Exploring pseudohalide substitution in α-cobalt-based layered hydroxides

Abstract

While halide substitution has significantly influenced the electrical and magnetic properties of α-layered hydroxide frameworks (α-LH), the incorporation of pseudohalides remains limited. In this study, we present a detailed investigation of two-dimensional cobalt-layered hydroxides modified with tricyanomethanide (C₄N₃⁻) and thiocyanate (SCN⁻) pseudohalides, synthesized via a simple epoxide route at room temperature. Pseudohalide incorporation induces subtle structural modifications relative to pristine cobalt-chloride layered hydroxide (α-Co-Cl), including changes in interlayer spacing and the confirmation of a distinct bridging coordination in thiocyanate-modified samples. Magnetic measurements reveal broadly similar behavior across all samples, with the thiocyanate compound reflecting a structural difference that affects its magnetic response. These findings underscore the influence of pseudohalides on the structure and the effect of pseudohalide substitution on the magnetic response of α-cobalt-based layered hydroxides, demonstrating the chemical and structural versatility of Simonkolleite-like hydroxides as tunable materials for designing novel hybrids with dynamic structures.