skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: A molecular T-pentomino for separating BTEX hydrocarbons
Abstract Methods to separate molecules (e.g., petrochemicals) are exceedingly important industrially. A common approach for separations is to crystallize a host molecule that either provides an enforced covalent cavity (intrinsic cavity) or packs inefficiently (extrinsic cavity). Here we report a self-assembled molecule with a shape highly biased to completely enclose space and, thereby, pack efficiently yet hosts and allows for the separation of BTEX hydrocarbons (i.e., benzene, toluene, ethylbenzene, xylenes). The host is held together by N → B bonds and forms a diboron assembly with a shape that conforms to a T-shaped pentomino. A T-pentomino is a polyomino, which is a plane figure that tiles a plane without cavities and holes, and we show the molecule to crystallize into one of six polymorphic structures for T-pentomino tiling. The separations occur at mild conditions while rejecting similarly shaped aromatics such as xylene isomers, thiophene, and styrene. Our observation on the structure and tiling of the molecular T-pentomino allows us to develop a theory on how novel synthetic molecules that mimic the structures and packing of polyominoes can be synthesized and—quite counterintuitively—developed into a system of hosts with cavities used for selective and useful separations.  more » « less
Award ID(s):
2221086
PAR ID:
10494634
Author(s) / Creator(s):
; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
Nature Communications
Volume:
15
Issue:
1
ISSN:
2041-1723
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Angewandte Chemie)
    null (Ed.)
    We use classical cavity molecular dynamics simulations to investigate the effect of optical cavity environment on vibrational energy transfer and relaxation. For a small fraction of vibrationally hot CO2 molecules immersed in a liquid-phase CO2 thermal bath, in a cavity that supports a cavity mode in resonance with the CO asymmetric stretch vibration, forming collective vibrational strong coupling (VSC) and a cavity mode accelerates hot molecule relaxation. This acceleration stems from the fact that polaritons can be transiently excited during the nonequilibrium process, which facilitates intermolecular vibrational energy transfer. The VSC effects on these rates (i) resonantly depend on the cavity mode detuning, (ii) cooperatively depend on Rabi splitting, and (iii) collectively scale with the number of hot molecules. This behavior weakens with increasing cavity size (at constant molecular density), that is, constant Rabi splitting) but remains meaningful up to cavities containing 10^4 molecules 
    more » « less
  2. ; ; ; (, Soft Matter)
    Entropy compartmentalization provides new self-assembly routes to colloidal host–guest (HG) struc- tures. Leveraging host particle shape to drive the assembly of HG structures has only recently been proposed and demonstrated. However, the extent to which the guest particles can dictate the structure of the porous network of host particles has not been explored. In this work, by modifying only the guest shape, we show athermal, binary mixtures of star-shaped host particles and convex polygon-shaped guest particles assemble as many as five distinct crystal structures, including rotator and discrete rotator guest crystals, two homoporous host crystals, and one heteroporous host crystal. Edge-to-edge alignment of neighboring stars results in the formation of three distinct pore motifs, whose preferential formation is controlled by the size and shape of the guest particles. Finally, we confirm, via free volume calculations, that assembly is driven by entropy compartmentalization, where the hosts and guests contribute differently to the free energy of the system; free volume calculations also explain differences in assembly based on guest shape. These results provide guest design rules for assembling colloidal HG structures, especially on surfaces and interfaces. 
    more » « less
  3. ; (, Chemical Science)
    Optical cavities hold great promise to manipulate and control the photochemistry of molecules. We demonstrate how molecular photochemical processes can be manipulated by strong light–matter coupling. For a molecule with an inherent conical intersection, optical cavities can induce significant changes in the nonadiabatic dynamics by either splitting the pristine conical intersections into two novel polaritonic conical intersections or by creating light-induced avoided crossings in the polaritonic surfaces. This is demonstrated by exact real-time quantum dynamics simulations of a three-state two-mode model of pyrazine strongly coupled to a single cavity photon mode. We further explore the effects of external environments through dissipative polaritonic dynamics computed using the hierarchical equation of motion method. We find that cavity-controlled photochemistry can be immune to external environments. We also demonstrate that the polariton-induced changes in the dynamics can be monitored by transient absorption spectroscopy. 
    more » « less
  4. ; ; (, Chemical Science)
    By placing Mg-porphyrin molecules in a chiral optical cavity, time reversal symmetry is broken, and polariton ring currents can be generated with linearly polarized light, resulting in a circular dichroism signal. Since the electronic state degeneracy in the molecule is lifted by the formation of chiral polaritons, this signal is one order of magnitude stronger than the bare molecule signal induced by circularly polarized light. Enantiomer-selective photochemical processes in chiral optical cavities is an intriguing future possibility. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, bioRxiv)
    Abstract Incorporation of colloidal quantum emitters into silicon-based photonic devices would enable major advances in quantum optics. However, deterministic placement of individual sub-10 nm colloidal particles onto micron-sized photonic structures with nanometer-scale precision remains an outstanding challenge. Here, we introduce Cavity-Shape Modulated Origami Placement (CSMOP) that leverages the structural programmability of DNA origami to precisely deposit colloidal nanomaterials within lithographically-defined resist cavities. CSMOP enables clean and accurate patterning of origami templates onto photonic chips with high yields. Soft-silicification-passivation stabilizes deposited origamis, while preserving their binding sites to attach and align colloidal quantum rods (QRs) to control their nanoscale positions and emission polarization. We demonstrate QR integration with photonic device structures including waveguides, micro-ring resonators, and bullseye photonic cavities. CSMOP therefore offers a general platform for the integration of colloidal quantum materials into photonic circuits, with broad potential to empower quantum science and technology. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email