Preparation, crystal structure, and spectroscopic, chemical, and electrochemical properties of (2E,4E)-4-[4-(dimethylamino)phenyl]-1-(3-guaiazulenyl)-1,3-butadiene compared with those of (E)-2-[4-(dimethylamino)phenyl]-1-(3-guaiazulenyl)ethylene

Wittig reaction of 3-[4-(dimethylamino)phenyl]propanal (5) with (3-guaiazulenylmethyl)triphenylphosphonium bromide (4) in ethanol containing NaOEt at 25 °C for 24 h under argon gives the title (2E,4E)-1,3-butadiene derivative 6E in 19% isolated yield. Spectroscopic properties, crystal structure, and electrochemical behavior of the obtained new extended π-electron system 6E, compared with those of the previously reported (E)-2-[4-(dimethylamino)phenyl]-1-(3-guaiazulenyl)ethylene (12), are documented. Furthermore, reaction of 6E with 1,1,2,2-tetracyanoethylene (TCNE) in benzene at 25 °C for 24 h under argon affords a new Diels-Alder adduct 8 in 59% isolated yield. Along with spectroscopic properties of the [π4+π2] cycloaddition product 8, the crystal structure, possessing a cis-3,6-substituted 1,1,2,2-tetracyano-4-cyclohexene unit, is shown. Moreover, reaction of 6E with (E)-1,2-dicyanoethylene (DCNE) under the same reaction conditions as the above gives no product; however, this reaction in p-xylene at reflux temperature (138 °C) for four days under argon affords a new Diels-Alder adduct 9 in 54% isolated yield. Although reaction of 6E with DCNE in toluene at reflux temperature (110 °C) for four days under argon provides 9 very slightly, reaction of 6E with dimethyl acetylenedicarboxylate (DMAD) in toluene at reflux temperature for two days under argon yields a new Diels-Alder adduct 10, in 58% isolated yield, which upon oxidation with MnO₂ in CH₂Cl₂ at 25 °C for 1 h gives 11, converting a (CH₃)₂N-4″ into CH₃NH-4″ group, in 37% isolated yield. The crystal structure of 11 supports the molecular structure 10 possessing a partial structure cis-3,6-substituted 1,2-dimethoxycarbonyl-1,4-cyclohexadiene. The title basic studies on the above are reported in detail.     

Reactions of (E)-1,2-di(3-guaiazulenyl)ethylene and 2-(3-guaiazulenyl)-1,1-bis(4-methoxyphenyl)ethylene with tetracyanoethylene (TCNE) in benzene: comparative studies on the products and their spectroscopic properties

Reactions of the title ethylene derivatives, (E)-1,2-di(3-guaiazulenyl)ethylene (1) and 2-(3-guaiazulenyl)-1,1-bis(4-methoxyphenyl)ethylene (2), with a 2 M amount of TCNE in benzene at 25 °C for 24 h under argon give new cycloaddition compounds, 1,1,2,2,11,11,12,12-octacyano-3-(3-guaiazulenyl)-8-isopropyl-5,10-dimethyl-1,2,3,6,9,10a-hexahydro-6,9-ethanobenz[a]azulene (3) from 1 and 1,1,2,2,11,11,12,12-octacyano-8-isopropyl-3,3-bis(4-methoxyphenyl)-5,10-dimethyl-1,2,3,6,9,10a-hexahydro-6,9-ethanobenz[a]-azulene (4) from 2, respectively, in 66 and 87% isolated yields. Comparative studies on the above reactions as well as the spectroscopic properties of the unique products 3 and 4, possessing interesting molecular structures, are reported and, further, a plausible reaction pathway for the formation of these products is described.     

