The N,N'-bis[4-(4-n-alkyloxybenzoyloxy)benzylidene]phenylene-1,3-diamines: mesophase behaviour and physical properties

A homologous series of banana-shaped compounds (n =1-12) is described. The short-chain derivatives exhibit a B₆ phase, while B₆/B₁ dimorphism is found for the pentyloxy and hexyloxy homologues. The B₁ phase of the compounds having longer alkyloxy chains is changed to a B₂ phase for the compounds with n =11 and 12. The phase characterization was performed using their optical textures and by means of X-ray investigations. Transition enthalpies were measured using DSC. In addition, density measurements were performed on one selected homologue. The compound n =8 exhibiting a B₁ phase was investigated also by high-pressure DTA.     

Crystal structure of [N,N'-bis(5-chlorosalicylidene)-1,3-diaminopropane]iron(II).

The crystal structure of the title compound has been determined. The coordination geometry about the iron(II) center is a tetrahedrally distorted square plane formed by the four-coordinate N2O2 donor set of the Schiff-base imine-phenol ligand. Molecules of the title compound are not planar. The two Schiff-base moieties, which themselves are reasonably planar, are inclined at an angle of 31.5(1) degrees.     

Synthesis and Crystal Structure of Bisaqua-[N,N'-bis(3,5-dichlorosalicylidene)-1,3-diaminopropano]zinc(II)

1 INTRODUCTION N,N?-Bis(salicylidene)-1,3-diaminopropane (BSDP) is a versatile tetradentate ligand, which forms stable complexes with a large number of transition metals[1～3]. However, the complexes related to the BSDP deriva- tive,N,N?-bis(3,5-dichlorosalicylidene)-1,3-diamino- propane (BCDP), have been seldom reported. The prime interest in these complexes is their ability to afford functional solid materials with potentially controllable properties and novel molecular struc- tur…     

3-[N-(4-甲基苯基)氨基羰基]-5-[4-(4-甲酸基苯甲氧基)苯亚甲基]-2,4-噻唑烷二酮的合成

以对甲苯胺和对甲基苯甲酸甲酯为起始原料,经NBS溴化、亲核取代、酸水解和Knoevenagel缩合等6步反应合成了抗细菌生物膜化合物—3-[N-(4-甲基苯基)氨基羰基]-5-[4-(4-甲酸基苯甲氧基)苯亚甲基]-2,4-噻唑烷二酮,总收率57.3％,其结构经1H NMR,ESI-MS和元素分析确证.     

Novel bent-shaped liquid crystalline compounds II. Synthesis and properties of the 1,3-bis4-[4-(4-alkyloxybenzoyloxy)benzylidene]aminophenoxypropan-2-ols

A series of new symmetric dimer compounds was synthesized, constaining 2-hydroxy-1,3-dioxypropylene as the central linkage and terminal alkyl chains with different lengths. The chemical structures of the liquid crystal dimers (2ES-n) were examined by FTIR and ¹H NMR spectroscopy. Their mesomorphism, thermodynamic properties and optical textures were investigated by differential scanning calorimetry, polarizing optical microscope and X-ray diffraction. For homologues with terminal propyloxy and butyloxy chains, no liquid crystalline phase was observed. Homologues with pentyloxy and hexyloxy terminal chains showed nematic phases, while those with heptyloxy, octyloxy, nonyloxy and decyloxy terminal chains displayed nematic phases and smectic phases. The results confirmed that the liquid crystalline phase changes from nematic to smectic as the terminal chain length increases.     

Effects of reducing structural symmetry on mesophase behaviour: the synthesis and characterization of the 2-alkoxy-6-[4-(4-alkoxyphenyl)buta-1,3-diynyl]naphthalenes

Unsymmetrical 2-alkoxy-6-[4-(4-alkoxyphenyl)buta-1,3-diynyl]naphthalenes were synthesized and their mesomorphic properties studied. In addition to an increase the mesophase temperature range of 10°C, the melting temperatures are significantly lower while there is a less pronounced decrease in the clearing temperatures when compared with those of the symmetrical 1,4-bis(6-alkoxy-2-naphthyl)butadiynes. Further reducing the symmetry by introducing the two terminal chains of unequal length shows little effect on the mesogenic properties. Shortening the linker from a butadiynyne unit to an ethyne unit significantly reduces the overall mesophase and nematic temperature ranges but the smectic range markedly increases.     

