Rotational dynamics of propylene in ZSM-5 zeolitic frameworks

Location dependent orientational structure and dynamics of ethane in ZSM5

“…The troughs and peaks exhibited in the OCFs shown in Figure 5 are a signature of such librational motion. This has been observed for propylene in ZSM5 [21].…”

“…The correlation times obtained from the first and second order OCFs in this study are smaller than those obtained for propylene in ZSM5 [21]. This is reasonable, as a smaller moment of inertia of ethane would make it faster compared to propylene.…”

“…The librational motion of propylene in ZSM5 was found to completely trace the whole orientational space when the propylene molecules transit from one type of channel to the other [21]. Thus overall, there appeared to be no preference for a particular orientation.…”

“…For example, the rotation of acetylene, propane, propylene and 1,3-butadiene have been found to be isotropic in Na-Y zeolite, with pore size (1.2 nm) more than twice the kinetic diameter of these molecules, both experimentally and when studied using computer simulations [16 -20]. When the confining space is reduced further, as in ZSM5 with pore dimensions of about 0.55 nm, the rotational motion of propylene is found to be hindered and exhibits librational motion [21]. A similar hindrance to isotropic rotation of ethane in Na-ZSM5 was observed in neutron scattering experiments [22].…”

Structure and Dynamics of Confined C-O-H Fluids Relevant to the Subsurface: Application of Magnetic Resonance, Neutron Scattering, and Molecular Dynamics Simulations

“…In terms of real molecules, several QENS experiments and MD simulation studies have been undertaken to study acetylene (Mitra et al, 2004;Gautam et al, 2006), ethane (Jobic et al, 1992;Chong et al, 2005), propane (Sayeed et al, 2003), propylene (Sharma et al, 2009(Sharma et al, , 2010, butane (Jobic et al, 1993), butadiene (Gautam et al, 2007(Gautam et al, , 2008, and pentane (Jobic et al, 2009) in different zeolites. In addition to a focus on the translational diffusion, rotational motion of these molecules in zeolites has also been studied exclusively (Jobic et al, 1992;Mukhopadhyay et al, 2004;Gautam et al, 2010Gautam et al, , 2016). One particular system of interest here is ethane in AlPO 4 -5.…”