The preparation of derivatives of 2,2′-(2,6-naphthalenediylidene)bis(1,3-dithiole) (nbdt): New donors for organic metals

Routes from 2,6-bis(bromomethyl)naphthalene to compounds (3) and (4) are described. A complex between (4) and iodine has been obtained.     

Photogeneration of charge carriers and their transport properties in poly[bis(p-n-butylphenyl)silane

The photocarrier generation mechanism and mobility in poly[bis(p-n-butylphenyl)silane] (PBPS) thin films doped with a variety of electron acceptors are studied by time-resolved microwave conductivity (TRMC) measurements. It was found that fullerene is a suitable electron acceptor for PBPS as it provides the highest product of photocarrier generation yield phi and mobility Sigmamu under excitation at 532 and 355 nm. The observed high phiSigmamu value of 4.5 x 10(-3) cm(2)/(V s) under excitation at 193 nm (6.39 eV) can be attributed to the direct ionization of PBPS molecules. The photoinduced electron transfer between C(60) and PBPS was investigated in a solution sample by laser flash photolysis under excitation at 532 nm. On the basis of the extinction coefficient of PBPS(*+), transient absorption of PBPS(*+) provides a maximum value of phi of 0.83% for the electron-transfer reaction from PBPS to (3)C(60). On the basis of this value of phi, the intrinsic intrachain mobility of holes on the PBPS backbone is estimated to be higher than 1.7 x 10(-2) cm(2)/(V s), suggesting the presence of a high conducting path along the Si backbone of PBPS.     

Synthesis of low band gap [1,2,5]-thiadiazolo[3,4-g]quinoxaline and pyrazino[2,3-g]quinoxaline derivatives by selective reduction of benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole

The reduction of a dithienylbenzobisthiadiazole derivative TBBT can be performed selectively so as to afford either [1,2,5]-thiadiazolo[3,4-g]quinoxaline (TQ) or pyrazino[2,3-g]quinoxaline (PQ) derivatives. This approach offers a much milder, shorter, and more efficient route to PQ and TQ derivatives than current methods. It is further shown how the optical and electrochemical properties of PQ and TQ can be tuned by choice of appropriate substituents.     

1,1,1,3,3,3-Hexamethyltrisilanylene-bridged bis(cyclopentadienyl)tetracarbonyldiiron and its derivatives: Synthesis,properties and molecular structures

The title ring-bridged bis(cyclopentadienyl)diiron complexes [η⁵,η⁵-C₅H₄–Si(SiMe₃)₂–C₅H₄]Fe₂(CO)L(μ-CO)₂ [L = CO (1), P(OPh)₃ (2), P(OMe)₃ (3), PPh₃ (4), PMe₃ (5)] that contain exocyclic Si–Si bonds attached to the bridging silicon atom have been synthesized. The Si–Si bonds were found to be stable to the intramolecular iron centers under both thermal and photochemical conditions, in sharp contrast to the facile cleavage of the Si–Si bond in 1,1,2,2-tetramethyldisilanylene-bridged analogous complexes. The stability of the Si–Si bonds in the present cases may be attributed to the fact that these Si–Si bonds are spatially unapproachable by the intramolecular coordinatively unsaturated iron centers. Molecular structures of 1 and 2 have been determined by X-ray diffraction methods. An obvious conformational change due to substitution of CO for P(OPh)₃ was observed.     

Electronic properties of two isomeric charge transfer [2.2]paracyclophanes

The emission spectra and the zero field splitting parameters of the two diastereomeric 4,7-dicyano-12,15-dimethoxy-[2.2] paracyclophanes 3 and 4 in comparison to the corresponding monomers 1 and 2 were investigated in order to study the orientation dependence of charge transfer (CT) interactions. The general results in glasses (PMMA) are: broad structureless emission bands with large spectral overlap between fluorescence and phosphorescence; strong reduction of the zero field splitting parameters D and D* by a factor of two for the pseudo-ortho isomer 3 and by a factor of four for the pseudo-geminal isomer 4 showing the strong effect of the geometrical orientation. In single crystals of the same phanes the zero field parameters were found to be further reduced to about one fifth of the value of the monomers which indicates, in accordance with the emission spectra, an additional intermolecular interaction between adjacent phanes.     

Synthesis, properties, and structures of benzo[1,2-b:4,5-b']bis[b]benzothiophene and benzo[1,2-b:4,5-b']bis[b]benzoselenophene

Employing two consecutive cyclization reactions, benzo[1,2-b:4,5-b']bis[b]benzochalcogenophenes, which are pi-extended heteroarenes, were efficiently synthesized. Their electronic and crystal structures were elucidated on the basis of UV-vis spectra, electrochemical measurements, and X-ray structural analyses.     

