Chemiluminogenic features of 10-methyl-9-(phenoxycarbonyl)acridinium trifluoromethanesulfonates alkyl substituted at the benzene ring in aqueous media

10-Methyl-9-(phenoxycarbonyl)acridinium trifluoromethanesulfonates bearing alkyl substituents at the benzene ring were synthesized, purified, and identified. In the reaction with OOH(-) in basic aqueous media, the cations of the compounds investigated were converted to electronically excited 10-methyl-9-acridinone, whose relaxation was accompanied by chemiluminescence (CL). The kinetic constants of CL decay, relative efficiencies of light emission, chemiluminescence quantum yields, and resistance toward alkaline hydrolysis were determined experimentally under various conditions. The mechanism of CL generation is considered on the basis of thermodynamic and kinetic parameters of the reaction steps predicted at the DFT level of theory. The chemiluminescence efficiency is the result of competition of the electrophilic center at C(9) between nucleophilic substitution by OOH(-) or OH(-) and the ability of the intermediates thus formed to decompose to electronically excited 10-methyl-9-acridinone. Identification of stable and intermediate reaction products corroborated the suggested reaction scheme. The results obtained, particularly the dependency of the "usefulness" parameter, which takes into account the CL quantum yield and the susceptibility to hydrolysis, on the cavity volume of the entity removed during oxidation, form a convenient framework within which to rationally design chemiluminescent 10-methyl-9-(phenoxycarbonyl)acridinium cations.     

1H and 13C NMR spectra, structure and physicochemical features of phenyl acridine-9-carboxylates and 10-methyl-9-(phenoxycarbonyl)acridinium trifluoromethanesulphonates--alkyl substituted in the phenyl fragment

The 1H and 13C NMR spectra of twelve phenyl acridine-9-carboxylates--alkyl-substituted in the phenyl fragment--and their 10-methyl-9-(phenoxycarbonyl)acridinium salts dissolved in CD3CN, CD3OD, CDCl3 and DMSO-d6 were recorded in order to examine the influence of the structure of these compounds and the properties of the solvents on chemical shifts and 1H-(1)H coupling constants. Experimental data were compared with 1H and 13C chemical shifts predicted at the GIAO/DFT level of theory for DFT(B3LYP)/6-31G** optimised geometries of molecules, as well as with values of 1H chemical shifts and 1H-(1)H coupling constants, estimated using ACD/HNMR database software to ensure that the assignment was correct. To investigate the relations between chemical shifts and selected structural or physicochemical characteristics of the target compounds, the values of several of these parameters were determined at the DFT or HF levels of theory. The HOMO and LUMO energies obtained at the HF level yielded the ionisation potentials and electron affinities of molecules. The DFT method provided atomic partial charges, dipole moments, LCAO coefficients of pz LUMO of selected C atoms, and angles reflecting characteristic structural features of the compounds. It was found that the experimentally determined 1H and 13C chemical shifts of certain atoms relate to the predicted dipole moments, the angles between the acridine and phenyl moieties, and the LCAO coefficients of the pz LUMO of the C atoms believed to participate in the initial step of the oxidation of the target compounds. The spectral and physicochemical characteristics of the target compounds were investigated in the context of their chemiluminogenic ability.     

2,2’─呋喃联吡咯型联体杂环化合物的合成

在强极性的醇酸体系中，利用Knorr－Paal反应制得了呋喃联吡咯系的13个新化合物，并进行了红外光谱、质谱、核磁共振谱及元素分析测定。     

Spectral and photophysical studies of substituted indigo derivatives in their keto forms.

