02165nas a2200253   4500008004100000022001400041245008400055210006900139260000800208300001500216490000700231520135000238653001601588653001701604653001101621653001701632100002201649700002201671700002601693700002101719700002801740700003001768856011301798       2022                        eng d  a1861-472800aCoordination flexibility aided CO2-specific gating in an iron isonicotinate MOF0 aCoordination flexibility aided CO2specific gating in an iron iso  cFEB  ae2021013050 v173 a<p>
	Coordination flexibility assisted porosity has been introduced into an Iron-isonicotinate metal-organic framework (MOF), (Fe(4-PyC)(2) . (OH). The framework showed CO2-specific gate opening behavior, which gets tuned as a function of temperature and pressure. The MOF ` s physisorptive porosity towards CO2, CH4, and N-2 was investigated; it adsorbed only CO2 via a gate opening phenomenon. The isonicotinate, representing a borderline soft base, is bound to the hard Fe3+ centre through monodentate carboxylate and pyridyl nitrogen. This moderately weak binding enables isonicotinate to spin like a spindle under the CO2 pressure opening the gate for a sharp increase in CO2 uptake at 333 mmHg (At 298 K, the CO2 uptake increases from 0.70 to 1.57 mmol/g). We investigated the MOF ` s potential for CO2/N-2 and CO2/CH4 gas separation aided by this gating. IAST model reveals that the CO2/N-2 selectivity jumps from 325 to 3131 when the gate opens, while the CO2/CH4 selectivity increases three times. Interestingly, this Fe-isonicotinate MOF did not follow the trend set by our earlier reported Hard-Soft Gate Control (established for isostructural M2+-isonicotinate MOFs (M=Mg, Mn)). However, we account for this discrepancy using the different oxidation state of metals confirmed by X-ray photoelectron spectroscopy and magnetism.</p>
10aCO2 capture10aflexible MOF10agating10aIsonicotinic1 aSingh, Himan, Dev1 aNandi, Shyamapada1 aChakraborty, Debanjan1 aSingh, Kirandeep1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan  uhttps://library.ncl.res.in/content/coordination-flexibility-aided-co2-specific-gating-iron-isonicotinate-mof