Syntheses of dibenzo[c,e][1,2]diselenin and related novel chalcogenide heterocyclic compounds

Reaction of 2,2′-dilithio-1,1′-binaphthyl with selenium followed by air oxidation gives a mixture of dinaph-thoselenophene and dimer and oligomers of 2,2′-diseleno-1,1′-binaphthyl. 2,2′-Dilithio-1,1′-biphenyl reacts with selenium to afford dibenzo[c,e][1,2]diselenin. Structures of the dimeric 2,2′-diseleno-1,1′-binaphthyl and dibenzo[c,e][1,2]diselenin have been confirmed by X-ray crystallographic analyses. Similar reaction of 2,2′-dilithio-1,1′-binaphthyl with sulfur or tellurium gives a mixture of dinaphthothiophene and dinaphtho[2,1-c:-1′,2′-e][1,2]dithiin or a mixture of dinaphthotellurophene and oligomer of 2,2′-ditelluro-1,1′-binaphthyl, respectively. Dibenzotellurophene and oligomer of 2,2′-ditelluro-1,1′-biphenyl are obtained from reaction of 2,2′-dilithio-1,1′-biphenyl with tellurium.     

Platinum complexes of dibenzo[1,2]dithiin, dibenzo[1,2]dithiin oxides and related polyaromatic hydrocarbon ligands

The synthesis of platinum bisphosphine complexes of biphenyl- 2,2'-dichalcogenates and the oxides of dibenzo[1,2]dithiin and related ligand systems by oxidative addition to [Pt(PPh(3))(4)] is reported. We also describe the synthesis of a new compound, dibenzothiophen-4-yldiselenide and its simple platinum complex (obtained by oxidative addition). All complexes have been fully characterised, principally by using multinuclear NMR spectroscopy and in six cases by means of single-crystal X-ray diffraction studies. The majority are simple S/S or Se/Se complexes, however the addition of dibenzo[1,2]dithiin trioxide to [Pt(PPh(3))(4)] gives a bimetallic system, [Pt[2-[S(O)],2'-[S(O)(2)]-biphen}(PPh(3))](2), containing a central Pt(2)S(2)O(2) core in which the ligand behaves as a tridentate S,S,O donor.     

Dibenzo[d,h][1,3,6,7,2]dioxadithiasilonin: Synthesis and characterization

The reaction of 2,4-di-t-butylphenol, 4 , with sulfur monochloride gave the trithiobisphenol 5 rather than the expected dithiobisphenol 7 . The thiol 6 was obtained by the reduction of 5 with zinc under acidic conditions. The dithiobisphenol 7 was prepared by the oxidative coupling of 6 with iodine under alkaline conditions. The dibenzo[d,h][1,3,6,7,2]dioxadithiasilonin 8 was prepared by the reaction of 7 with dichlorodimethylsilane using triethylamine as an acid acceptor. No change was observed in the ¹H nmr spectrum of 8 upon cooling to ?55°, which suggests that the ΔG* for ring inversion is less than the corresponding eight-membered dibenzo[d,g][1,3,2]dioxasilocin and dibenzo[d,g][1,3,6,2]dioxathiasilocin 1 and 2 , respectively. The spectral data and elemental analysis are fully in accord with the nine-membered silonin structure.     

The Synthesis of Dibenzo[3n]crown-n by Novel Methods and their Cation Binding Studied by Fluorescence Spectroscopy. Part IV

