A hybrid ruthenium alkynyl/zinc porphyrin “Cross Fourchée” with large cubic NLO properties

Abstract

A new Zn(ii) porphyrin-cored ruthenium alkynyl dendrimer (2) containing twelve Ru(κ(2)-dppe)2 bis-alkynyl fragments has been prepared in two steps from 5,10,15,20-tetra(4-ethynylphenyl)porphyrinatozinc(ii) and shown to be highly active for third-harmonic generation (THG) at 1907 nm.

Synthesis, characterization and third-order nonlinear optical properties of a dodecaruthenium organometallic dendrimer with a zinc(ii) tetraphenylporphyrin core

“…Six oxidation waves were detected (Figure 1) for which differential pulse voltammetry (DPV) gives the approximate ratio 1:1:8:4:1:(≥)8. Thus, contrary to our earlier proposal, 43 the Ru(II)/Ru(III) oxidations of the peripheral and inner trans-Ru(κ 2 -dppe) 2 fragments possibly overlap. Based on their intensity in a two-to-one ratio, the first oxidation of the Ru(II) centres belonging to the carbon-rich wedges 24 are apparently not resolved from that of the chemically distinct Ru(II) centres closer to the porphyrin core in 5 2 .…”

“…Accordingly, the voltammogram of 5 2 recorded under similar conditions possesses these features but the porphyrin-based waves, close to the solvent edges, were difficult to detect. 43 To improve their detection, the CV was then recorded in THF which offered a slightly larger potential window. Six oxidation waves were detected (Figure 1) for which differential pulse voltammetry (DPV) gives the approximate ratio 1:1:8:4:1:(≥)8.…”

“…42 Some of these investigations have been previously communicated. 43 In particular, THG measurements indicated better NLO responses for 5 2 and 7 at 1907 nm, once the γ THG values had been corrected for the molecular mass of the molecules. Presently, additional Z-scan measurements conducted between 500 and 1800 nm for these molecules give the spectral dependence of their NLO response on a broader frequency range and provide more insight on the impact of the structural changes between 4-X, 5 n and 7.…”

Nonlinear optical properties of meso-Tetra(fluorenyl)porphyrins peripherally functionalized with one to four ruthenium alkynyl substituents

“…Figure 1), can possess strong nonlinear absorption properties in the near-IR region. More recently, and taking advantage of the coordination site available on the peripheral Ru(II) atoms, the π-manifold was expanded by either Ru(II)-containing dendrons (2) 18 or organoiron-alkynyls (3). 16,19 Larger third-J o u r n a l P r e -p r o o f order NLO responses and significant nonlinear absorption in the near-IR were seen for both 2 and 3, as exemplified by the impressive values found for the maximal "effective" twophoton absorption cross-sections (σ 2 ) in this spectral range.…”

Syntheses and quadratic nonlinear optical properties of 2,7-fluorenylene- and 1,4-phenylene-functionalized o-carboranes

“…ortho-Carborane (o-Cb) is an efficient electron-acceptor comparable in strength to the tetrafluorophenyl group, 17,18 and therefore has potential in donor-π-bridge-acceptor (D-B-A) assemblies of interest in nonlinear optics, but the quadratic nonlinear optical (NLO) performance of Cb dyads has thus far remained modest, and few efficient examples are extant. [19][20][21] In contrast to the dearth of studies with o-Cb-based compounds, there has been considerable success in synthesizing quadratic NLO-active D-B-A compounds with organic and inorganic donor and acceptor groups and phenyleneethynylene-based, [22][23][24][25][26][27][28][29] phenylenevinylene-based, 5,[30][31][32][33][34] and other π-bridges, 24,[35][36][37][38] which has afforded a large number of NLO-efficient examples, and thereby facilitated the development of design rules for the optimization of NLO performance. One observation is that the quadratic NLO coefficient β generally increases with π-bridge lengthening in such compounds, 30,31,36,[39][40][41] but the solubilities of the compounds usually decrease upon increasing the length of the bridge.…”