Herein, we have proposed a novel two-dimensional (2D) carbon allotrope, namely pentagraphyne (PG-yne), which is energetically favourable than other graphyne members, including experimentally synthesized graphyne and graphdiyne monolayer. State-of-the-art theoretical calculations confirm that the new carbon allotrope is not only dynamically, thermally, and mechanically stable but also can withstand temperatures up to 1000 K. It shows intrinsic semiconducting nature and the band gap is tuned by the application of strain. It possesses a high electron mobility of 2.52 × 10³ cm² V⁻¹ s⁻¹ and exhibits extraordinary optical features covering the entire visible region and a part of the UV region as well. Remarkable carrier mobility along with its superior optical performance renders it to be a potential candidate for future electronics, photovoltaic solar cells, and optoelectronic devices.

The present study emphasizes on structural, opto-electronic, vibrational, and nonlinear properties, at the electronic structure level, on the 4-fluoro-4-hydoxybenzophenone molecule using the first principles calculation. Detailed vibrational assignments of the wavenumbers are carried out on the basis of potential energy distribution and a good agreement between the reported and calculated wavenumbers has been observed. Furthermore, the molecular electrostatic potential surface predicts the reactive site of the molecule. From the time dependent density functional theory analysis of UV-visible spectra, a red shift has been observed at the maximum absorption wavelength when the gaseous medium is replaced by a solvent medium. The 4-fluoro-4-hydroxybenzophenone molecule possesses large hyperpolarizability value which implies its usefulness in nonlinear optical applications.