Physical Chemistry Chemical Physics

doi: 10.1039/d2cp90178apmid: N/A

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doi: 10.1039/d2cp90179jpmid: N/A

A graphical abstract is available for this content

doi: 10.1039/d2cp90180cpmid: N/A

Bolognesi, P.; Avaldi, L.

doi: 10.1039/d2cp03079apmid: 36124990

Photoelectron–photoion(s) coincidence, PEPICO, experiments with synchrotron radiation have become one of the most powerful tools to investigate dissociative photoionization thanks to their selectivity. In this paper their application to the study of molecular species of biological interest in the gas phase is reviewed. Some applications of PEPICO to the study of potential radiosensitizers, amino acids and small peptides and opportunities offered by the advent of novel methods for the production of beams of these molecules are discussed.

Panwaria, Prakash; Das, Aloke

doi: 10.1039/d2cp02070jpmid: 35822956

Herein, a perspective on the recent understanding of weak n → π* interaction obtained using different experimental and theoretical approaches is presented. This interaction is purely an orbital interaction that involves the delocalization of the lone pair electrons (n) on nitrogen, oxygen, and sulfur to the π* orbitals of CO, CN, and aromatic rings. The n → π* interaction has been found to profoundly influence the stabilization of peptides, proteins, drugs, and various small molecules. Although the functional properties of this non-covalent interaction are still quite underestimated, there are recent demonstrations of applying this interaction to the regulation of synthetic chemistry, catalysis, and molecular recognition. However, the identification and quantification of the n → π* interaction remain a demanding task as this interaction is quite weak and based on the electron delocalization between the two orbitals, while hyperconjugation interactions between neighboring atoms and the group involved in the n → π* interaction are simultaneously present. This review provides a comprehensive picture of understanding the n → π* interaction using different experimental approaches such as the X-ray diffraction technique, and electronic, NMR, microwave, and IR spectroscopy, in addition to quantum chemistry calculations. A detailed understanding of the n → π* interaction can help in modulating the strength of this interaction, which will be further helpful in designing efficient drugs, synthetic peptides, peptidomimetics, etc.

Wang, Ridong; Hunter, Nicholas; Zobeiri, Hamidreza; Xu, Shen; Wang, Xinwei

doi: 10.1039/d2cp02126apmid: 35942687

In the last two decades, tremendous research has been conducted on the discovery, design and synthesis, characterization, and applications of two-dimensional (2D) materials. Thermal conductivity and interface thermal conductance/resistance of 2D materials are two critical properties in their applications. Raman spectroscopy, which measures the inelastic scattering of photons by optical phonons, can distinct a 2D material's temperature from its surrounding materials', featuring unprecedented spatial resolution (down to the atomic level). Raman-based thermometry has been used tremendously for characterizing the thermal conductivity of 2D materials (suspended or supported) and interface thermal conductance/resistance. Very large data deviations have been observed in literature, partly due to physical phenomena and factors not considered in measurements. Here, we provide a critical review, analysis, and perspectives about a broad spectrum of physical problems faced in Raman-based thermal characterization of 2D materials, namely interface separation, localized stress due to thermal expansion mismatch, optical interference, conjugated phonon, and hot carrier transport, optical–acoustic phonon thermal nonequilibrium, and radiative electron–hole recombination in monolayer 2D materials. Neglect of these problems will lead to a physically unreasonable understanding of phonon transport and interface energy coupling. In-depth discussions are also provided on the energy transport state-resolved Raman (ET-Raman) technique to overcome these problems and on future research challenges and needs.

Yumoto, Go; Kanemitsu, Yoshihiko

doi: 10.1039/d2cp02826cpmid: 36106456

Lead halide perovskite nanocrystals are attracting considerable interest as next-generation optoelectronic materials. Optical responses of nanocrystals are determined by excitons and exciton complexes such as trions and biexcitons. Understanding of their dynamics is indispensable for the optimal design of optoelectronic devices and the development of new functional properties. Here, we summarize the recent advances on the exciton and biexciton photophysics in lead halide perovskite nanocrystals revealed by femtosecond time-resolved spectroscopy and single-dot spectroscopy. We discuss the impact of the biexciton dynamics on controlling and improving the optical gain.

Graneri, Matthew H. V.; Wild, Duncan A.; McKinley, Allan J.

doi: 10.1039/d2cp03434dpmid: 36004581

The interaction between water and phosphine isolated in solid argon matrices has been investigated. Infrared spectra of matrices containing water and phosphine, as well as their deuterium and 18O isotopologues, revealed that a weak hydrogen bonded complex is formed, with an O–H⋯P bonding motif. This was supported by high level ab initio calculations, which predict a binding energy of only 5.1 kJ mol−1 (430 cm−1).

Bose, Amartya; Walters, Peter L.

doi: 10.1039/d2cp03030fpmid: 36102915

The recently introduced multisite tensor network path integral (MS-TNPI) method [Bose and Walters, J. Chem. Phys., 2022, 156, 24101] for simulating quantum dynamics of extended systems has been shown to be effective in studying one-dimensional systems coupled with local baths. Quantum transport in these systems is typically studied at a constant temperature. However, temperature seems to be a very obvious parameter that can be spatially changed to control this transport. Here, MS-TNPI is used to study the “non-equilibrium” effects of an externally imposed temperature profile on the excitonic transport in one-dimensional Frenkel chains coupled with local vibrations. We show that in addition to being important for incorporating heating effects of excitation by lasers, temperature can also be an interesting parameter for quantum control.

Richardson, Vincent; de Aragão, Emília Valença Ferreira; He, Xiao; Pirani, Fernando; Mancini, Luca; Faginas-Lago, Noelia; Rosi, Marzio; Martini, Luca Matteo; Ascenzi, Daniela

doi: 10.1039/d2cp02458fpmid: 36102850