Mixed titanium-hafnium chloridometallate complexes

作者：Robe Emmanuel; Maria Sebastien; Richard Philippe; Poli Rinaldo^*

来源：European Journal of Inorganic Chemistry, 2007, (17): 2434-2442.

DOI：10.1002/ejic.200700056

• titanium
• hafnium
• chloridometallate complexes
• mixed-metal complexes

The addition of either NEt(3)BzCl or [Ph3PNPPh3]Cl (1 equiv. chloride per metal) to a 1:1 mixture of HfCl4 and TiCl3 in SOCl2 results in Ti oxidation and leads to the corresponding salts of the [TiHfCl10](2-) ion. A solution IR investigation in the v(M-Cl) region indicates that this ion is in equilibrium with the homodimetallic [Ti2Cl10](2-) and [Hf2CI10](2-) ions. An X-ray study of the NEt(3)Bz(+) salt reveals an edge-sharing bioctahedral dianion sitting on a crystallographic inversion centre. The crystal is a solid solution of different species with compositional disorder at the metal site, each metal position having the occupancy Ti0.685Hf0.315. The M-M and M-Cl distances have intermediate values between those of the homodimetallic analogues. The results of DFT calculations rationalize the structural, energetic and M-Cl bonding differences. An electrochemical investigation, in comparison with that of [Ti-2 Cl-10](2-) and the parallel IR studies, provides further information on the solution equilibria. Adventitious hydrolysis during the crystallization of the [Ph3PNPPh3](+) salt affords crystals of [Ph3PNPPh3](2)[Cl3Ti(mu-O)HfCl5], whose dianion contains a tetrahedral Ti-IV centre and an octahedral Hf-IV centre bridged by an oxygen atom. A bond-length analysis allows the description of this dianion as containing the hitherto unknown [Ti(O)Cl-3](-) complex, which acts as an oxygenbased donor ligand to [HfCl5](-).

• 出版日期2007-6