Format

Send to

Choose Destination
See comment in PubMed Commons below
Inorg Chem. 2013 Mar 4;52(5):2353-60. doi: 10.1021/ic301857h. Epub 2013 Feb 11.

A porous 4-fold-interpenetrated chiral framework exhibiting vapochromism, single-crystal-to-single-crystal solvent exchange, gas sorption, and a poisoning effect.

Author information

1
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), Department of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, People's Republic of China. zmh@mailbox.gxnu.edu.cn

Abstract

The synthesis and characterization of a 4-fold-interpenetrated pseudodiamond metal-organic framework (MOF), Co(II)(pybz)2·2DMF [pybz = 4-(4-pyridyl)benzoate], are reported. N,N-Dimethylformamide (DMF) of the channels can be removed to give the porous framework, and it can also be exchanged for methanol, ethanol, benzene, and cyclohexane. It is a rare example of a stable MOF based on a single octahedral building unit. The single-crystal structures of Co(II)(pybz)2·2DMF, Co(II)(pybz)2, Co(II)(pybz)2·4MeOH, and Co(II)(pybz)2·2.5EtOH have been successfully determined. In all of them, the framework is marginally modified and contains a highly distorted and strained octahedral node of cobalt with two pyridine nitrogen atoms and two chelate carboxylate groups. In air, the crystals of Co(II)(pybz)2·2DMF readily change color from claret red to light pink. Thermogravimetric analysis and Raman spectroscopy indicate a change in coordination, where the carboxylate becomes monodentate and an additional two water molecules are coordinated to each cobalt atom. In a dry solvent, this transformation does not take place. Tests show that Co(II)(pybz)2 may be a more efficient drying agent than silica gel and anhydrous CuSO4. The desolvated Co(II)(pybz)2 can absorb several gases such as CO2, N2, H2, and CH4 and also vapors of methanol, ethanol, benzene, and cyclohexane. If Co(II)(pybz)2 is exposed to air and followed by reactivation, its sorption capacity is considerably reduced, which we associate with a poisoning effect. Because of the long distance between the cobalt atoms in the structure, the magnetic properties are those of a paramagnet.

PMID:
23398593
DOI:
10.1021/ic301857h
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Support Center