Effect of phenols and carboxylic acids on photochromism of 1-alkyl-2-(arylazo)imidazoles

Palladium(II)-iodo-{1-alkyl-2-(arylazo)imidazole} complexes: Synthesis, structure, dynamics of photochromism and DFT computation

“…Light irradiation may be associated with excitation to electronically high energy state which undergoes several molecular, electronic, vibrational and rotational changes followed by nonradiative deactivation. Mechanistic investigation by different spectroscopic routes [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]58,59] suggest the cleavage of M-N(azo) bond followed by bond rotation/flipping leading to isomerisation and formation of cis-isomer. In the complexes, [Pd(Raai-C n H 2n+1 )I 2 ] (7,8) we do not observe photoisomerisation even after prolong exposure to UV light irradiation; however, [Pd(Raai-C n H 2n+1 ) 2 I] 2 [Pd 2 I 6 ] (9-14) show photoisomerisation.…”

“…In our studies, 1-alkyl-2-(arylazo)imidazole (Raai-C n H 2n+1 ) both free ligand and coordinated one exhibit photochromic activity. We have examined the effect of metal ion coordination, H + addition, other external parameters (like innocent molecules, micelles, and reverse micelle) [24][25][26][27][28][29][30][31][32][33][34][35][36][37] on the photochromic activity.…”

Effect of Rate and Quantum Yield of 1-alkyl-2-(arylazo) Imidazoles on the Surface of Silver Nps

“…Isomeric change of RaaiR / We have been exploring the trans-cis photoisomerisation of RaaiR / (Scheme 1) and the compounds with different metal [9][10][11][12][13][14][15][16] . The impact of microenvironment (in presence of micelles, reverse micelle, aromatic acids, phenols, hydrocarbons) on the photoisomerisation of RaaiR / has been examined for last few years [17][18][19][20][21] . Use of light energy as stimulant has huge dominance over other influences like thermal, magnetic, mechanical, electrical, redox etc.…”

Arylazoimidazole Coordinated and Naphthalene-Dicarboxylato Bridged Polymers of Co(II) and Photochromic Zn(II) Complexes

“…Azobenzene undergoes optically stimulated reversible cis/trans isomerization. − The conformational change is coupled with a significant change of volume; trans -azobenzene is linear, rod-shaped (length, 9 Å), and less space demanding, whereas cis -azobenzene (length, 5.5 Å) is bent shaped and demands a larger space. − A combination of such kind of smart moieties in the CPs or metal–organic frameworks (MOFs) , may construct a fascinating and challenging class of materials. The conformational change of azo benzene in the MOF cavity shows light-stimulated sorption behavior, such as the absorption of a significant amount of CO 2 at dark, and upon light irradiation, CO 2 is released. − …”

“…In the search of new azo functionalized photochromes, 1-alkyl-2-(arylazo)­imidazoles exhibit potential optical stimulated structural isomerization and have been employed to examine the effect of substituents of different electronic activity, nature of solvent, presence of foreign innocent molecules and micelles, coordination with metal ions preferably d 8 (low spin) and d 10 electronic structure. − This has motivated us to synthesize an arylazoimidazole bonded coordination polymer. Optically induced structural change of 1-alkyl-2-(arylazo)­imidazoles (RaaiR / ) − ,− (photochromism, Scheme ) has been examined vastly in the solution phase. − However, the inclusion of a photoswitching molecule, azoimidazole motif to organic linker, or binding to the metal node as an integrated part of CPs (film phase) has not been studied. Development of such an optically sensitive new class of switching material is the subject of the present research interest.…”