The dibenzo[3n]crown-n were synthesised from1,2-bis(o-hydroxyphenoxy)ethane obtained from 1,2-bis(o-formylphenoxy)ethane via Bayer-Willigeroxidations with H₂O₂/CH₃COOH in good yields. The cyclic condensation of 1,2-bis(o-hydroxyphenoxy)ethanewith dichlorides, and ditosylates of polyethylene glycols in DMF/Me₂CO₃ gave the macrocyclesdibenzo[15]crown-5, dibenzo[18]crown-6, dibenzo[21]crown-7 anddibenzo[24]crown-8. The structures were identified using IR, mass, ¹H and ¹³C NMR spectroscopy. Therecognition of the molecules for the cations, Li⁺, Na⁺, K⁺, Rb⁺ and Zn²⁺were conducted quantitatively with steady state fluorescencespectroscopy. The 1:1 association constants in acetonitrileshowed a good relation of the appropriate size of the macrocyclic ether towards the fitting cationradii. Namely, dibenzo[15]crown-5 was the best for Li⁺ binding and more than 100 times better thanNa⁺ and K⁺. Dibenzo[21]crown-7 was excellent for Rb⁺ binding while K⁺ is 100 timesless preferred. The largest crown ether studied, dibenzo[24]crown-8, exhibited the order of binding power,Rb⁺ > K⁺ > Na⁺. Zn²⁺ displayed, however, a marked binding with only dibenzo[18]crown-6.p>     

Enhanced Optical Properties of Azaborole Helicenes by Lateral and Helical Extension

The synthesis and characterization of laterally extended azabora[5]-, -[6]- and -[7]helicenes, assembled from N-heteroaromatic and dibenzo[g,p]chrysene building blocks is described. Formally, the π-conjugated systems of the pristine azaborole helicenes were enlarged with a phenanthrene unit leading to compounds with large Stokes shifts, significantly enhanced luminescence quantum yields (Φ) and dissymmetry factors (g_lum). The beneficial effect on optical properties was also observed for helical elongation. The combined contributions of lateral and helical extensions resulted in a compound showing green emission with Φ of 0.31 and |g_lum| of 2.2×10⁻³, highest within the series of π-extended azaborahelicenes and superior to emission intensity and chiroptical response of its non-extended congener. This study shows that helical and lateral extensions of π-conjugated systems are viable strategies to improve features of azaborole helicenes. In addition, single crystal X-ray analysis of configurationally stable [6]- and -[7]helicenes was used to provide insight into their packing arrangements.     

Synthesis of Highly Luminescent Chiral Nanographene

Chiral nanographenes with both high fluorescence quantum yields (Φ_F) and large dissymmetry factors (g_lum) are essential to the development of circularly polarized luminescence (CPL) materials. However, most studies have been focused on the improvement of g_lum, whereas how to design highly emissive chiral nanographenes is still unclear. In this work, we propose a new design strategy to achieve chiral nanographenes with high Φ_F by helical π-extension of strongly luminescent chromophores while maintaining the frontier molecular orbital (FMO) distribution pattern. Chiral nanographene with perylene as the core and two dibenzo[6]helicene fragments as the wings has been synthesized, which exhibits a record high Φ_F of 93 % among the reported chiral nanographenes and excellent CPL brightness (B_CPL) of 32 M⁻¹ cm⁻¹.     

The reaction of sulfur with dilithio compounds. The syntheses and structures of phenanthro [1, 10-cd]-1,2-dithiole and phenanthro[4,5-cde] [1,2]dithiin

The sequential reaction of selected polycyclic aromatic hydrocarbons with butyllithium/TMEDA/hexane and sulfur allows preparation of ring-fused dithiins, dithioles, and thiophenes. In this manner, phenanthrene has been converted to phenanthro[4,5-cde][1,2]dithiin and phenanthro[1,10cd]-1,2-dithiole. Yellow crystals of the dithiin form in C2/c (#15) space group with Z = 4, a = 13.537(3) Å, b = 8.933(2) Å, c = 9.601(4) Å, and β = 116.19 (2)°; while orange crystals of the dithiole form in P2₁2₁2₁ (#19) space group with Z = 4, a = 4.1507(5) Å, b = 14.436(3) Å, and c = 16.972(3) Å. Full structures have been determined for both compounds.     

