Zirconium phenylphosphonate-anchored methyltrioxorhenium as novel heterogeneous catalyst for epoxidation of cyclohexene

Phosphonate/quaternary ammonium copolymers as high-efficiency antibacterial coating for metallic substrates

Designing a coating material with efficient bactericidal property to cope with bacterial associated infections is highly desirable for metallic implants and devices. Here, we report phosphonate/quaternary ammonium copolymers, p(DEMMP-co-TMAEMA), as the new type of metal anchorable high-efficiency antibacterial coating. Seven p(DEMMP-co-TMAEMA) polymers with varied cationic components were precisely prepared via random radical polymerization. Copolymers were constructed on titanium alloy (TC4) substrates based on strong covalent bonding between the phosphonate group and metallic substrates through a one-step process as evidenced by XPS and water contact angle tests. A robust relationship between the composition of the copolymers and the bactericidal ability endowed to TC4 substrates was established. Results showed that the copolymer, with the pDEMMP content even as low as 6.3%, was able to anchor onto TC4 substrates. With the increase of cationic pTMAEMA content from 4.0 to 93.7% in the coating copolymer, the bactericidal ability endowed to the TC4 substrates was steadily increased from 39.4 to 98.8% for S. aureus and from 70.0 to 99.4% for E. coli after 8 h's of contacting. All p(DEMMP-co-TMAEMA) coating on TC4 substrates showed limited cytotoxicity to C2C12 cells. Notably, the phosphonate/quaternary amine copolymers can be easily constructed on diverse biomedical metals such as titanium (Ti), stainless steel (SS), and Ni/Cr alloys with significantly increased antibacterial performance, demonstrating the potency of the copolymer as the general high-efficiency antibacterial coating for diverse bio-metals.

Octanuclear nickel phosphonate core forming extended and molecular structures

Three new nickel(ii) phosphonate complexes {[Na₂Ni₈(L)₆]·nSolv}_m (L = SAA³⁻ (1), BSAA³⁻ (2), NAA³⁻ (3); Solv = H₂O, MeOH; m = ∞ (1, 2), 1 (3)) possessing a new octanuclear {Ni₈} phosphonate core were obtained and studied in detail.

Combined solid-state NMR, FT-IR and computational studies on layered and porous materials

Understanding the structure-property relationship of solids is of utmost relevance for efficient chemical processes and technological applications in industries. This contribution reviews the concept of coupling three well-known characterization techniques (solid-state NMR, FT-IR and computational methods) for the study of solid state materials which possess 2D and 3D architectures and discusses the way it will benefit the scientific communities. It highlights the most fundamental and applied aspects of the proactive combined approach strategies to gather information at a molecular level. The integrated approach involving multiple spectroscopic and computational methods allows achieving an in-depth understanding of the surface, interfacial and confined space processes that are beneficial for the establishment of structure-property relationships. The role of ssNMR/FT-IR spectroscopic properties of probe molecules in monitoring the strength and distribution of catalytic active sites and their accessibility at the porous/layered surface is discussed. Both experimental and theoretical aspects will be considered by reporting relevant examples. This review also identifies and discusses the progress, challenges and future prospects in the field of synthesis and applications of layered and porous solids.

New molecular heptanuclear cobalt phosphonates: synthesis, structures and magnetic properties

Synthesis, structures and magnetic properties (strong anisotropy, ferromagnetic and antiferromagnetic interactions) of novel {Co₇} homoleptic molecular cobalt phosphonates with a similar structure motif are described.

Hexanuclear iron(iii) α-aminophosphonate: synthesis, structure, and magnetic properties of a molecular wheel

A new hexanuclear molecular iron phosphonate complex, [Fe₆(HAIPA)₁₂(OH)₆]·nH₂O (1·nH₂O) (H₂AIPA = NH₂(CH₃)₂CP(O)(OH)₂, (2-aminopropan-2-yl)phosphonic acid), was synthesized from Fe²⁺ and Fe³⁺ salts in water by interaction with the ligand sodium salt.

