The roles of the coordination modes of bridging ligands for the formation of two 3D metal–organic coordination networks

CrystEngComm ◽  
2010 ◽  
Vol 12 (11) ◽  
pp. 3437 ◽  
Author(s):  
Si-Tang Yan ◽  
Lian-Xu Shi ◽  
Fei-Fei Sun ◽  
Chuan-De Wu
Keyword(s):  
Coordination Networks ◽  
Bridging Ligands ◽  
Coordination Modes ◽  
Metal Organic

scholarly journals Synthesis, Structures, and Water Adsorption of Two Coordination Polymers Constructed by M(II) (M = Ni (1) and Zn (2)) with 1,3-Bis(4-Pyridyl)Propane (bpp) and 1,2,4,5-Benzenetetracarboxylate (BT4−) Ligands

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2222
Author(s):  
Chih-Chieh Wang ◽  
Wei-Cheng Yi ◽  
Zi-Ling Huang ◽  
Tsai-Wen Chang ◽  
Wen-Chi Chien ◽  
...  
Keyword(s):  
Coordination Polymers ◽  
Metal Organic Framework ◽  
X Ray Diffraction ◽  
Bridging Ligands ◽  
Coordination Modes ◽  
Distorted Octahedral ◽  
Metal Organic ◽  
Nitrogen Donors ◽  
Oxygen Donors ◽  
Monodentate Coordination

Two coordination polymers (CPs), with chemical formulas {[Ni2(bpp)2(BT)(H2O)6] 1.5(EtOH) 1.5H2O}n (1) and [Zn(bpp)(BT)0.5]·5H2O (2) (bpp = 1,3-bis(4-pyridyl)propane, and BT4− = tetraanion of 1,2,4,5-Benzenetetracarboxylic acid), have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. In compound 1, the coordination environments of two crystallographically independent Ni(II) ions are both distorted octahedral bonded to two nitrogen donors from two bpp ligands and four oxygen donors from one BT4- ligand and three water molecules. Both bpp and BT4− act as bridging ligands with bis-monodentate and 1,4-bis-monodentate coordination modes, respectively, connecting the Ni(II) ions to form a 2D layered metal-organic framework (MOF). Adjacent 2D layers are then arranged orderly in an ABAB manner to complete their 3D supramolecular architecture. In 2, the coordination environment of Zn(II) ion is distorted tetrahedral bonded to two nitrogen donors from two bpp ligands and two oxygen donors from two BT4− ligands. Both bpp and BT4- act as bridging ligands with bis-monodentate and 1,2,4,5-tetrakis-monodentate coordination modes, respectively, connecting the Zn(II) ions to form a 3D MOF. The reversible water de-/adsorption behavior of 1 between dehydrated and rehydrated forms has been verified by cyclic Thermogravimetric (TG) analyses through de-/rehydration processes. Compound 1 also exhibits significant water vapor hysteresis isotherms.

Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

2019 ◽  
Author(s):  
Andrew Rosen ◽  
M. Rasel Mian ◽  
Timur Islamoglu ◽  
Haoyuan Chen ◽  
Omar Farha ◽  
...  
Keyword(s):  
Density Functional ◽  
Metal Organic Frameworks ◽  
Redox Activity ◽  
Screening Methods ◽  
Bridging Ligands ◽  
Metal Centers ◽  
Computational Screening ◽  
Open Metal Sites ◽  
Metal Organic ◽  
Unsaturated Metal Sites

<p>Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O<sub>2</sub> and N<sub>2</sub> adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br<sup>-</sup>, μ-Cl<sup>-</sup>, μ-F<sup>-</sup>, μ-SH<sup>-</sup>, or μ-OH<sup>-</sup> groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O<sub>2</sub> affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O<sub>2</sub>. In contrast with O<sub>2</sub> adsorption, N<sub>2</sub> adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V<sup>2+</sup> open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl<sup>-</sup> ligands of M<sub>2</sub>Cl<sub>2</sub>(BBTA) (H<sub>2</sub>BBTA = 1<i>H</i>,5<i>H</i>-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH<sup>-</sup> groups would significantly enhance the strength of O<sub>2</sub> adsorption at the open metal sites without a corresponding increase in the N<sub>2</sub> affinity. Experimental investigation of Co<sub>2</sub>Cl<sub>2</sub>(BBTA) and Co<sub>2</sub>(OH)<sub>2</sub>(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O<sub>2</sub> at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH<sup>-</sup><sub> </sub>ligands and the presence of H-bonding interactions between the μ-OH<sup>-</sup> bridging ligands and the O<sub>2</sub> adsorbate.</p>

scholarly journals 3D Metal–Organic Frameworks Based on Co(II) and Bithiophendicarboxylate: Synthesis, Crystal Structures, Gas Adsorption, and Magnetic Properties

