Molecular materials for switchable nonlinear optics in the solid state, based on ruthenium-nitrosyl complexes

Abstract

The promising class of (polypyridine-ruthenium)-nitrosyl complexes capable of high yield Ru-NO/Ru-ON isomerization is targeted as a potential molecular device for the achievement of complete NLO switches in the solid state. A computational investigation conducted at the PBE0/6-31+G** DFT level for benchmark systems of general formula [R-terpyridine-Ru II Cl 2 (NO)](PF 6 ) (R being a substituent with various donating or withdrawing capabilities) leads to the suggestion that an isomerization could produce a convincing NLO switch (large value of the b ON /b OFF ratio) for R substituents of weak donating capabilities. Four new molecules were obtained in order to test the synthetic feasibility of this class of materials with R = 4 0 -p-bromophenyl, 4 0 -p-methoxyphenyl, 4 0 -p-diethylaminophenyl, and 4 0 -p-nitrophenyl. The different cis-(Cl,Cl) and trans-(Cl,Cl) isomers can be separated by HPLC, and identified by NMR and X-ray crystallographic studies.

On the molecular structure of (E)-3-(9H-fluoren-2-yl)-1-(pyridin-2-yl)prop-2-en-1-one, theoretical calculations and SXRD studies

“…We recently reported the use of azachalcones as chemical intermediates in the synthesis of 2,2':6',2''-terpyridines, a family of tridentate ligands whose coordination behavior towards Ru(II) has shown promising results in the photoinduced release of nitric oxide [23][24].…”

Second-order nonlinear optics in coordination chemistry: An open door towards multi-functional materials and molecular switches

“…In a perspective of NLO switch, the properties of 20 suggests that Ru II (NO) complexes with a coordination sphere containing chloride and polypyridinic ligand should fulfill the above requirement -2-. The possibility to fulfill the requirement -1-was targeted on the related Ru II (terpy) complexes 21 (Chart 5) [65]. Complexes 21 possess a C 2 symmetry, which leads to the assumption that the associated ˇ vectors are directed along the symmetry axis and arise from a balance between both Ru II → NO and Ru II → Rpyridine charge transfers in these derivatives.…”

“…The dotted lines are extrapolations for ˇ values on the entire extent of the donor/acceptor domain of R substituents. The possibility for photo-induced ˇo ff to ˇon switch is illustrated by the double arrow (Hammett constant around −0.15) (see ref[65]). photo-induced metastable state, according to the following equilibrium [62]: Na 2 [Fe II (CN) 5 (NO)]·2H 2 O Na 2 [Fe II (CN) 5 (ON)]·2H 2 O…”

Ruthenium(II)-nitrosyl polypyridinyl Complexes: from NO/ON Isomerization to NO delivery

“…By virtue of the donor/acceptor capabilities of the R substituent, the possibility for a balance in charge transfer from Ru II to either NO or the R-substituted pyridine may be envisioned. In order to consider a large domain of donating/accepting capabilities, the situations with R=NH 2 and NO 2 were fully investigated [13]. The DFT computed are presented in Figure 3.…”