Expectation and surprise in group 13 organometallics: molecular vs. polymeric aggregation of Me2Ga and Me2In norcamphor oximates

Abstract

Whereas (meso)-[(norcamphor oximato)GaMe₂]₂ (1) exhibits the dimeric M₂O₂N₂ motif favoured by organo group 13 metal oximates, the Me₂In derivative [{(meso)-[(norcamphor oximato)InMe₂]₂}₂]_∞ (2) aggregates distinctly different with the In atoms adopting coordination number (CN) = 5; compound 2 is the first oximato-based chain-like coordination polymer in group 13 organometallics; it comprises alternating M₂O₂N₂ and M₂O₂ ring dimers interconnected via two types of a fifth dative bond (O→In and N→In) to yield the new {M₄O₄N₄}_∞ motif; the calculated energetics of the heteroatom rings involved in 1 and 2 confirm the diverging aggregational behaviour of Ga and In.