Synthesis and intramolecular charge-transfer interaction of janusene containing the tropylium ring (5,5a,6,11,11a,12-hexahydro-5,12-(1,2-benzeno)-6,11-(1,2-tropylio)naphthacene cations)

The tropylium analogues of janusene having the tropylium ring at the “Face” and “Lateral” positions have been synthesized, and their intramolecular charge-tranfer interactions examined.     

New strategies and building blocks for functionalised 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene derivatives,including pyrrolo-annelated derivatives and pi-extended systems with intramolecular charge-transfer

A range of new functionalised 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (TTFAQ) derivatives have been synthesised from the key di(halomethyl) building blocks, 10-[4,5-bis(bromomethyl)-1,3-dithiol-2-ylidene]-anthracene-9(10H)-one 10, 10-[4,5-bis(chloromethyl)-1,3-dithiol-2-ylidene]anthracene-9(10H)-one 11 and 9-[4,5-bis(chloromethyl)-1,3-dithiol-2-ylidene]-10-[4,5-bis(hexylsulfanyl)- 1,3-dithiol-2-ylidene]-9,10-dihydroanthracene 18. A Diels-Alder strategy comprising trapping of the transient exocyclic diene 19, which is derived from 18, with 1,4-naphthoquinone leads to the aromatised TTFAQ anthraquinone system 21. Horner-Wadsworth-Emmons olefination of 21 with the anion generated from reagent 22 gave the fused bis(TTFAQ) structure 23. Pyrrolo-annelated derivatives 30-34 have been obtained in a sequence of reactions from compound 10. Mono-formylation of the pyrrole ring of 32 and 33 under Vilsmeier conditions gave 35 and 36 which upon reaction with 2,4,5,7-tetranitrofluorene gave the donor-pi-acceptor diads 38 and 39. Cyclic voltammetry (CV) in solution for all the TTFAQ derivatives shows the typical quasi-reversible two-electron oxidation wave of the TTFAQ core at potentials which vary slightly depending on the substituents. For example, the value of Eox is raised by the electron withdrawing anthraquinone and tetranitrofluorene units of 21 and 38, respectively. The CV of the conjugated TTFAQ dimer 23 showed two, two-electron oxidation waves corresponding to the sequential formation of 23(2+) and 23(4+) (delta Eox = 130 mV) providing evidence for a significant intramolecular electronic interaction, i.e. the dication 23(2+) acts as a conjugated donor-pi-acceptor diad, thereby raising the oxidation potential of its partner TTFAQ unit. Spectroelectrochemical studies on 23 support this explanation. A strong intramolecular charge transfer band at lambda max 538 nm is seen in the UV-Vis spectra of the TTFAQ-pi-tetranitrofluorene diads 38 and 39. The X-ray crystal structures are reported for compounds 30, 33 and 34. The pyrrolo-TTFAQ moiety adopts a saddle-shape with the central ring of the dihydroanthracene moiety folded along the C(9) ... C(10) vector in each case. Significant intermolecular interactions are observed in the structures.     

Synthesis and crystal structure of 9,10-dihydro-9,10-etheno-1,8-dichloro-11-diphenylphosphinyl-12-(diphenylphosphinylethynyl)anthracene

The title compound, 9,10-dihydro-9,10-etheno-1,8-dichloro-11-diphenylphosphinyl-12-(diphenylphosphinylethynyl)anthracene (1), has been synthesized and its crystal structure has been determined. The compound 1 crystallized into the triclinic space group P-1 with =74.837(4)°, β=88.156(4)°, γ=65.398(4)°, Z=2, D_c=1.352 gcm⁻³. In the crystal structure of 1a, one chloroform molecule was included by the compound 1 with a 1:1 ratio and the existence of non-classical intermolecular C–HO hydrogen bonds, intramolecular C–HCl and C–HO hydrogen bonds and π–π stacking were observed.     

Photoinduced charge-transfer between ferrocene derivatives and chloroform molecules confined in poly(methyl methacrylate) thin films

The changes in the electronic absorption spectra (UV-Vis) (after photoexcitations) of poly(methyl methacrylate) (PMMA) thin films doped with a ferrocene derivative and containing chloroform molecules as impurities, have been studied as a function of photoexcitation wavelength (210–750 nm), photoexcitation time (duration), amount of ferrocene derivative in the film and amount of chloroform molecules present in the film. Occurrence of photoinduced charge-transfer between some ferrocene derivatives and chloroform molecules confined in the PMMA thin films has been observed. The effects of the substitution group (attached to the ferrocene unit) on the photoinduced changes are discussed.     

