The structure of oxotitanium phthalocyanine: a gas-phase electron diffraction and computational study

Abstract

The gas-phase molecular structure of oxotitanium phthalocyanine (TiOPc) has been studied by a synchronous gas electron diffraction and mass spectrometric experiment, and density functional theory calculations using the B3LYP hybrid method and cc-pVTZ basis sets. The molecule has an equilibrium structure of C_4v symmetry with a convex macrocycle. The titanium atom is out-of-the-plane of the four central nitrogen atoms and forms a square pyramid with them, with the following parameters: r(Ti–N) = 2.090(5) Å, r(N⋯N) = 2.813(9) Å (the side of the pyramid base), z(Ti)–z(N) = 0.614 Å (the height of the pyramid). Compared to solid-state crystal structures, the Ti–O distance in gas-phase TiOPc is shortened and the Ti–N distance is elongated, which can be attributed to significant intermolecular interaction in the crystals.