Solvent-vapour-assisted pathways and the role of pre-organization in solid-state transformations of coordination polymers

Abstract

The structural transformations of a family of coordination polymers that entrap small arenes (toluene, xylene) by Ag(I) coordination has been investigated. The study highlights the role in these transformations of vapour–solid interactions and pre-organization in the solid state.

Topochemical control in desolvation of coordination polymers

“…These phenomena require dramatic structural reorganization (Caira & Nassimbeni, 1996), which contrasts with the rigidity typically associated with the crystalline state. Now Brammer and co-workers (Wright et al, 2015) explore this idea further by investigating a family of silver-phenazine coordination polymers: {[Ag 4 (O 2 C(CF 2 ) 2 -CF 3 ) 2 (phenazine) 2 (arene) k ]ÁJ(arene)} n (arene = toluene, xylene). In these compounds the aromatic solvent has a double function: as a ligand it is coordinated to open metal sites and as a guest it is included within the cavities present in the structures.…”

Arene Selectivity by a Flexible Coordination Polymer Host

“…Materials that are porouso nt he molecular scale have been in use for many years in applications involving molecular separation. Fixed-pore materials, exemplified by zeolites and related inorganicp orousm aterials, [1] have been joined over the past [15][16][17][18][19][20] years by an umber of new classes materials of porous materials, most prominently metal-organicf rameworks (MOFs), [2,3] but also covalent organic frameworks (COFs) [4] and other polymeric or framework materials. [5] These materials have the advantage of being modulari nd esign,e nabling tunability of properties, including pore size, shape and chemical composition.…”

“…[8][9][10][11][12] Many of this last class of materials, although lacking conventional porosity, may be described as exhibiting latent porosity, whereby guest uptake is combined with molecular mobility in the solid state, which enables guest encapsulation. [13][14][15][16][17] We have developed ac lass of 1D coordination polymers based on silver(I) perfluoroalkylcarboxylate dimer units linked through diimine ligands, such as substituted pyrazineo rp henazine (Scheme1), that are able to trap smallm olecules betweent he polymers and exchange these guests in ar eversible manner. [16] These materials are crystalline and the guest exchange proceeds with retention of crystallinity,a llowing the process to be followed by in situ diffraction studies in addition to av arietyo fo ther physical methods.…”

“…Recently,w er eported the encapsulation of small arene guests (toluene, xylenes) in one such coordination polymer [Ag 4 {O 2 C(CF 2 ) 2 CF 3 } 4 (phen) 2 -(arene) n ]·m (arene) (phen = phenazine) and examinedt he role of these guests in templatingsolid-state transformations. [17] In the present study we explore the encapsulation of benzene, toluene, o-xylene, m-xylene and p-xylene by the coordination polymer [Ag 4 (O 2 CCF 3 ) 4 (phen) 3 ]( 1)d uring its self-assembly from the solution phase. This resultsi nt he crystalline materials [Ag 4 (O 2 CCF 3 ) 4 (phen) 3 ]·phen·arene (1·phen·arene), in which the arenesa ct as co-guestsa longside non-coordinated phenazine.…”

“…This polymerica rrangement is analogoust ot he structure of silver(I)p erfluoroalkylcarboxylate coordination polymers of the formula [Ag 4 (O 2 CR f ) 4 (L) 3 ]( R f = perfluoroalkyl group;L = diimine ligand)d escribed in our previous work. [16,17] In each 1·phen·arene material additional non-coordinated phenazine molecules are included as guests, situated between each of the doublybridging phenazine linkersi nap-stacked manner.T wo equivalents of the arene used as solventa re also present as guests per repeat unit of the polymer.T hese molecules (toluene, pxylene or benzene) are p-stacked on both sides of the electron-deficient central ring of the singly-bridging phenazine ligands.T he arenes are crystallographically ordered and each arene molecule is related to another by ac entre of symmetry located in the centre of those phenazine ligands ( Figure 1).…”