Piezochromic luminescence and aggregation induced emission of 9,10- bis[2-(2-alkoxynaphthalen-1-yl)vinyl]anthracene derivatives

Four derivatives of 9,10-bis[2-(2-alkoxynaphthalen-1-yl)vinyl]anthracene (BNAs) were designed, successfully synthesized and characterized by spectrofluorometer, powder wide-angle X-ray diffraction (PXRD) and differential scanning calorimetry experiments (DSC), etc. It was found that these compounds exhibited aggregation-induced emission phenomenon. Moreover, these target compounds displayed reversible color change from yellow to orange upon pressing and annealing process. Interestingly, all of BNAs obviously presented red-shifted piezofluorochromic (PFC) properties and behaved mainly length dependence of alkoxy group, in which, BNA displayed the largest PFC spectral shift (Δl_PFC=26 nm). The PXRD profiles demonstrated the transformation from crystalline to amorphous state upon grinding, and the mechanism of PFC behaviors was proposed. Thus, changing the length of alkoxyl chain could be an alternative way to tune their PFC behaviors.     

1-(2-pyridyl)-3,4-dihydro-6,7-dimethoxyisoquinoline and some of its hydrogenated and N-substituted derivatives

The preparation of 1-(2-pyridyl)- and 1-(2-piperidyl)-substituted, partly hydrogenated derivatives of 6,7-dimethoxyisoquinoline is described.     

四(4-三甲胺苯)卟啉与其抗体相互作用的紫外可见和圆二色谱研究

四(4-三甲胺苯)卟啉与单抗体3B6结合后，有显的增色效应，反映了卟啉与抗体是刚性紧密结合的，抗体的抗原结合部位有芳香族氨基酸存在，并且产生巨大的诱导效应．用紫外(UV)可见和圆二色谱(CD)分析四(4-三甲胺苯)卟啉同抗体的结合，表明(四(4-三甲胺苯)卟啉与单抗体，既有1：1结合又有2：1结合．     

Polarographic determination of 9,10-anthraquinone and its 1,2- 1,4- and 1,8-dihydroxy derivatives in chloroform Application to the analysis of papers and black liquors

The polarographic behaviour of 9,10-anthraquinone (I) and some of its dihydroxy derivatives, such as alizarin (II), quinizarin (III) and chrisazin (IV) has been studied in the presence of proton donors of HA and HB⁺ type. After optimization of conditions for reversible reduction of the anthraquinones, various polarographic techniques were used for the determination of anthraquinones in chloroform. In the dc method, the relative standard deviation for the determination of 1mM concentrations was about 1.5%. In the ac method, the detection limit was 0.1 μg/ml and the relative standard deviation for determination at the 0.2 μg/ml level was 2%. The proposed methods are usable for the simultaneous determination of I and II, II and III, II and IV, and have been applied to the determination of 9,10-anthraquinone in papers and black liquors.     

Photoaddition of water and alcohols to the anthracene moiety of 9-(2'-hydroxyphenyl)anthracene via formal excited state intramolecular proton transfer

The title compound undergoes efficient photoaddition of a molecule of a hydroxylic solvent (H(2)O, MeOH, (Me)(2)CHOH) across the 9- and 10-positions of the anthracene moiety to give isolable triphenylmethanol or triphenylmethyl ether type products. The reaction is believed to proceed via a mechanism involving water-mediated formal excited state intramolecular proton transfer (ESIPT) from the phenolic OH to the 10-position of the anthracene ring, generating an o-quinone methide intermediate that is observable by nanosecond laser flash photolysis, and is trappable with nucleophiles. A "water-relay" mechanism for proton transfer seems plausible but cannot be proven directly with the data available. Irradiation in deuterated solvents led to incorporation of one deuterium atom at the methylene position in the photoaddition product, and partial deuterium exchange of the 10-position of recovered starting material, consistent with the proposed formal excited state proton transfer mechanism. The deuterium exchange and photoaddition reach maximum quantum efficiency at approximately 5 M water (in CH(3)CN or CH(3)OH), with no reaction observed in the absence of a hydroxylic solvent, demonstrating the sensitivity of this type of ESIPT to solvent composition.     

