The effect of pressure on Cu-btc: framework compression vs. guest inclusion

Abstract

Here we present detailed structural data on the effect of high pressure on Cu-btc. Application of pressure causes solvent to be squeezed into the pores until a phase transition occurs, driven by the sudden compression and expansion of equatorial and axial Cu-O bonds.

Research Update: Mechanical properties of metal-organic frameworks – Influence of structure and chemical bonding

“…Though these guests are not part of the extended framework skeleton, it has been shown that they can affect the mechanical behavior (e.g., compressibility) of the respective MOF quite drastically. 30,32 We have recently demonstrated that this is particularly true for flexible and responsive MOFs, which are able to change their structure reversibly upon adsorption of different guests. 57 By analogy with the previously discussed [Zn 2 (bdc) 2 (dabco)] n framework, [Zn 2 (NO 2 -bdc) 2 (dabco)] n (NO 2 -DMOF; NO 2 -bdc = 2-nitro-1,4-benzenedicarboxylate) undergoes distinct changes in network geometry upon exchange of guest molecules (Fig.…”

Pore Shape Modification of a Microporous Metal–Organic Framework Using High Pressure: Accessing a New Phase with Oversized Guest Molecules

“…Sc2BDC3(ip) does not therefore experience the stabilizing effect of channel 'super-filling' which occurs with methanol, which also occurs in other MOFs with one, two and three-dimensional channel connectivity. 15,23,30 Larger di-branched hydrocarbons can also penetrate into the pores of Sc2BDC3 at high pressures. Using 2,3-dimethylbutane and 2-methylheptane as hydrostatic media, a similar transformation is observed (see Figure 5a and b), though in each case the rotation is not as significant as in Sc2BDC3(ip): 21.2° for 2,3-dimethylbutane and 28.2° for 2-methylheptane.…”

Structural aspects of metal-organic framework-based energy materials research at Diamond

“…Beamline I19 has played a pivotal role in the recent development and exploitation of highpressure crystallographic methods and it has already contributed to landmark high-pressure investigations of well-known MOFs [30][31][32][33][34][35]. We have begun studies of the behaviour of our own more flexible MOFs, several of which possess outstanding gas storage or separation properties, at pressures of up to 100 kbar.…”