The semiempirical SCF MO method MSINDO (modified symmetrically orthogonalized intermediate neglect of differential overlap) [T. Bredow and K. Jug, Electronic Encyclopedia of Computational Chemistry, 2004] is extended to the calculation of excited state properties through implementation of the configuration interaction singles (CIS) approach. MSINDO allows the calculation of periodic systems via the cyclic cluster model (CCM) [T. Bredow et al., J. Comput. Chem., 2001, 22, 89] which is a direct-space approach and therefore can be in principle combined with all molecular quantum-chemical techniques. The CIS equations are solved for a cluster with periodic boundary conditions using the Davidson-Liu iterative block diagonalization approach. As a proof-of-principle, MSINDO-CCM-CIS is applied for the calculation of optical spectra of ZnO and TiO(2), oxygen-defective rutile, and F-centers in NaCl. The calculated spectra are compared to available experimental and theoretical literature data. After re-adjustment of the empirical parameters the quantitative agreement with experiment is satisfactory. The present approximate approach is one of the first examples of a quantum-chemical methodology for solids where excited states are correctly described as n-electron state functions. After careful benchmark testing it will allow calculation of photophysical and photochemical processes relevant to materials science and catalysis.
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http://dx.doi.org/10.1039/c1cp22871d | DOI Listing |
Inorg Chem
January 2025
College of Chemistry and Chemical Engineering, Xi'an Shiyou University, Xi'an 710065, China.
Luminescent lanthanide compounds stand out for their distinctive characteristics including narrow emission bands, substantial Stokes shifts, high quantum yields, and unique luminescent colors. However, Ln is highly susceptible to vibrational quenching from X-H (X = O/N) high-energy oscillators in the embedded organic antenna, resulting in significant nonradiative energy dissipation of the D excited states of Ln. Herein, we introduce a strategy based on supramolecular interactions to modulate the nonradiative transitions in a new Zn-Tb heterometallic compound, [ZnTb(HL)(NO)Cl]·2CHCN·HO (), based on a phenyl-substituted pyrazolinone-modified salicylamide-imide ligand ().
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada.
N-heterocyclic carbene (NHC)-protected gold nanoclusters display high stability and high photoluminescence, making them well-suited for fluorescence imaging and photodynamic therapeutic applications. We report herein the synthesis of two bisNHC-protected Au nanoclusters with π-extended aromatic systems. Depending on the position of the π-extended aromatic system, changes to the structure of the ligand shell in the cluster are observed, with the ability to correlate increases in rigidity with increases in fluorescence quantum yield.
View Article and Find Full Text PDFChem Asian J
January 2025
Kyoto Institute of Technology: Kyoto Kogei Sen'i Daigaku, Faculty of Molecular Chemistry and Engineering, Goshokaido-cho, Matsugasaki, Sakyo-ku, 606-0962, Kyoto, JAPAN.
Heteroarene-fused heteroles have attracted considerable attention owing to their unique electronic and photophysical properties. The bridging element plays a crucial role in determining the electronic characteristics of the resulting π-conjugated molecules. In this study, we synthesized a series of heteroarene-fused benzo[b]arsoles and investigated their structures and photophysical properties.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0309, United States.
Controlling molecular actions on demand is a critical step toward developing single-molecule functional devices. Such control can be achieved by manipulating the interactions between individual molecules and their nanoscale environment. In this study, we demonstrate the conformational transition of a single pyrrolidine molecule adsorbed on a Cu(100) surface, driven by vibrational excitation through tunneling electrons using scanning tunneling microscopy.
View Article and Find Full Text PDFAnal Chem
January 2025
Experimental Physics III, TU Dortmund University, Dortmund 44227, Germany.
Spectral dispersion in low-field nuclear magnetic resonance (NMR) can significantly affect NMR spectral analysis, particularly when studying complex mixtures like metabolic profiling of biological samples. To address signal superposition in these spectra, we employed spectral editing with selective excitation pulses, proving it to be a suitable approach. Optimal control pulses were implemented in low-field NMR and demonstrated their capability to selectively excite and eliminate specific amino acids, such as phenylalanine and taurine, either individually or simultaneously.
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