Spiro[1,3-benzoxathiepin-4(5H),1′-cyclohexa[2,4]diene]-2,2′-dione,a Novel Heterocyclic Ring System

The 4,4′,6,6′-tetrasubstituted 2,2′-alkylidenebis(phenols) 1 reacted with CISCOI to give spiro[1,3-benzoxathiepin-4(5H), 1′-cyclohexa[2,4]diene]-2,2′-diones 4 , together with cyclic carbonates 5 . The structures of the products were elucidated mainly by ¹³C-NMR and ¹H-NMR spectroscopy.     

Synthesis of (pyridinyl)-1,2,4-triazolo[4,3-a]pyridines

Methods for the synthesis of (pyridinyl)-1,2,4-triazolo[4,3-a]pyridines were developed. The principal route to the required intermediate 2-chloropyridines was based on rearrangements of mono N-oxides of 2,2′-bipyridine, 2,3′-bipyridine, 3,3′-bipyridine, 2,4′-bipyridine and 4,4′-bipyridine with phosphorus oxychloride. Reaction of 3,3′-bipyridine 1-oxide or 2,2′-bipyridine 1-oxide with phosphorus oxychloride gave mixtures of chloro isomers. Reaction with acetic anhydride, 3,3′-bipyridine 1-oxide and 2,2′-bipyridine 1-oxide gave exclusively [3,3′-bipyridine]-2(1H)-one and [2,2′-bipyridine]-6(1H)-one, respectively. 1,2,4-Triazolo[4,3-a]pyridines with pyridinyl groups at the 5,6,7 and 8 positions were synthesized.     

(Perhalogenmethylthio)heterocyclen. XXI. Reaktionen halogenierter perhalogenmethylthiopyrrole: Salz- und radikalbildung,dimerisierung

2-Chloro-3,4,5-tris(trifluoromethylthio)pyrrole ( 2a ), 3-Chloro-2,4,5-tris(trifluoromethylthio)pyarrole ( 2b ) and 3,4-dichloro-2,5-bis(trifluromoethylthio)pyrrole ( 2c ) react with silver nitrate/silver acetate in good yield to give the corresponding N-silver salts 3a-c . Compound 2b forms with an aqueous potassium hydroxide solution the N-potassium salt 4 . Compounds 3a and 3b react with iodine to give the dimeers 2,2′-dichloro-3,3,′ 4,4′5,5′-hexakis(trifluoromethylthio)-2,2′-bi-2H-pyrrolyl ( 5a ) and 3,3′-dichloro-2,2′,4,4′,5,5′-hexakis(trifluoromethylthio)-2,2′-bi-2H-pyrrolyl ( 5b ). The dimers dissociate in solution to the corresponding pyrrolayl radicals. The esr and endor spectra of 3-chloro-2,4,5-tris(trifluoromethylthio)pyrrolyl were measured; coupling constants are given. For the newly prepared substances melting-points, ¹⁹F-nmr and ir spectroscopical data are provided.     

Heat-curable polyaromatic keto-ether-sulfones. XIV. More polymers with 2,2′-diphenylethynyl-4,4′-diphenyl units and their rearrangement products

Polymers were prepared from 4,4′-diphenoxydiphenylsulfone, isophthaloyl dichloride, and bis-p-phenoxyphenyl-4,4′-(2,2′-dibromodiphenyl)ketone, 2,2′-dibromodiphenyl-4,4′-dicarbonyl dichloride, or bis-p-phenoxyphenyl-4,4′-(2,2′-diphenylethynyldiphenyl)ketone in Friedel-Crafts type of polymerization. Bromine groups were subsequently replaced with phenylacetylene residues, and the polymers were cured at high temperatures, with the apparent formation of benzanthracene linkages. Cured polymers exhibited higher softening points, decreased solubilities, and, in some instances, higher melting points than their uncured precursors. Significant weight losses occurred during isothermal aging tests.     

Cyclisation of benzils

Treatment of several substituted benzils [3,3′- and 4,4′-dimethyl-; 2,2′-, 3,3′- and 4,4′-dichloro-; 3,3′-dibromo-; 4-(N,N-dimethylamino)-] with an excess of chlorosulfonic acid gave the corresponding 3-chloro-2-phenylbenzofuran disulfonyl dichlorides. Disubstitution was confirmed by microanalytical and spectral data for the corresponding bis(N,N-dimethylaminsulfonamides). The positions of electrophilic substitution were not confirmed with 3,3′-dimethyl-, 2,2′- and 3,3′-dichlorobenzils. With 4,4′-dichlorobenzil, a smaller amount of chlorosulfonic acid enabled the isolation of 3,6,4′-trichloro-2-phenylbenzofuran-5-sulfonyl chloride, which was identified by X-ray analysis of the N,N-dimethylsulfonamide. The cyclisation failed with 3,3′-dimethoxy-, and 3,3′- and 4,4′-dinitrobenzils. The results have been interpreted mechanistically.     

Convenient Synthesis of 2,2′- and 4,4′-Methylenebisphenols with Bulky Alkyl Substituents and Evaluation of Their Antioxidant Activity

The work is devoted to a convenient procedure of the synthesis of 2,2′- and 4,4′-methylenebisphenols with alkyl substituents in heterogeneous catalysis. This compounds were obtained with yields up to 87% by reflux of 2,4- or 2,6-dialkylphenols with HCHO in n-octane in the presence of KSF clay. We found that the antioxidant activity on DPPH test for two novel methylenebisphenols having isobornyl fragments was comparable with control drugs.     

Heteroleptic ruthenium sensitizers that contain an ancillary bipyridine ligand tethered with hydrocarbon chains for efficient dye-sensitized solar cells

New heteroleptic ruthenium complexes have been synthesized and used as the sensitizers for dye‐sensitized solar cells (DSSCs). The ancillary bipyridine ligand contains rigid aromatic segments (fluorene‐, carbazole‐, or dithieno[3,2‐b:2′,3′‐d]pyrrole‐substituted bipyridine) tethered with a hydrophobic hexyl substituent. The conjugated aromatic segment results in significant bathochromic shift and hyperchromic effects in these complexes compared with Z907 (cis‐[Ru LL′ (NCS)₂]; L =4,4′‐dicarboxylic acid‐2,2′‐bipyridine, L′ =4,4′‐dinonyl‐2,2′‐ bipyridine). The long hydrocarbon chains help to suppress the dark current if appropriately disposed. DSSCs that use these complexes exhibit very impressive conversion efficiencies (5.94 to 6.91 %) that surpass that of Z907 ‐based (6.36 %) DSSCs and are comparable with that of N719 ‐based standard cells (7.13 %; N719 =cis‐di(thiocyanato)bis(2,2′‐bipyridyl‐4,4′‐dicarboxylato)ruthenium(II) bis(tetrabutylammonium)) fabricated and measured under similar conditions (active area: 0.5×0.5 cm²; AM 1.5 sunlight).     

Enolethers. XXI. Synthesis of 5,5′-disubstituted 4,4′-bipyrimidines

1,6-Dialkoxy-3,4-diones 3 are easily accessible by acylation of enol ethers 1 with oxalyl chloride and subsequent elimination of hydrogen chloride using triethylamine. The open-chain 2,5-dimethyl derivative 3b is converted with amidines 4a-c and S-methylisothiourea (4d) , respectively, to give 2,2′-disubstituted 5,5′-dimethyl-4,4′-bipyrimidines 5a-d . The dihydrofuran and dihydropyran derivatives 3c and 3d , however, react with benzamidine (4c) in dimethylformamide only in the presence of calcium hydride as condensation agent yielding 5,5′-bis(2-hydroxyethyl)- and 5,5′-bis(3-hydroxypropyl)-2,2′-diphenyl-4,4′-bipyrimidine 6a and b.     

