Bis[μ3‐1,8‐bis(triisopropylsilylamido)naphthalene]bis(tetrahydrofuran)di‐μ3‐oxido‐dimanganese(III)disodium

The solid‐state structure of the title compound, [Na₂Mn₂(C₃₂H₅₆N₂OSi₂)₂O₂] or [1,8‐C₁₀H₆(NSiⁱPr₃)₂Mn(μ₃‐O)Na(THF)]₂, which lies across a crystallographic twofold axis, exhibits a central [Mn₂O₂Na₂]⁴⁺ core, with two oxide groups, each triply bridging between the two Mn^III ions and an Na⁺ ion. Additional coordination is provided to each Mn^III centre by a 1,8‐C₁₀H₆(NSiⁱPr₃)₂ [1,8‐bis(triisopropylsilylamido)naphthalene] ligand and to the Na⁺ centres by a tetrahydrofuran molecule. The presence of an additional Na...H—C agostic interaction potentially contributes to the distortion around the bridging oxide group.     

Development of an Unsymmetrical Cyclopropenimine-Guanidine Platform for Accessing Strongly Basic Proton Sponges and Boron-Difluoride Diaminonaphthalene Fluorophores

An unsymmetrical guanidine-cyclopropenimine proton sponge DAGUN and the related BF₂-chelate DAGBO are reported. Insight into the structural, electronic, bonding and photophysical properties of these two molecules are presented. Joint experimental and theoretical studies reveal the protonated form of DAGUN possesses an intramolecular N⋅⋅⋅H−N hydrogen bond which affords a high experimental pK_BH+ of 26.6 (computed=26.3). Photophysical studies show that in solution DAGUN displays a green emission at 534 nm, with a large Stokes shift of 235 nm (14,718 cm⁻¹). In contrast, the conjugate acid DAGUN-H⁺ is only weakly emissive due to attenuated intramolecular charge transfer. X-ray diffraction studies reveal that DAGBO contains a stable tetracoordinate boronium cation, reminiscent of the well-established BODIPY family of dyes. In solution, DAGBO exhibits a strong blue emission at 450 nm coupled with a large Stokes shift (Δλ=158 nm, Δν=11,957 cm⁻¹) and quantum yield of 62 %, upon excitation at 293 nm. DAGBO sets the stage as the first entry into a new class of boron-difluoride diaminonaphthalenes (BOFDANs) that represent highly fluorescent and tunable next-generation dyes with future promise for biosensing and bioimaging applications.     

Monoxidised Sulfur and Selenium Derivatives of 1,8‐Bis(diphenylphosphino)naphthalene: Synthesis and Coordination Chemistry

Treatment of 1,8‐bis(diphenylphosphino)naphthalene (dppn, 1 ) with stoichiometric amounts of sulfur or selenium in toluene at 80 °C selectively afforded the diphosphine monochalcogenides 1‐Ph₂P(C₁₀H₆)‐8‐P(:S)Ph₂ (dppnS, 2 a ) and 1‐Ph₂P(C₁₀H₆)‐8‐P(:Se)Ph₂ (dppnSe, 2 b ). The ³¹P{¹H} NMR spectrum of 2 b showed an unusually large ⁵J(P–Se) value, which indicates a significant through‐space coupling component. The monosulfide acted as a bidentate P,S‐ligand towards platinum(II) ( 3 a ), whereas the corresponding monoselenide complex ( 3 b ′) lost elemental selenium with formation of the previously reported complex [PtCl₂(dppn)‐P,P′] ( 3 ). Treatment of dppnSe with [(nor)Mo(CO)₄] (nor = norbornadiene) led to formation of [(dppnSe)Mo(CO)₄‐P,Se] ( 3 b ). Solutions of the latter slowly deposited Se with formation of [(dppn)Mo(CO)₄‐P,P′] ( 4 ) which was also obtained by independent synthesis from 1 and [(nor)Mo(CO)₄]. All isolated new compounds were characterised by a combination of ³¹P, ¹H, ¹³C and ⁷⁷Se ( 2 b ) NMR spectroscopy, IR spectroscopy, mass spectrometry and elemental analysis. Single‐crystal X‐ray structure determinations were performed for dppnSe ( 2 b ), [PtCl₂(dppnS)‐P,S] ( 3 a ), [(dppnSe)Mo(CO)₄‐P,Se] ( 3 b ) and [(dppn)Mo(CO)₄‐P,P′] ( 4 ). In 2 b steric effects cause the naphthalene ring to be distorted and force the phosphorus atoms by 65 and 59 pm to opposite sides of the best naphthalene plane. In the metal complexes 3 a , 3 b and 4 the phosphino‐phosphinochalcogenyl systems act as bidentate ligands through the P and the chalcogen atoms. The naphthalene systems are again distorted. The two independent molecules of 4 differ in their conformations.     

