Girolamis early work focused on the synthesis of transition metal compounds with metal-hydrogen and metal-carbon bonds, especially those possessing unusual electronic structures.  In 1989, Girolami and Morse showed that  was of trigonal prismatic molecular geometry as indicated by X-ray crystallography. This rare molecular geometry was attributed to second-order Jahn-Teller distortions in this d metal complex. Girolamis group accurately predicted that other d ML species such as , , and W(CH) would also prove to have trigonal prismatic geometry. Girolami also discovered the first titanium alkyl/alkene complex in 1993, which models the key intermediate in Ziegler-Natta catalysis. Later model studies of C-H, B-H, and Si-H activation by transition metal complexes led to his current work on approaches to the isolation of stable alkane complexes.