Structure of a transition metal-containing polyyne

Abstract

Electron diffraction and low-dose, high-resolution imaging techniques have been used to obtain structural information for a rigid-rod polyyne containing platinum atoms directly bonded into the main chain. The high-resolution images show details of the arrangement of the molecular chains into crystallites ~50 nm in diameter; dislocations and grain boundaries have also been imaged. A combination of electron diffraction and information derived from image processing of the high-resolution images indicates a unit cell in which parameters of a = 2.08 nm, c = 1.20 nm, and 90°< d < 93°have been measured and where b has tentatively been assigned as ~1.9 nm. The variations in /3 relate to improvements in the degree of orientation of the polymer chains that arise from slight stretching of the thin films.

Electrochemical investigations of platinum phenylethynyl complexes

“…Reductive elimination mechanisms have been observed at Pt(IV) centers before [24][25][26], particularly in complexes containing phosphine ligands. Phosphine ligand dissociation has been observed at d 6 octahedral Pt(IV) in this scheme [27]. Applied to this system, a reductive elimination mechanism as shown in Scheme 1 comprises the following.…”

“…Platinum phenylethynyl complexes in monomeric [1][2][3] and polymeric [4][5][6][7] forms have been the subject of intense study in recent years, on account of their pconjugation. These materials have shown nonlinear optical properties [8,9] and may potentially be used in lasers, light-emitting diodes, and conductance switches.…”

Evolution of lowest singlet and triplet excited states with number of thienyl rings in platinum poly-ynes

“…The IR and NMR spectral features of 2 and 3 are consistent with the polymer structures shown above and are similar to other platinum arylene-acetylide polymers previously reported. [17][18][19] The IR spectra of the polymers display a single sharp CwC absorption at ca. 2087 cm Ϫ1 ͑2͒ and 2086 cm Ϫ1 ͑3͒, which together with the singlet signal observed in each 31 P NMR spectrum reveal a trans configuration of the ligands around Pt II ͑-CwC-͒ 2 moieties in these squareplanar polymeric species.…”

Spatial extent of the singlet and triplet excitons in transition metal-containing poly-ynes

“…[4][5][6][7][8] Interest in these compounds lies mainly in the large enhancement of the spin-orbit coupling induced by the heavy atoms. This coupling allows for an efficient intersys-tem crossing and consequently leads to a huge yield of triplet excitons ͑close to 100% 4 ͒, which can then be probed more easily by conventional optical spectroscopy.…”