Synthesis and Characterization of Co0.8-x Nix Zn0.2 Fe2O4 Ferrites by Williamson–Hall and Size–Strain Plot Methods

The Co-Zn ferrite (x=0.00) and Nickel doped Co-Zn ferrites (x=0.24) was synthesized by low cost solid state reaction method and characterized by XRD technique. The X-ray diffraction results for the samples showed the formation of single phase cubic spinel. The lattice constant and particle size for Co-Zn ferrite(x=0.00) is found to be 8.3465 Å and 26.72 nm and for Nickel doped (x=0.24) it is 8.3440 Å and 24.21nm. Micro strain (ε), Dislocation density(ρD), Hopping lengths (LA and LB), Bond lengths (A - O and B-O), Ionic radii (rA and rB), Texture coefficients (Thkl) and Standard deviation (σ) are also reported. The particle size is confirmed by scanning electron microscope (SEM). The Williamson-Hall plot and stress-strain plot also employed to understand the mechanical properties of materials

Reactivity of Alkynes with M-C Bonds generated through C-H Activation

Transition metal-catalyzed C-H activation and functionalization with various coupling partners is a well-explored area of research. Among the various coupling partners used, alkynes occupy a prominent position on account of their varied reactivity. Due to their low steric demand and a high degree of unsaturation they effectively overlap with metal d-orbitals and form multiple bond-forming events giving rise to complex skeletons that are otherwise challenging to synthesize. This makes alkyne one of the most successful coupling partners in terms of the number of useful transformations. Remarkably, by changing the reaction conditions and transition-metals from 5d to 3d, the behaviors of alkynes also change. Despite enormous explorations with alkynes, there are still a lot more possible ways by which alkynes can be made to react with M-C bonds generated through C-H activation. Especially with the development of new high and low valent first-row metal catalysts, there is plenty of scope for this chemistry to evolve as one of the most explored areas of research in coming years. Therefore, a review on this topic is both timely and useful for synthetic chemists who are working in this area. In this review, we have highlighted the diverse reactivity of alkynes with various transition metals and their applications along with some of our thoughts on future prospects