Germanium phthalocyanine, GePc, and the reduced complexes SiPc(pyridine)2 and GePc(pyridine)2 containing antiaromatic π-electron circuits

The reaction of GeCl2(dioxane) with K2Pc(DMF)(4) yields germanium phthalocyanine, GePc. GePc dissolves in pyridine to form GePc-(py)(2), The H NMR spectrum of GePc(py)(2) and nucleus-independent chemical shift (NICS) calculations on GePc(NMe3)(2) both show the presence of a strong paratropic ring current. That ring current, along with the bond-length alternation in the crystal structure of GePc((t)BuFy)(2), indicates the presence of an antiaromatic pi-electron circuit in GePc(py)(2), SiPc(py)(2) was synthesized, and its electronic structure is similar to that of GePc(py)(2).