Rasha Anayah – Solutions to Climate Change

Dr. Rasha Anayah has a PhD in Chemistry from Johns Hopkins University. Throughout her research career, she has worked on utilizing her tools in chemistry to solve practical problems. Currently, she is working at the interface of materials chemistry, electrochemistry, and renewable energy to design metal-organic frameworks and other materials for use in next-generation batteries. Her research for the past 8 years has largely focused on developing solutions to climate change.

Published Work

Electrochemical host–guest interactions in a disordered oligosilyl coordination polymer

Rasha I. Anayah, Brian G. Diamond, Christopher H. Hendon and V. Sara Thoi

Abstract

We synthesize and study the charge transfer properties of a oligosilyl coordination polymer formed from zirconium clusters. Although the product lacks long range order, spectroscopic and computational evidence suggest that the metal–ligand bond is formed, and the principle crystallographic reflections closely match those simulated from inter-node spacings matching that of the ligand. The porous polymer allows for the incorporation of guest molecules as demonstrated by the intercalation of 7,7,8,8-tetracyanoquinodimethane (TCNQ). Charge transfer is predicted from DFT and experimentally observed by infrared spectroscopy, solid-state 29Si nuclear magnetic spectroscopy, and voltammetry.

https://scholar.google.com/citations?view_op=view_citation&hl=en&user=VXkJa_sAAAAJ&citation_for_view=VXkJa_sAAAAJ:IjCSPb-OGe4C

https://pubs.rsc.org/en/content/articlelanding/2024/tc/d4tc03032j

Chemoinformatic-Guided Engineering of Polyketide Synthases

Amin Zargar, Ravi Lal, Luis Valencia, Jessica Wang, Tyler William H. Backman, Pablo Cruz-Morales, Ankita Kothari, Miranda Werts, Andrew R. Wong, Constance B. Bailey, Arthur Loubat, Yuzhong Liu, Yan Chen, Samantha Chang, Veronica T. Benites, Amanda C. Hernández, Jesus F. Barajas, Mitchell G. Thompson, Carolina Barcelos, Rasha Anayah, Hector Garcia Martin, Aindrila Mukhopadhyay, Christopher J. Petzold, Edward E. K. Baidoo, Leonard Katz, Jay D. Keasling

Abstract

Polyketide synthase (PKS) engineering is an attractive method to generate new molecules such as commodity, fine and specialty chemicals. A significant challenge is re-engineering a partially reductive PKS module to produce a saturated β-carbon through a reductive loop (RL) exchange. In this work, we sought to establish that chemoinformatics, a field traditionally used in drug discovery, offers a viable strategy for RL exchanges. We first introduced a set of donor RLs of diverse genetic origin and chemical substrates into the first extension module of the lipomycin PKS (LipPKS1). Product titers of these engineered unimodular PKSs correlated with chemical structure similarity between the substrate of the donor RLs and recipient LipPKS1, reaching a titer of 165 mg/L of short-chain fatty acids produced by the host Streptomyces albus J1074. Expanding this method to larger intermediates that require bimodular communication, we introduced RLs of divergent chemosimilarity into LipPKS2 and determined triketide lactone production. Collectively, we observed a statistically significant correlation between atom pair chemosimilarity and production, establishing a new chemoinformatic method that may aid in the engineering of PKSs to produce desired, unnatural products.

https://scholar.google.com/citations?view_op=view_citation&hl=en&user=VXkJa_sAAAAJ&citation_for_view=VXkJa_sAAAAJ:u5HHmVD_uO8C

Phosphorus-Functionalized Organic Linkers Promote Polysulfide Retention in MOF-Based Li–S Batteries

Avery E. Baumann, Rasha I. Anayah, V. Sara Thoi

Abstract

Metal–organic frameworks (MOFs) have been an area of intense research for their high porosity and synthetic tunability, which afford them controllable physical and chemical properties for various applications. In this study, we demonstrate that functionalized MOFs can be used to mitigate the so-called polysulfide shuttle effect in lithium–sulfur batteries, a promising next-generation energy storage device. UiO-66-OH, a zirconium-based MOF with 2-hydroxyterephthalic acid, was functionalized with a phosphorus chloride species that was subsequently used to tether polysulfides. In addition, a molecular chlorophosphorane was synthesized as a model system to elucidate the chemical reactivity of the phosphorus moiety. The functionalized MOFs were then used as a cathode additive in coin cell batteries to inhibit the dissolution of polysulfides in solution. Through this work, we show that the functionalization of MOF with phosphorus enhances polysulfide redox and thereby capacity retention in Li–S batteries. While demonstrated here for polysulfide tethering in batteries, we envision this linker functionalization strategy could be more broadly utilized in separations, sensing, or catalysis applications.

https://scholar.google.com/citations?view_op=view_citation&hl=en&user=VXkJa_sAAAAJ&citation_for_view=VXkJa_sAAAAJ:9yKSN-GCB0IC

From Molecules to Porous Materials: Integrating Discrete Electrocatalytic Active Sites into Extended Frameworks

Soumyodip Banerjee, Rasha I. Anayah, Carter S. Gerke, V. Sara Thoi

Abstract

Metal–organic and covalent–organic frameworks can serve as a bridge between the realms of homo- and heterogeneous catalytic systems. While there are numerous molecular complexes developed for electrocatalysis, homogeneous catalysts are hindered by slow catalyst diffusion, catalyst deactivation, and poor product yield. Heterogeneous catalysts can compensate for these shortcomings, yet they lack the synthetic and chemical tunability to promote rational design. To narrow this knowledge gap, there is a burgeoning field of framework-related research that incorporates molecular catalysts within porous architectures, resulting in an exceptional catalytic performance as compared to their molecular analogues. Framework materials provide structural stability to these catalysts, alter their electronic environments, and are easily tunable for increased catalytic activity. This Outlook compares molecular catalysts and corresponding framework materials to evaluate the effects of such integration on electrocatalytic performance. We describe several different classes of molecular motifs that have been included in framework materials and explore how framework design strategies improve on the catalytic behavior of their homogeneous counterparts. Finally, we will provide an outlook on new directions to drive fundamental research at the intersection of reticular-and electrochemistry.