The spectral and photophysical properties of indigo derivatives with di-, tetra-, and hexa-substitution in their neutral (keto) form are investigated in solution. The study comprises absorption and emission spectra, together with quantitative measurements of quantum yields of fluorescence (phi(F)) and singlet oxygen formation (phi(Delta)) and fluorescence lifetimes. The energy difference between the HOMO and LUMO orbitals is dependent on the degree (number of groups) and relative position of substitution. The phi(F) and phi(Delta) values were found to be very low S(0) internal conversion yields and thus, with the other data, to determine the rate constants for all decay processes. From these, several conclusions are drawn. Firstly, the radiationless rate constants, k(NR) , clearly dominate over the radiative rate constants, k(F) , (and processes). Secondly, the main deactivation channel for the compounds in their keto form is the radiationless S(1) approximately approximately -->S(0) internal conversion process. Finally, although the changes are relatively small, internal conversion yield seems to be independent of the overall pattern of substitution. A more detailed investigation of the decay profiles with collection at the blue and red emission of the fluorescence band of indigo and one di-substituted indigo reveals the decays to be bi-exponential and that at longer emission wavelengths these appear to be associated with both rise and decay times indicating that two excited species exist, which is consistent with a keto-excited form giving rise (by fast proton transfer) to the enol-form of indigo. Evidence is presented which supports the idea that intramolecular (and possibly some intermolecular) proton transfer can explain the high efficiency of internal conversion in indigo.     

Carotenoid radical anions and their protonated derivatives

In this study, we report the protonation reactions for astaxanthin and canthaxanthin radical anions in methanol, alkaline methanol, and aqueous 2% Triton X-100 at different pH values. The pKa values for the corresponding alpha-hydroxy radical derivatives of astaxanthin, canthaxanthin, and beta-apo-8'-carotenal were estimated in 2% Triton X-100. Also, the effects of the microenvironment and the structure of the carotenoids on the protonation rate constant are discussed.     

The synthesis of (9S)-9-alkyl-9-hydroxyerythromycin A derivatives and their ketolides

A short, concise synthesis of a novel series of (9S)-9-alkyl-9-hydroxyerythromycin A derivatives and their corresponding ketolides, is described. The key chemical transformation is a stereoselective addition of organomagnesium or organolithium agents to the 9-position of the suitably protected macrolide templates 8 and 13.     

Preparation of substituted 9,10-dihydro-9-sila-3-azaanthracenes and their derivatives

3-Methyl-4-dimethylphenylsilylpyridine and 3-methyl-4-methyldiphenylsilylpyridine, which were obtained from -picoline and dimethylphenylchlorosilane and methyldiphenylchlorosilane, respectively, were converted by catalytic dehydrocyclization to 9,9-dimethyl-9,10-dihydro-9-sila-3-azaanthracene and 9-methyl-9-phenyl-9,10-dihydro-9-sila-3-azaanthracene. The corresponding silaazaanthrones were obtained from them and were converted to tertiary silaazaanthrols with a methyl or phenyl group attached to the C₁₀ atom. On the basis of an analysis of data from the PMR spectra of the silaazaanthracenes it was assumed that they exist in the form of an equilibrium mixture of boat conformations. 9-Methyl-9-phenyl-10-methylene-9,10-dihydro-9-sila-3-azaanthracene was obtained in the form of a stable crystalline substance by dehydration of the corresponding silaazaanthrol. Potassium tert-butoxide cleaves the Si-C bond in the silaazaanthrone system; this was confirmed by isolation of 1,2-dimethyl-1,2-diphenyl-1,2-bis (2-nicotinoylphenyl)disiloxane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 240–244, February, 1981.     

Di-isophorone and related compounds. Part 9 1-(substituted)aminodi-isophoranes and their cyclodehydration products

The interaction of 1-chlorodi-isophor-2(7)-en-3-one (or its 5,11-bisnorhomologue) with aromatic, heteroaromatic, or saturated heterocyclic amines produces 1-(substituted)aminodi-isophor-2(7)-3n-3-ones by nucleophilic replacement of the bridgehead halogen. Subsequent cyclodehydration affords, in certain examples, substituted 2,3,5,6,7,8-hexahydro-1H,9h-5,8a-methanocycloocta[gh]phenanthridines (2,3-dehydro-1-anilinodi-isophor-2,7-dien-3-ols). Some physical and chemical properties of these novel amines and condensed pentacylic bases are described.Part 8,Allen, A. A., Kurzer, F., Mh. Chem.112, 617 (1978).     

