[Mo(CO)3(isatH)(PPh3)] Mo(CO)6 (0.20 g; 0.76 mmol), isatin (0.06 g; 0.33 mmol), and PPh3 (0.09 g; 0.33 mmol) were mixed in ca 30 ml tetrahydrofuran. The mixture was degassed and heated to reflux for 4 hours, where the color of the solution changed from yellow to dark red. The reaction mixture was cooled and the solvent was removed under vacuum. The obtained solid was washed several times with hot benzene and petroleum ether to give brown crystals with a yield of 55% based on the metal. [W(CO)3(isatH)(PPh3)] A similar procedure was performed as in the case of [Mo(CO)3(isatH)(PPh3)] but the reaction time was 11 hours (reddish brown powder, yield 48%).