Design of a metal-organic framework with enhanced back bonding for the separation of N2 and CH4

K. Lee, W. C. Isley Iii, A. L. Dzubak, P. Verma, S. J. Stoneburner, L.-C. Lin, J. D. Howe, E. D. Bloch, D. A. Reed, M. R. Hudson, C. M. Brown, J. R. Long, J. B. Neaton, B. Smit, C. J. Cramer, D. G. Truhlar, and L. Gagliardi, Design of a metal-organic framework with enhanced back bonding for the separation of N2 and CH4 J . Am. Chem. Soc. 136 (2),  698–704 (2014) http://dx.doi.org/10.1021/ja4102979

Abstract: Gas separations with porous materials are economically important and provide a unique challenge to fundamental materials design, as adsorbent properties can be altered to achieve selective gas adsorption. Met-al-organic frameworks represent a rapidly expanding new class of porous adsorbents with a large range of possibilities for designing materials with desired func-tionalities. Given the large number of possible frame-work structures, quantum mechanical computations can provide useful guidance in prioritizing the synthesis of the most useful materials for a given application. Here, we show that such calculations can predict a new metal-organic framework of potential utility for the separation of dinitrogen from methane, a particularly challenging separation of critical value for utilizing natural gas. An open V(II) site incorporated into a metal-organic frame-work can provide a material with a considerably higher enthalpy of adsorption for dinitrogen than for methane, based on strong selective back bonding with the former but not the latter.


© Berend Smit 2013