An efficient novel synthesis of beta-(azuleno[1,2-b]benzothienyl)- and beta-(azuleno[2,1-b]benzothienyl)-alpha,beta-unsaturated ketones by the tropylium ion-mediated intramolecular furan ring-opening reaction and X-ray investigation of methyl ketone derivative

Intramolecular reaction of 2-tropylio-3-(5-substituted 2-furyl)benzothiophenes (3), prepared from the corresponding 2-cycloheptatrienyl-3-(5-substituted 2-furyl)benzothiophenes (2), afforded the beta-(azuleno[1,2-b]benzothienyl)-alpha,beta-unsaturated ketones (4), which are otherwise difficult to obtain, in moderate yields. The reaction involves a ring-opening process of the furan ring by intramolecular attack of the tropylium ion onto the 2-position of the furan ring. Similarly, beta-(azuleno[2,1-b]benzothienyl)-alpha,beta-unsaturated ketones (8) were obtained from the corresponding 3-tropylio-2-(5-substituted 2-furyl)benzothiophenes (7) albeit in lower yields. The molecular and crystal structures of the methyl ketone derivative, 8a, are discussed on the basis of X-ray structure analysis.     

Role of edge-to-face interaction between aromatic rings in clathrate formation of 1-benzoyl-2-hydroxyindoline derivatives with benzene. X-ray crystal and PM6 analyses of the interaction

(4-Nitrophenyl- and 4-chlorophenyl)(2-hydroxy-3,3-dimethylindolin-1-yl)methanone (4a,b) serve as clathrate hosts for benzene guests. X-ray crystal analyses of the inclusion compounds of 4a and 4b with benzene indicate that the ‘edge-to-face interaction’ plays an important role in the formation of the inclusion complexes with benzene as well as in the host-host interactions. PM6 molecular orbital calculations were found to reproduce the characteristic structural features of both intra- and intermolecular edge-to-face interactions.     

Experimental and density functional studies on two structurally similar antipyrine derivatives: 4-(2-hydroxy-5-nitrobenzylidene-amino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one

The Schiff base compounds, 4-(2-hydroxy-5-nitr- obenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpy- razol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenz- ylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one, have been synthesized and characterized by elemental analysis, IR, and X-ray single crystal determination. Density functional calculations of the structures, natural bond orbitals, and frontier molecular orbitals and Mülliken charge analysis on the compounds were performed at B3LYP/6-31+G(d) level of theory. Vibrational frequencies were also predicted, assigned, and compared with the experimental values, which supported each other.     

Condensation of N-(p-nitrobenzyl)-10,10-dimethyl-9,10-dihydro-10-sila-2-azaanthracene bromide and its 9-oxo derivative with acetylenedicarboxylic ester

Carbanions derived from N-(p-nitrobenzyl)-dihydrosilaazaanthracene condense with acetylenedicarboxylic ester to form substituted silanaphthoindolizines and silaazaaceanthrenes. The analogous salt of the 9-oxo derivative gave the oxo substituted silanaphthoindolizine. The compounds obtained were subjected to reduction, hydrolysis, and opening of the sila-ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 707–711, May, 1987.     

1,2-bis(4-Hydroxyphenyl)-3,4-dihydro-6-hydroxynaphthalene, a photofluorogenic ligand for the estrogen receptor

Abstract— 1,2-bis(4-Hydroxyphenyl)-3,4-dihydro-6-hydroxynaphthalene (6) is a non-steroidal ligand for the estrogen receptor that displays photofluorogenic properties. It binds to the receptor with an affinity greater than that of estradiol (150%), and it is esentially non-fluorescent. However, upon brief UV irradiation in protic media it is converted efficiently to an aryl tetraenedione system (8) that is highly fluorescent, but has low affinity for the receptor (0.35%). The aryltetraenedione has a complex electronic spectrum, with absorbance (and fluorescence excitation) bands extending beyond 450 nm. Both the maxima (ε_max) and the intensity (φ_f of the fluorescence emission of the aryl tetraenedione are solvent dependent. The tetraenedione (8) is structurally related to a tetraenedione (13) obtained by photocyclization of diethylstilbestrol(l0); since tetraenedione 13 is essentially non-fluorescent, it appears that the aryl dienone chromophore in 8 is responsible for its fluorescence. Photolysis of 6 in non-protic media results in a direct photocyclization-oxidation to benzodihydrochrysene system 9 that is unstable and has less desirable fluorescent properties. The formation of 8 from 6 in protic media (as contrasted to the formation of 9 in non-protic media) is thought to arise from the competition that operates on the primary photocyclization product, dihydrophenanthrene (7): In protic media, ketonization proceeds more rapidly than oxidation (aromatization), while in aprotic media, oxidation is more rapid. This photofluorogenic ligand for the estrogen receptor should enable interesting fluorescence binding studies with the estrogen receptor to be performed.     

Synthesis of methyl derivatives of uronic acids. I. Synthesis of methyl (methylα-D-galactopyranosid)uronate and its 2-, 3-, and 4-O-methyl ethers

Alternative unidirectional methods for synthesizing methyl (methyl α-D-galactopyranosid)uronate and its mono-O-methyl ethers by the oxidation (with CrO₃-H₂SO₄-acetone) of the corresponding methyl O-benzyl-O-methyl-α-D-galactopyranosides having unsubstituted 6-OH groups to the corresponding methyl O-benzyl-O-methyl-α-D-galactouronic acids followed by esterification with CH₂N₂ and the catalytic hydrogenolysis of the benzyl groups are proposed.     

Stable ion study of benzo[a]pyrene (BaP) derivatives: 7,8-dihydro-BaP, 9,10-dihydro-BaP and its 6-halo derivatives, 1- and 3-methoxy-9,10-dihydro-BaP-7(8H)-one,as well as the proximate carcinogen BaP 7,8-dihydrodiol and its dibenzoate,combined with a comparative DNA binding study of regioisomeric (1-, 4-, 2-) pyrenylcarbinols

A stable ion study of a series of BaP derivatives is reported. 7,8-Dihydro-BaP 1 gives a persistent bay-region benzyliclike carbocation which shows extensive charge delocalization into the pyrene moiety. In contrast, a "benzylic" carbocation can not be generated from 9,10-dihydro-BaP 2. Introduction of bulky substituents at peri C-6 of 9,10-dihydro-BaP (as in 4 and 5) prevents side reactions (dimerization) to the extent that the initially formed carbocation undergoes rearrangement to generate the corresponding bay-region "benzylic" carbocation as a persistent species. Introduction of methoxy substituents into the 1- or 3-positions of 9,10-dihydro-BaP-7(8H)-one (6,7) increases its electrophilic reactivity to the extent that stable carboxonium-arenium dications are produced in FSO3H-SO2ClF. A detailed NMR study (at 500 MHz) of the resulting mono- and dications is reported, and charge delocalization mode (as well as conformational aspects) are addressed. Other oxidized derivatives of BaP such as the 7,8-dihydrodiol 9 and the 7,8-dihydrodibenzoate 8 are not suitable models for stable ion study because of competing O-protonation (and elimination). Energies for various possible arenium ions and regioisomeric "benzylic" cations were computed by the DFT method at the B3LYP/6-31G(d)//B3LYP/6-31G(d) level or by AM1 for comparison with the experimental results. These findings provide further evidence in support of the stability sequence: 1-pyrenyl > 4-pyrenyl > 2-pyrenyl in alpha-pyrene-substituted carbocations as models for the intermediates arising from BaP-epoxide ring opening. In an effort to provide a parallel, a series of alpha-pyrenylcarbinols were subjected to a DNA binding study using human MCF-7 cells. The results/trends are discussed and compared with the stable ion data.     

The Coordination Chemistry of 1,2-Bis[(diphenylphosphino)methyl]benzene with Nickel(II), Palladium(II), Platinum(II), and Platinum(0) and the X-Ray Crystals Structure of [Pt{1,2-bis[(diphenylphospino)methyl]benzene}(C2H4)]

The preparation of complexes [MX₂( 1 )] (M = Ni, Pd, and Pi; X - Cl, Br, and I; 1 = 1,2-bis[(diphenylphosphino)methyl]benzene). [Pt(OSO₂CH₃)Et( 1 )], [Pt(alkene)( 1 )] (alkene - C₂H₂, and CH₂ = CHCN), and [( 1 )Pt-(μ-H)₂PtH( 1 )][BPh₄] is reported. Their ¹H- and ³¹P-NMR spectra were recorded and used lor structural assignments. The X-ray crystal structure of [Pt(C₂H₄)( 1 )] was determined. It is shown that the P? Pt? P bond angle in this complex differs significantly from those found in related compounds with monodentate phosphines, and that this difference is likely to be due to intramolecular contacts.     

Far-IR spectra of charge-transfer complexes between IX (X = Cl,Br or I) and trans-1,2-bis(4-pyridyl)ethylene, 1,2-bis(4-pyridyl)ethane and 4,4′-

Far-IR spectra of charge-transfer complexes of trans-1,2-bis(4-pyridyl)ethylene (Bpe), 1,2-bis(4-pyridyl)ethane (Bpa) and 4,4′-bipyridyl (4,4′-