Proton transfer along the internal hydrogen bonds in excited Schiff bases. Photochromism in symmetric systems with two equivalent reaction sites

Grabowska, Anna; Kownacki, K.; Kaczmarek, Ł.

doi:10.1016/0022-2313(94)90304-2

Cited by 40 publications

(17 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…So, we have in hand the molecule SMA, still simple enough to be the attractive object for the advanced theoretical calculations of the electronic and vibrational stucture. A common chromophore of all photochromic Schiff bases postulated in earlier studies [5][6][7][8] is most probably fairly well represented by SMA molecule. The remarkable localization of the electronic excitation and the proton transfer reactivity leading to the photochromic transient, is now a matter of experimental evidence.…”

Section: Discussionmentioning

confidence: 99%

“…In a series of our recent papers [5][6][7][8] we studied a large family of Schiff bases, partly synthesised for the first time, partly kindly presented by Prof. Mauyama and Dr Inabe. The main aim was to compare stuctures possessing two equivalent proton transfer (PT) reaction sites with simpler systems that could be regarded as "halves" of their symmetric counterparts.…”

mentioning

confidence: 99%

“…The main conclusion was [5][6][7][8] that the spectral manifestation of photochromism, e.g. the long living transient absorption, the time resolved resonance Raman response, as well as two fluorescences of two different transients, are surprisingly independent of the overall stucture of the molecule.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Structural Aspects of Photochromism of the Internally H-Bonded Schiff Bases. "A Minimal Chromophore"

1995

View full text Add to dashboard Cite

The final limiting stage of structural simplification of photochromic Schiff base was reached by the following statement: two molecules, sa1icyli-dene methylamine and its butyl analogue, show transient absorption bands (at room temperature) peaking at 22000 cm 1 . These bands are characteristic of the phenomenon of photochromism. They are similar to the corresponding spectra detected earlier for several larger, symmetric systems belonging to tłe same family. Experimentał characterizatioii of both molecules was compared with the theoretical calculations: geometry optimizatioii and transition energies, performed for enol, keto, and the photochromic form of salicylidene methylamine.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Structural Aspects of Photochromism of the Internally H-Bonded Schiff Bases. "A Minimal Chromophore"

1995

View full text Add to dashboard Cite

show abstract

“…The best known photochromic Schiff base is salicylideneaniline (SA). This molecule and its derivatives have been widely studied over a wide span of time [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In SA and its derivatives, the intramolecular hydrogen bonding opens a possibility of fast proton transfer between different tautomers followed by isomerization changes, leading to a metastable photochromic modification of the initial structure.…”

Section: Introductionmentioning

confidence: 99%

Substituent effects on the absorption and vibrational spectra of some 2-hydroxy Schiff bases: DFT/TDDFT, natural bond orbital and experimental study

et al. 2015

View full text Add to dashboard Cite

The electronic structure of salicylideneaniline (SA) and some of its derivatives are investigated both experimentally and theoretically. The equilibrium geometric structures of the studied compounds are determined at the B3LYP/6-311++G** level of theory. A set of 12 substituted SA derivatives is considered in the present work. The choice of these substituents aims to create a push-pull system on the SA basic structure which would shade light onto its photo physics. The electronic absorption spectra of SA are recorded in the UV-VIS region, in both polar and nonpolar solvents. Assignments of the observed electronic transitions are facilitated via time-dependent density functional theory (TDDFT) computations at the same level of theory. Electronic configurations contributing to each excited state are identified and the relevant MOs are characterized. The extent of delocalization and intramolecular charge transfer are estimated and discussed in terms of natural bond orbitals (NBO) analysis and second order perturbation interactions between donor and acceptor MOs. Solvent effects on the electronic absorption spectra are discussed in terms of the difference in polarizabilities of the ground and excited states. FTIR spectra of SA and its derivatives are measured in KBr platelets. Detailed vibrational assignments are given based on the calculated potential energy distributions. "IR marker bands" that characterize the SA framework are identified. The effect of substituents, the nature of the characteristic "marker bands", and intensity quenching of some bands are discussed.

show abstract

“…[57][58][59] The proton-transfer mechanism along the internal hydrogen bonds was investigated, and it was shown that in molecules with two equivalent internal hydrogen bonds, only one proton translocated. 59 Other examples in which theoretical calculations were applied in the study of photochromism include an MNDO/3 study on dihydroindolizines, 60,61 the use of PPP electron densities as an aid for estimating the linear dichromism (LD) and magnetic circular dichromism (MCD) of symmetric dialkoxyanthracenes, 62 and studies of the structures of unusual twisted cis zwitterionic azomethines, 63 a synthetic 4',7-dihydroxyflavylium chloride, 64 nitro derivatives of salicylideneaniline and 2-(2'-hydroxyphenyl)benzothiazole, 65 4-bromo-N-salicylideneaniline, 66 and pentafulvadiene derivatives. 67 There was also an interesting study of proton transfer in the excited state.…”

Section: Other Photochromic Systemsmentioning

confidence: 99%

Molecular Modeling Calculations

Nakamura

Organic Photochromic and Thermochromic Compounds

View full text Add to dashboard Cite

Photochromic molecules provide a unique opportunity for the practical application of theoretical chemistry, molecular modeling, and molecular simulation, since their molecular properties directly determine the function of devices. 1 Recent remarkable developments of computer hardware and software have opened a new horizon in material design, namely, the combination of computational studies and experimental approaches to offer an understanding of function on a molecular level. 2 This does well for the future design of functional materials.The requirements for the design of photochromic compounds are, among others, the adjustment of absorption wavelength and intensity, the attainment of thermal stability, clarification of reaction mechanism, and enhancement of quantum yield. The purpose of this chapter is to review recent computational studies in consideration of these requirements. ABSORPTION WAVELENGTH AND INTENSITYThe first event of the photochromic reaction is light absorption. Therefore, how efficiently the molecules of a photochromic compound absorb a given wavelength of light is the first concern. Practical applications often require the use of a limited range of wavelengths of the light source, and, as a result, molecules must be adjusted to the light source. We will include some work on organic functional dyes in this section, since most important studies are on organic dyes. The pioneering work reported in this area has used the Pariser-Parr-Pople

show abstract

Proton transfer along the internal hydrogen bonds in excited Schiff bases. Photochromism in symmetric systems with two equivalent reaction sites

Cited by 40 publications

References 5 publications

Structural Aspects of Photochromism of the Internally H-Bonded Schiff Bases. "A Minimal Chromophore"

Structural Aspects of Photochromism of the Internally H-Bonded Schiff Bases. "A Minimal Chromophore"

Substituent effects on the absorption and vibrational spectra of some 2-hydroxy Schiff bases: DFT/TDDFT, natural bond orbital and experimental study

Molecular Modeling Calculations

Contact Info

Product

Resources

About