Electronic,optical, and charge transport properties of A-π-A electron acceptors for organic solar cells: Impact of anti-aromatic π structures

Anti-aromatization and isomerization are found to be an effective way to tune the optoelectronic properties of A-π-A electron acceptors for organic photovoltaics.     

Synthesis and properties of tricyclo[6.4.1.0]trideca-1,3(6),7,9,11-pentaene

A new cyclobutene-fused 1,6-methano[10]annulene was synthesized by pyrolysis of the sulfone and sulfinate adducts of 3,4-bis(methylene)-1,6-methano[10]annulene and its physical and chemical properties were disclosed.     

New heterocyclic structures. [1,2,5]Thiadiazolo[3′,4′:4,5]pyrimido-[2,1-b][1,3]thiazine and thiazolo[3,2a][1,2,5]thiadiazolo[3,4-d]pyrimidine

Derivatives of two new molecular structures, namely, 7,8-dihydro-6H,10H-[1,2,5]thiadiazolo[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazin-10-one and 6,7-dihydro-9H-thiazolo[3,2-a][1,2,5]thiadiazolo[3,4-d][pyrimidin-9-one, and derivatives of N-substituted sulfamic acid, namely, (8-amino-3,4-dihydro-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-on-7-yl)sulfamic acid and (7-amino-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidin-5-on-6-yl)sulfamic acid, were separated out as by-products in the reduction reaction of 8-amino-3,4-dihydro-7-nitroso-2H,6H-pyrimido[2,1- b][1,3]thiazin-6-one and 7-amino-2,3-dihydro-6-nitroso-5H-thiazolo[3,2-a]pyrimidin-5-one derivatives, respectively, with sodium hydrosulfite. A mechanism of reaction, which hypothesizes the action of sodium hydrosulfite in an asymmetic form, is proposed. The results of single-crystal X-ray investigation on 7,8-dihydro-6H,10H-[1,2,5]thiadiazolo[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazin-10-one (R = 0.032 for 863 reflections) and (8-amino-3,4-dihydro-2H,6H-pyrimido[2,1-b]- [1,3]thiazin-6-on-7-yl)sulfamic acid, sodium salt (R = 0.028 for 3507 reflections) are reported.     

苯并咪唑苯并异喹啉酮及其衍生物的电子结构和光谱性质的理论研究

采用密度泛函、含时密度泛函和单激发组态相互作用(CIS)方法研究了苯并咪唑苯并异喹啉酮(1)及其衍生物的电子结构特性和光谱性质,并用极化连续模型考虑了溶剂的影响.结果表明,化合物1及其衍生物的吸收和荧光发射过程的电子垂直跃迁是由于分子内的电荷迁移.化合物1中取代基的位置及给吸电子能力影响其HOMO-LUMO能隙和电荷迁移量.在分子中引入吸电子和给电子取代基,均使最大吸收波长和最大荧光发射波长红移,计算的结果与实验结果吻合得较好.     

Synthesis of volatile bis[bis(trimethylsilyl)amide]-substituted boron derivatives

Russian Journal of General Chemistry - General strategy for the synthesis of organoboron compounds containing bis(trimethylsilyl)amide substituents has been suggested.     

Synthesis of [1,3]dithiole and spiro[1,3]dithiole thiopyran derivatives of the [1,2]dithiolo[1,4]thiazine ring system

We report the synthesis of some new polysulfur-nitrogen heterocycles by cycloaddition reactions to readily available tricyclic condensed 1,2-dithiole-3-thiones. Thus, treatment of bis[1,2]dithiolopyrrole ketothione 1 with diacyl acetylenes gave the bis-aducts 2a-d. On the other hand, cycloaddition of bis[1,2]dithiolo[1,4]thiazine ketothione 3 with 1 equiv of acyl or diacyl acetylenes gave [1,3]dithiolylidenyl[1,2]dithiolo[1,4]thiazines 4a-f in fair to high yields. Catalysis by scandium triflate was used in the reactions that implied the less reactive dipolarophiles. Treatment of 3 with 2 equiv of DBA gave the bis-aduct 5a, and reaction of 4c with DMAD gave the mixed bis-adduct 5b. Cyclic voltammetry of selected examples showed irreversible processes that were influenced by the electrochemical activity of peripheral groups bonded to the heterocyclic system.     

