Utilisation of a dianionic pentadentate ligand in group 13 chemistry

Using the pentadentate tetrapyrazolylpyridyl diborate (B2Pz4Py) ligand allowed for the isolation of overall seven group 13 complexes, which have been fully characterised and whose solid-state structures were obtained by single -crystal X-ray diffraction analysis. The aluminium chloride (1) and bromide (2) complexes as well as the gallium chloride (3) and iodide (4) complexes are accessible by deprotonation of the ligand precursors [B2Pz4LiPyH]2 with lithium hexamethyldisilazide and subsequent reaction with aluminium and gallium trihalides. Using indium(I) chloride instead gives rise to the indium(III) bis(trimethylsily)amide complex 5. Chloride abstraction from the aluminium(III) complex 1 using a combination of TlBArF24 and TlPF6 affords the related aluminium(III) fluoride complex 6 while using the gallium(III) complex 3 yields the dinuclear cationic PF2O2- bridged gallium(III) complex 7.