Lasing and gain properties of a giant dipole molecule: 1-[p-(N,N-dimethylamino)phenyl]-4-(p-nitrophenyl)-1,3-butadiene

Laser tuning spectra, nanosecond gain spectra, and picosecond gain and absorption spectra of 1-[p-(N,N-dimethyl-amino)phenyl]-4-(p-nitrophenyl)-1,3-butadiene (DMANPB) are reported. Its permanent dipole moment is found to be larger than 30 D in the lowest excited singlet state. The tuning ranges are 690–725, 695–745, and 705–755 nm in dioxane-acetone mixed solution with volume ratios of 1:0, 5:1, and 4:1, respectively.     

Effects of reducing structural symmetry on mesophase behaviour: the synthesis and characterization of the 2-alkoxy-6-[4-(4-alkoxyphenyl)buta-1,3-diynyl]naphthalenes

Unsymmetrical 2-alkoxy-6-[4-(4-alkoxyphenyl)buta-1,3-diynyl]naphthalenes were synthesized and their mesomorphic properties studied. In addition to an increase the mesophase temperature range of 10°C, the melting temperatures are significantly lower while there is a less pronounced decrease in the clearing temperatures when compared with those of the symmetrical 1,4-bis(6-alkoxy-2-naphthyl)butadiynes. Further reducing the symmetry by introducing the two terminal chains of unequal length shows little effect on the mesogenic properties. Shortening the linker from a butadiynyne unit to an ethyne unit significantly reduces the overall mesophase and nematic temperature ranges but the smectic range markedly increases.     

Mesomorphic behaviour of 1,3-phenylene bis[4-(4-alkoxyphenyliminomethyl)benzoates] and related compounds

DSC and X-ray diffraction studies on a series of 1,3-phenylene bis[4-(4-alkoxyphenyliminomethyl)benzoates] are presented. The only mesophase exhibited by the methoxy to hexadecyloxy homologues is of the smectic C type. The reversal of the iminomethyl linkage reduces drastically the incidence of a mesophase; that is, only the first five homologous members exhibit a smectic C phase in the series of 1,3-phenylene bis[4-(4-alkoxybenzylideneamino)benzoates]. Almost all the members in the second series become nematogenic by the chloro substitution at the 4-position of the 1,3-phenylene moiety. In addition, a smectic C phase is observable for the ethoxy to pentyloxy and also the tetradecyloxy and hexadecyloxy members. The second chloro-substituent introduced to the 6-position of the same central ring eliminates completely the smectic C phase and enhances the nematic thermal stability.     

Binary pnictogen azides--an experimental and theoretical study: [As(N3)4]-, [Sb(N3)4]-, and [Bi(N3)5(dmso)]2-

[PPh(4)][EI(4)] (E=As, Sb, Bi) salts were reacted with four and five equivalents of AgN(3) to form tetraazidopnictates and pentaazidopnictates of the type [PPh(4)][E(N(3))(4)] and [PPh(4)](2)[E(N(3))(5)], respectively. The synthesis of [PPh(4)][P(N(3))(4)] was also attempted from the reaction of P(N(3))(3) with [PPh(4)]N(3), but it yielded only the starting materials. Herein, we report the synthesis and structure elucidation of [PPh(4)][E(N(3))](4) (E=As, Sb) and pentaazidobismuthate, stabilized as the dimethyl sulfoxide (DMSO) anion adduct, [PPh(4)](2)[Bi(N(3))(5)(dmso)]. Successive anion formation along the series E(N(3))(3)+nN(3)(-) (n=1-3) and E(N(3))(5)+N(3)(-) was studied by density functional theory.     

1-[4-(二甲氨基)苯亚甲基氨基]-4-苯基硫脲的合成及手性晶体结构

对二甲氨基苯甲醛和苯基氨基硫脲缩合反应生成对二甲氨基苯甲醛缩氨基苯硫脲{1-[4-(dimethylamino)ben- zylidene]-4-phenylthiosemicarbazide}, 并从溶液中析出手性晶体. 元素分析、红外光谱、紫外光谱、核磁谱、质谱和X射线衍射测定其组成和结构. 晶体属正交晶系, P2₁2₁2₁空间群, a＝0.77038(14) nm, b＝1.1428(2) nm, c＝1.6726(3) nm, V＝1.4726(5) nm³, Z＝4, D_c＝1.346 g/cm³, F(000)＝632, μ＝0.219 mm^－1, 可观测点精修最终偏离因子: R＝0.0407, wR＝0.1157. 化合物的晶体结构和固态圆二色谱表明化合物在结晶过程中发生单一对映体的手性堆积.