Four Cd-Based Metal–Organic Frameworks with Structural Varieties Derived from the Replacement of Organic Linkers

Abstract

Four three-dimensional (3D) Cd-based metal–organic frameworks (MOFs), [Cd(pyip)­(dmf)] (1), [Cd(pyip)(doa)] (2), [Cd(pyip)­(pz)] (3) and [Cd(pyip)­(bipy)(H2O)0.5] (4) (dmf = N,N′-dimethylformamide, doa = 1,4-dioxane, pz = pyrazine, bipy = 4,4′-bipyridine) have been rationally designed and systematically synthesized by using 5-(pyridine-4-yl)isophthalic acid (H2pyip) and Cd(NO3)2·4H2O under solvothermal conditions. Compound 1 possesses a mineral-like 3,6-connected rtl network, and compounds 2–4 exhibit a 3,5-connected interpenetrating hms network constructed with 2-fold layers and bridging coligands pillars (doa, pz, and bipy), respectively. In compounds 2–4, doa, pz, and bipy act as pillars to extend the distance between the two layers from 7.34 to 11.36 Å, and the different conformations and lengths of the coligands have influenced the angles between the bridging ligands and the layers. Additionally, the four compounds exhibit strong luminescent emissions in the solid state at room temperature, and the latter three compounds exhibit robust architectures as evidenced by their permanent porosity and high thermal stability.

Advanced CdII complexes as high efficiency co-sensitizers for enhanced dye-sensitized solar cell performance

“…S2 †). 25 For 1, the first weight loss of 12.05% from 63 °C to 151 °C is attributed to the release of one coordinated water molecule, two HCl molecules and one HCOOH molecule (calcd: 13.26%). 26 The second weight loss of 53.14% (calcd: 54.67%) from 153 °C corresponds to the loss of three 4-HIBA ligands.…”

Construction, crystal structures, and luminescence properties of three coordination polymers from the same precursor, 4-(1H-benzimidazol-1-yl)benzonitrile

“…5 and 6, upon photoexcitation, Transition Met Chem complexes 2 and 3 show emission maxima at 382 (k ex = 310 nm) and 416 nm (k ex = 320 nm), respectively. These emission bands indicate some blue/red shifts compared with Htpb and Hbba, which can be attributed to the ligand-centered nature of the emission because the d 10 ions are difficult to oxidize or reduce [43,44].…”

Water de/adsorption associated with single‐crystal‐to‐single‐crystal structural transformation of a series of two‐dimensional metal–organic frameworks, [M(bipy)(C4O4)(H2O)2]·3H2O (M = Mn (1), Fe (2), and Zn (3), and bipy=4,4′‐bipyridine)

“…In the relevant approach, squarate, which possesses a four‐membered cyclic aromatic structure characterized by extensive π electron delocalization all over carbon and oxygen atoms, was widely used as a polyfunctional ligand, such as a bridging ligand with various coordination modes ( μ 2 – μ 8 bridges) to build up many coordination polymers (CPs) or metal–organic frameworks (MOFs) with novel extended networks, and also as a hydrogen bonding acceptor or a π–π stacking constructor for the stabilization of extended 3D supramolecular networks. N , N ,‐based ligands, such as 4,4′‐bipyridine (bipy), have also been widely used for the construction of many CPs or MOFs, including diamondoid, honeycomb, grid, T‐shape, ladder, brick‐wall, and octahedral frameworks [3h,12–17]. In the previous study, a series of interpenetrated CPs with squarate and bipy of {[M(C 4 O 4 )(bipy)(H 2 O) 2 ]·3H 2 O} ∞ (M = Mn, Fe, Co, and Ni) were synthesized under hydrothermal conditions, which show the reversible water de/adsorption properties of guest water molecules in the 1D channels by de/rehydration processes accompanied by color‐changing and structural variations, identified using X‐ray powder diffraction methods and thermogravimetric analysis (TGA) [3h,17].…”