Orbital directing effects in copper and zinc based paddle-wheel metal organic frameworks: the origin of flexibility†
Abstract
We have used density functional theory calculations to study non-periodic model systems for the ubiquitous layer-pillar metal organic frameworks built from paddle-wheel building blocks. Experimentally, these porous materials show nearly identical structures for both copper and zinc forming the paddle-wheel, but differ depending on the type of the metal center in their properties. Our theoretical results clearly reveal orbital directing effects for the d9 Cu(II) center, enforcing a square planar conformation, to be the main reason for the difference in contrast to the flexible d10 Zn(II) system. Surprisingly, this difference is directly visible in the structure of the bare vertex model without axial
- This article is part of the themed collection: Integrating functionality into metal–organic frameworks