41382-GB10
Synthetic, Structural, and Photocatalytic Studies of Open Framework Oxysulfides
We have developed a general and
versatile synthetic method that is capable of generating a large family of
low-connectivity open framework materials. Our method is based on the use of
various pre-synthesized boron imidazolate ligands that are subsequently linked
through monovalent cations (e.g., Li+ and Cu+) into
extended open-frameworks. There are several advantages with the synthetic
method reported here. First, it allows the use of ultra-light chemical elements
(e.g., Li and B) as framework vertices, which has a great potential for the
creation of low-density and high porosity adsorbents. Secondly, unlike the
Zn-im system in which it is usually difficult to create 3-connected Zn(im)3-
unit, both 4-connected B(im)4- and 3-connected HB(im)3-
can be readily synthesized, which greatly enhances the diversity of materials
accessible through our method.
By using the above synthetic
strategy, a total of nine boron imidazolate framework
materials have been made. In addition to the
zeolite-type 4-connected topology, both 3-connected and mixed
(3,4)-connected 3-D framework topologies have been realized, demonstrating the
versatility of our synthetic method. These
materials exhibit eight distinct topological features:3-D 4-connected zni net
(BIF-1 and BIF-2, BIF = Boron Imidazolate Framework),
dia net (BIF-3) and SOD net (BIF-4), 3-D (3,4)-connected sqc1436 net (BIF-5)
and (4.6.8)(4.62.83) net (BIF-6), 2-D 3-connected 4.82
layer (BIF-7), and 3-D 2-fold interpenetrating ths net (BIF-8) and srs
net (BIF-9).
(2) A New Zeolitic Topology with Sixteen-membered Ring and
Multidimensional Large Pore Channels
Two new 4-connected metal imidazolates with an
unprecedented 4-connected topology have been synthesized and structurally
characterized. TIF-1Zn exhibits permanent microporosity and has high thermal
stability. It features unusual topological features such as 3-, and 16-rings
and multidimensional large pore channels, which underlines the rich synthetic
and structural chemistry of imidazolate based porous frameworks that are yet to
be explored. (3) Novel
ion pair charge-transfer salts have been synthesized through the integration of
metal chalcogenide cluster anions and methyl viologen cations. The new
compounds show dramatically red-shifted UV-Visible absorptions, which provide a
new way to control optical and electronic properties of metal chalcogenides,
particularly in relation to their potential applications in solar cells.
