Photochromic Ruthenium Sulfoxide Complexes: Evidence for Isomerization Through a Conical Intersection

McClure, Beth Anne; Mockus, Nicholas V.; Butcher, Dennis P.; Lutterman, Daniel A.; Turró, Claudia; Petersen, Jeffrey L.; Rack, Jeffrey J.

doi:10.1021/ic900421v

Cited by 53 publications

(98 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…+ , [20] there is no evidence for the formation of an O-bonded excited state in the transient spectra, indicating that S!O isomerization occurs from a CT excited state of S-bonded character to the O-bonded ground state. Transient spectra were fitted to a bi-exponential rate law, yielding rate constants of 4.…”

Section: (Oso)]mentioning

confidence: 94%

Two‐Color Reversible Switching in a Photochromic Ruthenium Sulfoxide Complex

McClure

Rack

2009

Angew Chem Int Ed

View full text Add to dashboard Cite

Reversible, external triggering of molecules between two ground states is central to the operation of modern molecular machines. [1][2][3] A desirable trigger is light, as it provides an ample amount of energy in a short burst of time. Although light is commonly employed for the formation of many different types of metastable states, [4][5][6][7][8] in practice it is difficult to employ light to regenerate the initial ground state. The enthalpic and entropic factors that favor the photochemical generation of the metastable state from the ground state must necessarily be disfavored for the opposing photochemical reaction. Moreover, the photoproduct often reverts to the ground state thermally. Irradiation of photochromic compounds yields metastable states that exhibit distinct electronic structures compared to their ground states.[9] Whilst a number of organic photochromic compounds feature reversible or two-color photoswitching between metastable and ground states, such reactivity is rare in transition metal complexes.[10]Herein, we report our findings on a ruthenium sulfoxide complex that features two-color photochromism.The complex [Ru(bpy) 2 (pySO)](PF 6 ) 2 (bpy = 2,2'-bipyridine, pySO = 2-(isopropylsulfinylmethyl)pyridine) was prepared from reaction of cis-[Ru(bpy) 2 Cl 2 ] with pySO. The structure and formulation of the complex was verified by oneand-two-dimensional 1 H NMR, IR spectroscopy, and elemental analysis. The 1 H NMR spectrum is consistent with the presence of two isomers, which are most likely diastereomers, as both the ruthenium and sulfur centers are chiral. Elemental analysis of the isomeric mixture supports this assignment. The lowest-energy transition in the electronic spectrum occurs at 370 nm (e = 7250 cm À1 m À1 ) and is assigned to a Ru dp!bpy p* charge-transfer transition based on its energy and intensity (Figure 1). This transition is similar to that observed for other chelating S-bonded sulfoxides.[11] Furthermore, the structurally characterized complex [Ru(bpy) 2 (py)(dmso)] 2+ (dmso = dimethylsulfoxide), which has no chelation, features a maximum absorbance at 400 nm for the S-bonded isomer.[12]Therefore, the chelate complex exhibits an additional 2000 cm À1 of stabilization relative to the non-chelate form. White light irradiation of [Ru(bpy) 2 (pySO)]2+ in propylene carbonate solution results in a decrease in the absorbance at 370 nm concomitant with an increase at 472 nm (Figure 1, inset). In accord with other ruthenium sulfoxide complexes, [13] the spectral changes indicate an intramolecular S!O isomerization, with an isosbestic point at 408 nm. However, the observed spectral changes are muted in comparison to these other complexes. We questioned whether or not this spectrum represented a photostationary state. Accordingly, irradiation of this solution with 355 nm light resulted in a more pronounced absorbance at 472 nm (quantum efficiency F S!O = 0.11(2)). This value is similar to that of the Obonded isomer of [Ru(bpy) 2 (py)(dmso)] 2+ (476 nm) [12] and [Ru(bpy) 2 (pic)] + (483...

show abstract

Section: (Oso)]mentioning

confidence: 94%

Two‐Color Reversible Switching in a Photochromic Ruthenium Sulfoxide Complex

McClure

Rack

2009

Angew Chem Int Ed

View full text Add to dashboard Cite

show abstract

“…This is a conventional argument to explain the photochemistry of ruthenium polypyridine complexes. [51] 2+ (where OSO is 2-methylsulfinylbenzoate), [37,49] indicating an efficient conversion of photonic energy to potential energy. These large quantum yields indicate that the mechanism for photoisomerization may be different from that proposed for photosubstitution.…”

Section: Photochemical Isomerization In Ruthenium and Osmium Dmso Commentioning

confidence: 99%

“…[37] In panel a are shown the spectra of S-and O-bonded isomers with transient spectra of each isomer shown in panels b and c, respectively. In b, the spectra of the S-bonded isomer reveal a bleach near 450 nm in the first few picoseconds concomitant with a broad featureless absorption at lower energy.…”

Section: (Oso)]mentioning

confidence: 99%

Isomerization in Photochromic Ruthenium Sulfoxide Complexes

McClure

Rack

2010

Eur J Inorg Chem

Self Cite

View full text Add to dashboard Cite

The spectroscopic properties of photochromic ruthenium sulfoxide complexes are reviewed. The mode of action is associated with an excited state SǞO isomerization triggered by light. These complexes feature large, positive Ru 3+/2+ reduction potentials indicative of stabilization of the Ru dπ orbital set. In addition, these compounds feature large quantum yields of isomerization. In aggregate, the data argue

show abstract

“…Here, a light-induced isomerization [38] is located at the SO group as depicted in Figure 4 for [Ru(bpy)

_{2}

(OSO)]

^{+}

(OSO) [39,40]. The MLCT transition

Ru normald π \to bpy π^{⋆}

is triggered by exposure to light of 380–440 nm [20,40]. In most sulfoxide compounds, a light-induced transfer from SI/SII to GS is not observed, but can be enabled by using pySO as switching ligand [41].…”

Section: Photophysical Properties Of Transition Metal Compoundsmentioning

confidence: 99%

“…In OSO, DFT calculations predict two metastable isomers, both having the SO rotated by

180^{\circ}

. They only slightly differ in the bonding angles of the benzene ligand [40]. The prediction is in line with the observation of a two-fold exponential thermal relaxation behavior from SI/SII to GS yielding two distinctive activation energies [20] and showing no dependence of the relaxation time constants on the probing wavelength as it was studied for

λ =

352 nm, 400 nm and 500 nm in Reference [42].…”

Section: Photophysical Properties Of Transition Metal Compoundsmentioning

confidence: 99%

Transition Metal Compounds Towards Holography

et al. 2012

View full text Add to dashboard Cite

We have successfully proposed the application of transition metal compounds in holographic recording media. Such compounds feature an ultra-fast light-induced linkage isomerization of the transition-metal–ligand bond with switching times in the sub-picosecond regime and lifetimes from microseconds up to hours at room temperature. This article highlights the photofunctionality of two of the most promising transition metal compounds and the photophysical mechanisms that are underlying the hologram recording. We present the latest progress with respect to the key measures of holographic media assembled from transition metal compounds, the molecular embedding in a dielectric matrix and their impressive potential for modern holographic applications.

show abstract

Photochromic Ruthenium Sulfoxide Complexes: Evidence for Isomerization Through a Conical Intersection

Cited by 53 publications

References 89 publications

Two‐Color Reversible Switching in a Photochromic Ruthenium Sulfoxide Complex

Two‐Color Reversible Switching in a Photochromic Ruthenium Sulfoxide Complex

Isomerization in Photochromic Ruthenium Sulfoxide Complexes

Transition Metal Compounds Towards Holography

Contact Info

Product

Resources

About