Expected and unexpected photoreactions of 9-(10-)substituted anthracene derivatives in cucurbit[n]uril hosts

By arranging substrates in a “reaction ready” state through noncovalent interactions, supramolecular nanoreactors/catalysts show high selectivity and/or rate acceleration features. Herein, we report the host–guest complexation of 9-(10-)substituted anthracene derivatives (G1–G3) with cucurbit[n]uril (CB[n], n = 8, 10), and the photoreactions of these derivatives in the presence of CB[n] hosts. Both CB[10] and CB[8] showed no obvious effects on the photoreaction of 9,10-disubstituted derivative G1. For G2 and G3, CB[10] operated as either a nanoreactor or catalyst (10%) for the photodimerization of two compounds with high selectivity and high yield. However, although CB[8] formed a 1 : 2 complex with G2, as also observed with CB[10], the photosolvolysis product (9-anthracenemethanol) was obtained quantitatively after photoirradiation of the CB[8]·2G2 complex. This unexpected photosolvolysis was rationalized by a plausible catalytic cycle in which anthracene acts as a photoremovable protecting group (PPG) and the carbonium ion intermediate is stabilized by CB[8].

The photodimerization of 9-substituted anthracene derivative was tremendously promoted by a catalytic amount of cucurbit[10]uril (CB[10]) in water. While CB[8] exclusively induced the photosolvolysis of the anthracene derivative.     

Regioselective addition of nucleophiles to 1-(phenoxycarbonyl)-3-trialkylstannylpyridinium salts

The regioselectivity of nucleophilic addition to 1-(phenoxycarbonyl)-3-trialkylstannylpyridinium salts was studied.     

Theoretical studies of parent 1-, 2-, 3-pyrazolines and their methylated derivatives

A theoretical study of the minima of 1-, 2-, and 3-pyrazolines as well as some methyl derivatives was performed using B3LYP/6-311++G(d,p) and CCSD(T) calculations. Conformation, tautomerism, basicity, protonation as well as NMR properties have been computationally studied. In general, the agreement with the available experimental results is excellent, highlighting the predictive potential of this type of study in the consideration of new compounds.     

2-[(9-苯基)-9H-3-咔唑基]-5-[(9-对甲苯基)-9H-3-咔唑基]吡啶的合成及其光谱性能

以咔唑和2,5-二溴吡啶为初始原料,经Ullmann反应、NBS亲电取代反应和Suzuki偶联等反应,合成了一种新型的磷光配体2-[(9-苯基)-9H-3-咔唑基]-5-[(9-对甲苯基)-9H-3-咔唑基]吡啶(5),其结构经1HNMR,ESI-MS及元素分析表征。研究了5在二氯甲烷中的荧光光谱和紫外吸收光谱。     

Spectral and thermal features of some novel iron(III) chelates with substituted 2-hydroxyaryloximes

The reaction products of five substituted 2-hydroxyaryloximes with Fe(III) ion were obtained and characterized by means of elemental analysis, conductometric measurements, magnetic moment determinations and spectroscopic data (IR and electronic absorption).The thermal stability and mode of decomposition were studied in air atmosphere by using TG-DTA. Kinetic analysis of the TG data was performed with the Coats-Redfern method to determine the apparent activation energies and the pre-exponential factor of the Arrhenius equation. Mass spectrometry was also used, and possible fragmentation patterns are given and discussed.Thanks are due to Tekkosha Hellas, Thessaloniki, for making available the thermogravimetric analysis facilities.     