Reactions of (1R,2S)-1,2-di(2-furyl)-1,2-di(3-guaiazulenyl)ethane and (1R,2S)-1,2-di(3-guaiazulenyl)-1,2-di(2-thienyl)ethane with tetracyanoethylene (TCNE) in benzene: comparative studies on the products and their spectroscopic properties

Reactions of the title meso forms, (1R,2S)-1,2-di(2-furyl)-1,2-di(3-guaiazulenyl)ethane (1) and (1R,2S)-1,2-di(3-guaiazulenyl)-1,2-di(2-thienyl)ethane (2), with a two molar amount of TCNE in benzene at 25 °C for 5 h (for 1) and 48 h (for 2) under oxygen give new compounds, 2,2,3,3-tetracyano-4-(2-furyl)-8-isopropyl-6-methyl-1,4-dihydrocyclohepta[c,d]azulene (3) and 2,2,3,3-tetracyano-8-isopropyl-6-methyl-4-(2-thienyl)-1,4-dihydrocyclohepta[c,d]azulene (4), respectively, in 74 and 21% isolated yields. Comparative studies on the above reactions as well as the spectroscopic properties of the unique products 3 and 4, possessing interesting molecular structures, are reported and, further, a plausible reaction pathway for the formation of these products is described.     

Preparation,molecular structures,and characteristic properties of (E)-1-(2-furyl)- and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylenes and (E)-1-(3-furyl)- and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylenes

Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also.     

The vibrational structure of (E,E')-1,4-diphenyl-1,3-butadiene Linear dichroism FT-IR spectroscopy and quantum chemical calculations

The title compound (DPB) was investigated by FT-IR spectroscopy in liquid solutions and by FT-IR linear dichroism (LD) measurements on samples aligned in stretched polyethylene. The LD data provided experimental assignments of molecular transition moment directions and vibrational symmetries for more than 40 vibrational transitions. The observed IR wavenumbers, relative intensities, and polarization directions were generally well reproduced by the results of a harmonic analysis based on B3LYP/cc-pVTZ density functional theory (DFT). The combined experimental and theoretical results led to proposal of a nearly complete assignment of the IR active fundamentals of DPB, involving reassignment of a number of transitions. In addition, previously published Raman spectra of DPB were well predicted by the B3LYP/cc-pVTZ calculations.     

Synthesis of substituted 1,2-di(alkylsulfonyl)indolizines. Molecular and crystal structure of 3-(4-fluorobenzoyl)-6-methyl-1,2-di(propylsulfonyl)indolizine

The reactions of substituted pyridinium salts with E-1,2-di(alkylsulfonyl)-1,2-dichloroethenes proceed regiospecifically. Heating of these reagents in chloroform in the presence of a threefold excess of Et₃N affords substituted 1,2-di(alkylsulfonyl)indolizines in high yields. The structures of the reaction products were confirmed by physicochemical methods, including X-ray diffraction. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1205–1209, May, 2005.     

A facile preparation, spectroscopic and chemical properties, crystal structures, and electrochemical behavior of monocarbenium ion compounds stabilized by 3-guaiazulenyl and dihydroxyphenyl (or hydroxymethoxyphenyl) groups

Reaction of guaiazulene (8) with 2,3-dihydroxybenzaldehyde (9) in methanol in the presence of hexafluorophosphoric acid (i.e., 65% aqueous solution) at 25 °C for 2 h gives (3-guaiazulenyl)(2,3-dihydroxyphenyl)methylium hexafluorophosphate (13) in 86% yield. Similarly, reaction of 8 with 2-hydroxy-3-methoxybenzaldehyde (10) [or 3,4-dihydroxybenzaldehyde (11) or 4-hydroxy-3-methoxybenzaldehyde (12)] under the same reaction conditions as for 9 affords the corresponding monocarbenium ion compound 14 (63% yield) [or 15 (43% yield) or 16 (77% yield)], respectively, each product of which is stabilized by 3-guaiazulenyl and dihydroxyphenyl (or hydroxymethoxyphenyl) groups. A facile preparation and crystal structures as well as spectroscopic, chemical, and electrochemical properties of 13-16, possessing two interesting resonance structures, respectively, i.e., a protonated o- (or p-) benzoquinonemethide form and a 3-guaiazulenylium ion form, in a solution of acetonitrile and further, in a single crystal, are reported.     

