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Multidentate nitrogen and phosphorous containing ligands are available for the synthesis of Metal Organic Frameworks (MOFs)

Chemical, physical, and mechanical properties of Metal-Organic Frameworks (MOFs) are highly influenced by organic ligands.  These ligands connect metal clusters, leading to materials with well-ordered structures.  In most cases, MOF linkers are aromatic carboxylic acids or molecules with N-containing aromatic rings.

07-0435, 1,4-Di(4'-pyrazolyl)benzene (H₂bpzb), also known as 1,4-benzenedi(4'-pyrazolyl) (H₂BDP), behaves as a tetradentate ligand where two pyrazolyl groups are bridged through benzene rings. Both nitrogen atoms on each pyrazolyl ring are able to bind metal atoms.^1,2  2,4,6-tris(4-pyridyl)-1,3,5-triazine (TPT) 07-3235, contains six nitrogen atoms, which can potentially donate electrons for binding. However, the three nitrogen atoms on the pyridyl groups seem to be more accessible.  Three pyridine groups can bind one metal ion, leaving the internal triazine site unbound.

In contrast to most nitrogen donors, MOF ligand 07-1942 [1, 4, 7, 10-Tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)] is cyclic, and has no aromatic rings.  An advantage of the DOTA heterofunction ligand is that it may link MOF units through carboxylic arms, and leave the four nitrogen atoms of tetraazacyclododecane core available for further coordination.⁴

Similar features are seen in the phosphine containing MOF linker 15-7170 [2-(Diphenylphosphino) terephthalic acid], which is functionalized not only with carboxylic groups but also with diphenylphosphine moieties.

References

1.  Science, 2013, 340, 960.
2.  J. Am. Chem. Soc., 2008, 130, 7848.
3.  Dalton Trans., 2014, 43, 7146.
4.  CrystEngComm., 2008, 10, 1126.
5.  Ind. Eng. Chem. Res., 2014, 53, 9120.

Featured Products

07-0435 1,4-Di(4'-pyrazolyl)benzene, min. 97% H₂BDP (1036248-62-0)
07-3235 2,4,6-(Tri-4-pyridinyl)-1,3,5-triazine, min. 97% TPT (42333-78-8)
07-1942 1,4,7,10-Tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid, min. 98% DOTA (60239-18-1)
15-7170 2-(Diphenylphosphino)terephthalic acid, 95% (1537175-69-1)

Related Products & Resources

MOF Linkers
Metal Organic Frameworks
Metal Organic Frameworks Booklet
Ligands & Chiral Ligands
Phosphine Products
Phosphorus Ligands and Compounds Booklet