Synthesis and DFT investigation of new bismuth-containing MAX phases

The M(n + 1)AX(n) phases (M = early transition metal; A = group A element and X = C and N) are materials exhibiting many important metallic and ceramic properties. In the present study powder processing experiments and density functional theory calculations are employed in parallel to examine formation of Zr(2)(Al(1−x)Bi(x))C (0 ≤ x ≤ 1). Here we show that Zr(2)(Al(1−x)Bi(x))C, and particularly with x ≈ 0.58, can be formed from powders even though the end members Zr(2)BiC and Zr(2)AlC seemingly cannot. This represents a significant extension of the MAX phase family, as this is the first report of a bismuth-based MAX phase

Antimicrobial Activity and Essential Oil Composition of a New T. argyrophyllum (C. Koch) Tvzel var. argyrophyllum Chemotype

WOS: 000278084700005PubMed ID: 20484836Water-distilled essential oils from flowers and stems of Tanacetum argyrophyllum var. argyrophyllum from Turkey were analyzed by GC and GC/MS. The flower oil of T argyrophyllum var. argyrophyllum was characterized with camphor 29.7%, borneol 12.0%, 1,8-cineole 8.4% and bornyl acetate 6.1%. Stem oil was characterized with camphor 26.6%, 1,8-cineole 17.5%, and borneol 15.0%. Our previous research and literature on the essential oil of this plant reported oils with high thujone content unlike the present study. Antibacterial activity of the oils were evaluated for five Gram-positive and five Gram-negative bacteria by using a broth microdilution assay. The highest inhibitory activity was observed against Bacillus cercus for stem oil (125 mu g/mL) when compared with positive control chloramphenicol it showed the same inhibition potency. However, the same oil showed lower inhibitory activity against B. subtilis. The flower oil did not show significant activity against the tested microorganisms. DPPH radical scavenging activity of the T argyrophyllum var. argyrophyllum oil was investigated at 15 and 10 mg/mL concentrations. However, the oils did not show any significant activity when compared to positive control alpha-tocopherol. Both of the oils showed toxicity to Vibrio fischeri in the TLC-bioluminescence assay.Scientific and Technological Research Council of Turkey [TUBITAK- TBAG 104T306]; Anadolu University [BAP-060301]This research was supported by The Scientific and Technological Research Council of Turkey (TUBITAK- TBAG 104T306). Antibacterial activity, Vibrio fischeri toxicity evaluations are supported by Anadolu University Research Funding (Project no: BAP-060301). Authors are grateful to Ms. Gamze Cayirdere for antimicrobial evaluations