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1269
Author(s):  
Vadim A. Dubskikh ◽  
Anna A. Lysova ◽  
Denis G. Samsonenko ◽  
Alexander N. Lavrov ◽  
Konstantin A. Kovalenko ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Adsorption ◽  
Magnetic Moments ◽  
Bet Surface Area ◽  
Separation Performance ◽  
Bridging Ligands ◽  
Magnetization Data ◽  
Metal Organic ◽  
Ch4 Adsorption ◽  
Gas Separation Performance

Three new 3D metal-organic porous frameworks based on Co(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc2−) [Co3(btdc)3(bpy)2]·4DMF, 1; [Co3(btdc)3(pz)(dmf)2]·4DMF·1.5H2O, 2; [Co3(btdc)3(dmf)4]∙2DMF∙2H2O, 3 (bpy = 2,2′-bipyridyl, pz = pyrazine, dmf = N,N-dimethylformamide) were synthesized and structurally characterized. All compounds share the same trinuclear carboxylate building units {Co3(RCOO)6}, connected either by btdc2– ligands (1, 3) or by both btdc2– and pz bridging ligands (2). The permanent porosity of 1 was confirmed by N2, O2, CO, CO2, CH4 adsorption measurements at various temperatures (77 K, 273 K, 298 K), resulted in BET surface area 667 m2⋅g−1 and promising gas separation performance with selectivity factors up to 35.7 for CO2/N2, 45.4 for CO2/O2, 20.8 for CO2/CO, and 4.8 for CO2/CH4. The molar magnetic susceptibilities χp(T) were measured for 1 and 2 in the temperature range 1.77–330 K at magnetic fields up to 10 kOe. The room-temperature values of the effective magnetic moments for compounds 1 and 2 are μeff (300 K) ≈ 4.93 μB. The obtained results confirm the mainly paramagnetic nature of both compounds with some antiferromagnetic interactions at low-temperatures T < 20 K in 2 between the Co(II) cations separated by short pz linkers. Similar conclusions were also derived from the field-depending magnetization data of 1 and 2.

Isopolymolybdate-induced organic–inorganic hybrid assemblies with copper ions and bichelate-bridging ligands

CrystEngComm ◽  
2014 ◽  
Vol 16 (43) ◽  
pp. 10017-10027 ◽  
Author(s):  
Xiu-Li Hao ◽  
Yuan-Yuan Ma ◽  
Yong-Hui Wang ◽  
Hong-Ying Zang ◽  
Yang-Guang Li
Keyword(s):  
Photocatalytic Activity ◽  
Copper Ions ◽  
Bridging Ligands ◽  
Inorganic Hybrid ◽  
Metal Organic ◽  
Hydrothermal Environment ◽  
Hybrid Assemblies

Heptamolybdate is used as a “molecular adaptor” to modulate the metal–organic coordination building units in the hydrothermal environment, with new polyoxometalate-induced hybrid assemblies isolated demonstrating good photocatalytic activity.

Three novel metal-organic frameworks with different coordination modes for trace detection of anthrax biomarkers

2021 ◽  
Author(s):  
Zhenzhong Cong ◽  
Mingchang Zhu ◽  
Ying Zhang ◽  
Wei Yao ◽  
Marina Kosinova ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Trace Detection ◽  
Coordination Modes ◽  
Metal Organic

Dipicolinate acid (DPA) is an anthrax biomarker. It's serious consequences make it's detection in great need. In this paper, three novel metal-organic frameworks (MOFs) with different coordination modes were synthesized...

scholarly journals Metal-organic magnets with large coercivity and ordering temperatures up to 242°C

Science ◽  
2020 ◽  
Vol 370 (6516) ◽  
pp. 587-592 ◽  
Author(s):  
Panagiota Perlepe ◽  
Itziar Oyarzabal ◽  
Aaron Mailman ◽  
Morgane Yquel ◽  
Mikhail Platunov ◽  
...  
Keyword(s):  
Metal Ions ◽  
Room Temperature ◽  
Building Blocks ◽  
Inorganic Materials ◽  
Coordination Networks ◽  
Critical Temperatures ◽  
Considerable Success ◽  
Organic Magnets ◽  
Metal Organic ◽  
Constituent Elements

