Chemistry of the phenoxazines

The -electron charges, bond orders, and energy levels of phenoxazin-3-one and eight of its mono- and diannelated derivatives were calculated by the Hückel MO LCAO method. The effect of the position of the annelated benzene ring on the electronic characteristics of the compounds was estimated. A satisfactory correlation between the experimental and calculated energies of the _{1 1} transitions was found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1316–1322, October, 1970.     

Research on the chemistry of phenoxazines

The reaction of 3-phenoxazinone, benzo[c]phenoxazin-3-one, and benzo[a]phenoxazin-9-one with piperidine and other similar amines leads to replacement of a hydrogen atom in the quinoid ring in the meta-position relative to the bridge nitrogen atom. Benzo[a]phenoxazin-9-one also forms 5,10-diamino derivatives. In all cases, the amine residue is displaced by thiophenol.     

Investigation of the chemistry of phenoxazines

Depending on the position of the annelated benzene ring, benzophenoxazinones add thiophenols in the benzenoid, quinonoid, or both parts of the molecule to give mono- or diarylmercapto derivatives. A substituent in the benzenoid portion of the molecule hinders polarographic reduction and shifts the visible absorption band bathochromically, while a substituent in the quinonoid portion has practically no effect on the E_1/2 value.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1345–1350, October, 1972     

Research in the chemistry of phenoxazines

Reaction of 7-acetoxy- or 7-ethoxy-3-phenoxazinone with amines gave 2- and 7-amino derivatives of 3-phenoxazinone.     

Research on the chemistry of phenoxazines

A third reaction center in the phenoxazinone molecule, viz., the 9 position in the benzenoid ring, was observed for the first time in the reaction of 3-phenoxazinone and its 2-hydroxy and 2-ethoxy derivatives with p-thiocresol. In conformity with this, 2,7,9-triarylthio derivatives are formed along with the usual 2,7-disubstituted derivatives of 3-phenoxazinone. The structures of the compounds obtained were confirmed by the PMR and EPR spectra and a number of chemical transformations.See [1] for Communication 11.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 40–44, January, 1980.     

Research in the chemistry of phenoxazines

The 2 position of the quinoid ring undergoes nucleophilic substitution in the reaction of 2-acetoxy- and 2-ethoxy-3-phenoxazinones with amines. In the case of 2- and 7-substituted derivatives of 3-phenoxazinone, replacement of a hydrogen atom or groups in the electrophilic center of the quinoid ring proceeds more readily than attack by the nucleophile on the 7 position in the benzo ring.See [1] for communication X.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1200–1202, September, 1978.     

Research on the chemistry of phenoxazines

Resorufin (7-hydroxy-3-phenoxazinone) reacts with thiophenols to give 2,8-di(arylthio) derivatives. The site of entry of the nucleophilic residues indicates protonation of resorufin at the ring nitrogen atom. The changes in the absorption spectra of the arylthio derivatives of resorufin in the visible region as a function of the pH of the solution are associated with the acid-base dissociation of these compounds with respect to the hydroxyl group. The ionization constants of some 2,8- and 2,4,6,8-tetrasubstituted resorufin derivatives were measured.See [1] for communication VI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 348–353, March, 1974.     

10-(O,O-dialkylphosphonoformyl)phenoxazines and phenothiazines

Conclusions A number of new 10-(O,O-dialkylphosphonoformyl) derivatives of phenoxazine and phenothiazine were obtained.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2624–2625, November, 1972.     

Heterocyclization of N-propenyl-substituted phenothiazines and phenoxazines using electrophiles in an anhydrous medium

10-Propenylphenothiazine reacts with a catalytic amount of BF₃·Et₂O in dry ethyl acetate via intramolecular heterocyclization of an intermediate dimeric cation to give mainly 1-ethyl-2-methyl-3-(phenothiazin-10-yl)-2,3-dihydro-1H-pyrido[3,2,1-k,l]phenothiazine and a minor product through fission of phenothiazine which is 1-ethyl-2-methyl-1H-pyrido[3,2,1-k,l]phenothiazine. Under similar conditions 10-propenylphenoxazine gave an oligomer (degree of polymerization 4.4) and the minor product 1-ethyl-2-methyl-1H-pyrido[3,2,1-k,l]phenoxazine likely formed similarly to the phenothiazine analog from the corresponding product of intramolecular heterocyclization (the latter not being observed in the reaction mixture). Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1855–1860, December, 2008.     

New long alkyl side-chain benzo[a]phenoxazines as micellisation probes

Several novel fluorescent benzo[a]phenoxazinium chlorides possessing a long aliphatic chain substituent at the 5-amino function of the heterocycle were efficiently synthesised. All compounds obtained absorbed and emitted at longer wavelengths with moderate to good fluorescent quantum yields. The photophysics of N-[10-methyl-5-(octylamino)-9H-benzo[a]phenoxazin-9-ylidene]ethanaminium chloride and N-[10-methyl-5-(dodecylamino)-9H-benzo[a]phenoxazin-9-ylidene]ethanaminium chloride was studied in Triton^® X-100 and in cetyltrimethylammonium bromide micellar media, demonstrating the capability of these fluorophores in detecting the micellisation process.     

法庭化学与化学

简单叙述了法庭化学与化学的关系，法庭化学是化学的一个特殊组成部分，化学的发展促进法庭化学的发展，法庭化学在侦破案件中起重要作用。本文还介绍了法庭化学研究的内容及与相关学科的关系。     

味觉化学之酸味化学*

酸是五味之一。食物酸味的产生是由于其中所含的酸性化合物。不同的酸味食物,所含的酸性化合物结构有所不同。从酸味的产生原理出发,对常见酸味食物中所含酸性化合物的结构及性质进行了介绍。     

味觉化学之甜味化学

甜,是一种令人愉快的味道,让人产生幸福的感觉,生物本质是甜味分子与甜味受体相互作用,经过复杂的传递过程然后激活大脑奖赏区释放神经递质多巴胺。从化学结构角度上看,甜味分子可分为:糖类(糖、糖衍生物、糖醇、糖苷),氨基酸类(二肽、蛋白质),磺酰胺类等,甜度值与分子结构密切相关。本文从分子结构层面阐述各类甜味分子及其甜度。     

味觉化学之苦味化学*

食物的苦味源于所含苦味的化学物质,按照生物碱、糖苷、多酚、萜、氨基酸和多肽及无机盐的结构分类,对常见的苦味化学物质进行了详细介绍。     

农药化学中的绿色化学

绿色化学是从根本上消除环境污染的必由之路。由于某些传统农药是引起环境污染的一个重要因素,因而对农药化学中的绿色化学进行研究和推广具有非常重要的意义。本文应用绿色化学原理,对农药化学中的一些绿色化学方法和技术作了简单介绍。