Issue 4, 2015

Guest dependent reversible single-crystal to single-crystal structural transformation in a flexible Gd(iii)-coordination polymer

Abstract

The ligand 2,6,2′,6′-tetranitro-biphenyl-4,4′-dicarboxylic acid (H2L) reacts solvothermally with [Gd(NO3)3]·6H2O to produce a flexible and porous metal–organic framework, {[Gd2(L)3(DMF)4]·(4DMF)·(3H2O)}n (1) (DMF = N,N′-dimethylformamide). An X-ray crystallographic study reveals that compound 1 contains a 3D framework structure with two different 1D channels (A and B) that are occupied by solvent DMF and water molecules. Crystals of 1 when kept in a dichloromethane solution of 4-chlorobenzaldedhyde (4-ClPhCHO) afford the daughter product {[Gd2(L)3(DMF)4]·(4-ClPhCHO)·(4DMF)}n (1a), via single-crystal to single-crystal (SC–SC) transformation, where lattice water molecules of channel B are replaced by guest aldehyde molecules. Likewise, exposure of 4-fluorobenzaldehyde (4-FPhCHO) and 4-methylbenzaldehyde (4-MePhCHO) vapors to fresh crystals of 1 afforded two isostructural daughter frameworks, {[Gd(L)1.5(DMF)(H2O)3]·(4-FPhCHO)·(DMF)·(3H2O)}n (1b) and {[Gd(L)1.5(DMF)(H2O)3]·(4-MePhCHO)·(2DMF)·(H2O)}n (1c), respectively. Here, the guest aldehyde molecules occupy both the channels of the framework. Interestingly, the latter transformations exhibit a drastic rearrangement of the framework channels followed by several ‘carboxylate-shift’ processes, and concomitant movement of the water molecules from the cavity to the metal center. Importantly, all the host–guest complexes revert back to the as-synthesized crystal when kept in fresh DMF, rendering the mother framework a flexible and dynamic container for the aromatic aldehydes. All these transformations transpire through an SC–SC fashion under ambient conditions, pointing to the high flexibility of the framework and “guest-responsive fitting” of the channels. All the compounds are characterized by X-ray crystallography, thermogravimetry, elemental analysis, powder X-ray diffraction measurements and infrared spectroscopy.

Graphical abstract: Guest dependent reversible single-crystal to single-crystal structural transformation in a flexible Gd(iii)-coordination polymer

Supplementary files

Article information

Article type
Research Article
Submitted
04 Қар. 2014
Accepted
08 Ақп. 2015
First published
12 Ақп. 2015

Inorg. Chem. Front., 2015,2, 395-402

Author version available

Guest dependent reversible single-crystal to single-crystal structural transformation in a flexible Gd(III)-coordination polymer

T. K. Pal, D. De, S. Neogi and P. K. Bharadwaj, Inorg. Chem. Front., 2015, 2, 395 DOI: 10.1039/C4QI00193A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements