ChemInform Abstract: Two Polymorphs of the Diazaphosphole Oxide C6H4(NH)2P(O)Ph.
Abstract
The polymorphous title compound (III) (space group Pnma, Z=4) forms in high yields as shown in the scheme, and in moderate yield (33%) from the reaction of the diamine (I) with PhP(OPh)2.
ChemInform Abstract
The polymorphous title compound (III) (space group Pnma, Z=4) forms in high yields as shown in the scheme, and in moderate yield (33%) from the reaction of the diamine (I) with PhP(OPh)2. A second polymorph (space group Cmca, Z = 8) is obtained in traces by crystallization of the cyclotetraphosphazane (C6H4N2(PhP)2)2 from toluene. The two polymorphs contain a planar C6N2 unit; however the PhP phosphorus is displaced slightly out of the plane. In both cases, each molecule is H-bonded from the P=O O atom to the N-H bond units on each of two adjacent molecules in the lattice. The two polymorphs do not differ significantly in basic molecular parameters or lattice H-bonding but rather in detail of how complete molecules are oriented relative to one another in the lattice.
