A5052568377- Molecular Spectroscopy and Structure
- Advanced Chemical Physics Studies
- Atmospheric Ozone and Climate
- Astrophysics and Star Formation Studies
- Spectroscopy and Laser Applications
- Healthcare Policy and Management
- Global Public Health Policies and Epidemiology
- Atomic and Molecular Physics
- Primary Care and Health Outcomes
- Astro and Planetary Science
- Health Systems, Economic Evaluations, Quality of Life
- Pharmaceutical industry and healthcare
- Inorganic Fluorides and Related Compounds
- Stellar, planetary, and galactic studies
- Pharmaceutical Economics and Policy
- Healthcare Systems and Challenges
- Spectroscopy and Quantum Chemical Studies
- Molecular spectroscopy and chirality
- Various Chemistry Research Topics
- Synthesis and characterization of novel inorganic/organometallic compounds
- Child and Adolescent Health
- Healthcare cost, quality, practices
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Atmospheric chemistry and aerosols
AstraZeneca (United States)
2025
Harvard University
2012-2024
Center for Astrophysics Harvard & Smithsonian
2015-2024
University of Washington
2020-2024
University of California, San Diego
2023-2024
Circadian (United States)
2024
VA San Diego Healthcare System
2023-2024
Cardiff Metropolitan University
2024
University of Colorado Boulder
2021-2023
Universidad Católica Santo Domingo
2023
Metal–organic frameworks (MOFs) are hybrid organic–inorganic nanoporous materials that exhibit regular crystalline lattices with relatively well-defined pore structures. Chemical functionalization of the organic linkers in structures MOFs affords facile control over size and chemical/physical properties, making attractive for a variety industrial applications including membrane-based gas separations. A wealth reports exists discussing synthesis MOFs; however, few exist MOF membranes. This...
Polycyclic aromatic hydrocarbons and polycyclic nitrogen heterocycles are thought to be widespread throughout the Universe, because these classes of molecules probably responsible for unidentified infrared bands, a set emission features seen in numerous Galactic extragalactic sources. Despite their expected ubiquity, astronomical identification specific has proven elusive. We present discovery benzonitrile ($c$-C$_6$H$_5$CN), one simplest nitrogen-bearing molecules, interstellar medium....
Zeolitic imidazolate frameworks (ZIFs) are hybrid organic-inorganic microporous materials that exhibit zeolite-like structures and can be synthesized with a wide range of pore sizes chemical functionality. ZIFs as thin films membranes interest for their applications in sensors gas separation. Here, we report method ZIF film membrane fabrication, based on support surface modification situ solvothermal growth, which has potential general application to other membranes. Our simple results...
The negative molecular ion C6H- has been detected in the radio band laboratory and identified envelope of IRC +10216 dense cloud TMC-1. spectroscopic constants derived from measurements 17 rotational lines between 8 187 GHz are identical to those astronomical data, establishing unambiguously that is carrier series with constant 1377 MHz first observed by K. Kawaguchi et al. +10216. column density toward both sources 1%-5% neutral C6H. These surprisingly high abundances for a imply if other...
Identifying PAHs in space Midinfrared spectroscopy has shown that polycyclic aromatic hydrocarbons (PAHs) are abundant many astronomical objects, but this technique cannot determine which specific PAH molecules present. Radio astronomy could provide individual identifications if the molecule is sufficiently and a large dipole moment, expected to produce numbers of very weak lines. McGuire et al. performed stacking matched filter analysis search for radio observations TMC-1, located within...
Polycyclic Aromatic Hydrocarbons (PAHs) have long been invoked in the study of interstellar and protostellar sources, but unambiguous identification any individual PAH has proven elusive until very recently. As a result, formation mechanisms for this important class molecules remain poorly constrained. Here we report first detection pure hydrocarbon PAH, indene (C$_9$H$_8$), as part GBT Observations TMC-1: Hunting Molecules (GOTHAM) survey. This provides new avenue chemical inquiry,...
We present laboratory rotational spectroscopy of five isomers cyanoindene (2-, 4-, 5-, 6-, and 7-cyanoindene) using a cavity Fourier-transform microwave spectrometer operating between 6-40 GHz. Based on these measurements, we report the detection 2-cyanoindene (1H-indene-2-carbonitrile; 2-C$_9$H$_7$CN) in GOTHAM line survey observations dark molecular cloud TMC-1 Green Bank Telescope at centimeter wavelengths. Using combination Markov Chain Monte Carlo (MCMC), spectral stacking, matched...
The negative molecular ion C8H- has been detected in the Galactic source TMC-1. Four rotational transitions have observed centimeter-wave band with NRAO 100 m Green Bank Telescope (GBT) at precisely frequencies calculated from recent laboratory spectroscopy of this large carbon chain anion. is about 5% as abundant C8H, or somewhat more than C6H- relative to C6H (1.6%). Improved values column densities and C6H, an upper limit for abundance smaller C4H- 0.014% respect C4H, also determined.