The mass spectrometry of DT-and monosubstituted biphenyls: Dependence of fragmentation patterns on position of substitution

This paper describes the mass spectroscopy of a series of biphenyl derivatives substituted in the 2,2′, 4,4′ and 2 positions. The substitutent functional groups are carbomethoxy, carbothoxy, carboxylic acid and hydroxymethyl. In addition, some results are reported on the spectroscopy of the d₅-carboethoxy derivatives, the 2- and 2,2′-αd₂- hydroxymethyl derivatives and fluorene-4-methanol. The molecular ions of the 4,4′-disubstituted biphenyl derivatives are far more stable than those of the 2,2′ isomers. It is also observed that the fragmentation patterns of these two sets of isomers are sharply different. Paradoxically, the 2-substituted biphenyl derivatives give relatively stable molecular ions and their fragmentation patterns are frequently different from those of the corresponding 2,2′-disubstituted biphenyls. The bulk of the evidence presented in this paper suggests that the usual sort of ‘ortho effect’ is not a significant factor in the fragmentation mechanisms proposed for the 2,2′-disubstituted biphenyl derivatives.     

1-D and 2-D coordination polymers of lead(II) thiocyanate with substituted 2,2′-bipyridine ligand

Two lead(II)-thiocyanato coordination polymers with 5,5′-dimethyl-2,2′-bipyridine (5,5′-dm-2,2′-bpy) and 4,4′-dimethoxy-2,2′-bipyridine (4,4′-dmo-2,2′-bpy) as chelating ligands were synthesized and characterized by elemental analysis, IR and ¹H-NMR spectroscopy, thermal behavior, and X-ray crystallography. These complexes have formulas [Pb(5,5′-dm-2,2′-bpy)(NCS)₂] _n (1) and [Pb(4,4′-dmo-2,2′-bpy)(NCS)₂] _n (2). The coordination numbers of Pb^II in 1 and 2 are four, PbN₄, with “stereo-chemically active” electron pairs and hemidirected coordination spheres. Considering Pb···S as weak bonds, 1 and 2 are 1- and 2-D coordination polymers, respectively. The supramolecular features in these complexes are guided/controlled by weak directional intermolecular interactions.     

Synthesis of inherently dissymmetric polyamides,

The preparation of polyamides from derivatives of optically active biphenic acid is described. The diacid chlorides chosen were 2,2′-dinitro-6,6′-dimethylbiphenyl-4,4′-dicarbonyl chloride and 2,2′-dichloro-6,6′-dimethylbiphenyl-4,4′-dicarbonyl chloride, the diamines were phenyldiamines (o-, m-, p-) piperazine, trans-2,5-dimethylpiperazine, and 1,2-piperaazolidine. Polymerization was carried out by the method of interfacial polycondensation. The polymers of aromatic diamines were insoluble in common organic solvents but soluble in dimethylformamide containing 5% lithium chloride, triesters of phosphoric acid, and methanesulfonic acid. The polymers of aliphatic diamines were also insoluble in common organic solvents but soluble in trifluoroethanol. All polymers had melting points higher than 280°C.     

Design,synthesis and magnetic properties of a ladderlike complex constructed by secondary building units

A secondary building unit (SBU), [Ni(2,2′-bipy)(5-npa)(H₂O)] _n [where 2,2′-bipy = 2,2′-bipyridine, 5-npa = 5-nitroisophthalic dianion], was synthesized as starting material of a polystep reaction. A ladderlike complex (LLC) Ni(II) coordination polymer, {[Ni(2,2′-bipy)(5-npa)(4,4′bipy)_0.5]·(H₂O)} _n , was constructed by polystep reaction using this SBU. In LLC, two SBUs were cross-linked by 4,4′-bipy [where 4,4′-bipy = 4,4′-bipyridine] forming a 1-D ladderlike structure. The magnetic properties of the LLC and SBU are discussed.     

4,10a-(Epidithio)-4,4a,10,10a-tetrahydro-1H-5-oxaanthracen-1-ones,tetracycles with a novel heterocyclic ring system

The 4,4′,6,6′-tetrasubstituted 2,2′-alkylidene-bisphenols 1 reacted with sulfur monochloride to give 4,10a-(epidithio)-4,4a,10,10a-tetrahydro-1H-5-oxaanthracen-1-ones ( 3 and 4 ). The structure of the products were elucidated by a combination of X-ray crystal-structure analysis and ¹H- and ¹³C-NMR spectroscopy.     

