Papers by MASOUD KAZEM-ROSTAMI
ACS Sustainable Chemistry & Engineering, 2023
Chemistry of Materials, 2023
New Journal of Chemistry , 2022
Tröger's base analogs (TBAs) present a pair of uniquely bent tetracyclic scaffolds that possess t... more Tröger's base analogs (TBAs) present a pair of uniquely bent tetracyclic scaffolds that possess two stereogenic amine groups with identical handedness. This work employs TBAs as chiral building blocks in the design of electron-rich (electron-donating) macrocycles, namely enantiopure Trögerophanes. These chiral donor macrocycles are then mechanically interlocked with an achiral electron-deficient (electron-acceptor) macrocycle—namely, cyclobis(paraquat-p-phenylene) (CBPQT4+)—that carries four positive charges. These electron donor and acceptor components are individually colorless but once mechanically interlocked to one another they generate a charge-transfer (CT) absorption band centered at around 525 nm turning the resulting chiral 2-catenanes purple in color. Strikingly, the circular dichroism spectra of the two opposing enantiomers of this 2-catenane show mirroring patterns and a Cotton effect in the region that corresponds to the CT mainly from 445 to 625 nm. This phenomenon attests to the transfer of chirality from the chiral donor Trögerophane to the achiral acceptor CBPQT4+ macrocycle and the amplification of chiroptical properties of the interlocked molecule whose structure is almost entirely rigid. Moreover, this work demonstrates the discriminatory interactions of the nitrogen-based stereocenters of Tröger's base with chiral acids. This discriminatory property enables the investigated chiral 2-catenane showing a moderate enantioenrichment while interacting with an amino acid and oxidizing it in a competitive photocatalytic aerobic oxidation process fueled by the energy of visible light absorbed within the CT region.
Journal of American Chemical Society, 2022
Tröger’s base (TB) and its derivatives have been studied extensively due to their unique concave ... more Tröger’s base (TB) and its derivatives have been studied extensively due to their unique concave shape stemming from the endomethylene strap. However, the strap-clipped TB chemistry has been largely overlooked in metal–organic framework (MOF) solids, leading to a gap in our knowledge within this field. In this work, we report the in situ strap elimination of a carboxylate-carrying TB in the presence of formic acid, both in solution and in Zr(IV)-based MOFs. In the solution system, the methanodiazocine nucleus can be exclusively transformed into an N,N′-diformyl-decorated phenhomazine derivative, regardless of the solvent used (DMF, DMA, or DEF), as unambiguously uncovered by single crystal X-ray crystallography. In contrast, while in the MOF synthetic system, the degree of derivatization reaction can be effectively controlled to give either the secondary diamine or formyl-decorated diamine, depending on the solvent used (DMF or DEF), resulting in the formation of two Zr-MOFs with 8-connected bcu (NU-1900) and 12-connected fcu (NU-407) topologies, respectively. The derivatization mechanism is proposed to be topology-guided and dependent on the local acid concentration during the MOF formation processes. Moreover, we discovered a novel post-synthetically water-induced in situ linker formylation process in NU-1900 through sequential formic acid elimination, migration, and condensation processes, affording an isostructural framework with the same linker as in NU-407, which further corroborates our proposed mechanism. Additionally, the highly defective NU-1900 with abundant accessible Zr sites was demonstrated to be an outstanding catalyst for the detoxification of a nerve agent simulant with a half-life of less than 1 min.
Journal of the American Chemical Society, 2022
Movies S1 to S2 NU-2000.cif NU-2001.cif NU-2001-300C-activated.cif Materials. All chemicals were ... more Movies S1 to S2 NU-2000.cif NU-2001.cif NU-2001-300C-activated.cif Materials. All chemicals were purchased from commercial suppliers and used as received. X-ray Diffraction Analyses. Powder X-ray diffraction (PXRD) patterns of MOFs were measured at room temperature on a STOE-STADIP powder diffractometer equipped with an asymmetric curved Germanium monochromator (CuKα1 radiation, λ = 1.54056 Å) and one-dimensional silicon strip detector (MYTHEN2 1K from DECTRIS). The line focused Cu X-ray tube was operated at 40 kV and 40 mA. The powder was placed between two Kapton foils and measured in transmission geometry in a rotating holder. Intensity data from 1 to 40 degrees two theta were collected. N 2 77 K Sorption Measurements. All samples were activated at 300˚C overnight under dynamic vacuum before collecting N 2 sorption measurements for surface area and porosity determination. N 2 adsorption and desorption isotherms on activated materials were measured on a Micromeritics 3Flex instrument at 77 K. Room Temperature Adsorption Measurements. All samples (~50 mg) were activated at 300˚C overnight under dynamic vacuum before collecting single-component adsorption measurements. Isotherms were collected for ortho, para, and meta-xylene for vapor uptake at room temperature on a Micromeritics 3Flex instrument. Thermogravimetric Analyses (TGA). TGA was performed on a TGA/DCS 1 system (Mettler-Toledo AG, Schwerzenbach, Switzerland). Samples were heated from 30 to 600 °C at a rate of 10 °C/min under air with flow rate 20 mL/min. Scanning electron micrographs (SEM) images were taken using a Hitachi SU8030 at the EPIC facility (NUANCE Center-Northwestern University). Samples were suspended in acetone and drop-casted on an aluminum stub and coated with OsO 4 to ~9 nm thickness in a Denton Desk III TSC Sputter Coater before imaging.
