Omar M. Yaghi

Well, the word complexity has been very frequently used since yesterday. Should we not try to define what we really mean with complexity? Is it size? Is it lack of symmetry? Or is it too many panels on a single slide? Is it dynamics, where we add at least a fourth dimension to describing

2023-10-07 Assigned to THE REGENTS OF THE UNIVERSITY OF CALIFORNIA reassignment THE REGENTS OF THE UNIVERSITY OF CALIFORNIA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ABEL, Anthony, ADAMS, Jeremy, CESTELLOS-BLANCO, Stefano, CLARK, DOUGLAS S., LYU, Hao, YAGHI, OMAR M., YANG, PEIDONG, ZHUMEKENOV, Ayan

The societal problems we face today in climate change, clean energy, clean air, clean water, food, and health impact everyone on our planet. Solutions to these will require innovations in materials to bring about a more sustainable and resilient future. Some progress in understanding the basic science underlying these problems is being made and it is beginning to drive the invention and discovery of new materials. However, currently, there is a gap between the materials we require and our ability to realize them. This is largely attributed to the fact that traditionally making extended chemical structures has been a trial-and-error activity with very little design expressed on the outcome of solid-state synthesis. This changed with the emergence of reticular chemistry, defined as the chemistry of linking molecular building blocks by strong bonds to make extended structures. As elaborated in the following, this new …

In drug discovery, molecular dynamics (MD) simulation for protein-ligand binding provides a powerful tool for predicting binding affinities, estimating transport properties, and exploring pocket sites. There has been a long history of improving the efficiency of MD simulations through better numerical methods and, more recently, by augmenting them with machine learning (ML) methods. Yet, challenges remain, such as accurate modeling of extended-timescale simulations. To address this issue, we propose NeuralMD, the first ML surrogate that can facilitate numerical MD and provide accurate simulations of protein-ligand binding dynamics. We propose a principled approach that incorporates a novel physics-informed multi-grained group symmetric framework. Specifically, we propose (1) a BindingNet model that satisfies group symmetry using vector frames and captures the multi-level protein-ligand interactions, and (2) an augmented neural differential equation solver that learns the trajectory under Newtonian mechanics. For the experiment, we design ten single-trajectory and three multi-trajectory binding simulation tasks. We show the efficiency and effectiveness of NeuralMD, with a 2000 speedup over standard numerical MD simulation and outperforming all other ML approaches by up to 80\% under the stability metric. We further qualitatively show that NeuralMD reaches more stable binding predictions compared to other machine learning methods.

We have developed two series of amine-functionalized zirconium (Zr) metal–organic framework-808 (MOF-808), which were produced by postsynthetic modifications to have either amino acids coordinated to Zr ions (MOF-808-AAs) or polyamines covalently bound to the chloro-functionalized structure (MOF-808-PAs). These MOF variants were comprehensively characterized by liquid-state 1H nuclear magnetic resonance (NMR) measurements and potentiometric acid–base titration to determine the amounts of amines, energy-dispersive X-ray spectroscopy to assess the extent of covalent substitution by polyamines, powder X-ray diffraction analysis to verify the maintenance of the MOF crystallinity and structure after postsynthetic modifications, nitrogen sorption isotherm measurements to confirm retention of the porosity, and water sorption isotherm measurements to find the water uptake in the pores of each member …

The introduction of molecularly woven three-dimensional (3D) covalent organic framework (COF) crystals into polymers of varying types invokes different forms of contact between filler and polymer. Whereas the combination of woven COFs with amorphous and brittle polymethyl methacrylate results in surface interactions, the use of the liquid-crystalline polymer polyimide induces the formation of polymer-COF junctions. These junctions are generated by the threading of polymer chains through the pores of the nanocrystals, thus allowing for spatial arrangement of polymer strands. This offers a programmable pathway for unthreading polymer strands under stress and leads to the in situ formation of high-aspect-ratio nanofibrils, which dissipate energy during the fracture. Polymer-COF junctions also strengthen the filler-matrix interfaces and lower the percolation thresholds of the composites, enhancing strength …

We synthesized two isoreticular furan-based metal–organic frameworks (MOFs), MOF-LA2-1(furan) and MOF-LA2-2(furan) with rod-like secondary building units (SBUs) featuring 1D channels, as sorbents for atmospheric water harvesting (LA = long arm). These aluminum-based MOFs demonstrated a combination of high water uptake and stability, exhibiting working capacities of 0.41 and 0.48 gwater/gMOF (under isobaric conditions of 1.70 kPa), respectively. Remarkably, both MOFs showed a negligible loss in water uptake after 165 adsorption–desorption cycles. These working capacities rival that of MOF-LA2-1(pyrazole), which has a working capacity of 0.55 gwater/gMOF. The current MOFs stand out for their high water stability, as evidenced by 165 cycles of water uptake and release. MOF-LA2-2(furan) is the first aluminum MOF to employ a double ‘long arm’ extension strategy, which is confirmed through single …

In this work, the rate-limiting diffusion mechanisms of MOF-303, MOF-333, and a multivariate (MTV) version of these metal–organic frameworks (MOFs), where the organic linkers are present in a 50/50 ratio, are identified and quantified using concentration swing frequency response (CSFR). The data show that the single-atom precision of MOFs allows for precise tuning of the diffusion rate that is not easily achieved in traditional adsorbent materials. The Maxwell-Stefan diffusivity as a function of loading was calculated to decouple the influence of molecular mobility and equilibrium effects. To further understand the diffusion process in these MOFs, samples with different crystal sizes were synthesized and diffusion rates were measured. The results show that the controlling diffusion length scale is similar between the small and large crystal samples, as evidenced by similar diffusion rate constants. The MOFs were then …