Study on the Ti K, L 2,3 , and M Edges of SrTiO 3 and PbTiO 3

Given the tremendous potential applications of excited state intramolecular proton transfer (ESIPT) systems, ESIPT molecules have received widespread attention. In this work, based on density functional theory (DFT) and time‐dependent DFT (TDDFT) methods, we theoretically study the excited state dynamical behaviors of salicyladazine (SA) molecules. Our simulated results show that the double intramolecular hydrogen bonds of SA are strengthened in the S1 state via exploring bond distances, bond angles, and infrared (IR) vibrational spectra. Exploring the frontier molecular orbitals (MOs), we confirm that charge redistributions indeed have effects on excited state dynamical behaviors. The increased electronic densities on N atoms and the decreased electronic densities on O atoms imply that charge redistribution may trigger the ESPT process. Analyzing the constructed S0‐state and S1‐state potential energy surfaces (PESs), we confirm that only the excited state single proton transfer reaction can occur although SA possesses two intramolecular hydrogen bonds. In this work, we clarify the specific ESIPT mechanism, which may facilitate developing novel applications based on the SA system in future.

Section: Structural Discussionmentioning

confidence: 99%

Section: Photoexcitation Processmentioning

confidence: 99%

A theoretical investigation on the excited state intramolecular single or double proton transfer mechanism of a salicyladazine system

Zhang

Zhao

Cheng

et al. 2019

“…In other words, these changes about chemical bond distances and bond angles indicate that the dual hydrogen bonds (O1 H2Á Á ÁN3 and O4 H5Á Á ÁN6) of BDABE should be strengthened in the S 1 state. [39][40][41][42][43][44][45][46][47] In addition, it is well known that the excited-state hydrogen bonding interactions could also be revealed by theoretical IR vibrational spectra. [48][49][50][51][52][53][54][55][56][57] Thus, we also simulated the IR vibrational spectra involved in hydrogen-bonding moieties, which is shown in Figure 4.…”

Section: Resultsmentioning

confidence: 99%

Theoretical insights into excited‐state process for the novel 2,3‐bis[(4‐diethylamino‐2‐hydroxybenzylidene)amino]but‐2‐enedinitrile system

Zhang

Yang

et al. 2019

In this present work, we clarify the excited‐state intramolecular proton transfer (ESIPT) mechanism for 2,3‐bis[(4‐diethylamino‐2‐hydroxybenzylidene)amino]but‐2‐enedinitrile (BDABE) system. We present the fact that excited‐state single proton transfer can occur along with one hydrogen bond, even though BDABE form consists of two intramolecular hydrogen bonds. Based on the density functional theory and time‐dependent density functional theory methods, we theoretically investigate and elaborate the excited‐state intramolecular dual hydrogen‐bonding interactions. By simulating the electrostatic potential surface, we verify the formation of dual intramolecular hydrogen bonds for BDABE molecule in the S0 state. Furthermore, comparing the primary bond lengths and bond angles as well as the infrared vibrational spectra, we find that the double hydrogen bonds should be strengthened in the S1 state. When it comes to photoexcitation process, we discover the charge redistribution around hydrogen bonding moieties. The increased electronic density around proton acceptor plays the important roles in strengthening hydrogen bonds and in facilitating ESIPT reaction. In view of the possible ESIPT reaction paths (i.e., stepwise and synchronization double proton transfer) for BDABE molecule, we explored the S0‐state and S1‐state potential energy curves. This work explains experimental results and further clarifies the excited‐state behaviors for BDABE system.

“…[1][2][3][4][5][6][7][8] Particularly, the hydrogen bonding interactions are crucial to maintain the stability of life-related biomacromolecules like RNA and DNA, also they have significant effects on the structures as well as the properties of materials. [9][10][11][12][13] It cannot be denied that various chemical reactions occur involved in hydrogen bonding. The proton transfer (PT) reaction, belonging to one of the most fundamental processes in chemical and biological fields, occurs along with the preexisting hydrogen bonding wires.…”

Section: Introductionmentioning

confidence: 99%

Insights into the excited state intramolecular proton transfer process and mechanism of the novel 3‐hydroxythioflavone system: A theoretical study

Wang

Zhao

et al. 2019

It is well known that the molecular excited state dynamical process plays important roles in designing and developing novel applications. In this work, based on density functional theory and time‐dependent density functional theory methods, we theoretically explored a novel 3‐hydroxythioflavone (3HTF). Through calculating the electrostatic potential surface of the 3HTF structure, we confirm the formation of intramolecular hydrogen bonding O2‐H3···O4. Our theoretically obtained dominating bond lengths and bond angles involved in hydrogen bonds demonstrate that the intramolecular hydrogen bonds should be strengthened in the S1 state. Coupling with the simulated infrared vibrational spectra, we further verify the enhanced hydrogen bonding O2‐H3···O4 in the S1 state. Upon photoexcitation, we found that the charge transfer characteristics around hydrogen bonding moieties play important roles in facilitating the excited state intramolecular proton transfer (ESIPT) process. Via constructing potential energy curves in both S0 and S1 states, we confirm the almost nonbarrier ESIPT reaction should be an ultrafast process that further explains the previous experimental phenomenon. At last, we search the S1‐state transition state (TS) structure along with ESIPT path, based on which we simulate the intrinsic reaction coordinate path that further confirms the ESIPT mechanism. We hope that our theoretical work could guide novel applications based on the 3HTF system in future.