[Ti(CO)4(η3-BH4)]− and [Ti(CO)4(η5-C4H4N)]−: The First Zerovalent Metal Complexes Containingη3-Borohydride and Pyrrolyl Ligands

Tridentate binding of BH4− to a zero-valent metal center was found for the first time in [Ti(CO)4(η3-BH4)]− (shown in the picture), which was obtained from the reaction of the carbonyl metalate anion [Ti(CO)6]2− with BH3⋅THF. Displacement of the unusually labile BH4− anion by a pyrrolyl anion provided the first metal(0) pyrrolyl complex [Ti(CO)4(η5-C4H4N)]−.