Related Experiment Video
Updated: Jun 3, 2026
07:07
Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology
Published on: March 12, 2015
Ultrafast Excited State Dynamics and Nonlinear Optical Properties of Ferrocene-Functionalized Chalcone Derivatives
Sunil Kumar Patel1, Shriya Saha1, Raja Mitra1
1School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Farmagudi, Ponda, Goa, India.
Chemistry, an Asian Journal
|June 2, 2026
Summary
Four new ferrocene-chalcone compounds show tunable ultrafast dynamics and nonlinear optical (NLO) properties. Bromine substitution enhances NLO performance, making these hybrids promising for photonic materials and optical limiting applications.
Area of Science:
- Materials Science
- Photochemistry
- Organic Chemistry
Background:
- Ferrocene-chalcone hybrids are explored for their unique electronic and optical properties.
- Understanding excited-state dynamics and nonlinear optical (NLO) responses is crucial for developing advanced photonic materials.
Purpose of the Study:
- Synthesize and characterize four ferrocene-functionalized chalcone derivatives.
- Investigate structure-property correlations in ultrafast excited-state dynamics and NLO responses.
- Establish guidelines for designing novel photonic materials.
Main Methods:
- Synthesis and full characterization (NMR, FTIR, mass spectrometry, electrochemistry, absorption spectroscopy).
- Femtosecond transient absorption spectroscopy (fs-TAS) for excited-state dynamics.
- Open-aperture Z-Scan experiments for nonlinear optical (NLO) properties, specifically two-photon absorption (TPA).
Main Results:
- Compounds exhibit rapid internal conversion to a stabilized intramolecular charge-transfer (ICT) state within picoseconds.
- ICT lifetimes are modulated by the acceptor moiety, influencing NLO activity.
- Pronounced reverse saturable absorption due to TPA was observed; the 3-bromophenyl derivative showed the highest TPA coefficient.
Conclusions:
- Halogen substitution, particularly bromine, significantly enhances electronic polarization and NLO performance.
- Ferrocene-chalcone hybrids are versatile platforms for designing photonic materials.
- Findings provide valuable insights for optical limiting and optoelectronic applications.
Related Concept Videos
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the contributions...
01:32UV–Vis Spectroscopy of Conjugated Systems
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent of conjugation in the...
One of the factors influencing λmax is the extent of conjugation in the...
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...