The electronic excitation energies and transition dipole moments are the essential ingredients to compute an optical spectrum of any molecular system. Here we extend the exciton scattering (ES) approach, originally developed for computing excitation energies in branched conjugated molecules, to the calculation of the transition dipole moments. The ES parameters that characterize contributions o...

The synthesis, crystal structure, and characterization of a silicon–silicon triply bonded species, disilyne with two bis[bis(trimethylsilyl)methyl]isopropylsilyl substituents, are described. The nature of the sp-hybridized silicon atoms is discussed from the viewpoint of spectroscopic results and theoretical calculations. The reactivity of the disilyne with alkali metals, tBuLi, and π-bonded co...

We have studied a series of bridged phenylacetylene macrocycles with topologies based on Platonic and Archimedean polyhedra, using density functional calculations to determine both their molecular structure and their electronic response to external magnetic fields (NICS maps). We are able to elucidate the interplay of aromaticity and anti-aromaticity as a function of structural parameters, in p...

Controlled ON/OFF stereocomplexation of dynamic helical polymer-metal nanoparticle nanocomposites─poly(phenylacetylene)-MNP nanocomposites (M = Au or Ag)─is presented. These novel hybrid materials can be found either as well-dispersed metal nanoparticles (MNPs) (stereocomplex OFF) fiber-like aggregates ON) with the distributed along material. A stereocomplex-MNP nanocomposite is formed by inter...

A highly efficient Ullmann homocoupling reaction of aryl halides using palladium (II) phosphine-ylide complexes as homogenous pre-catalysts under aerobic conditions has been developed without the need for any chemical co‐reducing agents. The procedure is relatively mild and appears to have broad applicability, being useful for the homocoupling of both electron-deficient and electron-rich aryl h...

Electron-hole pairs created upon optical excitation of conjugated dendrimers (fractal antenna macromolecules) are shown to be localized within segments connected by benzene rings substituted at the meta-position. The absorption spectra of two families of dendrimers are analyzed using collective electronic normal modes representing the changes in charge and bond-order distributions induced by th...

Puzzling Catalysis: A variated set of cationic or neutral square-planar rhodium complexes bearing a N-heterocyclic carbene and π-acceptor ligands have been synthesized. Divergent catalytic outcomes for phenylacetylene-methanol transformations resulted in function on each particular combination ligands, including alkyne hydroalkoxylation, dimerization polymerization reactions.

The crossed molecular beam experiment of the deuterated ethynyl radical (C(2)D; X(2)Sigma(+)) with benzene [C(6)H(6)(X(1)A(1g))] and its fully deuterated analog [C(6)D(6)(X(1)A(1g))] was conducted at a collision energy of 58.1 kJ mol(-1). Our experimental data suggest the formation of the phenylacetylene-d(6) via indirect reactive scattering dynamics through a long-lived reaction intermediate; ...

A phenylacetylene containing the l-valine ethyl ester pendant (PAA-Val) was synthesized and polymerized by an organorhodium catalyst (Rh(nbd)BPh₄) to produce the corresponding one-handed helical cis-poly(phenylacetylene) (PPAA-Val). PPAA-Val showed a unique temperature-triggered switchable helix-sense in chloroform, while it was not observed in highly polar solvents, such as N,N'-dimethylformam...