M. P. Pasechnik

New type of 2-alkyl-substituted 1,8-naphthyridine systems containing a phosphoryl group in the side chain

First organophosphorus derivatives of 2-alkyl-and 2,3-alkylene-substituted 1,8-naphthyridines were synthesized by the Friedländer reaction starting from 2-aminonicotinaldehyde and diphenylphosphoryl(cyclo)alkanones, respectively.

Amino-substitutedgem-diphosphonic acids: Dissociation mechanism and the structure of species in aqueous solutions

The mechanism of dissociation of amino-substitutedgem-diphosphonic acids R2N(CH2)nCR(PO3H2)2 with different lengths of the alkylidene chain and different substituents at the N atom was studied by vibrational (IR, Raman) and NMR (1H,14N,31P) spectroscopy using data of conformational analysis (molecular mechanical) data. The important role of intramolecular H-bonds and cyclic solvates for the stabilization of various conformations and tautomeric forms of ions was demonstrated. The spectral data that allow one to consider thegem-diphosphonate group as a single acidic center were found.

Synthesis and complexing properties of phosphoryl-substituted salicylaldimines

Starting from meta and ortho isomers of (diphenylphosphorylmethyl)anilines 2a,b, procedures were developed for the synthesis of new phosphoryl-substituted Schiff bases 3a,b serving as tridentate ligands. In alcoholic solutions, ligands 3a,b form complexes of different composition with praseodymium and neodymium nitrates. Only the M(L)2(NO3)3 complexes crystallized from solution regardless of the reactant ratio. According to the X-ray diffraction study and IR spectroscopy, one of the ligands in the complexes with ortho ligand 3b is coordinated in a bidentate fashion via the oxygen atom of the P=O group and the phenoxy oxygen atom, whereas the second ligand molecule forms a coordination bond with metal only via the phosphoryl oxygen atom. In the Pr(3a)2(NO3)3 complexes, both meta ligands 3a are involved in thebidentate O,O-coordination.

Complexation of (N, N-diethylthiocarbamoylmethyl) diphenylphosphine sulfide with silver nitrate. The structure of the [Ag{Ph2P(S)CH2C(S)NEt2}2]NO3 complex

Abstract(N, N-Diethylthiocarbamoylmethyl)diphenylphosphine sulfide, Ph2P(S)CH2C(S)NEt2, forms a distorted tetragonal bisligand complex [AgL2]NO3 with Ag+. The stability constant of the complex in acetonitrile was estimated by spectrophotometry (logK=3.7).

Complexation of (carbamoylmethyl)diphenylphosphine sulfide with silver nitrate. The structure of the polymeric complex [Ag2{Ph2P(S)CH2C(O)NH2}2(NO3)2] n

The reaction of (carbamoylmethyl)diphenylphosphine sulfide with AgNO3 yields the polymeric complex [Ag2{Ph2P(S)CH2C(O)NH2}2(NO3)2]n. Its structure was established by X-ray diffraction analysis. The coordination environments about both Ag+ cations are formed by five donor atoms, two of which are bonded to the metal atom substantially more weakly than the remaining three atoms. The compositions of the coordination polyhedra are different: ({AgSO′(C)O(N)O2(N′)} and {AgS′ SO(C)O2(N)}). The coordinated ligands differ in their functions: one ligand chelates the metal cation and its sulfur atom is additionally bonded to the second cation, while the second ligand acts as a bridge between the two different cations. The structure of the complex and the character of the interaction between the ligand and AgNO3 are substantially affected by the network of hydrogen bonds.

Amino-substituted gem-diphosphonic acids: structures of complexes with divalent metal cations in aqueous solutions

A comparative study of complexation of acids R2N(CH2)nCR(PO3H2)2 (R = H or Me; R = OH or H; n = 1 or 2) with the Ca2+, Mg2+, Zn2+, and Cu2+ cations in aqueous solutions was carried out by vibrational (IR and Raman) and electronic spectroscopy using the data of ESR spectroscopy and conformational analysis (molecular mechanics). The MOPCPO chelate ring is formed in all ML and MHL complexes. The involvement of the N atom in coordination was found only in the Cu2+ complexes and is determined by the structure of the ligand. The relationship between the stability constants and the structures of the complexes in aqueous solutions is analyzed.

The complexation of (N,N-diethylcarbamoylmethyl)diphenylphosphine sulfide with silver nitrate

The crystalline complex [Ag(L1)NO3]2 (A) was isolated by the interaction of (N,N-diethylcaibamoylmethyl)diphenylphosphine sulfide Ph2P(S)CH2C(O)NEt2 (L1) with AgNO3 in different solvents at the ratios of metal:ligand = 1∶1 and 1∶2. According to the X-ray data, complexA is a center-symmetric dimer with bridge sulfur atoms. The cations of the metal are in a tetrahedral environment formed by two S atoms and the O atoms of CO and NO3 groups. The interaction ofL1 with AgNO3 was studied in solution by IR spectroscopy, and the structures of the complexes formed are discussed.

Intramolecular hydrogen bonds in the copper(II) complex withcis,cis-1,3,5-tri[2-(diphenylphosphoryl)ethylamino]cyclohexane

The formation of intramolecular hydrogen bonds in the complex ofcis,cis-1,3,5-tri[2-(diphenylphosphoryl)cthylamino]cyclohexanc with the Cu2+ cation in different solvents has been studied by IR spectroscopy. Conformational analysis of the complex has been performed.

Spectral study of complexation ofcis,cis-1,3,5-tri[2-(diphenylphosphinyl)ethylamino]cyclohexane with copper(ii) and cobalt(ii) ions

The complexation ofcis,cis-1,3,5-tri[2-(diphenylphosphinyl)ethylamino]cyclohexane (L1) with Cu2+ and Co2+ cations has been studied in different solvents by means of UV-Vis, ESR, and IR spectroscopy. It has been shown that in the CuL1 complex the metal ion is pentacoordinated by three nitrogen atoms and two phosphinyl groups of the ligand and has a tetragonal-pyramidal environment. The conformation of the coordination polyhedron for the CuL1 complex depends on the solvent. In the CoL1 complex, as well as in the CoL2 complex, where L2 is 1,4,7-tris(2-diphenylphosphinylethyl)-1,4,7-triazacyclononane, the Co2+ ion has an octahedral environment and is bound to all donor atoms of the ligands.