Optical properties of inherently dissymmetric polyamides

A study of the optical rotatory dispersion (ORD), circular dichroism (CD), and ultraviolet spectra (UV) of polyamides derived from optically active biphenyl acid chlorides, and aromatic, and aliphatic diamines, was made. The optically active monomers were (–)-(S)-2,2′-dinitro-6,6′-dimethylbiphenyl-4,4′-dicarbonyl chloride and (–)-(S)-2,2′-dichloro-6,6′-dimethylbiphenyl-4,4′-dicarbonyl chloride. The diamines were o-, m-, and p-phenylenediamine, piperazine, trans-2,5-dimethylpiperazine, and 1,2-pyrazolidine. The ORD spectra of the o-phenylenediaminepolyamide taken in different solvents indicated the existence of some ordered structure in the least polar solvent. All other polyamides existed in a random coil conformation in the solvents employed.     

Architectural diversity of six coordination compounds based on (S)-(+)-mandelic acid and different N-donor auxiliary ligands: syntheses,structures, and luminescent properties

Six transition metal coordination compounds with H₂mand and different N-donor ligands, [Co(Hmand)₂(2,2′-bipy)]·H₂O (1), [Ni(Hmand)₂(2,2′-bipy)]·H₂O (2), [Ni(Hmand)₂(bpe)] (3), [Zn(Hmand)₂(2,4′-bipy)(H₂O)]·2H₂O (4), [Zn(Hmand)(bpe)(H₂O)]_n[(ClO₄)]_n·nH₂O (5), and [Zn(Hmand)(4,4′-bipy)(H₂O)]_n[(ClO₄)]_n (6), were synthesized under different conditions (H₂mand = (S)-(+)-mandelic acid, bpe = 1,2-di(4-pyridyl)ethane, 4,4′-bipy = 4,4′-bipyridine, 2,4′-bipy = 2,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine). Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, infrared spectra, thermogravimetric analysis, powder X-ray diffraction, and circular dichroism. Compounds 1 and 2 are isostructural (0-D structures), which are extended to supramolecular 1-D chains by hydrogen bonding. Compound 3 exhibits 1-D straight chain structures, which are further linked via hydrogen bond interactions to generate a 3-D supramolecular architecture. Compound 4 displays a discrete molecular unit. Neighboring units are further linked by hydrogen bonds and π–π interactions to form a 3-D supramolecular architecture. Compound 5 displays a 2-D undulated network, further extended into a 3-D supramolecular architecture through hydrogen bond interactions. Compound 6 possesses a 2-D sheet structure. Auxiliary ligands and counteranions play an important role in the formation of final frameworks, and the hydrogen-bonding interactions and π–π stacking interactions contributed to the formation of the diverse supramolecular architectures. Compounds 1, 2, 4, 5, and 6 crystallize in chiral space groups, with the circular dichroism spectra exhibiting positive cotton effects. Furthermore, the luminescent properties of 4–6 have been examined in the solid state at room temperature, and the different crystal structures influence emission spectra significantly.     

Excitation‐wavelength‐dependent charge transfer resonance of bipyridines on silver nanoparticles: surface‐enhanced Raman scattering study

Charge transfer (CT) resonance mechanisms of 2,2′‐bipyridine (2,2′‐BiPy), 2,4′‐bipyridine (2,4′‐BiPy), and 4,4′‐bipyridine (4,4′‐BiPy) on silver nanoparticle surfaces have been comparatively investigated by means of surface‐enhanced Raman scattering (SERS) at the excitation wavelengths of 457, 514, 633, and 785 nm. A combination of the electromagnetic (EM) and charge transfer (CT) contributions should affect the SERS intensities for the bipyridine compounds adsorbed on silver nanoparticle surfaces. The CT resonance is assumed to occur in dissimilar ways for the bipyridine compounds, as evidenced from their different excitation‐wavelength‐dependent SERS enhancement factors. Ab initio density functional theory (DFT) calculations at the level of B3LYP/LANL2DZ have been carried out for the bipyridine‐Ag complexes. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesen in der Carotinoid-Reihe 21. Mitteilung. Synthese von 2,2′-Diketo-spirilloxanthin (P 518) und 2,2′-Diketo-bacterioruberin

2,2′-Diketospirilloxanthin and 2,2′-diketobacterioruberin have been prepared via the corresponding 15,15′-dehydro compounds by condensation of 15,15′-dehydroapo-4,4′-carotenedial (C₃₀) with 3-methoxy-(resp. 3-hydroxy)-3-methyl-2-butanone. 2,2′-Diketospirilloxanthin was identical with natural P 518.     

