Department of Chemistry, Haverford College, 370 Lancaster Avenue, Haverford, Pennsylvania 19041, United States.
Inorg Chem. 2010 Dec 20;49(24):11261-3. doi: 10.1021/ic101612f. Epub 2010 Nov 23.
The novel ligand DIG(3)tren has three N',N''-diisopropylguanidinyl (DIG) moieties. We report on the structures of two cobalt complexes that show how an isopropylamino group from each DIG acts as a flap that can either close over the metal or rotate away from the metal to open up a site for auxiliary ligand binding. Two of the -NH(iPr) flaps are open in pink [Co(DIG(3)tren)(OAc)]OAc (1), and each of these flaps provides a hydrogen bond to stabilize acetate binding to trigonal bipyrimidal cobalt. The flaps are closed in blue [Co(DIG(3)tren)]BPh(4) (2), yielding a rare example of a trigonal (mono)pyramidal ML ion.
