A New Approach to the Synthesis of Nanocrystalline Cobalt Boride in the Course of the Thermal Decomposition of Cobalt Complexes [Co(DMF)₆]²⁺ with Boron Cluster Anions.

ABSTRACT: In the course of the study, nanocrystalline cobalt monoboride was prepared by thermal decomposition of precursors [Co(DMF)₆][An], where [An] = [B₁₂H₁₂]^2- (1), [trans-B₂₀H₁₈]^2- (2) or [B₁₀Cl₁₀]^2- (3) in an argon atmosphere. Three new salt-like compounds 1-3 were prepared when Co(NO₃)₂ was allowed to react with (Et₃NH)₂[An]. Compound 1 is new; the structures of compounds 2 and 3 have been previously reported. Samples 1-3 were annealed at 900 °C in argon to form samples 1a-3a, which were characterized by single crystal XRD for 1 and powder XRD for 1-3. Powder XRD on the products showed the formation of BN and CoB for 1a in a 1:1 ratio; 2a gave a higher CoB:BN ratio but an overall decreased crystallinity. For 3a, only CoB was found. IR spectra of samples 1a-3a as well as X-ray spectral fluorescence analysis for 3a confirmed these results. The nanoparticular character of the decomposition products 1a-3a was shown using TEM; quite small particle sizes of about 10-15 nm and a quite normal size distribution were found for 1a and 2a, while the decomposition of 3 gave large particles with 200-350 nm and a broad distribution.

SUBMITTER: Malinina EA 

PROVIDER: S-EPMC9823307 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature