The structure of four thallium tris(1H-pyrazol-1-yl)hydroborates in the solid state by X-ray crystallography and in solution by NMR and DFT-GIAO calculations

•New scorpionates are 333 derivatives due to equilibration between other isomers.•The four new structures correspond to racemates with Z′ = 1/3, 1/2 and 1.•The new structures have been compared with those reported in the CSD.•Steric effects and anomalies on N-Tl-N angles and Tl-N bond lengths were discussed.•Literature chemical shifts have been compared with GIAO/B3LYP calculated ones.