Synthesis and ion-selective properties of 1,2-bis[2-((2-diphenylphosphorylmethyl)phenoxy)ethoxy]cyclohexane (L) and its structural analogs. Crystal structure of L

Potentially hexadentate phosphoryl podands 1,2-bis[2-((2-diphenylphosphorylmethyl)phenoxy) ethoxy]cyclohexane (L), 1,2-bis[2-((2-diphenylphosphoryl)phenoxy)ethoxy]cyclohexane (L¹), and 1,2-bis[2-((2-diphenylphosphorylmethyl)phenoxy)ethoxy]benzene (L²) are synthesized. Stability constants of complexes formed by L, L¹, and L² with alkali-metal 2,4-dinitrophenolates in mixed THF—CHCl₃ solutions (4: 1 by volume) are determined. Electroanalytical characteristics of ion-selective electrodes with hexadentate phosphoryl podands having different structures used as active components of their plasticized membranes are compared for cations of alkali and alkaline-earth metals. The IR spectra are described. The crystal structure of L is studied by X-ray diffraction.     

Photochemical Reactions of Regioisomeric 2,2‐Dimethyl‐5,5‐diphenyl‐ and 5,5‐Dimethyl‐2,2‐diphenyl‐Substituted Diazo Ketones of a Tetrahydrofuran Series

The principal direction of conventional photolysis of the regioisomeric 2,2‐dimethyl‐5,5‐diphenyl‐ and 5,5‐dimethyl‐2,2‐diphenyl‐substituted 4‐diazodihydrofuran‐3(2H)‐ones 1a and 1b , respectively, is the Wolff rearrangement, while other photochemical processes, which are giving rise to the formation of C? H‐insertion, 1,2‐alkyl‐ or ‐aryl‐shifts, as well as H‐atom‐abstraction products occur to a much lower degree (Schemes 2 and 3). The ratio of similar reaction products from both regioisomers 1a and 1b is essentially independent of their structure, and a substantial effect of the relative position of the Ph and diazo group to each other on the yield of C? H‐insertion products does not occur. Based on stereochemical considerations, the Wolff rearrangement of diazodihydrofuran‐3(2H)‐ones apparently proceeds in a concerted manner, whereas the appearance in the reaction mixture of 1,2‐shift and H‐atom‐abstraction products points to the parallel generation during photolysis of singlet and triplet carbenes (Schemes 4 and 5).     

Structure and Ion-Selective Properties of 2-Phosphorylphenols

The structure and ion-selective properties of some 2-phosphorylphenols were studied. It was shown that, irrespective of the nature of the substituents on the benzene ring and on the phosphorus atom, these compounds exhibit potentiometric selectivity to cesium cation. The crystal structures of 2-(diphenylphosphoryl)-4-ethylphenol and 2-[(diphenylphosphoryl)methyl]phenol were established.     

Reactions of isocyanates with compounds containing active methylene groups in the presence of triethylamine

Compounds containing active methylene groups react with isocyanates of different structures in the presence of triethylamine to form functionally substituted amides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2323–2330, October, 2005.     

Aza-Michael reaction as an efficient method for the synthesis of first representatives of β-azahetaryl-β-diphenylphosphorylalkanones

Aza-Michael reaction of (E)-4-(diphenylphosphoryl)but-3-en-2-one (1) with a number of mono-and bicyclic nitrogen heterocycles proceeds regioselectively in the absence of catalysts with the formation of corresponding β-azahetaryl β-diphenylphosphoryl ketones; in the case of imidazole, the presence of chiral organic catalysts allows one to increase the yields of the adducts and to obtain them in enantiomerically enriched form.

     

Reactions of vinylphosphonates with piperazines

Russian Journal of General Chemistry - Dialkyl [2-(piperazin-1-yl)ethyl]phosphonates were obtained by the reactions of piperazine with dialkyl vinylphosphonates. The addition of...     

Synthesis and Structure of Quaternary Phosphonium Salts Based on Phosphorylated Sterically Hindered Phenols

Russian Journal of General Chemistry - A procedure was developed for the synthesis of quaternary phosphonium salts with two phosphorus atoms [P(III) and P(V)] based on phosphorylated hindered...     

Piezoresonance sensor for ammonia with polymaleic acid as the sensitive coating

Results of the study of a piezoresonance sensor with polymaleic acid as the sensitive coating for the determination of the concentration of ammonia in air are presented. The influence of the mass of the polymer coating, the flow rate of the carrier gas, and relative humidity on the performance characteristics of the sensor was studied. The mechanism of the interaction of ammonia with the sorbent in the presence of water vapors is proposed based on experimental data and quantum chemical calculation. It is found that the sensor exhibits high selectivity for ammonia in the presence of vapors of saturated and aromatic hydrocarbons. The detection limit for ammonia at the humidity 45–55% is 0.04 mg/m³, which makes it possible to determine ammonia at a level of the maximum permissible concentration for inhabited areas; the concentration characteristic of the sensor is linear in the concentration range 0.04-40 mg/m³.