Spatial structures of phosphorus-containing heterocyclic compounds - XXIV. Conformations of 2-X-4,5,6,7-dibenzo-1,3,2-dioxaphosphepanes

1. 2-X-4,5,6,7-Dibenzo-1,3,2-dioxaphosphenanes (X=Cl, OEt, OPh) have a twist form, and angle of twist with respect to the biphenyl bridge is equal to 41-48°. 2. The ethoxy radical in these compounds is characterized by a gauche orientation with respect to the P-O bond, and the phenoxyl group has a cis conformation. © 1981 Plenum Publishing Corporation

Three-dimensional structure of phosphorus-containing heterocycles - Communication 39. 2-hydro-2-oxo-4,5,7,8-dibenzo-1,3,2-dioxaphosphocins

By means of dynamic PMR spectrometry, UV spectra, dipole moments, and ab-initio SCF MO LCAO calculations of model compounds, it has been shown that for 2-hydro-2-oxo-4,5,7,8-dibenzo-4H-1,3,2-dioxaphosphocins there is characteristically a three-component equilibrium with the participation of both of the boat-chair forms and one boat form with equatorial position of the P-H bond. The thermodynamic characteristics of the equilibrium have been determined. © 1987 Plenum Publishing Corporation

Ionization constants and structure of seven- and eight-membered cyclic phosphorous acid derivatives

The spectral characteristics and ionization constants of some five-, seven-, and eight-membered cyclic arylenephosphorous acids were determined, and a conclusion regarding the effect of the size of the ring on the tautomerism of these compounds was made on their basis. © 1978 Plenum Publishing Corporation

Polyquinone synthesis by dehydrogenation agent 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone

In this article a new approach for polyquinone synthesis is proposed: Polymerization of hydroquinone or 1,4-benzoquinone by dehydrogenating agent 3,3',5,5'-tetra-tert-butyl-4,4'-diphenoquinone. Interest to this reaction is emerged from the knowledge of products may have a widespread application, polyquinone due to its π-conjugated structure with redox-active chains and 4,4'-bis(2,6-di-tert-butylphenol) due to good stabilizing efficiency in polymers. The obtained polyquinone was characterized by spectroscopic, elemental, NMR, EPR and GPC methods and its polymerized nature was proved