The conformational preferences and the self-associational behaviors of two hemin-derived porphyrin compounds, a tetramethyl ester and a liquid crystalline tetrakis(3,5-didodecyloxyphenyl)ester, have been studied by UV/vis and (1)H NMR spectroscopy in solution. Results indicate that the 3,5-didodecyloxyphenyl units play an important role in both the conformational and the self-associational behaviors of the mesomorphic tetraester. In the monomeric, nonassociated species, the two propionic 3,5-didodecyloxyphenyl esters establish mutual CH/pi interactions that restrict the fluctuative behavior of the chains. In the dimeric, self-associated species, intermolecular CH/pi interactions occur in addition to the pi-pi stacking of the porphyrin cores. The temperature-dependent addition of side CH/pi interactions to the pi-pi stacking of the porphyrin rings accounts for the observed tightening and for the slower dynamics of the dimeric structure. The relationship between the self-associational behavior and the mesomorphism of the hemin-derived porphyrin tetraesters is also discussed.
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http://dx.doi.org/10.1021/jp800475f | DOI Listing |
J Chem Inf Model
January 2025
Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025, China.
Tryptophan participates in important life activities and is involved in various metabolic processes. The indole and aromatic binuclear ring structure in tryptophan can engage in diverse interactions, including π-π, π-alkyl, hydrogen bonding, cation-π, and CH-π interactions with other side chains and protein targets. These interactions offer extensive opportunities for drug development.
View Article and Find Full Text PDFChemistry
January 2025
Institute of Chemical Research of Catalonia: Institut Catala d'Investigacio Quimica, -, Av. Països Catalans 16, 43007, Tarragona, SPAIN.
Noncovalent interactions are present in numerous synthetic and biological systems, playing an essential role in vital processes for life such as stabilization of proteins' structures or reversible binding in substrate-receptor complexes. Their study is relevant, but it presents challenges due to its inherent weak nature. In this context, molecular balances (MBs) are one of the most efficient physical organic chemistry tools to quantify noncovalent interactions, bringing beneficial knowledge regarding their nature and strength.
View Article and Find Full Text PDFSmall
January 2025
Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong, 999077, China.
Carbazole-derived self-assembled monolayers (SAMs) are promising materials for hole-extraction layer (HEL) in conventional organic photovoltaics (OPVs). Here, a SAM Cbz-2Ph derived from 3,6-diphenylcarbazole is demonstrated. The large molecular dipole moment of Cbz-2Ph allows the modulation of electrode work function to facilitate hole extraction and maximize photovoltage, thus improving the OPV performance.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
College of Environmental Science and Engineering, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China. Electronic address:
Here we covalently constructed abundant long-chain hydroxyl groups-functionalized magnetic microporous organic networks (MMON-2OH) for detection of eight Triazine herbicides (THs) in honey and water samples. MMON-2OH owned a high surface area (287.86 m²/g), enhanced water compatibility, and increased exposure of long-chain hydroxyl groups, which significantly improved enrichment capacity for THs.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Organic and Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Isoprenylation of the indole C3-position of tryptophan accompanied by cyclization (c-Trp) is one of the most attractive post-translational modifications because of C-C bond formation and drastic conformational alteration. As the modification generates two stereoisomers of the 6/5/5-fused ring system and consequently, a mixture of four possible conformations as considered in proline, it is expected to influence the biological activity in quorum sensing pheromone ComX containing the c-Trp residue. In this study, the simultaneous control of the amide equilibrium and pyrrolidine ring puckering was achieved by utilizing an N-carbamoylated and α-methylated 6/5/5-fused ring system.
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