Lower Elements of Groups V and VI

OSeO 100 . The ring in trimethylene selenite is a six-membered chair with the peripheral oxygen atom in an axial position Se-O (ring) = 1.780 0.008 A, Se-0(per) = 1.610 0.009 A, OSeO (ring) = 101 1°, and ZOSeO(per) = 115 2°. Both the selenites resemble their sulphur analogues (see above). 

There is much scope for future work on molecules containing lower elements of Groups V and VI. 

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