Palladium-catalyzed double cross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls: annulative approach to functionalized polycyclic aromatic hydrocarbons

This study demonstrates that the double cross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls proceeds smoothly with the aid of a catalytic amount of Pd(PPh₃)₄ in the presence of excess base to give a variety of polycyclic aromatic hydrocarbons, such as phenanthrenes, [5]helicene, dithienobenzenes, triphenylenes, dibenzo[g,p]chrysenes, and triphenyleno[1,2-b:4,3-b′]dithiophenes in good to high yields. It is noteworthy that the annulations using 2,2′-dibromooctafluorobiphenyl as an electrophile furnish the otherwise difficult to synthesize octafluorophenanthrenes and semi-fluorinated dibenzo[g,p]chrysenes in high yields.     

A Thermally Populated,Perpendicularly Twisted Alkene Triplet Diradical

Variable‐temperature NMR and ESR spectroscopic studies reveal that bis(dibenzo[a,i]fluorenylidene) 1 possesses a singlet ground state, 1 (S₀), while the 90° twisted triplet 1 (T₁) is populated to a small extent already at room temperature. Analysis of the increasing amount of paramagnetic 1 (T₁) at temperatures between 300 and 500 K yields the exchange interaction J_ex/h c=3351 cm⁻¹ and a singlet–triplet energy splitting of 9.6 kcal mol⁻¹, which is in excellent agreement with calculations (9.3 kcal mol⁻¹ at the UKS BP86/B3LYP/revPBE level of theory). In contrast, the zero‐field splitting parameter D is very small (calculated value −0.018 cm⁻¹) and unmeasurable.     

Charge-Transfer Salts of Ferrocene Derivatives with Bis(maleonitriledithiolato)metallate(III) Complexes ([M(mnt)2]−, M=Ni,Pt): A Ground-State High-Spin [(Ni(mnt)2)2]2− Dimer

New hexamethylated ferrocene derivatives containing thioether moieties (1,1′-bis[(tert-butyl)thio]-2,2′,3,3′,4,4′-hexamethylferrocene ( 3a , b )) or fused S-heteropolycyclic substituents (rac-1-[(1,3-benzodithiol- 2-yliden)methyl]-2,2′,3,3′,4,4′-hexamethylferrocene ( 5 ) and rac-1-[1,2-bis(1,3-benzodithiol-2-yliden)ethyl]-2,2′,3,3′,4,4′-hexamethylferrocene ( 14 )), as well as a series of ferrocene-substituted vinylogous tetrathiafulvalenes (1,1′-bis[1,2-bis(1,3-benzodithiol-2-yliden)ethyl]ferrocene ( 6a ), 1,1′-bis[1-(1,3-benzodithiol-2-yliden)-2-(5,6-dihydro-1,3-dithiolo[4,5-b] [1,4]dithiin-2-yliden)ethyl]ferrocene ( 6b ), [1,2-bis(1,3-benzodithiol-2-yliden)ethyl]ferrocene ( 21a ), [1-(1,3-benzodithiol-2-yliden)-2-(5,6-dihydro-1,3-dithiolo[4,5-b] [1,4]dithiin-2-yliden)ethyl]ferrocene ( 21b ), [1,2-bis(5,6-dihydro-1,3-dithiolo[4,5-b] [1,4]dithiin-2-yliden)ethyl]ferrocene ( 21c ), [1-(5,6-dihydro-1,3-dithiolo[4,5-b] [1,4]dithiin-2-yliden)-2-(1,3-benzodithiol-2-yliden)ethyl]ferrocene ( 21d )) were prepared and fully characterized. Their redox properties show that some of them are easily oxidized and undergo transformation to paramagnetic salts containing bis(maleonitriledithiolato)-metallate(III) anions [M(mnt)₂]⁻ (M=Ni, Pt; bis[2,3-dimercapto-κS)but-2-enedinitrilato(2⁻)]nickelate (1⁻) or -platinate (1⁻). The derivatives [ 3a ] [Ni(mnt)₂] ( 26 ), [ 3a ] [Pt(mnt)₂] ( 27 ), [Fe{(η⁵-C₅Me₄S)₂S}] [Ni(Mnt)₂] ( 28 ), [Fe{(η⁵-C₅Me₄S)₂S}] [Pt(mnt)₂] ( 29 ), [ 5 ] [Ni(mnt)₂]⋅ClCH₂CH₂Cl ( 30 ), [ 6a ] [Ni(mnt)₂] ( 31 ), [ 6a ] [Ni(mnt)₂]⋅ClCH₂CH₂Cl ( 31a ), [ 6a ] [Pt(mnt)₂] [ 32 ), and [ 6b ] [Ni(mnt)₂] ( 33 ) were prepared and fully characterized, including by SQUID (superconducting quantum interference device) susceptibility measurements. X-Ray crystal-structural studies of the neutral ferrocene derivatives 6a , b , 21c , d , and 1,1′-bis[1-(1,3-benzodithiol-2-yliden)-2-oxoethyl]ferrocene ( 23 ), as well as of the charge-transfer salts 26 – 28 , 30 , and 31a , are reported. The salts 28 and 30 display both a D⁺A⁻A⁻D⁺ structural motif, however, with a different relative arrangement of the [{Ni(mnt)₂}₂]²⁻ dimers, thus giving rise to different but strong antiferromagnetic couplings. Salt 26 exhibits isolated ferromagnetically coupled [{Ni(mnt)₂}₂]²⁻ dimers. Salt 27 displays a D⁺A⁻D⁺A⁻ structural motif in all three space dimensions, and a week ferromagnetic ordering at low temperature. Salt 31a , on the contrary, shows segregated stacks of cations and anions. The cations are connected with each other in two dimensions, and the anions are separated by a 1,2-dichloroethane molecule.     