Phosphonium Salts of 1,8‐Bis(diphenylphosphino)naphthalene: Molecular Structures and NMR‐spectroscopic Studies

A representative series of diphosphine monophosphonium salts [1‐Ph₂P(C₁₀H₆)‐8‐PRPh₂]⁺X^– ( 2 b : R = H, X = CF₃SO₃; 4 : R = Me, X = CF₃SO₃; 5 : R = C₆H₅CH₂ = Bn, X = Br) has been prepared by treatment of 1,8‐bis(diphenylphosphino)naphthalene (dppn, 1 ) with stoichiometric amounts of HSO₃CF₃ or CH₃SO₃CF₃ in CH₂Cl₂ at +20 °C and with C₆H₅CH₂Br in toluene at +80 °C. Their X‐ray crystal structures show that there is no evidence for dative P → P⁺ interactions. Instead, steric repulsion deflects the substituent groups to opposite faces of the naphthalene plane [splay angles: +11.4° ( 2 b ), +13.6° ( 4 ); +16.7° ( 5 )]. In solution 2 b , 4 , and 5 were dynamic according to ³¹P, ¹³C, and ¹H NMR spectroscopy. The fluxionality of 2 b involves rapid intramolecular proton exchange between the two phosphorus atoms, which slows down at low temperature, whereas the dynamic behaviour of 4 and 5 is interpreted in terms of hindered rotation of the bulky RPh₂P⁺ groups (R = Me or Bn) about the P–C(naphthyl) bond. Treatment of 1,8‐bis(diphenylphosphoryl)naphthalene (dppnO₂, 6 ) with HSO₃CF₃ gave the protonated bis(phosphine oxide), as the triflate salt, dppnO₂H⁺ CF₃SO₃^– ( 7 ). The X‐ray structure analysis of 7 revealed a highly strained molecule (P1…P2 365.5 pm) in which the P=O bonds point to the same face of the naphthalene plane to accommodate the proton. All isolated compounds were characterised by a combination of ³¹P, ¹H, and ¹³C NMR spectroscopy, IR spectroscopy ( 7 ), mass spectrometry and elemental analysis.     

Determination of Selenium with a Poly(1,8‐diamino‐naphthalene)‐Modified Electrode

The performance of a poly(1,8‐diaminonaphthalene)‐modified electrode for the determination of the Se(IV) ion in an aqueous medium was investigated with anodic stripping voltammetry without the pretreating of the sample. The experimental parameters for the analysis of Se(IV) were optimized and the characteristics of this polymer‐modified electrode were investigated by using cyclic voltammetry. The Se(IV) ions were chemically deposited onto the surface of the pDAN‐Au electrode in an acidic medium. The detection limit employing the anodic stripping differential pulse voltammetry was 9.0×10^?9 M for Se(IV) with 4.4 % of RSD. Satisfactory result for the determination of Se(IV) was acquired employing a certified standard urine reference material, SRM's 2670 (trace element in urine) with 4.1 ppb of SD.     

Chromium Bis(anthracene‐η6) Complexes – A DFT Study

Chromium bisanthracene‐η⁶ complexes are considered within the framework of density functional theory using LANL2DZ and 6‐31+G(d) basis sets and B3LYP functional. The complexation with both the same types of rings of anthracene decks (AA‐ and BB‐type complexes) and with different rings (AB‐type complex) are considered. The optimized geometries and the associated quantum chemical properties are comparatively discussed for the both types of basis sets used. LANL2DZ basis set yielded some unreasonable results. B3LYP/6‐31+G(d) level of calculations yielded the stability order as AA > BB > AB. IR spectra of AA and BB‐type complexes resemble each other. The C–H frequencies are almost the same for both of the anthracene decks, whereas they differ in the case of AB‐type complex. UV/Vis spectra of the complexes all absorb above 500 nm. AA and AB‐type complexes in contrast to BB‐type display rather complex pattern. The NICS(0) values of various rings in the complexes considered are obtained and discussed.     

