There are primarily two types of metal carbene complexes: Fischer carbenes and Schrock carbenes.
- Fischer carbenes are typically formed with late transition metals such as iron, chromium, and molybdenum. They are characterized by having an electron-rich carbene carbon, usually stabilized by electron-donating substituents. - Schrock carbenes, on the other hand, are associated with early transition metals like titanium, tungsten, and tantalum. These carbenes are usually electron-deficient and are stabilized by electron-withdrawing groups.
