phosphole−vinylene-bridged π-conjugated system have been revealed to depend strongly on the electronic character of the terminal functionalities. In particular, the polarizability at the excited-state has been found to be considerably greater than that in the ground state. High molecular hyperpolarizabilities obtained for the push−pull type of 2-aryl-5-styrylphospholes in the hyper-Rayleigh scattering measurements
New donor–π–acceptor organic (D–π–A) dyes composed of triarylamine, oligothiophene, and phosphole subunits were prepared, and their optical and photovoltaic properties were investigated. The regioselective α-lithiation of the thiophene ring of 2-(thiophen-2-yl)phospholes bearing an ester group, followed by treatment with tributyltin chloride afforded 2-(5-(tributylstannyl)thiophen-2-yl)phosphole derivatives
Symmetrically and unsymmetrically 2,5-difunctionalized phospholes bearing ester groups were prepared in a one-pot procedure from the corresponding diynes and dichloro-(phenyl) phosphine via titanacyclopentadienes. The observed optical properties of the functionalized phospholes show that the pi-conjugative push-pull interaction between the 2- and 5-substituents plays an important role in controlling the light-emitting efficiency.
Cobalt-Catalyzed Intramolecular [2 + 2 + 2] Cocyclotrimerization of Nitrilediynes: An Efficient Route to Tetra- and Pentacyclic Pyridine Derivatives
we wish to report the intramolecular [2 + 2 + 2] cocyclotrimerization of nitrilediynes catalyzed by the CoI2(dppe)/Zn system at 80 degrees C in CH3CN. Under these reaction conditions, various highly substituted nitrilediynes having steric conjunction at the alpha and beta positions to a nitrile group and a bulkier substitution at the terminal carbon of alkyne undergo [2 + 2 + 2] cocylotrimerization