Heterometallic Modular Metal–Organic 3D Frameworks Assembled via New Tris-beta-Diketonate Metalloligands: Nanoporous Materials for Anion Exchange and Scaffolding of Selected Anionic Guests
Articolo
Data di Pubblicazione:
2010
Citazione:
Heterometallic Modular Metal–Organic 3D Frameworks Assembled via New
Tris-beta-Diketonate Metalloligands: Nanoporous Materials for Anion
Exchange and Scaffolding of Selected Anionic Guests / L. Carlucci, G.M. Ciani, S. Maggini, D. M. Proserpio, M. Visconti. - In: CHEMISTRY-A EUROPEAN JOURNAL. - ISSN 0947-6539. - 16:41(2010), pp. 12328-12341. [10.1002/chem.201001256]
Abstract:
The modular engineering of
heterometallic nanoporous metal-organic
frameworks (MOFs) based on
novel tris-chelate metalloligands, prepared
using the functionalised b-diketone
1,3-bis(4’-cyanophenyl)-1,3-propanedione
(HL), is described. The
complexes [M(III)L3] (M=Fe3+, Co3+)
and [M(II)L3](NEt4) (M=Mn2+, Co2+,
Zn2+, Cd2+) have been synthesised and
characterised, all of which exhibit a distorted
octahedral chiral structure. The
presence of six exo-oriented cyano
donor groups on each complex makes
it a suitable building block for networking
through interactions with external
metal ions. We have prepared
two families of MOFs by reacting the
metalloligands [M(III)L3] and [M(II)L3]-
with many silver salts AgX (X=NO3-,
BF4-, PF6-, AsF6-, SbF6-, CF3SO3-, tosylate),
specifically the [M(III)L3Ag3]-
ACHTUNGTRENUNGX3·Solv and [M(II)L3Ag3]X2·Solv network
species. Very interestingly, all of these
network species exhibit the same type
of 3D structure and crystallise in the
same trigonal space group with similar
cell parameters, in spite of the different
metal ions, ionic charges and X- counteranions
of the silver salts. We have
also succeeded in synthesising trimetallic
species such as [ZnxFeyL3Ag3]-(ClO4)(2x+3y)·Solv and [ZnxCdyL3Ag3]-(ClO4)2·Solv (with x+y=1). All of the frameworks can be described as sixfold
interpenetrated pcu nets, considering
the Ag+ ions as simple digonal spacers.
Each individual net is homochiral, containing
only D or L nodes; the whole
array contains three nets of type D and
three nets of type L. Otherwise, taking
into account the presence of weak Ag-C sigma bonds involving the central carbon
atoms of the b-diketonate ligands of
adjacent nets, the six interpenetrating
pcu networks are joined into a unique
non-interpenetrated six-connected
frame with the rare acs topology. The
networks contain large parallel channels
of approximate hexagonal-shaped
sections that represent 37-48% of the
cell volume and include the anions and
many guest solvent molecules. The
guest solvent molecules can be reversibly
removed by thermal activation with
retention of the framework structure,
which proved to be stable up to about
270°C, as confirmed by TGA and
powder XRD monitoring. The anions
could be easily exchanged in singlecrystal
to single-crystal processes,
thereby allowing the insertion of selected
anions into the framework channels.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
anions; coordination polymers; heterometallic complexes; ion exchange; metal-organic frameworks; metalloligands; polymers
Elenco autori:
L. Carlucci, G.M. Ciani, S. Maggini, D.M. Proserpio, M. Visconti
Link alla scheda completa: