Synthesis, structures, and solution behavior of di- and trinuclear titanium(IV)--cyclophosphato complexes

The reaction of the cyclotetraphosphate ion (P(4)O(12)(4)(-)) with CpTiCl(3)] (Cp = eta(5)-C(5)Me(5)) gives (CpTi)(2)(P(4)O(12))(2)](2)(-) where the P(4)O(12) ligands adopt a saddle conformation, while that with (CpTiCl)(3)(mu-O)(3)] leads to (CpTi)(3)(mu-O)(3)(P(4)O(12))](-) containing a crown form P(4)O(12) ligand; both products feature their unique cage structures. On the other hand, the reactions of the cyclotriphosphate ion (P(3)O(9)(3)(-)) with (CpTiCl(2))(2)(mu-O)] and (CpTiCl)(3)(mu-O)(3)] afford (CpTi)(2)(mu-O)(P(3)O(9))(2)](2)(-) and (CpTi)(3)(mu-O)(3)Cl(P(3)O(9))](-), respectively, and in both cases the P(3)O(9) ligands bridge two titanium centers with an eta(2):eta(1) mode.