Tracking the Formation of a Series of Con (n=2, 6, 8) Clusters from Linear Co3 Precursor Clusters by Optimizing the Reaction Conditions.

Abstract: Starting from two low‐nuclearity linear synthesised Co3 precursors {[Co3L’2(H2O)6]⋅2NO3⋅4H2O} (1) and {[Co3L’2(H2O)6]⋅2NO3} (2) (here, H2L=bis((pyridine‐2‐yl)‐1,2,4‐triazol‐5‐yl)methane, H2L’=bis((pyridine‐2‐yl)‐1,2,4‐triazol −5‐yl)ketone), a series of Co3‐substituted complexes and two higher‐nuclearity Co(II) clusters {[Co8L6(μ3‐O)2]⋅5H2O} (3) and [Co6L4(MeOH)6(OAc)4] (4) have been synthesized and characterized through regulating solvent, anion, and pH conditions. For tracking the formation of higher‐nuclearity clusters, the single‐crystal X‐ray diffraction (SXRD), powder X‐ray diffraction (PXRD) and electrospray ionization mass spectrometry (ESI‐MS) analyses for the solid‐liquid phase at different times, revealed that [Co2L2] and [Co2L] species can combine together to form [Co4L3] species, which bridged each other through two [μ3‐O]2− ions in strong alkaline conditions, to get [Co8(μ3‐O)2L6] units in 3; which or combined [Co2L] species in weak alkaline conditions, to get [Co6L4] species in 4. And the antiferromagnetic coupling in 1–4 has been briefly investigated. [ABSTRACT FROM AUTHOR]