Axial functionalization of sterically hindered titanium phthalocyanines.

Several axially functionalized, weakly aggregating titanium phthalocyanines (Pc) have been synthesized and characterized. Soluble titanium dichlorido tetrakis-(1,1,4,4-tetramethyl-6,7-tetralino)-porphyrazine [Pc(#)TiCl(2)] (5) has been prepared by reductive cyclotetramerization of the respective dinitrile precursor in the presence of TiCl(4). 5 and the analogous oxido compound [Pc(#)TiO] (1) are versatile starting materials for the formation of other axially functionalized titanium phthalocyanines such as organoimido (6, 7), alkoxido and aryloxido (8, 9), peroxido (10), sulfido (12), disulfido (11), selenido (14) or diselenido (13) species. Furthermore the deprotonated ligand salts [Pc(#)M(2)] (M = Li (2), Na (3), K (4) are described. The reactivity of the titanium compounds was studied in atom group transfer reactions and ethene polymerization. The crystal structures of 5 and the free ligand Pc(#)H(2) are reported. 5 crystallizes from dichloromethane in the cubic space group Im3. The two chlorido ligands exhibit a cis arrangement. The free ligand Pc(#)H(2) crystallizes in the trigonal space group R3.