Wydział Chemii

Simone Melesi

Pietro Marabotti

Alberto Milani

Bartłomiej Pigulski

Nurbey Gulia

Piotr Pińkowski

Sławomir Szafert

Mirella Del Zoppo

Chiara Castiglioni

Carlo S. Casari

2024

Journal of Physical Chemistry A

128

2703-2716

10.1021/acs.jpca.3c07915

Naukowa

Angielski

Artykuł

We explored the optoelectronic and vibrational properties of a new class of halogen-terminated carbon atomic wires in the form of polyynes using UV–vis, infrared absorption, Raman spectroscopy, X-ray single-crystal diffraction, and DFT calculations. These polyynes terminate on one side with a cyanophenyl group and on the other side, with a halogen atom X (X = Cl, Br, I). We focus on the effect of different halogen terminations and increasing lengths (i.e., 4, 6, and 8 sp-carbon atoms) on the π-electron conjugation and the electronic structure of these systems. The variation in the sp-carbon chain length is more effective in tuning these features than changing the halogen end group, which instead leads to a variety of solid-state architectures. Shifts between the vibrational frequencies of samples in crystalline powders and in solution reflect intermolecular interactions. In particular, the presence of head-to-tail dimers in the crystals is responsible for the modulation of the charge density associated with the π-electron system, and this phenomenon is particularly important when strong I··· N halogen bonds occur.

CC-BY

http://dx.doi.org/10.1021/acs.jpca.3c07915

https://www.acs.org/content/acs/en.html