In the present work, coumarin substituted cyclotriphosphazenes were designed, synthesized and characterized for the first time. The reactions of sodium derivative of 3,3'-methylenebis(4-hydroxycoumarin), (dicoumarol, 1), with cyclotriphosphazene, (N3P3Cl6, 2), in a THF solution gave mono-spiro (3), bis-spiro (4) and tris-spiro (5) dicoumaroxy-substituted compounds. All dicoumaroxy-substituted cyclotriphosphazene compounds (3-5) were fully characterized by elemental analysis, IR, ESI mass spectrometry, H-1 and P-31 NMR spectroscopies. Generally, bulky diol derivatives prefer ansa-or bridged products by reacting with cyclotriphosphazene. But, surprisingly, dicoumarol which is also bulky diol derivative gave only spiro products in this study. The molecular structures of compounds (3-5) were also determined by X-ray crystallography. The crystal structures of these compounds were solved by direct methods and refined by full-matrix least squares. (C) 2013 Elsevier B.V. All rights reserved.