Abstract:
A microporous, partially fluorinated metal–organic framework
consisting of ZnII dimeric paddlewheel units, formulated
as [Zn(hfipbba)(4bpdb)0.5]·H2O (1) [hfipbba = 4,4-
(hexaflouroisopropylene)bis(benzoic acid); 4bpdb = 1,4-
bis(4-pyridyl)-2,3-diaza-1,3-butadiene], was synthesized by
room-temperature self-assembly and characterized structurally
by single-crystal XRD. Compound 1 adopts a 3D microporous
framework structure constituted by six-connected
ZnII dimeric paddlewheel nodes with {44.610.8}-net topology.
Further, rapid synthesis of phase-pure 1 by green synthetic
approaches such as mechanochemical and sonochemical
routes was achieved. The 3D framework of 1 houses 1D helical channels with narrow pore dimensions of about
3.114.17 Å and exhibits interesting gas-uptake (H2/CO2)
properties. The isosteric heats of adsorption Qst for H2 and
CO2 were estimated to be 8.8 and 36.4 kJmol–1, respectively.
Interestingly, solid-state conversion of 1 to phase-pure hexagonal
ZnO nanocrystals of 6.1 0.63 nm in size, embedded
in carbonaceous layers to form a ZnO–C nanocomposite
(NC), occurred on heating of 1 to 600 °C under vacuum for
2 h. The ZnO–C NC was characterized by XRD, UV/Vis, energy-dispersive
X-ray, and TEM analyses. The as-synthesized
ZnO–C NC exhibits good photocatalytic activity for the
degradation of methylene blue.
