Why magnesium is five-coordinate in methanol(phthalocyaninato)magnesium(II)

Acta Cryst. (2005). C61, m472–m475 [doi:10.1107/S0108270105029732]

The metallophthalocyanines exhibit a wide array of physical and chemical properties that can be profoundly affected by subtle changes in their structures. Shown here is methanol(η4-phthalocyaninato)magnesium(II), a recent addition to the list of compounds that fit this classification. Two types of intermolecular interactions drive the crystallization of this chemical: π–π dimerization and O–H···N hydrogen bonding. One interesting subtlety of the structure is that the phthalocyaninate ligand adopts a “hat visor” shape, a description put forth for the first time in describing this structure.

I. A. Guzei, R. W. McGaff and H. M. Kieler