MASS-SPECTRAL FRAGMENTATION STUDIES OF SOME HIGH-VALENT DIMERIC MANGANESE COMPLEXES WITH TETRADENTATE SCHIFF-BASE LIGANDS

Mass spectra of some high valent manganese complexes with tetradentate Schiff base as ligand of the type [Mn(SB)O-2] and [Mn-2(SB)(2)O(OH)] were measured. The mechanisms leading to different fragment ions were suggested. The fragmentation pattern of dimeric Mn-IV/Mn-IV species we re completely different from those of mixed Mn-III/Mn-IV species. One of the fragmentation modes of Mn-IV/Mn-IV is characterized by loss of metal, accomplished with hydrogen transfer to give a typical fragmenta tion pattern of the corresponding ligand. The salen and naphen complex es were also characterized by homolytic cleavage of the central C - C bond, while the salim and naphtm complexes are distinguished by unusua l fragmentation due to the loss of stable ailyl radical.