Synthesis, spectroscopic properties and crystal structure determination of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole derivatives

Substituted 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole derivatives 2, 3 and 6 were synthesized. 2-(2-Pyridin-4-yl-vinyl)-1H-benzimidazole 2 and 6-methyl-2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 3 were prepared by condensation reaction from 3-pyridin-4-yl-acrylic acid and corresponding 1,2-phenylenediamines in polyphosporic acid (PPA). 2,7,11-b-Triaza-benzo[c]fluorene 4 was prepared by photochemical dehydrocyclization reaction of ethanolic solution of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 2. 2-(2-Pyridin-4-yl-vinyl)-3H-benzimidazole-6-carbonitrile 6 was prepared by condensation reaction from 3-pyridin-4-yl-propenal and 4-cyano-1,2-phenylenediamine using p-benzoquinone as oxidants. The structure of novel benzimidazole derivatives has been studied by ¹H and ¹³C NMR, IR, MS, UV/Vis and fluorescence spectroscopy. The structure of 2-(2-pyridin-4-yl-vinyl)-1H-benzimidazole 2 was confirmed by X-ray single crystal structure analysis. The conformation of the molecule is E in regard to substituents position around vinyl double C=C bond. The non-planar molecules are mutually connected via the N–H···N and C–H···N type of intermolecular hydrogen bonds into infinite chains spreading along y axis.     

A facile preparation, the crystal structure, the chemical and electrochemical properties of [4-(dimethylamino)phenyl]-3-guaiazulenylmethylium tetrafluoroborate

Reaction of guaiazulene (1) with p-dimethylaminobenzaldehyde in methanol in the presence of tetrafluoroboric acid gives the title monocarbocation compound, [4-(dimethylamino)phenyl]-3-guaiazulenylmethylium tetrafluoroborate (2), in 90% yield. The title investigations of compound 2 compared with those of two other monocarbocations stabilized by a 3-guaiazulenyl group (i.e. phenyl-3-guaiazulenylmethyl and [4-(isopropyl)phenyl]-3-guaiazulenylmethyl cations) are reported.     

Pentacarbonylmanganato-Mn)1,3-bis(2-chlorophenyl)-1-triazenato-N 1,N 3-mercury. Preparation,properties, crystal and molecular structure

Summary Mixed mercury complexes of the type (2-XC₆H₄)₂-N₃HgMn(CO)₅ (X = F, Cl, Br or I) have been prepared by synproportionation of the respective symmetric compounds. The new air-stable complexes were characterized by i.r., u.V., n.m.r. and mass spectroscopy. The molecular structure of the title compound shows bidendate bonding of the triazenato ligand to mercury: Hg-N(1), 231 pm; Hg-N(3), 243 pm; Mn-Hg-N(1), 161 deg; Mn-Hg-N(3), 146 deg. The smallest Hg...Cl intramolecular nonbonding distance is 334 pm.     

3,5-二(2-吡嗪基)-4-氨基-1,2,4-三唑的水热合成及晶体结构

1,2,4-三唑及其衍生物作为配体与中过渡金属离子能形成多种配合物,这些配合物可表现出良好的生物活性或特殊的电磁性能.因此,过渡金属的三唑配合物的结构和物理特性引起了人们的广泛关注[1-6].     

New thermally stable cationic eta3-allyl(1,4-diphospha-(1,3)-butadiene)nickel complexes for ethylene polymerization

Nickel ethylene polymerization catalysts 1a,b bearing a P,P-ligand with two sp2-hybridized phosphorus atoms have been synthesized; their structure and polymerization studies have been reported for the first time.     

1,3-双[4-(4'-甲基)-氧化偶氮苯基-苯氧羰基]苯氧甲基-1,1,3,3- 四甲基二硅 氧烷的合成、晶体结构和液晶性能

合成了[CH3(C6H4)N2O(C6H4)COO(C6H4)OCH2Si(CH3)2]2O,经IR,1^HNMR和元素分析表征,并测定其单晶结构。结果表明,晶体属单斜晶系,空间群为P21/c,晶胞参数a=1.7557(1),b=1.0938(9),c=2.3300(1)nm,β=105.6(6)°,V=4.3116nm^3,Mr=855.07,Z=4,Dc=1.317g/cm^3,μ(CuKα)=6.335cm^-1,F(000)=900,最终的偏离因子R=0.0837,Rw=0.0913。该分子中,柔性的四甲基二硅氧烷嵌段与氧化偶介晶基团形成ABA结构齐聚物。两条刚性的介晶基链节的轴向几乎平行向上伸出。径长比(L/D)为4.23.该液晶化合物的要变温度K174.4N226.8Ⅰ.通过结构分析,讨论了该类化合物的结构对液晶相变行为的影响。