Solid state and solution study of some phosphoramidate derivatives containing the P(O)NHC(O) bifunctional group: Crystal structures of CCl2HC(O)NHP(O)(NCH3(CH2C6H5))2, p-ClC6H4C(O)NHP(O)(NCH3(CH2C6H5))2, CCl2HC(O)NHP(O)(N(CH2C6H5)2)2 and p-BrC6H4C(O)NHP(O)(N(CH2C6H5)2)2

Synthetic methods for several novel phosphoramidate compounds containing the P(O)NHC(O) bifunctional group were developed. These compounds with the general formula R₁C(O)NHP(O)(N(R₂)(CH₂C₆H₅))₂, where R₁ = CCl₂H, p-ClC₆H₄, p-BrC₆H₄, o-FC₆H₄ and R₂ = hydrogen, methyl, benzyl, were characterized by several spectroscopic methods and analytical techniques. The effects of phosphorus substituents on the rotation rate around the P–N_amine bond were also investigated. ¹H NMR study of the synthesized compounds demonstrated that the presence of bulky groups attached to the phosphorus center and electron withdrawing groups in the amide moiety lead to large chemical-shift non-equivalence (Δδ_H) of diastereotopic methylene protons. The crystal structures of CCl₂HC(O)NHP(O)(NCH₃(CH₂C₆H₅))₂, p-ClC₆H₄C(O)NHP(O)(NCH₃(CH₂C₆H₅))₂, CCl₂HC(O)NHP(O)(N(CH₂C₆H₅)₂)₂ and p-BrC₆H₄C(O)NHP(O)(N(CH₂C₆H₅)₂)₂ were determined by X-ray crystallography using single crystals. The coordination around the phosphorus center in these compounds is best described as distorted tetrahedral and the P(O) and C(O) groups are anti with respect to each other. In the compound Br-C₆H₄C(O)NHP(O)(N(CH₂C₆H₅)₂)₂ (with two independent molecules in the unit cell), two conformers are connected to each other via two different N–H?O hydrogen bonds forming a non-centrosymmetric dimer. In the crystalline lattice of other compounds, the molecules form centrosymmetric dimers via pairs of same N–H?O hydrogen bonds. The structure of CCl₂HC(O)NHP(O)(N(CH₂C₆H₅)₂)₂ reveals an unusual intramolecular interaction between the oxygen of CO group and amine nitrogen.     

Syntheses and structural study of trinuclear iron acetates [Fe3O(CH3COO)6(H2O)3]Cl· 6H2O and [Fe3O(CH3COO)6(H2O)3] [FeCl4]· 2CH3COOH

The structure of two trinuclear iron acetates [Fe₃O(CH₃COO)₆(H₂O)₃]Cl· 6H₂O (I) and [Fe₃O(CH₃COO)₆(H_2O)₃][FeCl₄] · 2CH₃COOH (II) was determined by X-ray diffraction analysis. Crystals I and II are ionic and belong to the orthorhombic system with parameters a = 13.704(3), b = 23.332(5), c = 9.167(2) Å, R = 0.0355, space goup P2₁2₁2 for I and a = 10.145(4), b = 15.323(6), c = 22.999(8) Å, R = 0.0752, space group Pbc2₁ for II. The complex cation [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ has a μ₃-O-bridged structure typical for trinuclear iron (III) compounds. As shown by Mössbauer spectroscopy, the iron(III) ions are in the high-spin state. In trinuclear cations, antiferromagnetic exchange interaction takes place between the Fe(III) ions with the exchange parameter J = -26.69 cm^?1 for II (Heisenberg-Dirac-Van Vleck model for D_3h, symmetry).     

