Pt-Tetraethynylethene Molecular Scaffolding: Synthesis and Characterization of a Novel Class of Organometallic Molecular Rods

Oligomeric and Polymeric Systems with a Cross-conjugated π-Framework

“…As an alternative to an aryl spacer, insertion of a transition metal was used by Diederich and co-workers to form σ-acetylide complexes linking TEE building blocks (Scheme ). , Dimeric species 100 and 101 were readily formed via reaction of the corresponding terminal acetylene with trans -[PtCl 2 (PEt 3 ) 2 ]. Polymerization of 101b under Glaser−Hay conditions in the presence of PhC⋮CH as an end-capping reagent gave oligomers 102a − f , which could be separated by GPC.…”

“…Running the same polymerization reaction while waiting 20 min to introduce the end-capping reagent resulted in polymer 103 ( n ave = 32) as an air-stable red solid that decomposed only above 250 °C. UV−vis absorption and third-order NLO characterization showed that the Pt centers acted as an insulator toward π-electron delocalization in these oligomers …”

Conjugated Oligoenynes Based on the Diethynylethene Unit

“…Pt−TEE molecular scaffolding has yielded PTA oligomers with Pt(PEt 3 ) 2 as spacer units . Both linear and nonlinear optical properties of the oligomers 141a − f 107c revealed an almost complete lack of π-electron conjugation along the backbones; that is, the Pt atoms act as insulating centers in these linear systems.…”

“…In agreement with inefficient π-electron conjugation along the linear backbone, the UV/vis spectrum of polymer 142 in CH 2 Cl 2 closely resembles the monodisperse oligomers, with λ MLCT appearing at 446 nm. This insulating behavior of the Pt(PEt 3 ) 2 spacer units contrasts with their ability to convey to some extent π-electron delocalization in the macrocyclic complex 143 . 107a,b The end absorption band of 143 is bathochromically shifted relative to the dimer 144 and extends well beyond 500 nm. Thus, electronic communication may exist along the rectangular perimeter of 143 .…”

Organometallic Complexes for Nonlinear Optics. 30.1 Electrochromic Linear and Nonlinear Optical Properties of Alkynylbis(diphosphine)ruthenium Complexes

“…Alkynylmetal complexes can have significant NLO properties and easily accessible oxidation states, [16][17][18][19][20]47,[55][56][57][58][59][60][61][62][63][64][65][66][67][68] We also report facile cubic NLO switching using the low-energy optical transitions for the oxidized forms of 3, 5, and the related complex trans-[Ru(CtCPh)Cl(dppm) 2 ] (6) by utilizing an optically transparent thin-layer electrochemical (OTTLE) cell, in a general procedure which could also be employed to switch quadratic nonlinearities. This is the first electrochromic switching of molecular nonlinear refraction and absorption.…”