Magnets derived from inorganic materials (e.g., oxides, rare-earth–based, and intermetallic compounds) are key components of modern technological applications. Despite considerable success in a broad range of applications, these inorganic magnets suffer several drawbacks, including energetically expensive fabrication, limited availability of certain constituent elements, high density, and poor scope for chemical tunability. A promising design strategy for next-generation magnets relies on the versatile coordination chemistry of abundant metal ions and inexpensive organic ligands. Following this approach, we report the general, simple, and efficient synthesis of lightweight, molecule-based magnets by postsynthetic reduction of preassembled coordination networks that incorporate chromium metal ions and pyrazine building blocks. The resulting metal-organic ferrimagnets feature critical temperatures up to 242°C and a 7500-oersted room-temperature coercivity.

scholarly journals Synthesis, Structural Characterization and Ligand-Enhanced Photo-Induced Color-Changing Behavior of Two Hydrogen-Bonded Ho(III)-Squarate Supramolecular Compounds

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1369 ◽  
Author(s):  
Wang ◽  
Ke ◽  
Feng ◽  
Ho ◽  
Chang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Uv Light ◽  
Squaric Acid ◽  
Water Molecules ◽  
Light Illumination ◽  
Supramolecular Architecture ◽  
Bridging Ligands ◽  
Coordination Modes ◽  
Oxygen Atoms ◽  
Hydrogen Bonded

Two coordination polymers (CPs) with chemical formulas, [Ho2(C4O4)2(C2O4)(H2O)8]·4H2O (1) and [Ho(C4O4)1.5(H2O)3] (2), (C4O42− = dianion of squaric acid, C2O42− = oxalate), have been synthesized and their structures were determined by single-crystal X-ray diffractometer (XRD). In compound 1, the coordination environment of Ho(III) ion is eight-coordinate bonded to eight oxygen atoms from two squarate, one oxalate ligands and four water molecules. The squarates and oxalates both act as bridging ligands with 1,2-bis-monodentate and bis-chelating coordination modes, respectively, connecting the Ho(III) ions to form a one-dimensional (1D) ladder-like framework. Adjacent ladders are interlinked via O–HO hydrogen bonding interaction to form a hydrogen-bonded two-dimensional (2D) layered framework and then arranged orderly in an AAA manner to construct its three-dimensional (3D) supramolecular architecture. In compound 2, the coordination geometry of Ho(III) is square-antiprismatic eight coordinate bonded to eight oxygen atoms from five squarate ligands and three water molecules. The squarates act as bridging ligands with two coordination modes, 1,2,3-trismonodentate and 1,2-bis-monodentate, connecting the Ho(III) ions to form a 2D bi-layered framework. Adjacent 2D frameworks are then parallel stacked in an AAA manner to construct its 3D supramolecular architecture. Hydrogen bonding interactions between the squarate ligands and coordinated water molecules in 1 and 2 both play important roles on the construction of their 3D supramolecular assembly. Compounds 1 and 2 both show remarkable ligand-enhanced photo-induced color-changing behavior, with their pink crystals immediately turning to yellow crystals under UV light illumination.

Modular Assembly of Two-Dimensional Metal–Organic Coordination Networks at a Metal Surface

2003 ◽  
Vol 42 (23) ◽  
pp. 2670-2673 ◽  
Author(s):  
Alexandre Dmitriev ◽  
Hannes Spillmann ◽  
Nian Lin ◽  
Johannes V. Barth ◽  
Klaus Kern
Keyword(s):  
Metal Surface ◽  
Two Dimensional ◽  
Coordination Networks ◽  
Modular Assembly ◽  
Metal Organic

Fabrication of metal–organic framework nanosheets and nanorolls with N-donor type bridging ligands

2013 ◽  
Vol 42 (43) ◽  
pp. 15267 ◽  
Author(s):  
Atsushi Kondo ◽  
Chin Chin Tiew ◽  
Fumiaki Moriguchi ◽  
Kazuyuki Maeda
Keyword(s):  
Metal Organic Framework ◽  
Bridging Ligands ◽  
Donor Type ◽  
Metal Organic ◽  
Organic Framework
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