Synthesis and crystal structure of bis (2-phenylethylammonium) dihydrogendimphosphate, [C6H5(CH2)2NH3]2H2P2O7

Chemical preparation, crystal structure and infrared absorption spectra are given for a new organic cation dihydrogendiphosphate. The new synthesized compound [C₆H₅(CH₂)₂NH₃]₂H₂P₂O₇; crystallized in the monoclinic system (P2_1/c space group) with Z = 4 and with the following unit-cell dimensions: a = 19.006(3); b = 10.718(2), c = 10.996(3) Å and β = 98.99(2) °. Its crystal structure was determined and refined down to R = 0,056 by using 3278 independent reflections. As in all atomic arrangements including acidic diphosphate groups; we can observe the formation of an infinite network of anions connected by strong H-bonds.     

Vaporization of Molecular Strontium and Barium β-Diketonates [Sr(15C5)(C5O2F6H)2] and [Ba(18C6)(C5O2F6H)2]. Structure-Thermochemical Approach

Vaporization of the barium molecular complex [Ba(18C6)(C₅O₂F₆H)₂] and the newly prepared strontium complex [Sr(15C5)(C₅O₂F₆H)₂] was studied using a semiempirical structure-thermochemical approach. The studies of intermolecular steric shielding of individual atoms and analysis of the possible intermolecular contacts in these complexes made it possible to identify the atoms and atom groups with significant contributions to the vaporization enthalpy. The hypothetical vaporization enthalpies were calculated by summing the contributions of groups. The melting and sublimation enthalpies were determined experimentally.     

Inorganic coordination polymers. XVIII. Observations on brittle and flexible films of {Cr[OP(CH3)(C6H5)O]2[OP(C8H17)2O]}x

Films of {Cr[OP(CH₃)(CH₆H₅)O]₂[OP(C₈H₁₇)₂O]}_x, formed during the reaction of {Cr(OH)[OP(CH₃)(C₆H₅)O]₂}_x with dioctylphosphinic acid, are either brittle or flexible depending on the details of the preparation of the chromium(III) bisphosphinate precursor. Both kinds of film appear to contain mainly triple-bridged chains. Differing degrees of randomness in distribution of the two kinds of phosphinate bridges and, hence, of the internally plasticizing octyl groups along the chain account for the observed differences in flexibility, x-ray diffraction patterns, and birefringence. The observed intrinsic viscosities of 9–18 dl/g indicate that these trisphosphinates form microgels rather than true solutions. The thermal degradation of these films proceeds by the oxidation and cleavage of the organic side groups. Addition of antioxidants to the flexible films significantly increases the longevity of their flexibility at 200°C.     

New rac‐XP(O)(OC6H5)(NHC6H4‐p‐CH3) [X = N(CH3)(cyclo‐C6H11) and NH(C3H5)] and rac‐(C6H5CH2NH)P(O)(OC6H5)(NH‐cyclo‐C6H11) mixed‐amide phosphinates

The mixed‐amide phosphinates, rac‐phenyl (N‐methylcyclohexylamido)(p‐tolylamido)phosphinate, C₂₀H₂₇N₂O₂P, (I), and rac‐phenyl (allylamido)(p‐tolylamido)phosphinate, C₁₆H₁₉N₂O₂P, (II), were synthesized from the racemic phosphorus–chlorine compound (R,S)‐(Cl)P(O)(OC₆H₅)(NHC₆H₄‐p‐CH₃). Furthermore, the phosphorus–chlorine compound ClP(O)(OC₆H₅)(NH‐cyclo‐C₆H₁₁) was synthesized for the first time and used for the synthesis of rac‐phenyl (benzylamido)(cyclohexylamido)phosphinate, C₁₉H₂₅N₂O₂P, (III). The strategies for the synthesis of racemic mixed‐amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N¹)P(=O)(O)(N²) environment. In (I) and (II), the p‐tolylamido substituent makes a longer P—N bond than those involving the N‐methylcyclohexylamido and allylamido substituents. In (III), the differences between the P—N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with the N—H unit in hydrogen‐bonding interactions, viz. an N—H...O=P hydrogen bond for (I) and (N—H)(N—H)...O=P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).