Nature Catalysis, 2022
All reagents were purchased from commercial suppliers (Aldrich, Fisher, Ambeed) and used without ... more All reagents were purchased from commercial suppliers (Aldrich, Fisher, Ambeed) and used without further purification. Pyrene derivatives, 1,6-bis(4-pyridyl)pyrene (1,6 PyBPY) and 2,7bis(4-pyridyl)pyrene (2,7 PyBPY) were synthesized following earlier reports 1,2 in the literature. All reactions and manipulations were carried out under a dry N2 atmosphere using standard Schlenk conditions. Thin-layer chromatography (TLC) was performed on silica gel 60 F254 TLC plates (Merck). Column chromatography was carried out using CombiFlash ® Automation Systems (Teledyne ISCO), employing both normal phase (RediSep Rf Gold® Normal-Phase Silica) and reverse phase (RediSep Rf Gold® Reversed-phase C18). Characterization Absorption spectra were acquired on a Varian Cary 5000 spectrometer in a 2-mm quartz cuvette in MeCN. All the spectra were baseline-corrected with a MeCN blank sample. The photoluminescence spectra of all samples were obtained with a Fluorolog-3 spectrafluorometer (Horiba Jobin Yvon) in a 2-mm quartz cuvette with 3-nm slit width and a front-phase geometry. The femtosecond and nanosecond transient absorption (fsTA/nsTA) apparatus has been described previously. 3 Nuclear magnetic resonance (NMR) spectra were recorded on Bruker Avance III 500 and 600 MHz spectrometers, with working frequencies of 500 and 600 MHz (1 H NMR) and 125 MHz (13 C NMR), respectively. Chemical shifts are reported in ppm relative to the signals corresponding to the residual non-deuterated solvents (CD3CN: δH = 1.94 ppm and δC = 1.32 ppm). High-resolution mass spectra (HRMS) were measured on an Agilent 6210 Time of Flight (TOF) LC-MS, using an ESI source, coupled with Agilent 1100 HPLC stack, using direct infusion (0.6
Cell Reports Physical Science, 2022
Copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions are efficient and selective, but ch... more Copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions are efficient and selective, but challenges remain in using it to prepare crystalline two-dimensional (2D) polymers. Here, Roy et al. show that a cyclophane-based, highly crystalline, 2D polymer synthesized by CuAAC at a liquid-liquid interface can become useful in making state-of-the-art nanofiltration membranes for water purification.
Industrial & Engineering Chemistry Research, 2022
This work describes the stripping and refining of cannabidiol (CBD) from hemp extracts using a wi... more This work describes the stripping and refining of cannabidiol (CBD) from hemp extracts using a wiped-film molecular distillation (WFMD) system. The process takes place in two stages, where the CBD gets stripped in the first stage and refined in the second stage. The main feed encompassing decarboxylated hemp extracts enters the stripping step at a CBD concentration of about 35.8 wt % and leaves at 48.0 wt %, where the majority of terpenes leave the extracts. In the refining stage, the effects of process conditions, including pressure, evaporation temperature, and condensation temperature, were examined using the response surface methodology (RSM) toward the maximum CBD concentration and recovery. A second-stage recovery of 92.66 wt % was achieved at the concentration of 80.19% by applying a pressure of 40 Pa, an evaporation temperature of 170 °C, and an internal condenser temperature of 20 °C. Analysis of the product showed that a low-pressure operation did not remove tetrahydrocannabinol from the CBD-rich product, thus proving to be an improper choice of WFMD for removing the psychoactive component. It was also found that the pressure reduction and increases in evaporation and condensation temperatures were contributing to higher CBD concentrations, although the condensation temperature had no effect on the recovery amount. The RSM and artificial neural network were further tested to assess their prediction capacity toward the efficiency and process performance. It was found that both models offer satisfying prediction capability, although the RSM had larger margins of error.
