Tuning Cobalt Coordination Architectures by Bis(1,2,4-triazol-1-ylmethyl)benzene Position Isomers and 5-Nitroisophthalate

In our effect to tune the Co­(II) coordination polymer
architectures,
three position isomers 1,2-, 1,3-, 1,4-bis­(1,2,4-triazol-1-ylmethyl)­benzene
and rigid 5-nitroisophthalate were used to assembly Co­(II) coordination
polymers [Co­(obtz)­(NO2-1,3-bdc)]n (1), [Co­(mbtz)­(NO2-1,3-bdc)­(CH3OH)]n (2), and [Co­(bbtz)­(NO2-1,3-bdc)­(H2O)]n (3). 1 is comprised of undulated two-dimensional
(2D) (4,4) networks. Two identical undulated layers are parallel interpenetrated
to each other to give a (2D → 2D) polycatenated 2D network.
The adjacent polycatenated 2D layers parallel polythreaded to form
a unique 3D network. 1 is an unusual 2D → 3D polythreaded
framework based on the polycatenated 2D layers. 2 shows
the double-layer structure through the hydrogen bonds and π···π
stacking interactions based on the undulated 2D (4,4) network. A 3D
supramolecular network is constructed through the π···π
stacking interactions interdouble layers. 3 exhibits
a 3-fold interpenetrating 4-connected 65·8-CdSO4 3D network. The powder X-ray diffraction, thermal stabilities,
and UV–vis spectroscopy of 1, 2,
and 3 were investigated.