Coordination chemistry of 2,6-bis(diphenylphosphorylmethyl)-4-methylphenol

The trifunctional ligand, 2,6-bis(diphenylphosphorylmethyl)-4-methylphenol (L ₂), forms complexes with cerium(III) nitrate having a ligand to metal ratio of 1: 1, 2: 1, and 3: 1. The structures of these complexes in the solid state and in solution were studied by X-ray diffraction, IR and NMR (¹H and ³¹P) spectroscopy, and conformational analysis (molecular mechanics). The 2: 1 complexes of L ₂ with lanthanum(III) and neodymium(III) nitrates were synthesized and characterized. In all complexes, the neutral ligand is coordinated through both phosphoryl oxygen atoms. The hydroxy oxygen atom is coordinated only in some complexes, and the hydrogen atom of the hydroxy group is involved in hydrogen bonding. The compositions and structures of the resulting complexes depend on the method of synthesis and the nature of solvent. The ligand was found to undergo easy inner-sphere oxidation. The structure of one of the transformation products was established by X-ray diffraction. Unlike the coordinated ligand, the free ligand is very stable to oxidation. Dedicated to Corresponding Member of the Russian Academy of Sciences T. A. Mastryukova. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2440–2454, November, 2005.     

Measurement of isotopic composition of selenium

Conclusions Measurement of the isotopic composition of selenium as the average of values of its isotopic abundance, determined as selenium hexafluoride and as metallic selenium, leads to a distortion of the amount of heavy isotopes due to the formation of hydrides, which are observed during the analysis of metallic selenium.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 150–152, January, 1973.     

Acid-base properties of substituted tetraphenylmethylenediphosphine dioxides

Conclusions Some tetraphenylmethylenediphosphine dioxides, substituted in the methylene bridge, were subjected to potentiometric titration in nitromethane with perchloric acid. The obtained values of the pK _a basicity constants (CH₃NO₂) obey a linear relationship with the ^* constants of the substituents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 199–201, January, 1972.     

Proton affinity of phosphoryl compounds and σΦ-substituent constants

Based on the familiar Hammett-type equation pK_a=pK_a ⁰- , CNDO/2 calculations, and known literature data, we have obtained a linear dependence of the proton affinity (PA) of phosphoryl compounds XYZPO on the sum of the constants. We have determined the center of protonation in the gas phase and the characteristics of the solvent effect on the basicity.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1334–1338, June, 1991.     

Synthesis and Ldasic Properties of O,O,O-Triethyl-N-(2-Pyridyl) Imidophosphates

Abstract

The phosphorus (111) compounds are known to react readily with arylazides resulting in the formation of imi-dophosphorus compounds (Staudinger reaction)¹.

We nave obtained O,O,O-triethyl-Ii-(2-pyridyl)imido-pnosphates by the reaction of triethylphosphites with 2-pyridylazides (existing as tetrazoles) with a good yield.     

The Structure of o-Hydroxyaryloxy-bis-(o-arylenedioxy)-phosphoranes and their Acid-Base Properties

Abstract

The crystalline phosphoranes have been obtained. IR-, UV- and NMR spectra of phosphoranes (Ia,b) and their interaction products with nitrogen bases have been investigated. It was determined that phosphoranes have structure (I) with pentacoordinate phosphorus and phenolic hydroxy group, while their products of interactions with nitrogen bases have the ionic structure (II) with hexacoordinate phosphorus (II). The X-ray difraction approves the structure (I) for phosphorane Ib.