The reactions of trimericphosphazenes with sodium [2, 2'-methylenebis(4-chlorophenoxide)] have been investigated. Experimental studies were carried out in argon atmosphere. The sodium aryloxides were prepared from methylenebis (4-chlorophenol) and sodium. The phosphazene and phenolate were reacted at -20 degrees C and then refluxed. After the reaction products (I and 2) were separated by column chromatography, the structures of the compounds were characterized by elemental analysis, IR, H-1-, C-13-, P-31-NMR, and mass spectroscopy. The compound I (spiro) crystallizes in the monoclinic space group Cm with unit cell parameters: a = 8.231(1), b = 16.242(2), c = 7.731(1) angstrom, beta = 103.31(1)degrees, V= 1005.8(2) angstrom(3), D-x = 1.796 g cm(-3) respectively. The crystal structures were solved by direct methods and refined by full-matrix least squares. (c) 2005 Elsevier B.V. All rights reserved.