Synthesis and liquid crystalline behaviour of substituted (E)-phenyl-4-(phenyldiazenyl) benzoate derivatives and their photo switching ability

Azobenzene derivatives containing phenyl/4-halogen-phenyl 4-{(E)-[4-(pent-4-en-1-yloxy)phenyl]diazenyl}benzoate group with different electronegative substituent (H, F, Cl, Br and I) at other end was synthesised. These azo-based benzoate derivatives have been characterised by FTIR, ¹H-NMR, ¹³C-NMR, elemental analyser, POM and UV-Vis spectroscopy. Photosaturation at 358 nm obtained after 82 s of UV irradiation and the longest thermal back relaxation time of 45 h recorded by UV-Vis. The azo derivative could be possible photolock under UV light, as observed by the improved thermal back relaxation time. The resulting photolockable chain of azobenzene might prove valuable in the development of optical device application. These azobenzene moieties also exhibit liquid crystalline behaviour with respect to the halogen substitution as an electron withdrawing group shows that strong structure property relationship exists among them.     

Fragmentations of protonated arginine, lysine and their methylated derivatives: concomitant losses of carbon monoxide or carbon dioxide and an amine

The fragmentation pathways of protonated arginine, protonated N(alpha),N(alpha)-dimethylarginine, the N(alpha),N(alpha),N(alpha)-trimethylarginine ion, three protonated N(epsilon),N(epsilon)-dimethyllysines, and three permanent lysine ions in which the charge is fixed by trimethylation are reported. Ion assignment was facilitated by (15)N-labeling and deuterium substitution. The chemistries are dominated by charge-induced elimination of the amino groups as neutrals, including dimethylamine, trimethylamine and guanidine. Competitive losses of the alpha-amino and side-chain amino groups were observed; these losses led to intermediates that had different structures and different subsequent dissociation reactions. Concomitant losses of CO or CO(2) with these amines were also commonly observed. However, the ionic products of amine losses did not subsequently lose CO or CO(2), suggesting strongly that in these concomitant eliminations, it is the CO or CO(2) that was first eliminated, followed immediately by the loss of the amine. Results of density functional theory calculations on protonated arginine and protonated N(alpha),N(alpha)-dimethylarginine reveal that, in such concomitant eliminations, the dissociating complex is vibrationally hot and the intermediate ion formed by losing CO or CO(2) can immediately dissociate to eliminate the amine.     

N-acyl (substituted) phenylglycine derivatives

Amidoalkylation of three benzoheterocycles, benzimidazole-2-one, 1,3-dihydrobenzo[c]-thiophene 2,2-dioxide and 1,3-dihydro-2,1,3-benzothiadiazole using N-acylhippuric acids was successful. The corresponding phenylglycine analogs were prepared by removal of the N-acyl protecting group.     

A convenient synthesis of polyfunctionally substituted 2-(arolyl-(arylsulfonyl)-methylene)-2,3-dihydrothiazoles and -thiazolidin-4-ones and their fused derivatives

Summary The reaction of phenyl isothiocyanate with arylsulfonylacetophenones1a–d in alkaline medium afforded the non-isolable intermediates2a–d. Upon reaction with some bromo compounds, the latter underwentin situ heterocyclization to afford the corresponding polyfunctionally substituted 2-(aroyl-(arylsulfonyl)-methylene)-2,3-dihydrothiazoles and-thiazolidin-4-ones. The structures of the newly synthesized compounds were assigned and confirmed on the basis of their elemental analyses, spectroscopic data, and alternative syntheses whenever possible.

---

Eine einfache Synthese von polyfunktionell substituierten 2-(Aroyl-(arylsulfonyl)-methylen)-2,3-dihydrothiazolen und -thiazolidin-4-onen und ihrer kondensierten Derivate

Zusammenfassung Die Reaktion von Phenylisothiocyanat mit den Arylsulfonylacetophenonen1a–d in alkalischem Medium führt zu den nicht isolierbaren Zwischenprodukten2a–d. Diese cyclisieren mit einigen Bromverbindungenin situ zu den entsprechenden polyfunktionell substituierten 2-(Aroyl-(arylsulfonyl)-methylen)-2,3-dihydrothiazolen und -thiazolidin-4-onen. Die Strukturen der neuen Verbindungen wurden aufgrund ihrer Elementaranalysen und ihrer spektroskopischen Daten aufgeklärt und, wenn möglich, durch alternative Synthesen bestätigt.