Mössbauer, Crystallographic, and Density Functional Theoretical Investigation of the Electronic Structure of Bis‐Ligated Low‐Spin Iron(II) Phthalocyanines

摘要: We present the crystal structure of pcFe(4-methylpiperidine)2 as a first example low-spin iron(II) phthalocyanine (pc) complex bis-axially coordinated by aliphatic amines. It is shown that electronic rather than steric effects are responsible for elongation Fe−N(axial) bond in pcFeL2 complexes. Using density functional theory, structures well Mossbauer isomer shifts and quadrupole splittings have been investigated large number pcFeL1L2 complexes, which axial ligands varying properties. The electron charge densities electric field gradients at iron ion were evaluated using locally dense basis approach with Wachters’ all-electron set ion, 6-311++G(2d) atoms directly bonded to 6-31G(d) two bonds away from 3-21G* all other atoms. A good correlation between theoretical experimental has observed complexes tested. also proposed model calculation spectral parameters adequate evaluation ligand conformation cases conformational flexibility