Eight-membered organosulfur heterocycles. Synthesis of dibenzo[d,g][1,3,6,2]dioxathiaphosphocin and dibenzo[d,g][1,3,6,2]dioxathiasilocin ring systems

The reaction of 2,2′-thiobisphenols with either phenylphosphonous dichloride or phosphorus trichloride followed by an alcohol gave derivatives of the dibenzo[d,g][1,3,6,2]dioxathiaphosphocin ring system. The analogous reaction of 2,2′-thiobisphenols with alkyl and aryl dichlorosilanes gave the heretofore unreported dibenzo[d,g][1,3,6,2]dioxathiasilocin ring system. The analytical and spectral data are reported.     

Synthesis and photorefractivity of poly[methyl‐3‐(7‐dibenzo[a,g]carbazolyl)‐propylsiloxane]

7H‐Dibenzo[a,g]carbazole‐substituted polysiloxane (PSX‐[a,g]BCz) has been synthesized by hexachloroplatinate (IV) hydrate polymerization from poly(methylhydrosiloxane) and 7‐ally‐7H‐dibenzo[a,g]carbazole. PSX‐[a,g]BCz composite showed large orientational birefringences because of both large dipole moments and high‐polarizability anisotropies of P‐IP‐DC chromophore associated with the effective conjugation along the polyene. The 50‐μm thick photorefractive material containing 30 wt % 2‐[3‐[(E)‐2(piperidino)‐1‐ethenyl]‐5,5‐dimethyl]‐2‐cyclohexenyliden]malononitrile showed a diffraction efficiency of 51% at 55 V/μm, which corresponded to a Δn of 3.45 × 10^?3. PSX‐[a,g]BCz composite shows a fast time constant of 0.42 s at 34 °C and 55 V/μm, which corresponded to the space‐charge field of 12 V/μm under 70 V/μm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1783–1791, 2008     

Synthesis of Novel 13a‐(ω‐Aminoalkyl)‐8‐oxoberbines by Means of Reaction of Homophthalic Anhydride with 1‐Substituted 3,4‐Dihydroisoquinolines. An Unexpected Formation of a Pyrrolo[3,4‐i]berbindione

