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Alcohols and α-hydroxyphosphonates undergo the addition to (chloromethyl)phosphonic(-phosphinic) iso(thio)cyanates, yielding phosphorylated (thio)urethanes. The latter undergo cyclization to form, depending on their structure, saturated or unsaturated five-membered P,N,O,S-containing heterocycles.

We have established that direct phosphorus-selenium spin-spin coupling constants in cyclic compounds with P=Se exocyclic and P-C endocyclic bonds are found in the range1JPSe=−708 to −859 Hz; in this case, it is greater for the axial orientation of P=Se than for the equatorial orientation.

Mixed-ligand NiIII complexes with α-nitroso-β-naphthol, β-nitroso-α-naphthol,o-ethylxanthate, andN,N-diethyldithiocarbamate as ligands have been studied by ESR in liquid and frozen solutions. The degrees of symmetry distortion for the first coordination sphere of these complexes have been determined. It is shown that the transition from planar square NiIIL2 complexes to more stable octahedral NiIIIL2L′ and NiIIILL2′ complexes occursvia the radical addition mechanism. A method for trapping short-lived radicals is suggested on the basis of the complex formation scheme.

NMR parameters of the phosphorus-containing molecules are known to be affected by the phosphorus coordination number. Very little has been published about the theory proper and about the correlation characteristics of this influence. In order to obtain some information about this problem we have synthesized a number of phospholene and oxaphospholene derivatives containing phosphorus in various valent states.

1. Nonempirical calculations were carried out for the first time for substituted phosphorinanes. The conformer with an axial methyl group at the phosphorus atom predominates in 5-methyl-1,3,5-dioxaphosphorinanes as well as in the 5-oxa and 5-thio derivatives. The conformer with an equatorial methyl group at the phosphorus atoms and axial N-H bonds predominates in 5-thio-5-methyl-1,3,5-diazaphosphorinanes. 2. CNDO/2 and ab initio calculations for 5-methyl-1,3,5-dioxaphosphorinanes and its 5-oxo derviatives show the same trend for change in the energies of the favored conformers. 3. The conformer with an axial phenyl group oriented approximately in the symmetry plane of the molecule predominates in 5-phenyl-1,3,5-dioxaphosphorinanes and their 5-oxo derivatives, while the conformer with an equatorial phenyl group oriented approximately in the molecular symmetry plane is favored in 1,3,5-triphenyl-1,3,5-diazaphosphorinane.

The possibility is discussed of using tautomerism to determine the conformational free energies of ring substituents, and the free energy of steric interaction of the substituents in the individual stereoisomers of 1-phenyl-3-carbomethoxyphosphorinan-4-one and its derivatives.

1. It was established by the PMR method that a two-component conformational equilibrium with approximately equal proportions of the trans and gauche rotamers is realized in solutions of the investigated β-halogenophenetoles in carbon tetrachloride. 2. The procedures for the empirical calculation of the3JHH constants are identically effective for the investigated compounds. 3. The spectral parameterA=N+1/3¦L¦ varies with variation of the temperature and the dielectric constant of the medium.

1. The geometrical structures of the chloroanhydrides of certain alkylsulfonic acids have been determined by study of vibrational and PMR spectra and measurements of dipole moments and Kerr constants. Increasing the size of the substituent at theα-carbon atom reduces the content of the conformer with trans orientation of the substituent relative to the phosphoryl group. 2. Comparison of the spectra of Cl2P(O)Alk and the spectra of complexes of these compounds with SnCl4, undissociated under the conditions of the present experiments, showed that band doubling in the 1250–1300 cm−1 region could not be entirely due to the establishment of a conformational equilibrium. 3. Free-atom interaction gives a satisfactory explanation of the geometrical structures established here.

In the equilibrium of 5-phenyl-2,4,6-triisopropyl-1,3,5-dioxaphosphorinane and its derivatives the stereoisomer with nonequivalent protons on the carbon atoms attached to phosphorus is found predominantly in the twist form.

1. The PMR spectra and conformations of dimethyl orthophthalate and dimethyl isophthalate were studied. 2. A theoretical estimation was made of the constants in the equation relating the value of the chemical shift to the charge distribution. 3. The experimental distribution of charge in dimethyl orthophthalate, dimethyl isophthalate, and methyl benzoate was obtained and is in qualitative agreement with the theoretical data.

The condensation of trialkyl phosphites with malonic, cyanoacetic, and acetoacetic esters and excess paraform proceeds with the formation of 5-membered cyclic esters of phosphonic acids. The structure of the obtained products was proved by the PMR, NMR, and IR spectra.