Non-isothermal Crystallization, Thermal Stability, and Mechanical Performance of Poly(L-lactic acid)/Barium Phenylphosphonate Systems

The introduction of a nucleating agent in semi-crystalline polymers is a frequently utilized way to improve the crystallization performance, and the use of a nucleating agent has a very great effect on the performance of the polymer in other areas including thermal stability and mechanical properties. In this investigation, barium phenylphosphonate (BaP) was prepared as a crystallization accelerator for Poly(L-lactic acid) (PLLA), and the non-isothermal crystallization behavior, thermal stability, and mechanical properties of PLLA modified by BaP were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and electronic tensile testing. Non-isothermal crystallization analysis showed that the BaP could significantly accelerate the crystallization of PLLA, and the non-isothermal crystallization peak shifted to a higher temperature with increasing concentration of BaP, however, the corresponding crystallization peak became wider. XRD results after non-isothermal crystallization confirmed the non-isothermal crystallization DSC results. Additionally, the addition of BaP did not change the crystal form of PLLA. A comparative study on thermal stability indicated that BaP decreased the onset decomposition temperature of PLLA, resulting from the formation of more tiny and imperfect crystals. Whereas the influence of BaP on the thermal decomposition profile of PLLA was negligible. In terms of mechanical properties, the tensile strength and elastic modulus of PLLA/BaP increased compared to the virgin PLLA, unfortunately, the elongation at break decreased.

A Study on Physical Performance for Poly(L-lactic acid) in Addition to Layered Strontium Phenylphosphonate

The organic-inorganic hybrid layered strontium phenylphosphonate (SrP) was synthesized by using strontium chloride and phenylphosphinic acid. And the influence of layered SrP on the crystallization behavior and thermal stability of poly(L-lactic acid) (PLLA) was investigated through DSC, XRD, and TGA. Both DSC and XRD results demonstrated that layered SrP had the powerful accelerated ability for PLLA crystallization, and in the range of studied concentration, 0.7 wt%–1 wt% is the optimum concentration range to achieve rapid crystallization of PLLA. Meantime, as a result, the increase of cooling rate in nonisothermal crystallization procedure seriously affected the crystallization accelerated efficiency of SrP. Thermal stability measurement showed that layered SrP could cause the onset decomposition temperature of PLLA to decrease, but the thermal decomposition behavior of PLLA hardly depended on the SrP concentration.

Multidimensional (0D to 3D) Alkaline-Earth Metal Diphosphonates: Synthesis, Structural Diversity, and Luminescence Properties

A series of new alkaline-earth metal diphosphonate frameworks were successfully synthesized under solvothermal reaction condition (160 °C, 3 d) using 1-hydroxyethylidene-1,1-diphosphonic acid (CH3C(OH)(H2PO3)2, hedpH4) as a diphosphonate building block and Mg(II), Ca(II), Sr(II), or Ba(II) ions as alkaline-earth metal ion centers in water, dimethylformamide, and/or EtOH media. These diphosphonate frameworks, (H2NMe2)4[Mg(hedpH2)3]·3H2O (1), (H2NMe2)2[Ca(hedpH2)2] (2), (H2NMe2)2[Sr3(hedpH2)4(H2O)2] (3), and [Ba3(hedpH2)3]·H2O (4) exhibited interesting structural topologies (zero-, one-, two-, and three-dimensional (0D, 1D, 2D, and 3D, respectively)), which are mainly depending on the metal ions and the solvents used in the synthesis. The single-crystal analysis of these newly synthesized compounds revealed that 1 was a 0D molecule, 2 has 1D chains, 3 was a 3D molecule, and 4 has 2D layers. All compounds were further characterized using thermogravimetric analysis, solid-state (31)P NMR, powder X-ray diffraction analysis, UV-vis spectra, and infrared spectroscopy. In addition, Eu(III)- and Tb(III)-doped compounds of 1-4, namely, (H2NMe2)4[Ln(x)Mg(1-x)(hedpH2)2(hedpH(2-x))]·3H2O (1Ln), (H2NMe2)2[Ln(x)Ca(1-x)(hedpH2)(hedpH(2-x))] (2Ln), (H2NMe2)2[Ln(x)Sr(3-x)(hedpH2)3(hedpH(2-x))(H2O)2] (3Ln), and [Ln(x)Ba(3-x)(hedpH2)2(hedpH(2-x))]·H2O (4Ln) (where Ln = Eu, Tb), were synthesized, and their photoluminescence properties were studied. The quantum yield of 1Eu-4Eu was measured with reference to commercial red phosphor, Y2O2S:Eu(3+) (YE), and the quantum yield of terbium-doped compounds 1Tb-4Tb was measured with reference to commercial green-emitting phosphor CeMgAl10O17:Tb(3+). Interestingly, the compound 2Eu showed very high quantum yield of 92.2%, which is better than that of the reference commercial red phosphor, YE (90.8%).