A new synthetic route has been developed for the preparation of 1-halo- and 1-alkyl-1-phenyltetrachlorocyclotriphosphazenes of general formula N3P3C14X(C6H6) (5), where X = C1, Br, or I, and N3P3C14(C6H5)(R) (6), where R = CH3, C2H5, nC3H7, n-C4H9, t-C3H7, or CH2CH=CH2, respectively. These compounds are prospective polymerization monomers, most of which cannot be prepared by other routes. The synthetic procedure involves the interaction of l,l′-diphenyl-3,3,3’,3’,5,5,5’,5′-octachlorobifcyclo-triphosphazene) (2) with LiBEt3H to give a triethylborane-substituted anion, 3. Anion 3 reacts with proton-releasing agents to give 1-hydrido-l-phenyltetrachlorocyclotriphosphazene (4) or with alkyl halides to give 6. The hydridophosphazene 4 reacts with halogen in CC14 to give 5. Alternatively, compounds 5 (X = Cl, Br) can be prepared via the reaction of 3 with CC14 or CHBr3, respectively. Compound 5 (X = Br) was found to react with NaF in acetonitrile at reflux to give exclusively N3P3C14F(C6H5). The structural characterization of these compounds by spectroscopic and mass spectrometric techniques is discussed, together with the reaction mechanism. In addition, the crystal and molecular structure of 5 (X = Cl) has been investigated by single-crystal X-ray diffraction techniques. The crystals are monoclinic with the space group P21/c and with a = 8.579 (1) Å, b = 14.612 (3) Å, c = 11.771 (3) Å, and β = 99.26 (1)° with V = 1456.4 (9) A3 and Z = 4.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry