PHOSPHORANE IMINATO COMPLEXES OF TITANIUN - THE CRYSTAL-STRUCTURES OF[TICL2(NPPH(3))2] AND [TICL3(NPME(2)PH)(CH3CN)](2)

[TiCl2(NPPh(3))(2)] has been prepared by the reaction of [TiCl3(NPPh(3 ))] with excess Me(3)SiNPPh(3) in a melt at 220 degrees C, forming col ourless crystals. [TiCl3(NPMe(2)Ph)(CH3CN)](2) is formed as yellow, mo isture sensitive crystals from acetontrile solutions of [TiCl3(NPMe(2) Ph)](2), which on its part has been obtained by the reaction of TiCl4 with Me(3)SiNPMe(2)Ph. The complexes are characterized by IR spectrosc opy and by crystal structure determinations. [TiCl2(NPPh(3))(2)]. Spac e group Fdd2, Z = 8, structure refinement with 2875 observed unique re flections, R = 0.039. Lattice dimensions at 19 degrees C: a = 2080.9, b = 3308.5, c = 973.6 pm. The compound forms monomeric molecules with bond lengths TiN of 179.0 pm and PN of 156.8 pm, which correspond with double bonds. The bond angle TiNP is 166.6 degrees. [TiCl3(NPMe(2)Ph) (CH3CN)](2). Space group P $($) over bar$$ 1, Z = 1, structure refinem ent with 2577 unique reflections, R = 0.039 for reflections with I > 2 sigma(I). Lattice dimensions at 20 degrees C: a = 856.6, b = 923.1, c = 1008.3 pm, alpha = 81.23 degrees, beta = 71.63 degrees, gamma = 81. 41 degrees. The compound forms centrosymmetric, dimeric molecules, in which the titanium atoms are linked via chloro bridges TiCl2Ti with Ti Cl bond lengths of 243.9 and 270.3 pm. In trans-position to the longer TiCl bonds the nitrogen atoms of the phosphorane iminato groups are c oordinated with bond lengths TiN of 173.9 pm and PN of 161.4 pm which again correspond with double bonds. The bond angle TiNP is 156.4 degre es.