The synthesis,characterization and reactions of a binuclear tetramethylplatinum(IV) complex

Reaction of excess MeLi and MeI with [PtCl₂SMe₂)₂] gives the first binuclear tetramethylplatinum(IV) complex [Pt₂Me₈(μ-SMe₂)₂]. The characterization of this complex, and its reactions with donor ligands to give cis-[PtMe₄L₂] (L₂ = Ph₂PCH₂PPh₂, Ph₂PCH₂CH₂PPh₂, 2,2′-bipyridyl, 1,10-phenanthroline or L = PMe₂Ph, PMePh₂) are described.     

Magnetic circular dichroism and absorption spectra of phosphinidene in noble-gas matrices

Electronic magnetic circular dichroism and absorption spectra are reported for the A 3pi(i) <-- X 3sigma- transitions of phosphinidene (PH) isolated in Ar, Kr, and Xe matrices at cryogenic temperatures (approximately 1.4-20 K) and over a range of magnetic field strengths (0-5 T). The results are analyzed by the method of moments, and parameters are extracted by fitting the experimental data to a model in which the A 3pi(i) term is split by spin-orbit (SO) coupling interactions, while the X 3sigma- term is split by spin-spin and higher-order SO coupling. The analysis indicates that, unlike the equivalent imidogen (NH) systems, ground-state PH radicals isolated in noble-gas matrices do not behave as free rotors. Trends in excited-state SO coupling constants are attributed to the external heavy-atom effect and guest-host orbital mixing. It is tentatively concluded that librational amplitudes of the guest radical decrease in the order Ar > Xe > Kr, probably as a consequence of competition between stronger guest-host interactions and larger matrix sites in heavier hosts.     

Dibenzothiophene-S,S-dioxide-fluorene co-oligomers. Stable, highly-efficient blue emitters with improved electron affinity

Incorporation of dibenzothiophene-S,S-dioxide units into conjugated fluorene oligomers changes the frontier orbital energy levels and presents an effective way to increase the electron affinity of these materials, which are highly fluorescent with bright blue emission in both solution and the solid state.     

Cyclopentanones—XVIII : The lithium-liquid ammonia reduction of some 2,3-dialkyl-(4-hydroxy)-2-cyclopentenones. the importance of the protonation of intermediate enolate anions on the stereochemical outcome

The stereochemical outcome of the lithium-liquid ammonia reduction of 2,3-dialkyl-4-hydroxy-2-cyclopentenones and 2,3-dialkyl-2-cyclopentenones possessing bulky substituents (i-propyl and t-butyl) is investigated, using different proton donors. The relative configuration of both alkyl groups in the reduction products is interpreted on the basis of the geometry of the transition state for protonation of the intermediate enolate anions formed during the reduction