Spin transition triggered by desorption of crystal solvents for a two-dimensional cobalt(ii) complex with hydrogen bonding

Abstract

[Co(5tpybNOH)₂](BPh₄)₂ (1; 5tpybNOH = 5,5′′-bis(N-tert-butyl hydroxylamino)-2,2′:6′,2′′-terpyridine) has a two-dimensional (2D) structure through a hydrogen bond between the NOH sites, as revealed by X-ray crystallography. The crystal solvents were desorbed above 300 K as shown by thermal analyses and powder X-ray crystallography. The removal of the crystal solvents allowed irreversible structural changes and a spin transition of the Co centre from S = 1/2 to 3/2.