Heterocyclic nitrogen donor complexes of aluminium, gallium and indium with weakly coordinating triflate anions

M(OTf)(3)(terpy)], whilst with 2,2' -bipyridyl (bipy) and 1,10-phenanthroline (phen) the products isolated were cis-[M(OTf)(2)(bipy)(2)]OTf (M = Al, Ga), cis-[In(OTf)(H2O)(bipy)(2)][OTf](2), cis-[Al(OTf)(2)(phen)(2)][OTf] and [In (H2O)(2)(phen)(2)][OTf](3). The X-ray structures of mer-[In(OTf)3(terpy)], cis-[Ga(OTf)2(bipy)(2)][OTf] and cis-[In (OTf)(H2O)(bipy)(2)][OTf](2), along with those of the minor by-products, cis-[Ga(H2O)(2)(phen)(2)][OTf](3) and the hydroxide-bridged dimer [{In(terpy)(OTf)}(2)(mu-OH)(2)][OTf](2) were also obtained, all of which show sixcoordination at the metal ion. While the anhydrous complexes show.1-coordination of the triflate to the metal ion, those species with coordinated water (or hydroxide) ligands show significant H-bonding interactions between the water H atoms and the O-atoms from triflate anions. The complexes were characterised by IR, H-1, C-13{H-1}, F-19{H-1} and 27Al NMR spectroscopy, together with microanalysis. The F-19{H-1} NMR spectra suggest that in MeCN solution the coordinated triflates are displaced by the solvent, but the original complexes appear to reform on removal of the MeCN in vacuo.

Automated summary

The study found that metal complexes formed in the experiment exhibited different coordination states and varied ligand substitution patterns.