Evaluation of the nonlinear optical properties for an expanded porphyrin Hückel-Möbius aromaticity switch

Abstract

The conformational flexibility of the expanded porphyrins allows them to achieve different topologies with distinct aromaticities and nonlinear optical properties (NLOP). For instance, it is possible to switch between Möbius and Hückel topologies applying only small changes in the external conditions or in the structure of the ring. In this work, we evaluate the electronic and vibrational contributions to static and dynamic NLOP of the Hückel and Möbius conformers of A,D-di-pbenzi[28]hexaphyrin(1.1.1.1.1.1) synthesized by Latos-Grażyński and co-workers [Angew. Chem., Int. Ed. 46, 7869 (2007)]. Calculations are performed at the HF, M052X, and CAM-B3LYP levels using the 6-31G, 6-311G(d), and 6-31+G(d) basis sets. Our results conclude that M052X/6-31G and CAM-B3LYP/6-31G methods provide a correct qualitative description of the electronic and vibrational contributions for the NLOP of expanded porphyrins. The studied systems show high NLOP with large differences between the Möbius and Hückel conformations (around 1 × 10 6 a.u. forγ ). The obtained results indicate that the expanded porphyrins are promising systems to manufacture Hückel-to-Möbius topological switches.

Performance of density functional theory in computing nonresonant vibrational (hyper)polarizabilities

“…[48][49][50][51] Although the electronic contributions to resonant and nonresonant (hyper)polarizabilities have been studied extensively using LC-DFT, [49][50][51][52][53][54][55][56] there is not much known yet as far as predictions of the vibrational counterpart is concerned. [35,[57][58][59][60][61][62][63] In this study, a set of the most popular XC functionals, including recent LC and screened exchange schemes, are used to evaluate the electronic and vibrational contributions to electric dipole (hyper)polarizabilities of PMI oligomers (with number of monomer units ranging from 2 up to 8; cf. Fig.…”

Exploring the chemical bonding, infrared and UV–vis absorption spectra of OH radicals adsorption on the smallest fullerene

“…However, there are some previously theoretical reports that the 6-31G basis set is also adequate to obtain qualitative results for exploring the L&NLO properties of molecules [58,59], and the diffuse functions have an small effect for these properties [60]. Herein, we have used the CAM-B3LYP/6-31G(d,p) level of theory to disclose the L&NLO properties of polyhydroxylated derivatives, this method gives a good performance for the evaluation of the L&NLO properties [43][44][45][46].…”

“…For example, Xu et al [15,16] studied the water-soluble derivatives C 60 (OH) x (x = 22,24), and found that the derivatives have the potential usage as an inhaled drug delivery, in which the hydroxyl radicals play key roles in asthma and chronic obstructive pulmonary diseases, the physical behavior of fullerenol products was observed to significantly differ from the parent materials [17]. In fact, there is a great challenge to find the global minima of the fullerenols, and the derivatives present a strong structural flexibility due to the rotation of the OH groups around the C-O bonds which are distributed differently on fullerene surface.…”

Computational Studies on Optoelectronic and Nonlinear Properties of Octaphyrin Derivatives

“…Various studies were performed for explaining the conformational switch between Hückel planar and Möbius twisted topologies of expanded porphyrins (Torrent-Sucarrat et al, 2012; Alonso et al, 2013, 2014; Marcos et al, 2014). Observations revealed that the nature of the meso-substituent is important for determining the relative stability of the Hückel−Möbius conformers and interconversion also between them is controlled by the barrier height (Torrent-Sucarrat et al, 2012; Marcos et al, 2014). Proft et al employed DFT at B3LYP/6-31G (d,p) level of theory to study the conformational preferences, interconversion pathways and aromaticity of N-fused [22] and [24] pentaphyrins.…”