Synthesis,crystal structures,and properties of copper(II) dicarboxylate complexes with [bis(2-pyridylcarbonyl)amido]

Four new complexes, [Cu₂(Bpca)₂(L¹)(H₂O)₂] · 3H₂O (I), [Cu₂(Bpca)₂(L²)(H₂O)₂] (II), [Cu₂(Bpca)₂(L³)] · 2H₂O (III), [Cu₂(Bpca)₂(L¹)(H₂O)] · 2H₂O (IV) (Bpca = bis(2-pyridylcarbonyl)amido, H₂L¹ = glutaric acid, H₂L² = adipic acid, H₂L³ = suberic acid, H₂L⁴ = azelaic acid) have been synthesized and characterized by single-crystal X-ray diffraction methods (CIF files CCDC nos. 1432836 (I), 1432835 (II), 817411 (III), and 817412 (IV)), elemental analyses, IR spectra. Structural analyses reveal that compounds I, II, and IV have similar structures [Cu(Bpca)]⁺ units bridged by dicarboxylate forming dinuclear units, whereas the dinuclear of compound III are edge-shared through two carboxylate oxygen atoms of different suberate anions. Hydrogen bonds are response for the supramolecular assembly of compounds I to IV. The temperature-dependent magnetic property of III was also investigated in the temperature range of 2 to 300 K, and the magnetic behaviour suggests weak antiferromagnetic coupling exchange.     

Bis(aldehydes): Versatile precursors for novel bis(14H-dibenzo[a,j]xanthenes), bis(pyrano[3,2-c:5,6-c']dichromenedione), and bis(dihydrobenzo[a]xanthenones) via multicomponent reactions

A synthesis of novel bis(4-(14H-dibenzo[a,j]xanthenes) and bis(dihydro-8H-benzo[a]xanthenones) was performed in good yields via pseudo-multicomponent, or multicomponent reactions, of bis-aldehydes with four equivalents of β-naphthol or with a mixture of two equivalents of each β-naphthol and dimedone in the presence of a catalytic amount of p-toluenesulfonic acid. Bis(pyrano[3,2-c:5,6-c′]dichromenediones) or tetrakis(4-hydroxy-2H-chromen-2-ones) could also be obtained in good yields through pseudo-multicomponent reactions of bis(aldehydes) with four molar ratio of 4-hydroxycoumarin.     

双[1,3-二(三甲硅基)环戊二烯基]四羰基二铁的反应性

题示化合物分子中的铁铁键被钠汞齐还原断裂, 生成相应的单核铁负离子, 后者分别与PhCOCl, PhCH~2Cl,ClCH~2COOC~2H~5, Ph~3SnCl 及Ph~2SnCl~2进行亲核取代反应,生成在铁原子上引入相应取代基的产物。题示化合物分别与卤素和二氯化汞反应, 生成铁铁键断裂的铁卤化物和铁氯汞化物。用X-射线测定了题示化合物与Ph~3SnCl反应生成产物的晶体和分子结构。     

Sorption and diffusion of organic vapors in poly[bis(trifluoroethoxy) phosphazene] and poly[bis(phenoxy)phosphazene] membranes

The sorption isotherms and diffusivities for vapors of some selected simple alcohols (methanol, ethanol, isopropanol, and 2-butanol), ketones (acetone, methyl ethyl ketone, and methyl isobutyl ketone), and aromatic compounds (benzene, toluene, and xylene) in poly[bis(trifluoroethoxy)phosphazene] (PTFEP) and poly[bis(phenoxy)phosphazene] (PPOP) were determined by integral sorption-desorption experiments at 35°C. The sorption isotherms for these compounds evaluated were almost linear to obey Henry's law for the determination of constant solubility of each solvent vapor species, and the corresponding permeabilities for them can be estimated according to the solution-diffusion model. The diffusivities for these vapors in PPOP (10⁻⁹∼10⁻⁸ cm²/s) were about one order smaller than those in PTFEP (10⁻⁸∼10⁻⁷ cm²/s) because the more rigid phenoxy groups and the higher crystallinity in PPOP may hinder the diffusion of sorbed molecules. Relatively weak dependence of diffusivity or permeability on the vapor activity (or concentration) was found, to be in contrast to the exponential dependence for many organic vapors in rubbery organic polymers, probably due to the limited increase of the free volume in sorption for these vapors in PTFEP and PPOP membranes.     

