyl Lewis^X epitope to give easy access to core‐unmodified compounds.     

Electrochemical Synthesis and Characterization of Zinc(II) Complexes with [(4‐Methylphenyl)Sulfonyl]‐1H‐Amido‐2‐Phenyl‐2‐Oxazolines

A series of [(4‐methylphenyl)sulfonyl]‐1H‐amido‐2‐phenyl‐2‐oxazoline ligands, HTs‐ROz, has been synthesized by the reaction of substituted 2‐(2‐aminophenyl)oxazolines and p‐toluensulfonyl chloride. The electrochemical oxidation of a sacrificial zinc anode in an acetonitrile solution of the corresponding ligand gave compounds of general formula [Zn(Ts‐ROz)₂]. All complexes have been characterized by microanalysis, IR and ¹H NMR spectroscopy and single‐crystal X‐ray diffraction. In all cases, the metal atom is coordinated by the nitrogen atoms of two monoanionic ligands.     

Coordination Mode of the Nickel(II) Cation with N‐Diisopropoxyphosphinyl‐p‐bromothiobenzamide

Reaction of the potassium salt of N‐diisopropoxyphosphinyl‐p‐bromothiobenzamide p‐BrC₆H₄C(S)NHP(O)(OiPr)₂ ( HL ) with Ni(NO₃)₂ in aqueous EtOH leads to complex of formula [Ni(HL‐O)₂(L‐O,S)₂] ( 1 ). The structure of 1 was investigated by single crystal X‐ray diffraction analysis, IR, ¹H and ³¹P{¹H} NMR spectroscopy, MALDI and microanalysis. The nickel(II) ion in 1 has a tetragonal‐bipyramidal environment, (O^ax)₂(O^eq)₂(S^eq)₂, with two neutral ligand molecules coordinated in axial positions through the oxygen atoms of the P=O groups. The equatorial plane of bipyramide is formed by two anionic ligands involving 1,5‐O,S‐coordination mode. The chelating ligands are bound in trans configuration.     

5‐Chloro‐3‐methylthio‐1,2,4‐thiadiazol‐2‐ium chlorides as useful synthetic precursors to a variety of 6aλ4‐thiapentalene systems

Title salts 3 were easily obtained by treatment of formimidoyl isothiocyanates 1 with a twofold excess of methanesulfenyl chloride. They showed interesting chemical behavior toward several nitrogen and carbon nucleophiles. Substitution reactions with isothioureas and acetamide in the presence of triethylamine gave the 1H, 6H‐6aλ⁴‐thia‐1,3,4,6‐tetraazapentalenes 7 and 6H‐6aλ⁴‐thia‐1‐oxa‐3,4,6‐triazapentalene 9 , respectively. Addition of p‐toluidine furnished the 5‐imino‐thiadiazole derivatives 10 , which reacted further with diverse heterocumulenes to yield the corresponding thiatriaza‐ and tetraazapentalene species 11 . The N,N′‐bis(1,2,4‐thiadiazol‐5‐ylidene)diaminobenzenes 13 were also prepared and reacted with phenyl isothiocyanate. Two stable rotational isomers were separated for the 1,2‐phenylene product 14b . Other π‐hypervalent sulfur compounds 16 were synthesized under similar conditions from salts 3 and methyl cyanoacetate or dimethyl malonate. The structural assignments were discussed on the basis of IR and NMR spectroscopic data and received additional support from X‐ray analysis of substrate 16a . © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:95–105, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10106     

Crystal structure,thermal properties and detonation characterization of bis(5‐amino‐1,2,4‐triazol‐4‐ium‐3‐yl)methane dichloride

Bis(5‐amino‐1,2,4‐triazol‐4‐ium‐3‐yl)methane dichloride (BATZM·Cl₂ or C₅H₁₀N₈²⁺·2Cl^?) was synthesized and crystallized, and the crystal structure was characterized by single‐crystal X‐ray diffraction; it belongs to the space group C2/c (monoclinic) with Z = 4. The structure of BATZM·Cl₂ can be described as a V‐shaped molecule with reasonable chemical geometry and no disorder, and its one‐dimensional structure can be described as a rhombic helix. The specific molar heat capacity (C_p,m) of BATZM·Cl₂ was determined using the continuous C_p mode of a microcalorimeter and theoretical calculations, and the C_p,m value is 276.18 J K^?1 mol^?1 at 298.15 K. The relative deviations between the theoretical and experimental values of C_p,m, H_T – H_298.15K and S_T – S_298.15K of BATZM·Cl₂ are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM·Cl₂ were estimated using the nitrogen equivalent equation according to the experimental density; BATZM·Cl₂ has a higher detonation velocity (7143.60 ± 3.66 m s^?1) and detonation pressure (21.49 ± 0.03 GPa) than TNT. The above results for BATZM·Cl₂ are compared with those of bis(5‐amino‐1,2,4‐triazol‐3‐yl)methane (BATZM) and the effect of salt formation on them is discussed.     

First Perphenylated carbo‐Oligoacetylenes: An Extension of the Polytriacetylene Family

The first examples of a novel family of sp‐carbon‐rich n‐π‐conjugated oligomers/polymers, namely carbo‐mers of polyacetylene, also referred to as “1,4‐PTA” isomers of the classical polytriacetylenes (1,2‐PTAs), are described in the perphenylated series. The two first representatives proved to be stable in solution, and exhibit a zig‐zag arrangement in the crystal state. The third member of the family, isolated in SnCl₂ matrix, proved to be stable in the solid state and was characterized by MALDI‐TOF MS, ¹H NMR, CPMAS ¹³C NMR, and absorption spectroscopy. An explanation for its reactivity in solution is proposed. The chromophoric properties in the visible region are shown to vary significantly and consistently along the series.     

ATP Sensing with Anthryl‐Functionalized Open‐Chain Polyaza‐alkanes

The anthryl‐functionalized open‐chain polyaza‐alkanes L ¹ , L ² , and L ³ have been synthesized, and their activity as fluorescent chemosensors has been studied in MeCN/H₂O 70 : 30 (v/v) and H₂O at 25° against the anions bromide, phosphate, sulfate, ATP, ADP, and GMP. The crystal structure of L ³ has been solved by single‐crystal X‐ray‐diffraction techniques. The emission intensity of L ¹ and L ² is selectively quenched in the presence of ATP at acidic pH in MeCN/H₂O 70 : 30 (v/v). In H₂O, the emission intensity of L ¹ and L ² is enhanced at neutral pH in the presence of ADP and ATP. The sensing behavior is discussed in terms of H‐bonding or electrostatic anion‐cation interactions. Receptor L ³ does not show any significant change in fluorescence emission upon addition of anions. Protonation constants of the three ligands and stability constants of L ² with phosphate and sulfate were determined by potentiometric titration in MeCN/H₂O. The stability constants obtained are compared with those obtained for the interaction of these anions with related open‐chain polyamines.