Quantum mechanical study of zinc-67 and nitrogen-14 electric field gradient tensors.

摘要

In this thesis it was found that quantum-mechanical calculations at the B3LYP level with medium-size basis sets, 6-31G(f) for Zn and 6-31G(d) for other atoms, can yield reliable 67Zn electric field gradient tensors for Zn(II) coordination complexes (i.e. where zinc is involved in ionic bonding). It is often sufficient to consider only ligands from the first coordination sphere around the zinc atom. One exception is that if the Zn center of interest is bonded to water molecules and the water molecules are involved in strong hydrogen bonds then ligands from the second coordination sphere must be included in the cluster model.; It was found that quantum-mechanical calculations at the B3LYP level with basis sets 6-311++G(d, p), can yield very accurate 14N EFG tensors using the molecular cluster approach; the accuracy is high enough that hydrogen bonding effects can be studied.