Metal–organic frameworks (MOFs) with phosphine
based ligands
are extremely attractive for catalysis. In this paper, phosphine has
been successfully incorporated for the first time into three-dimensional
(3D) MOFs. The MOFs are based on rigid L2M2 dimeric
secondary building blocks assembled from Cu(I) and a pyridyl diphosphine
ligand, 4-(3,5-bis(diphenylphosphino)phenyl)pyridine, with Br– (CuL-Br), Cl– (CuL-Br), or PF6
– (CuL-PF
6
) as counteranions. The structures have
a 4.122 net topology, which can be further simplified to
64.82-qtz. The MOFs contain 1D
homochiral channels. The PF6
– anions
hosted in the 1D channel of CuL-PF
6
can be readily exchanged with Br– or Cl– while keeping the framework intact. The materials
show anion-tunable flexible porosity. CuL-Br reveals
gradual uptake of MeOH, while CuL-PF
6
exhibits stepwise sorption for MeOH. The heterogeneous Lewis
acid catalytic activity of the MOFs has been shown in ketalization
reaction. CuL-Br and CuL-PF
6
are active in the reactions between ethylene glycol and 2-butanone/cyclohexanone,
up to 93% yield with 0.2 mol % catalyst loading. In contrast, no reaction
happens between ethylene glycol and bulky benzophenone, suggesting
profound size selectivity. The catalysts can be reused with the framework
left intact for three runs without loss of activity.
Rigid bridging terpyridyl phosphine and AgOTf form nanofibres to induce gelation of organic solvents, and the gel emits blue luminescence by suppressing π-π interactions between ligands.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.