Topology Analysis and Nonlinear-Optical-Active Properties of Luminescent Metal−Organic Framework Materials Based on Zinc/Lead Isophthalates

Abstract

Two 3D Zn(II) and Pb(II) isophthalates, [Zn(ip)]n (1) and [Pb4(mu4-O)(ip)3(H2O)]n (2) (H2ip = isophthalic acid), have been prepared under hydro(solvo)thermal conditions and characterized by single-crystal X-ray diffraction. The two complexes crystallize in different space groups (P4(3)2(1)2 for 1 and P2(1)/c for 2) and have different bridging modes of the ip ligand. The 3D framework of 1 is constructed by the interconnection of ZnO4 polyhedra via ip ligands, which represents a chiral net with PtS-type topology. In contrast, complex 2 is formed by the combination of Pb4O-cluster secondary building units and has a novel (3.4.5)(3(2).4(5).5(6).6(7).7(2)) topology, which is the first ever example of a (3,7)-connected net. Complex 1 displays a second harmonic generation efficiency of about 1.5 times that of KH2PO4. Optical properties and thermal stabilities of the two complexes have been studied. Additionally, the calculations of band structure and density of states of 1 have also been performed with the density functional theory method.

Structures and H2 Adsorption Properties of Porous Scandium Metal–Organic Frameworks

“…[1] The design and synthesis of such networks is driven by diverse potential applications in gas storage, [2] catalysis, [3] electrical conductivity, [4] luminescence, [5] magnetism [6] and optics. [7] Hydrogen has enormous potential as a sustainable, clean and efficient fuel. [8] Thus, many industrial economies are investing in the hydrogen economy [9] as a major contribution to sustainability and for use in the clean technologies of the future.…”

An unprecedented seven-connected coordination network based on octanuclear supertetrahedral lead(II) cluster as a secondary building unit

“…The free benzene-1,2,3-tricarboxylic acid ligand displays a fluorescent emission band at 440 nm (λ ex = 330 nm) based on the literature [33]. The observed largely red-shift of complex 1 from the 1,2,3-H 3 btc ligand emission may be assigned to the ligand-to-metal charge-transfer (LMCT) between delocalized π bonds of the 1,2,3-btc carboxylate groups and p orbitals of the Pb(II) centers [20,34].…”

“…Previous studies have indicated that metal coordination polymers containing lead(II) ions exhibit photoluminescent properties [18][19][20]. Thus, the photoluminescent property of complex 1 in the solid state has been investigated at room temperature.…”

“…Some transition metal-, lanthanide metal-, and main group metal-based coordination polymers have been structurally examined [12][13][14][15][16], and no attention has been given to the construction of heavy p-block lead(II) coordination polymer. On the other hand, compared with the transitional and lanthanide metal ions, lead(II) cation presents larger radius, wider coordination numbers (2-10), more variable stereochemical activity with the mixing of the 6p orbital and 6s orbital, which provide unique opportunities for the construction of unusual network topologies [17] and some important properties of luminescence, nonlinear optic and ion exchange [18][19][20]. Taking these points into account, by using Pb(NO 3 ) 2 as the metal source and an asymmetric benzene-1,2,3-tricarboxylic acid as ligand, we have fortunately isolated an unprecedented coordination framework {[(Me 2 NH 2 ) 4 [Pb 8 (μ 4 -O)(1,2,3-btc) 6 ]] 2 ·6DMF·2H 2 O} n (1) with octanuclear super- 18 ] clusters as nodes.…”

Syntheses, crystal structures and luminescent properties of two new Zn(II) coordination polymers based on rigid biphenyldicarboxylate

“…Thus, a large number of metal-organic frameworks (MOFs) based on carboxylate ligands design from 1D chains to 3D frameworks with different topologies were constructed from the versatile, rigid monoaromatic polycarboxylate ligands, such as 1,3,5-benzenetricarboxylate, 1,2-benzenebicarboxylate, 1,3-benzenebicarboxylate and 1,4-benzenebicarboxylate, etc. [13][14][15][16] while rigid biphenyl dicarboxylates as organic linkers are less reported [17][18][19]. As a continuation of our work [20,21], we have now undertaken a study of synthesis and X-ray crystal structure dominations of two zinc complexes [Zn(dpa)] n (1) and {[Zn 2 (dpa)(Pbim)(H 2 O) (OH)] •1.5 (H 2 O)} n (2) based on biphenyl-2,4′-dicarboxylic acid (2,4′-dpa) as the first linker ligand.…”