High-valent complexes

High-Valent Complexes of Ruthenium and Osmium Chi-Ming Che and Vivian Wing-Wah Yam... 

Transition metal carbene complexes have broadly been classified into Fischer-type and Schrock-type carbene complexes. The former, typically low-valent, 18-electron complexes with strong 7t-acceptors at the metal, are electrophilic at the carbene carbon atom (C ). On the other hand, Schrock-type carbene complexes are usually high-valent complexes with fewer than 18 valence electrons, and without n-accepting ligands. Schrock-type carbene complexes generally behave as carbon nucleophiles (Figure 1.4). 

Based on the donor sites of the ligands, as well as on the nuclearity and geometry, the high-valent complexes containing Mn + and Mn ions have been categorized into the ligand-based... 

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