The reaction of 1‐[ω‐(N‐acylated amino)alkyl]‐3,4‐dihydroisoquinolines ( 7a , 7b , 7c , 7d , 7e ) with homophthalic anhydride ( 1 ) leads to the formation of 8‐oxo‐13a‐[(N‐acylated amino)alkyl]‐8H‐dibenzo[a,g]quinolizine‐13‐carboxylic acids ( 8a–e ) with predomination of cis diastereomers, together with small amount of trans-8a . cis‐13a‐[(N‐Cbzaminomethyl)]‐8‐oxo‐dibenzoquinolizine‐13‐carboxylic acid ( cis-8a ) cyclized to the unknown dibenzo[a,g]pyrrolo[3,4‐i]quinolizinedione ( 10 ) upon moderate heating in methanol.     

Synthesis of diallyl‐containing polyimide and the effect of allyl groups on properties

A diallyl‐containing bisphenol, 1,1‐bis(3‐allyl‐4‐hydroxyphenyl)‐1‐(6‐oxido‐6H ‐dibenzo [c,e][1,2] oxaphosphorin‐6‐yl) ethane ( 1 ), was prepared by a two‐step procedure. Then, a diallyl‐containing diamine, 1,1‐bis(3‐allyl‐4‐(4‐aminophenoxy)‐phenyl)‐1‐(6‐oxido‐6H‐dibenzo [c,e][1,2] oxaphosphorin‐6‐yl)ethane ( 3 ), was prepared from the nucleophilic substitution of ( 1 ) with 4‐fluoronitrobenzene, followed by the reduction by Fe/HCl. A flexible polyimide ( 4 ) with curable diallyl linkages was prepared from the condensation of ( 3 ) and 4,4′‐oxydiphthalic anhydride in m‐cresol in the presence of isoquinoline. Curing polyimide ( 4 ) at 300 °C leads to thermosetting polyimide ( 5 ). We discussed the amounts of allyl group on T_g, coefficient of thermal expansion, and thermal stability of thermosetting polyimides, and found that thermal properties and dimensional stability of thermosetting polyimides increase with the amounts of cured allyl moieties. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 513–520     

Cascade C?N and C?O bond constructions for the synthesis of dibenzoimidazo[1,4]oxazepines catalyzed by CuI/o-phen

A novel method for the synthesis of dibenzo[b,f]imidazo[1,2-d][1,4]oxazepine derivatives was described via cascade Csp² N and Csp² O bond constructions. It was a crossed double Ullmann reactions using 4,5-diaryl-2-(2-hydroxylphenyl)-1H-imidazole as the double nucleophilic centers in the presence of Cs₂CO₃, while 1-bromo-2-iodobenzene was used as a substrate catalyzed by CuI and o-phenanthroline in good yields.     

Synthesis and spectral properties of 11‐[(o‐; and p‐substituted)‐phenyl]‐8‐[(o‐; m‐;p‐methoxy)phenylthio]‐3,3‐dimethyl‐2,3,4,5,10,11‐hexahydro‐1h‐dibenzo[b,e][1,4]diazepin‐1‐ones

The preparation of twelve novel 2,3,4,5,10,11‐hexahydro‐1H‐dibenzo[b,e] [1,4]diazepin‐l‐ones which have potentially useful pharmacological properties; by condensation and cyclization between 3‐{[4‐(o‐; m‐; p‐methoxy)phenylthio]‐1,2‐phenylenediamine}‐5,5‐dimethyl‐2‐cyclohexenone with (o‐; and p‐substi‐tuted)benzaldehyde. The structure of all final products were corroborated by ir, ¹H‐nmr, ¹³C‐nmr and ms.     