Aims.Following the recent detection of C6H- in laboratory and space we have succeeded studying microwave spectrum C4H-. We report here first this negative ion.
Here we report the synthesis of continuous HKUST-1 membranes on porous supports via secondary (i.e., seeded) growth method. A new seeding technique (“thermal seeding”) was developed to strongly anchor seed crystals α-alumina supports. It found critical have both organic ligands and copper species in suspension as well at elevated temperature. The were then hydrothermally grown into films. formation cracks fractures films prevented by controlling cooling drying processes after...
The negative molecular ion C3N− has been detected at millimeter wavelengths in a low-pressure laboratory discharge, and then with frequencies derived from the data envelope of IRC+10216. Spectroscopic constants measurements 12 transitions between 97 378 GHz allow rotational spectrum to be calculated well into submillimeter-wave band 0.03 km s−1 or better equivalent radial velocity. Four were IRC+10216 IRAM 30 m telescope precisely measurements. column density is 0.5% that C3N, approximately...
We present the first astronomical detection of a diatomic negative ion, cyanide anion CN-, as well quantum mechanical calculations excitation this through collisions with para-H2. CN- is identified observation J = 2-1 and 3-2 rotational transitions in C-star envelope IRC +10216 IRAM 30-m telescope. The U-shaped line profiles indicate that like large C6H-, formed outer regions envelope. Chemical model suggest species forms from reaction carbon anions N atoms, rather than radiative attachment...
Two consecutive rotational transitions of the long cyanopolyyne HC11N, J = 39 → 38 and 37, have been detected in cold dust cloud TMC-1 at frequencies expected from recent laboratory measurements by Travers coworkers, about intensities. The astronomical lines a mean radial velocity 5.8(1) km s-1, good agreement with shorter cyanopolyynes HC7N HC9N observed this very sharp line source [5.82(5) 5.84(5) respectively]. column density HC11N is calculated to be 2.8 × 1011 cm-2. abundance decreases...
We report the detection in envelope of C-rich star IRC +10216 four series lines with harmonically related frequencies: B1389, B1390, B1394, and B1401. The must arise from linear molecules mass size close to those C6H C5N. Three have half-integer rotational quantum numbers; we assign them 2Δ 2Σ− vibronic states its lowest (ν11) bending mode. fourth series, has integer J no evidence fine or hyperfine structure; it a constant 1388.860(2) MHz centrifugal distortion 33(1) Hz; is almost certainly...
The detection of E-cyanomethanimine (E-HNCHCN) toward Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra to laboratory rotational from a reaction product screening experiment. experiment uses broadband molecular spectroscopy monitor products produced in an electric discharge source using gas mixture NH3 and CH3CN. Several transition frequency coincidences between previously unassigned interstellar transitions have been assigned...
Metal-organic frameworks (MOFs) are attractive for gas separation membrane applications due to their microporous channels with tunable pore shape, size, and functionality. Conventional MOF fabrication techniques, namely in situ secondary growth, pose challenges wider commercial applications. These include reproducility, scalability, high manufacturing cost. Recognizing that the coordination chemistry of MOFs is fundamentally different from covalent zeolites, we developed a radically strategy...
The fraction of the collisionally stabilized Criegee species CH2OO produced from ozonolysis ethylene is calculated using a two-dimensional (E, J)-grained master equation technique and semiclassical transition-state theory based on potential energy surface obtained high-accuracy quantum chemical calculations. Our yield 42 ± 6% for agrees well, within experimental error, with available (indirect) results. Inclusion angular momentum in found to play an essential role bringing theoretical...
Astrochemistry lies at the nexus of astronomy, chemistry, and molecular physics. On basis precise laboratory data, a rich collection more than 200 familiar exotic molecules have been identified in interstellar medium, vast majority by their unique rotational fingerprint. Despite this large body work, there is scant evidence radio band for basic building blocks chemistry on earth─five- six-membered rings─despite long-standing sustained efforts during past 50 years. In contrast, peculiar...
Abstract Using data from the Green Bank Telescope (GBT) Observations of TMC-1: Hunting for Aromatic Molecules (GOTHAM) survey, we report first astronomical detection C 10 H − anion. The observations also provided necessary to refine spectroscopic parameters . From velocity stacked and matched filter response, is detected at >9 σ confidence level a column density <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>4.04</mml:mn>...
Polycyclic aromatic hydrocarbons (PAHs) are organic molecules containing adjacent rings. Infrared emission bands show that PAHs abundant in space, but only a few specific have been detected the interstellar medium. We 1-cyanopyrene, cyano-substituted derivative of related four-ring PAH pyrene, radio observations dense cloud TMC-1, using Green Bank Telescope. The measured column density 1-cyanopyrene is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"...