Geometry: Polyhedra and Networks

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Questions and Answers

What is the topology of the MOF structure with an octahedral node?

γ-polonium

δ-polonium

α-polonium (correct)

β-polonium

Which type of ligand can form 2D, 3D homo and bimetallic networks?

Benzene 1,4-dicarboxylate

Oxalate (correct)

Flexible Bis-Pyridyl Derivatives

Benzene tricarboxylic acid

What is the dimensionality of MOFs based on benzene 1,4-dicarboxylate?

Only 2D

1D to 3D (correct)

Only 3D

Only 1D

What is the name of the MOF synthesized by Yaghi et al. in 2003?

MOF-5 Signup and view all the answers

What is the name of the acid commonly used in MOFs with polynuclear building nodes?

Benzene tricarboxylic acid Signup and view all the answers

What is the term used to describe metal ions aggregated into clusters in MOFs?

Secondary Building Units Signup and view all the answers

What is the name of the process introduced by Yaghi and co-workers to synthesize MOFs?

Reticular chemistry Signup and view all the answers

What is the name of the SBU unit with a square paddle wheel structure?

Square paddle wheel [M2(COO)4] Signup and view all the answers

What was the first report of gas sorption in MOFs in 1997?

[M2(bpy)3(NO3)4].xH2O (M=Co, Ni, Zn) for CH4, N2, O2 gases Signup and view all the answers

What is the criterion for improvement in MOFs for gas sorption?

Interaction with the gas, interpenetration, doping, unsaturated metal sites and functionalization of ligands Signup and view all the answers

What is the structure of ZIF (zeolitic imidazolate framework)?

Truncated octahedron connected in a cubic manner over six membered ring Signup and view all the answers

What property is exhibited by MOF cationic framework with anions in the pores?

Anion exchange properties Signup and view all the answers

What is the application of MOFs in separation?

Separation of linear and branched alkenes Signup and view all the answers

Which MOF is used in cyanosilylation of aldehydes?

MIL-101 (Cr) Signup and view all the answers

What is the application of MOFs in catalysis?

Oxidation of hydrocarbons Signup and view all the answers

Who published a paper on asymmetric hydrogenation in MOFs in 2010?

Wenbin Lin Signup and view all the answers

In Wells notation for uniform nets, what does the (n, p) notation represent?

n is the size of the smallest circuit and p is the connectivity of nodes Signup and view all the answers

What is the Schläfli symbol of a dodecahedron?

{5,3} Signup and view all the answers

Which one of these topologies is most common in 3D Metal-Organic Frameworks (MOFs)?

diamond and primitive cubic (alpha-Po) Signup and view all the answers

Which compound represents a 2D sheet structure in MOFs with polypyridyl ligands?

[Zn(4,4’-bipyridine)2(H2O)2·SiF6]n Signup and view all the answers

What is the key feature of reticular chemistry?

Linking of molecular building blocks using strong bonds Signup and view all the answers

What is the connectivity of nodes in a honeycomb topology according to Wells notation?

3 Signup and view all the answers

Which molecular structure is described by MOF-2?

Layers of square topology connected by dinuclear Cu2+ paddle wheel SBUs Signup and view all the answers

Which type of MOFs are connected by bridging nitrito in a layer-pillared 3D framework?

[M(pyz)2(NO2)]ClO4 Signup and view all the answers

What is the topology of the MOF-5 framework?

Primitive cubic (pcu) topology Signup and view all the answers

What is the composition of the SBUs in MOF-5?

Octahedral Zn4O(—COO)6 Signup and view all the answers

What topology is exhibited by [Cu(bpy)2]PF6 in 3D MOFs?

Diamondoid Signup and view all the answers

What is the main characteristic of the (6,3) honeycomb topology?

6 is the number of nodes in the shortest circuit and 3 is the connectivity Signup and view all the answers

What can be used to expand the pore size in isoreticular MOFs?

Biphenyl, tetrahydropyrene, pyrene, and terphenyl Signup and view all the answers

What are the different connectors mentioned in HKUST-1?

M3O and M4O Nodes Signup and view all the answers

Which SBUs form the MOF: (MIL-88)?

M3O = V, Zn, Fe, Cr, and Cu Signup and view all the answers

What describes the topology of high nuclearity building nodes in the provided text?

Hexanuclear prismatic nickel cluster SBUs Signup and view all the answers

What type of polymeric nets are the most common interpenetrating 3D structures?

Diamondoid and alpha-polonium nets Signup and view all the answers

Which type of porous structure is known for reversible loss and absorption of guest molecules without phase change?

