Unusual formations of superoxo heptaoxomolybdates from peroxo molybdates

• Superoxo/peroxo heptaoxomolybdates were isolated from the peroxo solution accidently.
• They decompose into peroxo molybdates very quickly.
• Both contain a superoxo group [1.27(1) Å] in side-on fashion.

Two novel dioxygen heptaoxomolybdates K5[Mo7O22(O2)(OH)]Cl·6H2O (1) and K5[Mo7O22(O2)(O2)]·8H2O (2) were isolated from the solution of peroxo molybdate accidently. The solids were characterized by IR, EPR and X-ray single crystal analysis. Complex 1 contains a superoxo group with a short bond distance 1.27(1) Å, while 2 is a mixed complex with peroxo and superoxo groups [1.43(1), 1.27(1) Å]. All of the dioxygen groups coordinate to molybdenum atoms in side-on (η2) fashion. The two complexes are short-lived and will decompose into peroxo molybdates K5[Mo7O21(O2)2(OH)]·6H2O (3) and K6[Mo7O22(O2)2]·9H2O (4) very quickly.

Novel superoxo/peroxo heptaoxomolybdates were isolated from the solution of peroxo molybdate accidently, which decompose into peroxo molybdates very quickly. Both complexes 1 and 2 contain a superoxo group with a short bond distance 1.27(1) Å in side-on fashion.Figure optionsDownload as PowerPoint slide