Synthesis and properties of novel sulfonated polyimides from 2,2′‐bis(4‐aminophenoxy)biphenyl‐5,5′‐disulfonic acid

Novel sulfonated polyimides (SPIs) were prepared from 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTDA), 2,2′‐bis(4‐aminophenoxy)biphenyl‐5,5′‐disulfonic acid (oBAPBDS) with nonlinear configuration, and common nonsulfonated diamines. Water uptake (WU) in liquid and vapor, water stability, and proton conductivity σ of the resulting SPI membranes were investigated. They were soluble in m‐cresol and dimethylsulfoxide, and their WUs in liquid were much larger than those of the SPIs from other sulfonated diamines with linear configuration such as 4,4′‐bis(4‐aminophenoxy)biphenyl‐3,3′‐disulfonic acid (BAPBDS). NTDA‐oBAPBDS membrane was soluble in water at room temperature, whereas all the oBAPBDS‐based copolyimide membranes were insoluble in water and maintained mechanical strength after being soaked in distilled water at 80 °C for 40–1000 h. This much improved water stability was due to the enhanced solubility stability of membrane toward water. The water vapor sorption isotherms were rather similar between the SPIs with the nonlinear and linear configurations of sulfonated diamine moieties. The present SPIs with IECs of 1.8–2.6 meq/g, including NTDA‐BAPBDS, showed reasonably high proton conductivities under the highly humid conditions and roughly fell on the same σ–WU relation line. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1432–1440, 2004     

Synthesis and Redox Properties of Bis{4‐[bis(4‐methoxyphenyl)amino]‐2,6‐bis(2,4,6‐triisopropylphenyl)phenyl}diphosphene

Bis{4‐[bis(4‐methoxyphenyl)amino]‐2,6‐bis(2,4,6‐triisopropylphenyl)phenyl}diphosphene ( 1 ), possessing two bis(4‐methoxyphenyl)amino groups as redox sites as well as electron‐donating sources, was synthesized and isolated as a red solid. The cyclic voltammogram of 1 at −78° consisted of three reversible redox waves corresponding to two‐step oxidation of the triarylamine moieties and reduction of the diphosphene moiety. Introduction of the two amino groups also contributed to a red shift of the absorption maximum in the UV/VIS spectrum, which was responsible for the intense red color of 1 .     

A Stable Bis(benzocyclobutadiene)‐Annelated Tetraazapentacene Derivative

Biphenylene‐2,3‐dione is a powerful reagent to build up cyclobutadiene‐containing azapolyheterocycles. The target structures are formed in high yields through classical condensation of suitable aromatic diamines with the biphenylenedione. To achieve the title compound, the biphenylenedione is coupled with a diaminobenzothiadiazole derivative. Reductive cleavage of the thiadiazole ring and subsequent condensation with the biphenylenedione gives the title compound in which a central tetraazapentacene is flanked by two benzocyclobutadiene units. This compound is stable despite its extended π‐system and its optical features are blueshifted in comparison to those of the symmetrical tetraazapentacene.     

Synthesis and Characterization of Bis(azido)bis(2‐chloropyridine)palladium(II), Bis(azido)bis(3‐chloropyridine)palladium(II), Bis(azido)bis(quinoline)palladium(II), and the Crystal Structure of Bis(azido)bis(quinoline)palladium(II)

Three new monomeric complexes of palladium(II) azide with 2‐chloropyridine ( 1 ), 3‐chloropyridine ( 2 ), and quinoline ( 3 ), have been synthesized by reaction of palladium nitrate and the respective Lewis‐base with sodium azide in a water/acetone mixture. All three compounds were characterized by IR, Raman, and multinuclear NMR spectroscopy. The composition of the complexes were confirmed by elemental analysis. The spectroscopic investigations confirm terminal azide ligands in trans position. Complex 3 was also characterized by crystallographic methods. Each palladium atom of 3 is surrounded in a distorted square planar fashion by 4 nitrogen atoms. The terminal azide ligands are in trans position.     

Synthesis of new bis(2,4‐dimethyl‐5‐amino‐benzo[b][1,8]‐naphthyridines) and bis(benzo[b][1,8]naphthyridones) linked with methylene linear chain

The preparation of novel alkyl monobridged 2,4‐dimethyl‐5‐amino‐benzo[b][1,8]naphthyiridine and benzo[b][1,8]naphthyridone derivatives by phase transfer catalysis is reported.     

Synthesis and Investigation of 2,6‐Bis(picrylamino)‐3,5‐dinitro‐pyridine (PYX) and Its Salts

2,6‐Bis(picrylamino)pyridine ( 1 ; pre‐PYX) and 2,6‐bis(picrylamino)‐3,5‐dinitropyridine ( 2 ; PYX) were synthesized using an improved literature method. Compounds 1 and 2 were reinvestigated in detail and the X‐ray structures ( 1 : ρ=1.698 g cm^?3 at 173 K; 2 : ρ=1.757 g cm^?3 at 298 K) are given. The reactions of 2 with different bases, such as alkali metal hydroxides (sodium, potassium, rubidium, cesium), and N‐bases (ammonia, hydrazine, hydroxylamine, guanidinium carbonate, aminoguanidine bicarbonate) are reported, as well as metathesis reactions producing energetic salts. Several energetic compounds were synthesized and characterized for the first time using vibrational (IR, Raman) and multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, and DSC. The crystal structures of four energetic salts were determined using low temperature single‐crystal X‐ray diffraction. Heats of formation for the metal‐free species were calculated using the Gaussian 09 software. Detonation parameters were estimated using the EXPLO5 program. The sensitivities towards impact, friction, and electrostatic discharge were also determined.     

