The Reversible Electron Transfer Within Stimuli-Responsive Hydrochromic Supramolecular Material Containing Pyridinium Oxime and Hexacyanoferrate (II) Ions.

The structural and electronic features of the stimuli-responsive supramolecular inter-ionic charge-transfer material containing electron accepting -benzylyridinium-4-oxime cation (BPA4) and electron donating hexacyanoferrate (II) are reported. The study of reversible stimuli-induced transformation between hydrated reddish-brown (BPA4)[Fe(CN)]·10HO and anhydrous blue (BPA4)[Fe(CN)] revealed the origin of observed hydrochromic behavior. The comparison of the crystal structures of decahydrate and anhydrous phase showed that subsequent exclusion/inclusion of lattice water molecules induces structural relocation of one BPA4 that alter the donor-to-acceptor charge-transfer states, resulting in chromotropism seen as reversible reddish-brown to blue color changes.

A Detailed Kinetico-Mechanistic Investigation on the Palladium C-H Bond Activation in Azobenzenes and Their Monopalladated Derivatives.

Palladium C-H bond activation in azobenzenes with R and R at positions of the phenyl rings (R = NMe, R = H (); R = NMe, R = Cl (); R = NMe, R = I (); R = NMe, R = NO (); R = H, R = H ()) and their monopalladated derivatives, using -[PdCl(DMF)], has been studied in detail by H NMR spectroscopy in -dimethylformamide- (DMF-) at room temperature; the same processes have been monitored in parallel via time-resolved UV-vis spectroscopy in DMF at different temperatures and pressures. The final goal was to achieve, from a kinetico-mechanistic perspective, a complete insight into previously reported reactivity results. The results suggest the operation of an electrophilic concerted metalation-deprotonation mechanism for both the mono- and dipalladation reactions, occurring from the coordination compound and the monopalladated intermediates, respectively.

Mechanism of Mechanochemical C-H Bond Activation in an Azobenzene Substrate by Pd Catalysts.

Mechanism of C-H bond activation by various Pd catalysts under milling conditions has been studied by in situ Raman spectroscopy. Common Pd precursors, that is PdCl , [Pd(OAc) ] , PdCl (MeCN) and [Pd(MeCN) ][BF ] , have been employed for the activation of one or two C-H bonds in an unsymmetrical azobenzene substrate. The C-H activation was achieved by all used Pd precursors and their reactivity increases in the order [Pd(OAc) ] View Article and Find Full Text PDF