2nd Generation Signup and view all the answers

What is the best strategy to avoid interpenetration in porous structures?

Designing frameworks where interpenetration is forbidden Signup and view all the answers

Which type of interpenetration is observed in MOF-5?

Two-fold interpenetration Signup and view all the answers

Which of the following applications are relevant for porous CPs?

Gas storage and sensors Signup and view all the answers

Which of the following describes a porous structure that can change in response to external stimuli?

3rd Generation Signup and view all the answers

What type of porous structure has discrete cavities where guest molecules cannot pass out?

Dots (0D cavities) Signup and view all the answers

Which of the following is an example of a structure with 3D intersecting channels?

MOF-5 Signup and view all the answers

Study Notes

MOFs with Carboxylate Ligands

Oxalate ligands can form 2D and 3D homo and bimetallic networks depending on the choice of counter ions
When the counterion is NR4+, 2D layers of hexagonal honeycomb are formed

MOFs with Benzene 1,4-Dicarboxylate

Dimensionality: 1-3
Form 1D to 3D porous networks

MOFs with Benzene Tricarboxylic Acids

BTC, Benzene tricarboxylic acid, trimesic acid, e.g., HKUST-1
Form porous multidimensional networks
Flexible tripodal benzene-1,3,5-triacetic acid

MOFs with Polynuclear Building Nodes

Introduction of metal clusters into MOFs leads to new functional solid-state materials
Carboxylic acid ligands provide a wide range of rigid network due to their ability to aggregate metal ions into clusters termed as secondary building units (SBU)
Common SBUs: square paddle wheel [M2(COO)4], octahedral basic zinc acetate cluster, trigonal prismatic oxo-centered trimers, trigonal planar

Dinuclear Building Nodes

Square paddle wheel [Cu2(COO)4] SBUs are connected by ditopic BDC linkers to form layers of square topology

MOF-5

Composed of octahedral Zn4O(—COO)6 SBUs, consisting of four tetrahedral ZnO4 units sharing a common vertex, joined by ditopic BDC linkers to give a 3D framework structure of primitive cubic (pcu) topology
Open porous structure, with large cavities making up 61% of the unit cell volume and are filled with solvent molecules

Isoreticular MOFs

Pore size can be expanded with the use of long linkers, such as biphenyl, tetrahydropyrene, pyrene, and terphenyl

MOF with Two Different Connectors

Example: MOF with two different connectors, such as BTC and BDC

M3O and M4O Nodes (SBU)

M3O nodes: trigonal prism joint, example: [Fe3O(COO)6]
M4O nodes: octahedral joint, example: MOF-5, alpha-Po, stable up to 400°C and highly porous

High Nuclearity Building Nodes

High nuclearity clusters can form MOF SBUs, example: [Ni6(OH)6(1,4-cdc)3(H2O)6], 2D structure, hexanuclear prismatic nickel cluster SBU

Function of Porous MOFs

Gas sorption or storage, such as H2, CH4, and CO2
Criteria for improvement: interaction with the gas, interpenetration, doping, unsaturated metal sites, and functionalization of ligands

Zeolitic Imidazolate Framework (ZIF)

Sod: truncated octahedron, zinc(II) nitrate, and imidazolate-2-carboxyaldehyde (ICA)
Aperture of 3.5 Å and a pore size of 11.2 Å

MOFs in Catalysis

Catalysis, such as cyanosilylation of aldehydes, oxidation of hydrocarbons, oxidation of sulfides, and cycloaddition of CO2 and epoxides

MOF-5 and MIL-100

MOF-5: alpha-Po, stable up to 400°C and highly porous
MIL-100: Fe-based, catalytically active, and porous

MOF-101 (Cr)

Cyanosilylation of aldehydes, oxidation of hydrocarbons, oxidation of sulfides, and cycloaddition of CO2 and epoxides

Activation of CO2

MOFs can be used for the activation of CO2

Wells Notation

Honeycomb: (6,3) topology
Uniform net: (n,p) notation, where n is the size of the smallest circuit and p is the connectivity of nodes

Topology of Interpenetration

Interpenetrating: two or more networks penetrate without connecting each other

3D MOFs

Topologies: diamond, primitive cubic (alpha-Po), PtS, CdSO4, CaB6, NbO, and rutile
Examples: MOF-2, MOF-5, and HKUST-1

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Description

This quiz covers the concepts of Wells notation, Schlafli symbol, and uniform/non-uniform nets in geometry, with a focus on polyhedra and their topology.