Inhibitors of platelet aggregation. 4. [1,2,5]Thiadiazolo[3,4-c]acridines, 7,8,9,10-Tetrahydro[1,2,5] thiadiazolo[3,4-c]acridities,and 8,9-Dihydro-7H-cyclopenta[b][1,2,5] thiadiazolo[3,4-H]quinolines

The condensation of 4-amino-2,1,3-benzothiadiazole (IV) with diphenyliodonium-2-earboxylate gave N-(2,1,3-benzothiadiazoI-4-yl)anthranilic acid (V) (28%), which was cyclized with phosphorus oxychloride to 6-chloro[1,2,5]thiadiazolo[3,4-c]acridine (VI) (84%). Treatment of VI with 3-(dimethylamino)-1-propanethiol hydrochloride in phenol afforded 6-[ [3-(dimethylamino)-propyl]thio] [1,2,5]thiadiazolo[3,4-c]acridine (VII) (65%). The reaction of IV with a mixture of methyl and ethyl 2-oxocyclohexanecarboxylate gave the adduct, which was ring closed in Dowtherm to 7,9,10,1 1-tetrahydro[1,2,5] thiadiazolo[3,4-c]acridin-6(8H)one (VIII) (70%). Chlorination of VIII with phosphorus oxychloride gave 6-chloro-7,8,9,10-tetrahydro[1,2,5]thiadiazolo[3,4-c]acridine (IX) (84%), which was condensed with 3-(dimethylamino)-1-propanethiol hydrochloride in phenol yielding 6-[ [3-(dimethylamino)propyl]thio]-7,8,9,10-tetrahydrof 1,2,5]-thiadiazolo[3,4-c]acridine (X) (27%). 6-[ [3(1)imethylamino)propyl]thio]-8,9-dihydro-7H-cyclopenta[b] [1,2,5]thiadiazolo[3,4-h]quinoline (XIII) (25%) was prepared similarly from IV and a mixture of methyl and ethyl 2-oxocyclopentanecarboxylate via 7,8,9,10-tetrahydro-6H-cyclopenta[b][1,2,5]thiadiazolo[3,4-h]quinolin-6-one (XI) (85%) and 6-chloro-8,9-dihydro-7H-cyclopenta[b][1,2,5]thiadiazolof3,4-h]quinoline (XII) (56%). The effects of compounds VII-XIII as inhibitors of platelet aggregation are discussed.     

Synthesis and characterization of [1,2,5]chalcogenazolo[3,4-f]benzo[1,2,3]triazole and [1,2,3]triazolo[3,4-g]quinoxaline derivatives

The synthesis and characterization is reported of low bandgap [1,2,5]chalcogenazolo[3,4-f]benzo[1,2,3]triazole and [1,2,3]triazolo[3,4-g]quinoxaline derivatives that display higher solubility and stability then their thiadiazole counterparts, [1,2,5]chalcogenazolo[3,4-f]benzo[2,1,3]thiadiazole and [1,2,5]thiadiazolo[3,4-g]quinoxaline, respectively.     

The transformation of saccharin into derivatives of lmidazo[1,2-b] [1,2]-benzisothiazole and benzo[g] [1,2,5]thiadiazocine

Reaction of 3-(2-hydroxyethylamino) benzo[d]isothiazole 1,1-dioxide ( 5a ) with thionyl chloride gives a mixture of the expected chloroethyl derivative ( 5h ) and the rearranged saccharin 2-(2-aminoethyl)-3-oxo-2,3-dihydrobenzo[d]isothiazole 1,1-dioxide hydrochloride ( 6a ). Separate treatment of the chloroethyl compound ( 5h ) with dilute alkali gives the expected cyclization product 2,3-dihydroimidazo[1,2-b] [1,2] benzisothiazole 5, 5-dioxide ( 7a ). Acidification of the liquors of the above reaction yields the ring expanded derivative 6-oxo-3,4,5,6-tetrahydro-[2H]benzo[g][1,2,5]thiadiazocine 1,1-dioxide ( 12f ), a representative of a new ring-system. Treatment of the imidazo derivative ( 7a ) with concentrated hydrochloric acid again yields the N-substituted saccharin ( 6a ) which upon treatment with alkali also produces the thiadiazocine ( 12f ). In contrast, treatment of the imidazo compound ( 7a ) with alkali leads to attack on the sulphonamide function to give 2-(2-imidazolin-2-yl)benzenesulphonic acid ( 8 ). It is suggested that the multitude of chemical interconversions which can be induced within this series of compounds (Scheme II) can only be accounted for if two separate cyclol intermediates are invoked. Related reactions observed with variously substituted derivatives of the starting saccharin derivative ( 5a ) are discussed as are the spectral properties and chemical reactivity of the new compounds prepared.