We performed global minimum searches for the B(n) H(n+2) (n=2-5) series and found that classical structures composed of 2c-2e B-H and B-B bonds become progressively less stable along the series. Relative energies increase from 2.9 kcal mol(-1) in B(2) H(4) to 62.3 kcal mol(-1) in B(5) H(7). We believe this occurs because boron atoms in the studied molecules are trying to avoid sp(2) hybridization and trigonal structure at the boron atoms, as in that case one 2p-AO is empty, which is highly unfavorable. This affinity of boron to have some electron density on all 2p-AOs and avoiding having one 2p-AO empty is a main reason why classical structures are not the most stable configurations and why multicenter bonding is so important for the studied boron-hydride clusters as well as for pure boron clusters and boron compounds in general.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.201200506 | DOI Listing |
Comput Struct Biotechnol J
December 2024
School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong 250300, China.
Protein circular permutations are crucial for understanding protein evolution and functionality. Traditional detection methods face challenges: sequence-based approaches struggle with detecting distant homologs, while structure-based approaches are limited by the need for structure generation and often treat proteins as rigid bodies. Protein Language Model-based alignment tools have shown advantages in utilizing sequence information to overcome the challenges of detecting distant homologs without requiring structural input.
View Article and Find Full Text PDFHeliyon
January 2025
College of Since and Art, Department of Mathematics, King Khalid University, Mahayil, Saudi Arabia.
New developments in the field of chemical graph theory have made it easier to comprehend how chemical structures relate to the graphs that underlie them on a more profound level using the ideas of classical graph theory. Chemical graphs can be effectively probed with the help of quantitative structure-property relationship (QSPR) analysis. In order to statistically correlate physical attributes.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Laboratório Bioquímica e Biofísica, Instituto Butantan, São Paulo, Av. Vital Brasil 1500, São Paulo, SP 05503-900, Brazil. Electronic address:
Although proteins in snake venoms have been extensively studied and characterized, low-mass molecules remain relatively unexplored, mainly due to their low abundance, secondary role in envenomation, and some analytical technique limitations. However, these small molecules can provide new important data related to venom toxins' molecular structure, functions, and evolutionary relationships. This research aimed to characterize molecules below 10 kDa in the venoms of snakes from the Viperidae families (Bothrops, Agkistrodon, and Bitis) and compare two chromatographic approaches: reverse-phase chromatography (RP), a classic technique, and hydrophilic interaction liquid chromatography (HILIC), an alternative technique, both coupled with high-resolution mass spectrometry (HRMS).
View Article and Find Full Text PDFEur J Med Chem
January 2025
Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, No. 1 Xian Nong Tan Street, Beijing, 100050, PR China; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences & Research Unit of Peptide Science, Chinese Academy of Medical Sciences, 2019RU066, Lanzhou University, Lanzhou, 730000, PR China; Institute of Pharmaceutics, School of Pharmacy, 2019RU066, Lanzhou University, Lanzhou, 730000, PR China. Electronic address:
De novo design of antimicrobial peptides is a pivotal strategy for developing new antibacterial agents, leveraging its rapid and efficient nature. (XXYY), where X represents cationic residues, Y denotes hydrophobic residues, and n varies from 2 to 4, is a classical α-helix template. Based on which, numerous antimicrobial peptides have been synthesized.
View Article and Find Full Text PDFLight Sci Appl
January 2025
National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, 410082, Changsha, China.
Accurately and swiftly characterizing the state of polarization (SoP) of complex structured light is crucial in the realms of classical and quantum optics. Conventional strategies for detecting SoP, which typically involves a sequence of cascaded optical elements, are bulky, complex, and run counter to miniaturization and integration. While metasurface-enabled polarimetry has emerged to overcome these limitations, its functionality predominantly remains confined to identifying SoP within the standard Poincaré sphere framework.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!