The First Hexadithienylethene‐Substituted Tris(bipyridine)metal Complexes as Quadratic NLO Photoswitches: Combined Experimental and DFT Studies

Abstract

Flip the NLO switch! A straightforward access to hexadithienylethene-based photochromes by using a coordination-chemistry approach through the combination of bis(dithienylethene)bipyridyl ligands and metal ions (M = Zn, Fe) is reported. The photostability of the isomeric forms of the iron(II) complexes allows the photoswitching of second-order nonlinear optical (NLO) responses (see figure), and the results are rationalized with the help of time-dependent density functional theory.

Theoretical evidence of metal-induced structural distortions in a series of bipyrimidine-based ligands

“…8 In the previous decade, quadratic Non Linear Optical (NLO) properties of octupolar tetrahedral D 2d and octahedral late metal complexes (D 3 ) with large π-donor backbones have been investigated. 4,9,10 The idea of using bipyrimidine ligands arose for different reasons: (i) strong π-delocalization, (ii) non planarity between two bipyrimidine moieties promoted by lone pair's interactions between the nitrogen atoms of the two pyrimidine fragments, which gives access to a pseudotetrahedral octupolar symmetry and (iii) strong ability to chelate a metal and possibly give a supra-molecular assembly. [11][12][13][14][15][16][17][18] Recently, a new class of three-dimensional NLO-phores of D 2d symmetry based on donor-substituted styryl bipyrimidine cores has been investigated.…”

Optical signatures of borico dyes: a TD-DFT analysis

“…Amongst all possible first-principle approaches for investigating excited-state properties, Time-Dependent Density Functional Theory (TD-DFT) is certainly the most popular, with a continuously increasing number of published applications [13][14][15][16]. Beyond its widespread access in several quantum-chemical programs, three factors might explain the success of TD-DFT: 1) the possibility to tackle very extended molecules, e.g., possessing 300 atoms or even more if simplified approaches are used [17,18]; 2) the ease to combine TD-DFT with several environmental models allowing to accurately account for solvent and/or biochemical media [19,20]; 3) the availability of analytic first and second derivatives, allowing the optimization of the excited-state structures, as well as the determination of their vibrational patterns at a relatively small computational cost [21][22][23][24][25]. No other excited-state approach, but the much less accurate Configuration Interaction Singles (CIS) scheme, combines these key advantages.…”

Exploring Second-Order Nonlinear Optical Properties and Switching Ability of a Series of Dithienylethene-Containing, Cyclometalated Platinum Complexes: A Theoretical Investigation

“…53 ), the prominent characteristics of studied systems is that the β D-values are very large. We can see that the limitation of contrasts mainly due to the relatively large β values of open form (since they still possess relatively large π-conjugations), thus introducing multi-DTE units to coordinate with metal center may be a promising way to further increasing the contrasts and achieve the two goal of NLO switches in DTEcontaining systems (e.g., two recent studies reported by Le Bozec et al 34,35 ).…”