The photochemistry of several photochromic arene [e]-annelated dimethyldihydropyrenes (DHPs) was studied. These compounds have much larger photochemical ring opening quantum yields than the simple DHPs, making them potentially more useful as building blocks for photoswitchable materials.

We demonstrate live-cell STED microscopy of two protein species using photochromic green fluorescent proteins as markers. The reversible photoswitching of two markers is implemented so that they can be discerned with a single excitation and STED wavelength and a single detection channel. Dual-label STED microscopy is shown in living mammalian cells.

A class of tunable visible and near-infrared donor-acceptor Stenhouse adduct (DASA) photoswitches were efficiently synthesized in 2 to 4 steps from commercially available starting materials with minimal purification. Using either Meldrum's or barbituric acid "acceptors" in combination with aniline-based "donors" an absorption range spanning from 450 to 750 nm is obtained. Additionally, photoiso...

Spiropyrans are notable among different classes of photochromic compounds due to their large structural and electronic transformation upon isomerization. In order to parlay the electronic differences associated with the two isomeric forms into a materials based switch, the spiropyran ultimately requires a covalent attachment through a conjugated pathway. In this work a synthetic method was deve...

Certain organic compounds posess the ability to change color under the influence of light, called photochromism. This change is often due to ultrafast chemical transition from open to closed ring isomers (photocyclization). Information thechnology applications of these photochromics require the reverse transformation to be very slow in the dark. We have applied Density Functional Theory (DFT) m...

Michaelis Menten catalysis by a T-photochromic system has been analyzed numerically. Using an appropriate set of rate constants and quantum yields, we have evidenced an enhanced photo-responsiveness at a medium light intensity: the plot of the initial rate vs. light intensity is bell-shaped. This emergent phenomenon can be qualified as hormetic catalysis. The analysis of the chemical flows show...