- and -Isomers and Fermi Resonance of Acetic Acid in Acetonitrile Revealed by 2D IR.

Acetic acid exists as - and -isomers in a low-temperature rare-gas matrix. However, in aprotic acetonitrile, its IR spectrum in the C═O stretch region exhibits a multiple-band feature, which is not clearly understood by conventional FTIR spectroscopy. In this regard, two-dimensional infrared (2D IR) spectroscopy is applied to understand the origin more deeply.

Synergistic Buried Interface Regulation of Tin-Lead Perovskite Solar Cells via Co-Self-Assembled Monolayers.

Tin-lead (Sn-Pb) perovskite solar cells (PSCs) hold considerable potential for achieving efficiencies near the Shockley-Queisser (S-Q) limit. Notably, the inverted structure stands as the preferred fabrication method for the most efficient Sn-Pb PSCs. In this regard, it is imperative to implement a strategic customization of the hole selective layer to facilitate carrier extraction and refine the quality of perovskite films, which requires effective hole selectivity and favorable interactions with Sn-Pb perovskites.

Systematic investigation of coupling between symmetric and antisymmetric stretches of D2O in CHCl3 by 2D IR.

The coupling between the symmetric (νs) and antisymmetric (νa) OD stretch modes of monomeric D2O in CHCl3 is investigated using polarization-dependent two-dimensional infrared (2D IR) spectroscopy supported by numerical 2D IR simulations based on the exciton-band theory. The relationship between the local modes' and the exciton states' parameters is systematically studied, including center frequencies, diagonal anharmonicities, coupling, and off-diagonal anharmonicity. The mean coupling between νs and νa is accurately evaluated to be -49.

Scattering Elimination of Heterodyne-Detected Two-Dimensional Infrared Spectra Using Choppers and Shutters.

Obtaining high-quality 2D IR spectra of heterogeneous samples such as perovskite films or metal-organic framework powder is hampered by severe light scattering. In the pump-probe (PP) method, this problem can be circumvented by phase cycling. However, in the heterodyned photon echo (HPE) method, phase cycling does not function as effectively as the PP method.