New crystalline modification of polyselenomethylene by polymerization of 1,3,5,7‐tetraselenocane

Abstract

The cyclic symmetrical-formals, symmetrical-thioformals, and their polymers have been largely investigated in recent years. In contrast symmetrical-selenoformalsl and their p~l y m e r s z~~ have received comparatively little study. This paper, which will be a cmtribution to this field, deals with a new preparative method of 1,3,5triselenane and of hexagonal polyselenomethylene and the isolation of a new oligomer, the ryclic tetramer of selenoformaldehyde, 1,3,5,7-tetraselenorane I, previously unknown in the literature.

Structure−Property Relationships of Polyselenoethers [−(CH2)ySe−]x(y= 1, 2, and 3) and Related Polyethers and Polysulfides

“…These polymers include the third chalcogen element, selenium. As far as we know, only PMSe has been synthesized and characterized by X-ray diffraction, and two crystal structures have been found: a hexagonal cell of a single (21/11) helical chain; – an orthorhombic cell of two (2/1) helical chains, – where ( m / t ) indicates the helical pitch of m monomeric units per t turns. The melting point ranges from 185 to 190 °C, being comparable to that of PMO (163−189 °C).…”

1,3,5,7-Tetraselenocane

“…The compound was prepared by Russo, Mortillaro, Credali & De Checchi (1966) and the crystals were grown from light petroleum.…”