In situ studies of reversible solid–gas reactions of ethylene responsive silver pyrazolates

Abstract

Solid–gas reactions and in situ powder X-ray diffraction investigations of trinuclear silver complexes {[3,4,5-(CF₃)₃Pz]Ag}₃ and {[4-Br-3,5-(CF₃)₂Pz]Ag}₃ supported by highly fluorinated pyrazolates reveal that they undergo intricate ethylene-triggered structural transformations in the solid-state producing dinuclear silver–ethylene adducts. Despite the complexity, the chemistry is reversible producing precursor trimers with the loss of ethylene. Less reactive {[3,5-(CF₃)₂Pz]Ag}₃ under ethylene pressure and low-temperature conditions stops at an unusual silver–ethylene complex in the trinuclear state, which could serve as a model for intermediates likely present in more common trimer–dimer reorganizations described above. Complete structural data of three novel silver–ethylene complexes are presented together with a thorough computational analysis of the mechanism.