Rechargeable Sodium-Ion Battery Based on Polyazaacene Analogue Anode

The high theoretical specific capacity, strong structural designability and relatively inexpensive manufacturing cost make the exploration of organic electrode materials more attractive in recent years. In this article, owing to the large π-conjugated structure, plenty of nitrogen heteroatoms and multiring aromatic system, polyazaacene analogue poly(1,6-dihydropyrazino[2,3 g]quinoxaline-2,3,8-triyl-7-(2H)-ylidene-7,8-dimethylidene) (PQL) was applied as the anode in sodium-ion batteries (SIBs). PQL was almost insoluble in conventional liquid organic electrolyte (1 M NaClO₄ in ethylene carbonate (EC)/dimethyl carbonate (DMC) (v:v=1 : 1) with 5 % fluoroethylene carbonate (FEC)), which strongly improved its cycle stability. The initial discharge capacity was obtained to be 1825 mAh g⁻¹ at the current density of 100 mA g⁻¹ and stabilized at 317 mAh g⁻¹ after 400 cycles with the coulombic efficiency as high as 97 %. It not only showed good rate capability at high current densities (202, 183 mAh g⁻¹ at 1 A g⁻¹ and 1.5 A g⁻¹) but also had a superior energy density around 290 Wh kg⁻¹.     

Conformational analysis and electronic structure calculations of S-1,2-bis(2-dibutenoyl)glycerol and S-1,2-bis(2,4-hexadienoyl)glycerol,two analogues of 1,2-bis(2,4-octadecadienoyl)-sn-glycero-3-phosphorylcholine

As a model for 1,2-bis(2,4-octadecadienoyl)-sn-glycero-3-phosphorylcholine, a doubly unsaturated membrane-forming lipid molecule, force-field (MMP2) calculations were performed on S-1,2-bis(2-dibutenoyl)glycerol, and CNDO/S-calculations 2

1 CNDO: Complete neglect of differential overlap, a semi-empirical quantum-mechanical method.

on the derived minimum-energy conformations of S-1,2-bis(2,4-hexadienoyl)glycerol. The energy hypersurface especially with respect to the dihedral angles along the C(1)-C(2) and the two C O ester bonds was explored and the rotational strength as a function of these angles was calculated. The two gauche-forms were found to be most stable, with a slight preference for the g⁻-form. The experimental circular dichroism data obtained for 1,2-bis(2,4-hexadienoyl)-sn-glycero-3-phosphorylcholine, the corresponding phosphorylcholine, indicate a dynamic equilibrium between two forms of opposite chirality possibly involving the g⁺-and the g⁻-forms.     

Bright Luminescence by Combining Chiral [2.2]Paracyclophane with a Boron–Nitrogen-Doped Polyaromatic Hydrocarbon Building Block

Novel BN-doped compounds based on chiral, tetrasubstituted [2.2]paracyclophane and NBN-benzo[f,g]tetracene were synthesized by Sonogashira–Hagihara coupling. Conjugated ethynyl linkers allow electronic communication between the π-electron systems through-bond, whereas through-space interactions are provided by strong π–π overlap between the pairs of NBN-building blocks. Excellent optical and chiroptical properties in racemic and enantiopure conditions were measured, with molar absorption coefficients up to ϵ=2.04×10⁵ M⁻¹ cm⁻¹, fluorescence quantum yields up to Φ_PL=0.70, and intense, mirror-image electronic circular dichroism and circularly polarized luminescence signals of the magnitude of 10⁻³ for the absorption and luminescence dissymmetry factors. Computed g_lum,calcd. values match the experimental ones. Electroanalytical data show both oxidation and reduction of the ethynyl-linked tetra-NBN-substituted paracyclophane, with an overlap of two redox processes for oxidation leading to a diradical dication.     

Fluorescence quantum yield of the two novel macrocyclic lactams

Fluorescence quantum yield of two novel compounds—dibenzo[c,k]-1,2-dithia-6,9-diazacyclododecane-5,10-dione (1) and dibenzo[c,k]-1,2-dithia-6,9-diaza-7-methylcyclododecane-5,10-dione (2) was studied by Williams method using anthracene as a reference.