Pyrene based fluorescent probes

by Jagdish Kumar Katla and Sriram Kanvahby Jagdish Kumar Katla and Sriram Kanva

Influence of methyl and nitro groups on photoinduced behavior of dipheny lbutadiene derivatives

by Veerbhadraiah Palakollu, Jagdish Kumar Katla and Sriram Kanvah Gundimed

Trifluoromethyl substituted cyanostyrenes: fluorescent organogel fibrillar self-assemblies

by Jagadish Katla, Akshay J. M. Nair and Sriram Kanva

Influence of imidazolium ionic liquids on fluorescence of push-pull diphenylbutadienes

A series of donor–acceptor substituted diphenylbutadienes have been synthesized and their fluorescence properties in organic solvents and imidazolium ionic liquid media were investigated. Substituted diphenylbutadienes show remarkable solvatochromic emission in polar solvents and in ionic liquids due to intramolecular charge transfer. Interestingly, diphenylbutadiene containing methoxy donor and nitro acceptor exhibits excitation dependent emission behaviour in ethanol. Excitation dependent emission studies of fluorophores in ionic liquids show distinct emission signals due to the locally excited and the charge transfer states revealing the existence of two species. Time resolved experiments show single exponential decay in organic solvents and bi-exponential decay in ionic liquids media,an indication of interaction of fluorophores with different microenvironments.by Anuji K. Vasu et al

Photophysical studies of pyrenyl cyanostyrenes: effect of trifluoromethyl substitution on gelation

α-Cyanostyrenes bearing a planar pyrene unit and electron withdrawing trifluoromethyl units were designed and synthesized. The conformational restriction due to the presence of the cyano group on the double bond favors aggregation induced emission in aqueous media. The styrylpyrenes aggregate to form microstructures influenced by π–π stacking, cyano and CF3 substituent interactions. Importantly confluence of the pyrene ring and simple trifluoromethyl (CF3) unit allows the formation of a stable organogel with bathochromic shifts in emission. The formation of aggregates and the gel was substantiated using 1H NMR spectroscopy and scanning electron microscopy. The stability of the gels was assessed using rheology investigations and rationalized by single crystal X-ray data.by Jagadish Kumar Katla, Abhijeet Ojha, Akshay J. M. Nair, Rangan Krishnan and Sriram Kanva