Journal of the American Chemical Society, 2022
Three achiral polycyclic aromatic fluorophores─namely, 1-pyrenecarboxylic acid, 9-anthracenecarbo... more Three achiral polycyclic aromatic fluorophores─namely, 1-pyrenecarboxylic acid, 9-anthracenecarboxylic acid, and perylene-3,9-dicarboxylic acid─were chosen based on their desired properties before being incorporated into the construction of a K+-carrying gamma-cyclodextrin (γ-CD)-based metal–organic framework (CD-MOF-1) and γ-CD-containing hybrid frameworks (CD-HFs). Among these fluorophores, only the pyrene-carrying one shows significant noncovalent bonding interactions with γ-CD in solution. This fluorophore is encapsulated in a CD-HF with a trigonal superstructure instead of the common cubic CD-MOF-1 found in the case of the other two fluorophores. Single-crystal X-ray diffraction analysis of the trigonal CD-HF reveals a π-stacked chiral positioning of the pyrene-carrying fluorophore inside the (γ-CD)2 tunnels and held uniformly around an enantiomorphous 32 screw axis along the c direction in the solid-state structure. This helix-like structure demonstrates an additional level of chirality over and above the point-chiral stereogenic centers of γ-CD and the axial chirality associated with the self-assembled π-stacked fluorophores. These arrangements result in specifically generated photophysical and chiroptical properties, such as the controlled emergence of circularly polarized luminescence (CPL) emission. In this manner, a complete understanding of the mechanism of chirality transfer from a chiral host (CD-HF) to an encapsulated achiral fluorophore has been achieved, an attribute which is often missing in the development of materials with CPL.
Journal of Thermal Analysis and Calorimetry, 2019
The present study investigates the effects of substituents, structural rigidity, tautomerism, hyd... more The present study investigates the effects of substituents, structural rigidity, tautomerism, hydrogen bonding interaction, and spatial hindrance on the thermal stability of some azo compounds including bisazo Tröger base analogs (BATBAs). The relatively large structures of BATBAs allow assessing their thermal stability before reaching the sublimation or boiling point. BATBAs carry two identical azo groups per molecule resulting in an intense and detectable sign of decomposition. Unlike most azo dyes, BATBAs are not ionic and prevent the complexity of decomposition associated with simultaneous dehydration. A few commercial azo dyes are also analyzed to evaluate the generality of the conclusion.
Organic Chemistry Frontiers, 2017
This article describes the synthesis and characterization of azo derivatives of the Hünlich base.... more This article describes the synthesis and characterization of azo derivatives of the Hünlich base. The possession of modifiable extremities, a Λ-shaped core, and photo-responsive groups are features of these novel products. Such materials may provide a handy tool-kit including a set of photoswitches with a specific response to external stimuli.
Synlett , 2017
Hünlich’s base modification has resulted in introducing a series of versatile Λ-shaped building b... more Hünlich’s base modification has resulted in introducing a series of versatile Λ-shaped building blocks presented in this work. The methods are optimized to provide convenient approaches in the quicker production of these new building blocks in low-cost and low-risk.
Synthesis, 2017
The production of azo derivatives of a di-amino analogue of Tröger’s base (Hünlich base), by empl... more The production of azo derivatives of a di-amino analogue of Tröger’s base (Hünlich base), by employing the standard procedures of diazotization, azo-coupling and Williamson etherification is described here. These versatile molecules possess a Λ-shaped core, photoswitchable groups and some carry two modifiable extremities to enable further synthesis or molecular assembly. The synthesis is straightforward and requires inexpensive starting materials, which facilitates their application to different fields of research such as light-driven molecular machine design.
Journal of Molecular Structure, 2018
Bisazo Tröger base analogs are claw-looking molecules that carry two identical but independent ph... more Bisazo Tröger base analogs are claw-looking molecules that carry two identical but independent photoswitching groups. These bisazo compounds, like dual switches, can be at EE, EZ, and ZZ photoisomerization states while the ∧-shape void of Tröger base scaffold may also introduce an additional possibility of stereoisomerism by holding the photoisomerizable groups in endo or exo positions. To date, the exact molecular geometries of the isomerizable analogs of Tröger's base have not been elaborated. Owing to the special features and potential applications of these molecules, herein their photoisomerization is probed. The gleaned data from 15N isotope labeling and a variety of spectroscopic, spectrophotometric, crystallographic, and computational techniques have revealed the structure of the studied photoisomers and suggested their use in the design of molecular pull and push mechanisms, light driven actuators, and artificial muscles.
New Journal of Chemistry, 2019
The enantiomer separation of a chiral Tröger's base analog and its use, as an optically active bu... more The enantiomer separation of a chiral Tröger's base analog and its use, as an optically active building block, in the construction of molecular superstructures are presented. Various strategies are illustrated here for the attachment of azo photoswitches to the Tröger's base scaffold without racemizing its stereogenic centers. The resulting optically active photoswitches introduced chirality, thermochromic, and phototunable properties to an achiral liquid crystal host. The doped mesophases reflected specific wavelengths of light owing to the formation of self-organized helical superstructures. These observations illustrate the potential use of the presented products as liquid crystal dopants.
Books by MASOUD KAZEM-ROSTAMI
Prime Archives in Agricultural Research: Volume 2, 2021
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Papers by MASOUD KAZEM-ROSTAMI
Books by MASOUD KAZEM-ROSTAMI
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URL: https://videleaf.com/recent-advances-in-cannabinoid-extraction-from-hemp/