The coordination geometry of the tetrapyridine copper(II) complex in zeolite Cu-NaY and mesoporous siliceous MCM-41 material is investigated by two-dimensional proton and deuterium hyperfine sublevel correlation (HYSCORE) spectroscopy. Different orientations of the pyridine ligands with respect to the complex plane of the tetrapyridine copper(II) complex were found in the two materials. The ligands are predominately arranged with their molecular plane perpendicular to the complex plane in zeolite Cu-NaY. Otherwise, in Cu-MCM-41 materials the ligands have a mean orientation of their molecular plane parallel to the complex plane. However, the two-dimensional hyperfine sublevel correlation spectra reveal severe distortions of the overall complex. The different coordination geometries of the tetrapyridine copper(II) complex in both materials result from the interaction of the complex with the inner surface of each molecular sieve. Consequently, much severe distortion of the complex geometry was found in the mesoporous Cu-MCM-41 material with its amorphous wall structure in comparison to crystalline Y zeolite. The-incorporation of the tetrapyridine Cu(II) complex into Y zeolite also alters the electron spin density distribution within the complex. The results indicate a substantial influence of the framework of the Y zeolite on the unpaired electron of the encapsulated complex.