Multicoordinational excited state twisting of indan-1,3-dione derivatives

Twisted Hemithioindigo Photoswitches: Solvent Polarity Determines the Type of Light-Induced Rotations

“…However, because of the presence of a rotatable C–C single bond, there is another possible de-excitation mechanism, which involves rotation of that single bond instead of the double bond. For HTIs with planar geometry, bearing substituents with moderate electronic effects, such de-excitation pathways have not been described so far, as their behavior can be explained satisfactorily by exclusive double-bond rotation. , However, in related stilbenes with strong donor–acceptor substitution, twisted intra­molecular charge-transfer (TICT) , species, which are formed by motions along a single-bond rotation coordinate, − have frequently been discussed. , Similar behavior has also been described for substituted styrenes . Recently, aryl­amine-substituted stilbenes have been found to de-excite exclusively via the formation of TICT species in polar solvents but undergo efficient double-bond isomerization in nonpolar solvents. − …”

Synthesis and Physical Properties of Red Luminescent Glass Forming Pyranylidene and Isophorene Fragment Containing Derivatives

“…Compound molecules with two bulky acceptor groups are probably strongly distorted in solid films, so that molecular chains connecting acceptor and donor moieties are twisted. Such twisting usually leads to a red-shift in the molecular fluorescence and to fast non-radiative relaxation [44]. The twisted molecules form energy traps in solid films, which may be populated during the excitation diffusion.…”

Cu(II) complexes of 4- and 5- nitro-substituted heteroaryl cinnamoyl derivatives and determining their anticoagulant activity

“…A series of new Cu(II), Zn(II), Pb(II) Cd(II) complexes of 2AID were synthesized and based on NMR (in solution and solid state) and EPR spectroscopy for paramagnetic complexes were characterized [19]. Some of the studies concern excited state twisting, as for N,Ndimethylaminobenzylidene-1,3-indandione and derivatives [20][21][22]. Recently, selective electrochemical fluorination (SEF) of 1-indanone, 2-indanone and 1,3-indandione were carried out in Et 3 N.4HF ionic liquid by Ilayaraja and Noel [23].…”