Thiophene-containing heteroarenes are one of the most well-known classes of π-conjugated building blocks for photoactive molecules. Isomeric naphthodithiophenes (NDTs) are at the forefront of this research area due to their straightforward synthesis and derivatization. Notably, NDT geometries that are bent - such as naphtho[2,1-:3,4-']dithiophene (α-NDT) and naphtho[1,2-:4,3-']dithiophene (β-NDT) - are seldom employed as photoactive small molecules. This report investigates how remote substituents impact the photophysical properties of isomeric α- and β-NDTs. The orientation of the thiophene units plays a critical role in the emission: in the α(OHex)R series conjugation from the end-caps to the NDT core is apparent, while in the β(O-Pent)R series minimal change is observed unless strong electron acceptors, such as β(O-Pent)(PhCF), are employed. This push-pull acceptor-donor-acceptor (A-D-A) fluorophore exhibits positive fluorosolvatochromism that correlates with increasing solvent polarity parameter, (30). In total, these results highlight how remote substituents are able to modulate the emission of isomeric bent NDTs.
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http://dx.doi.org/10.1039/d4ra04850d | DOI Listing |
Inorg Chem
January 2025
Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
This paper provides extensive studies of [IrCl(Ph-py)(morph-CH-terpy-κN)]PF (), [Ir(Ph-py)(morph-CH-terpy-κN)]PF (), [IrCl(Ph-py)(Ph-terpy-κN)]PF (), and [Ir(Ph-py)(Ph-terpy-κN)]PF () designed to demonstrate the possibility of controlling the photophysical properties of mono- and bis-cyclometalated complexes [IrCl(Ph-py)(R-CH-terpy-κN)]PF and [Ir(Ph-py)(R-CH-terpy-κN)]PF through a remote electron-donating substituent introduced into the 4'-position of 2,2':6',2″-terpyridine (terpy) via the phenyl linker. The attachment of the morpholinyl (morph) group was evidenced to induce dramatic changes in the emission characteristics of the monocyclometalated Ir(III) systems with coordinated R-CH-terpy ligand (κN). In solution, the obtained complex [IrCl(Ph-py)(morph-CH-terpy-κN)]PF was found to be a rare example of dual-emissive Ir(III) systems.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 2, Singapore, 117543, Singapore.
Asymmetric synthesis relies on seamless transmission of stereochemical information from a chiral reagent/catalyst to a prochiral substrate. The disruption by substrates' structural changes presents a hurdle in innovating generality-oriented asymmetric catalysis. Here, we report a strategy for substrate adaptability by exploiting a fundamental physicochemical phenomenon-ion hydration, in developing remote desymmetrization to access P-stereogenic triarylphosphine oxides and sulfides.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1 EW, U.K.
Cooperativity between H-bonding interactions in networks is a fundamental aspect of solvation and self-assembly in molecular systems. The interaction of a series of bisphenols, which make an intramolecular H-bond between the two hydroxyl groups, and quinuclidine was used to quantify cooperativity in three-component networks. The presence of the intramolecular H-bond in the bisphenols was established by using H NMR spectroscopy in solution and X-ray crystallography in the solid state.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States.
Understanding how changes in structure translate to changes in molecular shape is key to catalyst optimization and molecular design in medicinal chemistry and materials. One key contributor to the molecular shape is the relative orientation of substituents on a scaffold. Macrocyclic metacyclophanes display their two arenes in a parallel or antiparallel fashion, resulting in or conformations that lead to disparate relative orientations of the aryl substituents.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States.
A remote carbonyl group up to six atoms away from the acetal group can induce 1,2-asymmetric induction in nucleophilic substitution reactions of acyclic acetals. Isolation of a cyclic carbonate under Lewis acidic conditions and computational studies suggested that the remote carbonyl group participated through the formation of a cyclic dioxocarbenium ion intermediate. The stereochemical outcomes depended on the size of the alkyl substituent and that of the nucleophile employed.
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