Synthesis of Bis{(S‐methyl)azolespoly(ethylene oxide)} from 3,6‐dioxa‐1,8‐octanedithiol

Bis(1,3,4‐oxadiazoles) 4 , 5 and bis(1,2,4‐triazoles) 6a , 6b have been prepared from 3,6‐dioxa‐1,8‐octanedithiol 1 through a multistep reaction sequence. Compound 4 reacted with the appropriate alkyl halide in the presence of potassium carbonate in refluxing acetone to give the corresponding bis(S‐alkylated‐1,3,4‐oxadiazoles) 7a , 7b . The title compound 8 was prepared by condensing 4 with benzoyl bromide in the presence of triethylamine. Further, 6,9‐dioxa‐3,12‐dithiotetradecanedihydrazide 3 was converted to bis{N′‐(phenylaminocarbonyl) hydrazides} and bis{N′‐(phenylaminocarbonothioyl)hydrazides} 9a , 9b using phenylisocyanate and phenylthioisocyanate, respectively, which underwent cyclization in alkaline medium to produce 6,9‐dioxa‐3,12‐dithiotetradecane bis(4‐phenyl‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one) and their 3‐thio analogs 10a , 10b . The new compounds 4 , 5 , 6 , 7 , 8 , 9 , 10 were characterized by their IR, ¹H‐NMR, ¹³C‐NMR, MS, and elemental analyses.     

Synthesis and characterization of novel fluorinated polyimides based on 2,7‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene

A new trifluoromethyl‐substituted bis(ether amine) monomer, 2,7‐bis(4‐amino‐2‐trifluoromethylphenoxy)naphthalene, was synthesized. It led to a series of novel fluorinated polyimides by thermal and chemical imidization routes when reacted with various commercially available aromatic tetracarboxylic dianhydrides. Most of the polyimides obtained from both routes were soluble in many organic solvents, such as N,N‐dimethylacetamide. All the polyimides could afford transparent, flexible, and strong films with low moisture absorptions of 0.3–0.6%, low dielectric constants of 2.52–3.27 at 10 kHz, and an ultraviolet–visible absorption cutoff wavelength at 377–436 nm. The glass‐transition temperatures of the polyimides were in the range of 244–297 °C, and the 5% weight‐loss temperatures were higher than 550 °C. For a comparative study, a series of analogous polyimides based on 2,7‐bis(4‐aminophenoxy)naphthalene were also prepared and characterized. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2001–2018, 2003     

稀土双(11-钨硅酸)钾的质子导电性研究(英)

研究了K13［Ln（SiW11O39）2］nH2O（Ln=La，Ce，Pr，Nd，Sm，Gd）的质子导电性研究表明其导电性不仅与物质本性有关，也与外界条件如温度、频率等有关，不同结构的杂多化合物给出不同结构的质子导电性．总结了质子导电性随温度、结晶水数目、频率的变化总趋势．基于实验数据得出一些重要结论，所得数据未见文献报道．     

Comparative structural analysis of 2,7‐diethoxy‐1,8‐bis(4‐phenoxybenzoyl)naphthalene and its homologues: orientation of the 4‐phenoxybenzoyl groups at the 1‐ and 8‐positions of the naphthalene ring

The title molecule, C₄₀H₃₂O₆, possesses crystallographically imposed twofold symmetry, with the central two C atoms of the naphthalene unit sited on the rotation axis. The two 4‐phenoxybenzoyl groups in the molecule are twisted away from the attached naphthalene unit, with a torsion angle of 66.76 (15)° between the naphthalene unit and the carbonyl group (C—C—C=O), and are oriented in mutually opposing directions (anti orientation). There is an apparent difference in the conformations of the 4‐phenoxybenzoyl groups at the 1‐ and 8‐positions of the naphthalene ring between the title molecule and its methoxy‐bearing homologue [Hijikata et al. (2010). Acta Cryst. E 66 , o2902–o2903]. Whilst the 4‐phenoxybenzoyl groups in 2,7‐diisopropoxy‐1,8‐bis(4‐phenoxybenzoyl)naphthalene [Yoshiwaka et al. (2013). Acta Cryst. E 69 , o242] are situated in the same anti orientation as the title molecule, those of 2,7‐dimethoxy‐1,8‐bis(4‐phenoxybenzoyl)naphthalene are oriented in the same direction with respect to the naphthalene ring system, i.e. in a syn orientation.