Hydrothermal syntheses,crystal structures and thermal stability of two divalent metal phosphonates with a layered and a 3D structure

Two new divalent metal phosphonates, [Cu₂{CH₃C(OH)(PO₃)₂}(H₂O)₂]?·?0.5H₂O (1) and [NH₃CH₂CH₂NH₃][Zn₃{CH₃C(OH)(PO₃)₂}₂(H₂O)]?·?H₂O (2), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The structure of 1 comprises [Cu₃(hedp)₂]^2? layers connected by [CuO₄] units to form a 3D open-framework structure with a one-dimensional channel system along the b axis. In 2, the connections of alternately arranged [ZnO₄] tetrahedra, [ZnO₆] octahedra and [CPO₃] tetrahedra via vertex-sharing result in a 2D layered structure. The protonated ethylenediamine cations and water molecules are located between adjacent layers.     

Hydrothermal syntheses,crystal structures,and thermal stability of two new 3D open-framework metal(II) phosphonates

This article reports the hydrothermal synthesis and characterization of two new phosphonate compounds NaCo[O₃PCH(OH)CO₂] (1) and NaMn[O₃PCH(OH)CO₂] (2) based on 2-hydroxyphosphonoacetic acid (H₃L). Their structures have been characterized by single-crystal X-ray diffraction as well as with elemental analysis, infrared spectroscopy and thermogravimetric analysis. The two isomorphous compounds crystalline in the orthorhombic, space group Pbca: Crystal data for 1: a?=?10.1827(8)?Å, b?=?9.6673(8)?Å, c?=?10.7853(9)?Å, V?=?1061.70(15)?ų, Z?=?8, R ₁?=?0.0252, wR ₂?=?0.0577; Crystal data for 2: a?=?10.4309(18)?Å, b?=?9.7913(17)?Å, c?=?10.9012(19)?Å, V?=?1113.4(3)?ų, Z?=?8, R ₁?=?0.0194, wR ₂?=?0.0536. In the two compounds, the metal atoms are octahedrally coordinated; all oxygen atoms from the H₃L ligand are involved in coordination. The overall structures can be described as a 3D open framework with channels running along the a axis and the charge-compensating Na⁺ cations being located at the intersections of these channels.     

Reaction of trifluoromethylated β-alkoxyenones with tris(trimethylsilyl) phosphite: A temperature influence on regioselectivity

The interaction of tris(trimethylsilyl) phosphite (TMSO)₃P and E-trifluoromethyl-β-alkoxyenones CF₃C(O)CHCHOEt and CF₃C(O)CHC(OMe)Me yielded mixtures of E-1,2- and Z-1,4-adducts, CF₃C(OTMS)[P(O)(OTMS)₂]CCH(OAlk)R 2 and CF₃(OTMS)CCHCR(OAlk)[P(O)(OTMS)₂] 3 where R and Alk = H and Me, or both Me. Conversion of these 1,2-adducts to 1,4-isomers was effected by increased temperature or by exposure to more tris(trimethylsilyl) phosphite. Acid hydrolysis of 2b (R and Alk = Me) gave ketophosphonic acid CF₃C(OH)[P(O)(OH)₂]CH₂COMe in 88% yield, whereas hydrolysis of 2a (R = H and Alk = Et) with KOH in methanol gave CF₃C(OH)[P(O)(OK)₂]CHCHOEt in 37% yield. Acid hydrolysis of 3a (R = H and Alk = Et) and 3b (R and Alk = Me) gave phosphonic acid CF₃C(OH)₂CHCHP(O)(OH)₂ in 82% yield and trifluoromethylated 1,2λ⁵σ⁴-oxaphosphol-3-en.     

Synthesis of new polyhalogenoalkyl-containing phosphonates with an enaminone core and their use in the preparation of fluorinated heterocycles

A number of polyhalogenoalkyl-containing phosphonates with an enaminone core were synthesized from readily available β-alkoxyvinyl polyhalogenoalkyl ketones by successive bromination, amination, and Arbuzov reaction. The new phosphonates were used for the syntheses of five- and six-membered heterocycles bearing both trifluoromethyl and methylenephosphonate groups.     

The effects of cetylpyridinium bromide micelles on the kinetics of alkaline hydrolysis of alkylp-nitrophenyl chloromethylphosphonate

Study of the kinetics of alkaline hydrolysis of alkylp-nitrophenyl chloromethylphosphonates in micellar solutions of cetylpyridinium bromide showed that the observed rate constant depends on the hydrophobicity of the substrates. A minor increase in the length of the alkyl chain in the substituent increases the catalytic effect in the series Et<Bu<C₆H₁₃. Further increase in the substrate hydrophobicity results in a decrease in the bimolecular rate constant in the micellar phase. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 279–282, February, 1999.     

On phosphorus chemical shift anisotropy in metal (IV) phosphates and phosphonates: A 31P NMR experimental study

The phosphorus chemical shift anisotropies, ³¹PΔcs, and asymmetry parameters η were measured by the ³¹P{¹H} NMR experiments in static and low-frequency spinning samples of the zirconium phosphates and phosphonates and also in the mixed Zr (IV)/Sn (IV) phosphate/phosphonate material. The data obtained have shown a 111 connectivity in the HPO₄ and PO₃ groups, which does not change at modification and intercalation of the materials. The ³¹PΔcs values of the phosphonate groups (43–49 ppm) significantly surpass the values characterizing the HPO₄ groups (23–37 ppm). The ³¹P Δcs values obtained for the metal (IV) phosphates were discussed in terms of P-O distances. The ³¹P chemical shift anisotropy parameters can help at elucidation of local structures in phosphate and phosphonate materials.