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#TiCl2] (5) has been prepared by reductive
cyclotetramerization of the respective dinitrile precursor in the
presence of TiCl4. 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#M2] (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#H2 are reported. 5 crystallizes from dichloromethane
in the cubic space group Im3̅. The two chlorido
ligands exhibit a cis arrangement. The free ligand Pc#H2 crystallizes in the trigonal space group R3̅.