Bala Subramaniam

Bio: Bala Subramaniam is an academic researcher from University of Kansas. The author has contributed to research in topics: Catalysis & Supercritical fluid. The author has an hindex of 46, co-authored 285 publications receiving 7525 citations. Previous affiliations of Bala Subramaniam include University of California, Irvine & Archer Daniels Midland.

CO2-Expanded Solvents: Unique and Versatile Media for Performing Homogeneous Catalytic Oxidations

Abstract: The work summarized here demonstrates a new concept for exploiting dense phase CO2, media considered to be “green” solvents, for homogeneous catalytic oxidation reactions. According to this concept, the conventional organic solvent medium used in catalytic chemical reactions is replaced substantially (up to 80 vol %) by CO2, at moderate pressures (tens of bars), to create a continuum of CO2-expanded solvent media. A particular benefit is found for oxidation catalysis; the presence of CO2 in the mixed medium increases the O2 solubility by ca. 100 times compared to that in the neat organic solvent while the retained organic solvent serves an essential role by solubilizing the transition metal catalyst. We show that CO2-expanded solvents provide optimal properties for maximizing oxidation rates that are typically 1−2 orders of magnitude greater than those obtained with either the neat organic solvent or supercritical CO2 as the reaction medium. These advantages are demonstrated with examples of homogeneous o...

Green Chemistry: Principles and Practice

Abstract: Green Chemistry is a relatively new emerging field that strives to work at the molecular level to achieve sustainability. The field has received widespread interest in the past decade due to its ability to harness chemical innovation to meet environmental and economic goals simultaneously. Green Chemistry has a framework of a cohesive set of Twelve Principles, which have been systematically surveyed in this critical review. This article covers the concepts of design and the scientific philosophy of Green Chemistry with a set of illustrative examples. Future trends in Green Chemistry are discussed with the challenge of using the Principles as a cohesive design system (93 references).

Recent advances in catalytic hydrogenation of carbon dioxide

Abstract: Owing to the increasing emissions of carbon dioxide (CO2), human life and the ecological environment have been affected by global warming and climate changes. To mitigate the concentration of CO2 in the atmosphere various strategies have been implemented such as separation, storage, and utilization of CO2. Although it has been explored for many years, hydrogenation reaction, an important representative among chemical conversions of CO2, offers challenging opportunities for sustainable development in energy and the environment. Indeed, the hydrogenation of CO2 not only reduces the increasing CO2 buildup but also produces fuels and chemicals. In this critical review we discuss recent developments in this area, with emphases on catalytic reactivity, reactor innovation, and reaction mechanism. We also provide an overview regarding the challenges and opportunities for future research in the field (319 references).

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg