Optical and Photophysical Properties

Melinger JS, Pan YC, Kleiman VD, Peng ZH, Davis BE, McMorrow D, Lu M (2002) J Am Chem Soc 124 12002-12012 Optical and photophysical properties of light-harvesting phenylacetylene mono-dendrons based on unsymmetrical branching... 

Optical and photophysical properties of entrapped organic molecules... 

III. OPTICAL AND PHOTOPHYSICAL PROPERTIES A. Energy Gap Law for Triplet States... 

Because of their optical and photophysical properties, metal complexes offer many advantages compared to other systems [74]. Reversibility and tunabiUty by incorporating different metal ion and ligand substituents make coordination chemistiy particularly attractive. 

Karpov, S. V. Slabko, V. V. Optical and photophysical properties of fractal-structured metal sols , Novosibirsk SB RAS, 2003,265 p. 

The presence of oxidized thienyl groups in the conjugated chain of oligo- and polythiophenes deeply modifies their optical and photophysical properties with respect to their fully aromatic counterparts. Absorption and emission wavelengths are red shifted by several nanometers, owing to increased n-electron... 

Belletete, E. R. Garcia, M. Leclerc, G. Durocher, Intermolecular interactions in conjugated oligothiophenes. 3. Optical and photophysical properties of quaterthiophene and substituted quaterthiophenes in various environments, J. Phys. Chem. A, 103, 3864-3875 (1999). 

To study the optical and photophysical properties of in microemulsion we have used Ti02 NPs which are synthesized by solgel method as described earlier. The microemulsion was prepared using the following composition (2g NaLS/1.8cc water/ 46.5 cc cyclohexane/9.5 cc 1-butanol). The diameter of this water pool is around 4-5 nm. Pileni et al. [22] have shown an empirical relation between Wg and r as r = 1.5 Wq (where r is the radius of the water pool for microemulsion). According to Adhikari et al. [23], the water droplet size is 4.2nm in the present microemulsion studied. T1O2 NPs in this study can just fit in the water pool (Figure 18.1). 

We have studied optical and photophysical properties of TiOj NPs, where the NPs are dispersed in the water core of a microemulsion. We have observed that the optical absorption of NP does not change in the microemulsion however, the emission quantum yield increases drastically. As an indirect band-gap semiconductor Ti02 NPs are nonemissive but due to the surface modification by surfactant molecules in the microemulsion the particles become emissive. 

Valence excitations These are excitations involving the promotion of a valence electron from a bonding or nonbonding orbital to a virtual orbital. According to the specific character of the orbitals involved (e.g., tt, n, a orbitals) the excitations can be further characterized as tttt, im, na, ... The valence excitations are the most important for the optical and photophysical properties of organic molecules. 

In this accoimt, it is clear that a wide variety of ferrocenylacetylide complexes functionalized with the fluorene unit have been investigated. The properties of these compounds were eompletely elucidated by speetroscopic, electrochemical and X-ray structural techniques. The experimental results were also correlated with the theoretieal calculations. These metalated systems have shown interesting optical, structural and redox characteristics. In many cases, variation of the 9-substituents on the fluorenyl ring ean influence the optical and photophysical properties of these redox-active materials. 

Arora and Overberger [215] have studied the optical and photophysical properties of carbazolyl-substituted A/ -acylated polyethylenimines (23 a) and dehydroalanine main-chain polymers (23b). It was established by UV spectroscopy that a local conformational order of the carbazole groups is present in these polymers. Only monomer emission was detected by steady state and... 

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