Thienylmercury(II) polypyrazolylborates (Tp∗ = hydridotris-(3,5-dimethylpyrazol-1-yl)borato, TpMe = hydridotris(3-methylpyrazol-lyl)borato, pzTp = tetrakis(pyrazol-I-yl)borato) have been synthesised and characterised through elemental analysis, electrical conductivity, molecular weights, and spectral measurements (IR in the solid state and 1H, 13C, 199Hg NMR in solution). The structure of [(5-Me)T