Cleav

Overview

Cleav-like nitrobenzyl photocages were developed initially for Ca²⁺ by Graham Ellis-Davies in the 1980s.[1] Exposure to light initiates a photoreaction that cleaves a carbon-heteroatom bond adjacent to a aromatic nitro group. The ZinCleav complexes developed by the Burdette group exhibit up to a > 1 * 10⁸ fold decrease in metal binding affinity upon uncaging, which can be rationalized by the chelate effect. The Burdette group has reported on ZinCleav-1, ZinCleav-2 and CuproCleav-1. Several other Cleav derivatives are being developed.

Photolysis of Cleav photocaged complexes

The suffix Cleav is evocative of the metal ion release mechanism a photo-induced bond cleavage that fragments the ligand. This class of ligands includes the ZinCleav photocaged complexes. The prefix refers to the metal ion being caged. ZinCleav ligands are designed as zinc photocages.