A new version of the multireference Mukherjee's coupled cluster method with perturbative triexcitations has been formulated, which is based on the uncoupled approximation applied to the triples equation. In contrast to the method developed by Evangelista et al. [J. Chem. Phys. 132, 074107 (2010)], the proposed approach does not require to solve the equation for T(3) amplitudes iteratively, yet yields results of essentially the same quality. The method, abbreviated as MR MkCCSD(Tu), has been implemented in the ACES II program package and its assessment has been performed on the BeH(2) model and on the tetramethyleneethane molecule.
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http://dx.doi.org/10.1063/1.3573373 | DOI Listing |
Chemistry
December 2024
Pandit Deendayal Energy University, Chemistry, Gandhinagar, Gujarat-382077, India, Gandhinagar, INDIA.
The accurate discrimination among various volatile organic compounds, especially ethanol and acetone possess a serious concern for metal oxide based chemiresistive sensors. The work presents a systematic approach to address the issue by utilizing superior sensing potentiality of Zn0.5Ni0.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry, Panskura Banamali College, Panskura RS, West Bengal 721152, India.
In this study, a tetradentate Schiff-base ligand (HL), synthesized by the condensation of ethylenediamine with 2-hydroxy-3-methoxy-5-methylbenzaldehyde, was reacted with either manganese salts or manganese salts in the presence of various pseudohalides in methanol. This reaction resulted in the formation of five mononuclear Mn complexes: [Mn(L)(HO)](NO)·1/2HO·1/2CHOH (), [Mn(L)(HO)](ClO)·HO (), [Mn(L)(N)(HO)]·1/3HO (), [Mn(L)(NCS)(HO)] (), and [Mn(L)(HO)](dca) () (where dca is dicyanamide ion). X-ray crystallography revealed that the Mn centers adopt a hexa-coordinate pseudo-octahedral geometry, where the equatorial plane is constructed with phenoxo oxygen and imine nitrogen atoms from the Schiff base ligand, while the axial positions are occupied by water molecules or a combination of water and pseudohalides.
View Article and Find Full Text PDFCirc Cardiovasc Interv
December 2024
Cardiovascular Clinical Research Center, Department of Medicine, NYU Grossman School of Medicine, New York, NY (H.R.R., L.P., S.B., J.S.H.).
Background: The relationship between the extent and severity of stress-induced ischemia and the extent and severity of anatomic coronary artery disease (CAD) in patients with obstructive CAD is multifactorial and includes the intensity of stress achieved, type of testing used, presence and extent of prior infarction, collateral blood flow, plaque characteristics, microvascular disease, coronary vasomotor tone, and genetic factors. Among chronic coronary disease participants with site-determined moderate or severe ischemia, we investigated associations between ischemia severity on stress testing and the extent of CAD on coronary computed tomography angiography.
Methods: Clinically indicated stress testing included nuclear imaging, echocardiography, cardiac magnetic resonance imaging, or nonimaging exercise tolerance test.
Chem Asian J
December 2024
Ramakrishna Mission Residential College, Dept of Chemistry, Narendrapur, Kolkata-103, 700103, Kolkata, INDIA.
The article reports a hitherto-unknown aromatic proton transfer (APT) to the o-amine function chelated to manganese(II) ion and disintegration of the molecule generating an aryne intermediate. The reaction of (NQ)-NH(AQ) (o-HLH) with manganese(II) acetate in boiling DMF generates [MnII(o-HL-)2], where the o-HLH ligands undergo disintegration forming manganese(II) complexes of AQ and an 1,4- naphthoquinonyne intermediate based on benzoquinone ring, that has been defined as [NQ-2H] (NQ and AQ abbreviate respectively 1,4-naphthoquinone and 8-aminoquinoline fragments). The disintegration reaction of o-HLH depends on the metal precursor used, solvent and temperature.
View Article and Find Full Text PDFJ Chem Theory Comput
December 2024
Aix Marseille University, CNRS, ICR, Marseille 13397, France.
Nonadiabatic dynamics simulations complement time-resolved experiments by revealing ultrafast excited-state mechanistic information in photochemical reactions. Understanding the relaxation mechanisms of photoexcited molecules finds application in energy, material, and medicinal research. However, with substantial computational costs, the nonadiabatic dynamics simulations have been restricted to ultrafast timescales, typically less than a few picoseconds, thus neglecting a wide range of photoactivated processes occurring in much longer timescales.
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