Dataset Information

Tuning of the photophysical and electrochemical properties of symmetric and asymmetric conjugated thiophenoazomethines.

ABSTRACT: A synthetic route towards symmetric and asymmetric thiophenoazomethines was accomplished by reaction of the readily available amine with various aldehydes. Investigation of a series of thiophenoazomethines obtained by this method indicates that the terminal groups and the degree of conjugation have a great effect on the electronic absorption and energy levels of the conjugated compounds, particularly the effect of terminal groups. The terminal withdrawing and donating groups of thiophenoazomethines led to the formation of an electronic push-pull, push-push and pull-pull system, which can perturb the electronic transitions between the ground and excited states. The flexible chain substituents on the thiophene units, which improve its solubility, also result in bathochromic absorption, but have limited effect on the energy level.

SUBMITTER: Liu S

PROVIDER: S-EPMC9079336 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tuning of the photophysical and electrochemical properties of symmetric and asymmetric conjugated thiophenoazomethines.

Liu Shengzhen S Wu Ti T Zhu Qi Q Pu Jialing J Chen Guangxue G Zhang Weimin W Li Zhongxiao Z

RSC advances 20180403 23

A synthetic route towards symmetric and asymmetric thiophenoazomethines was accomplished by reaction of the readily available amine with various aldehydes. Investigation of a series of thiophenoazomethines obtained by this method indicates that the terminal groups and the degree of conjugation have a great effect on the electronic absorption and energy levels of the conjugated compounds, particularly the effect of terminal groups. The terminal withdrawing and donating groups of thiophenoazomethi ...[more]

PMID: 35541274

Similar Datasets

Project description:In the present study, the influence of the hydrogen bonding for the one- and two-photon absorption of the prototypical squaraine dye is investigated with quantum chemistry tools. The central squaraine unit is bound by strong hydrogen bonds with 4-substituted N,N'-diphenylurea and, alternatively, N,N'-diphenylthiourea molecules, which affects to a high extend the properties of the squaraine electron accepting moiety, thus shifting its maximum absorption wavelength and enhancing the TPA cross section. The replacement of oxygen by sulfur atoms in the squaraine central ring, known to affect its photophysical behavior, is considered here as the way of modifying the strength and nature of the intermolecular contacts. Additionally, the influence of the oxygen-by-sulfur replacement is also considered in the N,N'-diphenylurea moiety, as the factor affecting the acidity of the N-H protons. The introduction of the sequence of the substituents of varying electron-donating or electron-withdrawing characters in the position 4 of N,N'-diphenyl(thio)urea subsystems allows to finely tune the hydrogen bonding with the central squaraine unit by further modification of the N-H bond characteristics. All of these structural modifications lead to the controlled adjustment of the electron density distribution, and thus, the properties affected such as transition moments and absorption intensity. Ab initio calculations provide strong support for this way of tailoring of one- or two-photon absorption due to the obtained strong hypsochromic shift of the maximum one-photon absorption wavelength observed particularly for thiosquaraine complexes and an increase in the TPA wavelength together with the increase in the TPA cross section. Moreover, the source of the strong modification of the thiosquaraine OPA in contrast to the pristine oxosquaraine upon N,N'-diphenyl(thio)urea substitution is determined. Furthermore, for the first time, the linear dependence of the non-additivity in the interaction energy on the Hammett substituent constant is reported. The stronger the electron-donating character of the substituent, the larger the three-body non-additive components and the larger their percentage to the total interaction energy.

Project description:The series of complexes [XRu(CO)(L-L)(L')2][PF6] (X = H, TFA, Cl; L-L = 2,2'-bipyridyl, 1,10-phenanthroline, 5-amino-1,10-phenanthroline and 4,4'-dicarboxylic-2,2'-bipyridyl; L'2 = 2PPh3, Ph2 PC2H4PPh2, Ph2PCH═CHPPh2) have been synthesized from the starting complex K[Ru(CO)3(TFA)3] (TFA = CF3CO2) by first reacting with the phosphine ligand, followed by reaction with the L-L and anion exchange with NaPF6. In the case of L-L = phenanthroline and L'2 = 2PPh3, the neutral complex Ru(Ph3P)(CO)(1,10-phenanthroline)( TFA)2 is also obtained and its solid state structure is reported. Solid state structures are also reported for the cationic complexes where L-L = phenanthroline, L2 = 2PPh3 and X = Cl and for L-L = 2,2'-bipyridyl, L2 = 2PPh3 and X = H. All the complexes were characterized in solution by a combination of 1H and 31P NMR, IR, mass spectrometry and elemental analyses. The purpose of the project was to synthesize a series of complexes that exhibit a range of excited-state lifetimes and that have large Stokes shifts, high quantum yields and high intrinsic polarizations associated with their metal-to-ligand charge-transfer (MLCT) emissions. To a large degree these goals have been realized in that excited-state lifetimes in the range of 100 ns to over 1 μs are observed. The lifetimes are sensitive to both solvent and the presence of oxygen. The measured quantum yields and intrinsic anisotropies are higher than for previously reported Ru(II) complexes. Interestingly, the neutral complex with one phosphine ligand shows no MLCT emission. Under the conditions of synthesis some of the initially formed complexes with X = TFA are converted to the corresponding hydrides or in the presence of chlorinated solvents to the corresponding chlorides, testifying to the lability of the TFA Ligand. The compounds show multiple reduction potentials which are chemically and electrochemically reversible in a few cases as examined by cyclic voltammetry. The relationships between the observed photophysical properties of the complexes and the nature of the ligands on the Ru(II) is discussed.

Dataset Information

Tuning of the photophysical and electrochemical properties of symmetric and asymmetric conjugated thiophenoazomethines.

Publications

Tuning of the photophysical and electrochemical properties of symmetric and asymmetric conjugated thiophenoazomethines.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets