Thiocyanate coordination mode

thiocyanate can coordinate through nitrogen, sulfur, or both ends, and can bridge several metal centres. A linkage label specifies donor atoms, whereas the bridging index ${\mu }_n$ specifies the number of connected metals. A short C–N bond and long C–S bond favour an $\mathrm{N}\equiv \mathrm{C}-{\mathrm{S}}^{-}$ description; greater C–S and smaller C–N bond orders give more ${}^{-}\mathrm{N}=\mathrm{C}=\mathrm{S}$ character. Internal distances alone need not determine how many metals are attached.

A ${\mu }_3$ thiocyanate connecting three metal centres. In layered first-row divalent metal thiocyanates, its nitrogen coordinates one metal and its sulfur coordinates two others, giving an $\mathrm{M}{\mathrm{N}}_2{\mathrm{S}}_4$ octahedral coordination environment.