Synthesis and characterization of alt‐bipyridinylene‐phenylene copolymers containing ruthenium(II) complexes

Poly{bis(4,4′‐tert‐butyl‐2,2′‐bipyridine)–(2,2′‐bipyridine‐5,5′‐diyl‐[1,4‐phenylene])–ruthenium(II)bishexafluorophosphate} ( 3a ), poly{bis(4,4′‐tert‐butyl‐2,2′‐bipyridine)–(2,2′‐bipyridine‐4,4′‐diyl‐[1,4‐phenylene])–ruthenium(II)bishexafluorophosphate} ( 3b ), and poly{bis(2,2′‐bipyridine)–(2,2′‐bipyridine‐5,5′‐diyl‐[1,4‐phenylene])–ruthenium(II)bishexafluorophosphate} ( 3c ) were synthesized by the Suzuki coupling reaction. The alternating structure of the copolymers was confirmed by ¹H and ¹³C NMR and elemental analysis. The polymers showed, by ultraviolet–visible, the π–π* absorption of the polymer backbone (320–380 nm) and at a lower energy attributed to the d–π* metal‐to‐ligand charge‐transfer absorption (450 nm for linear 3a and 480 nm for angular 3b ). The polymers were characterized by a monomodal molecular weight distribution. The degree of polymerization was approximately 8 for polymer 3b and 28 for polymer 3d . © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2911–2919, 2004     

Synthesis and characterization of lead(II) complexes with substituted 2,2′-bipyridines,trifluoroacetate, and furoyltrifluoroacetonate

Two substituted 2,2′-bipyridine lead(II) complexes, [Pb(5,5′-dm-2,2′-bpy)(tfac)₂] _n (1) (5,5′-dm-2,2′-bpy?=?5,5′-dimethyl-2,2′-bipyridine and tfac?=?trifluoroacetate) and [Pb₂(4,4′-dmo-2,2′-bpy)₂(ftfa)₄] (2) (4,4′-dmo-2,2′-bpy?=?4,4′-dimethoxy-2,2′-bipyridine and ftfa?=?furoyltrifluoroacetonate), have been synthesized and characterized by elemental analysis, IR, ¹H NMR, and ¹³C NMR spectroscopies, thermal behavior, and X-ray crystallography. Complexes 1 and 2 are 1D coordination polymer and dinuclear complex, respectively. The supramolecular features in these complexes are guided by weak directional intermolecular interactions.     

Lead(II) complexes of 2,2′-diamino-4,4′-bithiazole (DABTZ) including crystal structure of a novel 1D chain polymer, [PB(DABTZ)(μ-SCN)(μ-NO3)] n

Three new 2,2′-diamino-4,4′-bithiazole (DABTZ) lead(II) complexes were synthesized and characterized by elemental analyses, IR-, ¹H-NMR-, and ¹³C-NMR-spectroscopy. The single crystal X-ray structural analysis of [Pb(DABTZ)(μ-SCN)(μ-NO₃)] _n shows the complex to be a 1D chain polymer as a result of sequential thiocyanate and nitrate bridging. The Pb atoms are seven-coordinated by two nitrogen atoms of the 2,2′-diamino-4,4′-bithiazole, three nitrate and two thiocyanate ligands. The arrangement of the 2,2′-diamino-4,4′-bithiazole, nitrate and thiocyanate ligands does not suggest a gap in the coordination around the Pb^II ion, caused by a stereo-active lone pair of electrons on lead(II) where the coordination around the lead atoms is the less common holodirected.