Strategies for Electrooptic Film Fabrication. Influence of Pyrrole−Pyridine-Based Dibranched Chromophore Architecture on Covalent Self-Assembly, Thin-Film Microstructure, and Nonlinear Optical Response
作者:Antonio Facchetti、Luca Beverina、Milko E. van der Boom、Pulak Dutta、Guennadi Evmenenko、Atindra D. Shukla、Charlotte E. Stern、Giorgio A. Pagani、Tobin J. Marks
An iron(III) complex [Fe(salten)(Mepepy)]BPh4 containing only one photoisomerizableligand (Mepepy) has been synthesized, it exhibits a thermally-induced spincrossover in the solid state and in solution H2salten = 4-azaheptamethylene-1,7-bis(salicylideneiminate); Mepepy = 1-(pyridin-4-yl)-2-(N-methylpyrrol-2-yl)ethene}. The photoisomerizations of both the free and coordinated Mepepy ligand have been
Photothermal studies of the room temperature photo-induced spin state change in the Fe(III)(salten)(mepepy) complex
作者:Audrey Mokdad、Randy W. Larsen
DOI:10.1016/j.ica.2010.06.016
日期:2010.10
The complex [Fe(III)(salten)(mepepy)] BPh(4) (salten = 4-azaheptamethylene-1,7-bis(salicylideneiminate; mepepy = 1-(pyridin-4-yl)-2-(N-methylpyrrol-2-yl)-ethene; BPh(4) = tetraphenyl borate) has been investigated to determine the volume and enthalpy changes associated with the room temperature photoinduced spin crossover. Here we report the photophysical properties of the trans to cis isomerization of the mepepy ligand as well as the spin crossover of the Fe(III)(salten)(mepepy) complex in acetonitrile: water mixtures using photoacoustic calorimetry (PAC). The PAC studies indicate that the trans to cis transition of the mepepy ligand occurs faster than the similar to 20 ns response time of the acoustic detector and gives rise to a negligible volume change (0.7 +/- 0.3 mL mol(-1)) and an enthalpy change of 33 +/- 10 kcal mol(-1). These results are consistent with the loss of a charge assisted hydrogen bond between a water molecule and the pyridyl ring of the mepepy upon photoisomerization. In the case of Fe(III)(salten)( mepepy) photoexcitation, PAC results indicate that the high-spin to low-spin transition, also occurring in less than or similar to 20 ns, gives rise to small volume and enthalpy changes (0.9 mL mol(-1) and 4 kcal mol(-1)). Analysis of the results indicate that the observed thermodynamics are related to a distortion of the Fe(II)(salten)(mepepy) complex associated with the cleavage of an Fe center dot center dot center dot N bond upon spin conversion. (C) 2010 Elsevier B.V. All rights reserved.
A Ratiometric Near-Infrared Fluorogen for the Real Time Visualization of Intracellular Redox Status during Apoptosis
作者:Giridharan Saranya、Palapuravan Anees、Manu M. Joseph、Kaustabh K. Maiti、Ayyappanpillai Ajayaghosh
DOI:10.1002/chem.201700839
日期:2017.5.29
of glutathione (GSH) as a potential biomarker for tracking apoptosis. For this purpose, we introduced a near-infrared (NIR) squaraine dye that is capable of sensing GSH in a ratiometric manner by switching its emission from NIR (690 nm) to visible region (560 nm). The favourable biocompatible attributes of the probe facilitated the realtime monitoring of apoptotic process in line with the conventional