Selecting the Mechanism of Surface-Enhanced Raman Scattering Effect using Shell Isolated Nanoparticles and an Oxo–Triruthenium Acetate Cluster Complex

Santos, Jonnatan J.; Toma, Sérgio Hiroshi; Monezi, Natália M.; Ando, Rômulo Augusto; Cório, Paola; Araki, Koji

doi:10.1021/acs.inorgchem.9b01618

Cited by 3 publications

(11 citation statements)

References 33 publications

(44 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are few examples in the literature of systematic Raman spectroscopy studies of triruthenium clusters, although they are very interesting from a spectroelectrochemical point of view, as well as on the perspective of resonance Raman spectroscopy, they are scarce probably because synthesizing them can be quite tricky and nontrivial. ,, One important point that makes the Raman studies of triruthenium clusters incompatible with resonance Raman technique is the photo and thermal sensitivity of these compounds in near-infrared region.…”

Section: Resultsmentioning

confidence: 99%

“…The 4-pyridylterpyridine (pytpy) ligand was prepared according to the method described by Hanan et al The [Ru 3 O(CH 3 COO) 6 (py) 2 (pytpy)]PF 6 cluster, as recently published, was prepared by reacting stoichiometric amounts of the asymmetric clusters [Ru 3 O(CH 3 COO) 6 (py) 2 (MeOH)]PF 6 and the ditopic 4-pyridyl-terpyridine (pytpy) bridging ligand in dichloromethane. Thus, 300 mg (3.0 × 10 –4 mol) of the [Ru 3 O (CH 3 COO) 6 (py) 2 (MeOH)]PF 6 cluster were solubilized in 30 mL of a CH 3 OH/CH 2 Cl 2 mixture (1:1 v/v) in which was added 93 mg (3.0 × 10 –4 mol) of the pytpy linker dissolved in 10 mL of CH 2 Cl 2 .…”

Section: Methodsmentioning

confidence: 99%

“…On the other hand, by SERS, it was possible to observe a great difference in their spectra when varying their redox states. We recently demonstrated that the oxygen stretching modes in the [Ru 3 O] center can be observed in great intensity even with SHINERS-type nanoparticles, demonstrating that this great intensification is related to an intensification of the SERRS type …”

Section: Introductionmentioning

confidence: 99%

“…This contribution is one of the most controversial since many authors consider it as part of the chemical mechanism and others consider it as an individual component . As recently published, we can consider CHEM and rR contributions independently, which has been proven using shell-isolated nanoparticles (SHIN) …”

Section: Introductionmentioning

confidence: 99%

“…Oxo–triruthenium acetate clusters or just triruthenium clusters are well-known for their electrochemical properties and spectroelectrochemical properties, where it is possible to modulate their absorption employing electrochemical potential. − Recently, this class of compounds was subject to relevant publications in several areas such as transport and release of nitric oxide and anticancer activity, electrochromic and catalytic properties, − and we have been studying the interaction of triruthenium clusters on electrodes and with gold nanoparticles. ,, …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Unveiling Anomalous Surface-Enhanced Resonance Raman Scattering on an Oxo–Triruthenium Acetate Cluster Complex by a Theoretical–Experimental Approach

et al. 2020

Self Cite

View full text Add to dashboard Cite

Surface-enhanced Raman spectroscopy (SERS) has been explored by the most diverse areas of research over the past 40 years, with more special attention from analytical chemistry. Although there is a great consensus that there are two mechanisms that contribute most to the observation of the phenomenon (electromagnetic (EM) and charge transfer (CT)), several anomalies are observed, especially when studying complexes of transition metals. In this article, we present a theoretical and experimental study of Raman and SERS of an oxo–triruthenium acetate cluster ([Ru3O (CH3COO)6(py)2(pytpy)]), where it was possible to observe one of these “anomalies” of the SERS effect, in this case, an unexpected enhancement of the vibrational stretching mode of the oxo group. This cluster had its electrochemical and spectroelectrochemical properties studied by cyclic voltammetry and electronic spectroscopy in the visible and near-infrared, where it was possible to observe the fully reversible waves of the ruthenium sites (separated by 1.00 V) and the terpyridinic ligand and how the absorption of this complex varies drastically when reduced electrochemically. The molecular orbitals and electronic transitions of this cluster were calculated by time-dependent density-functional theory (TDDFT), where it can be noted that the HOMO orbitals are almost exclusively composed of the atomic orbitals of ruthenium and the LUMO orbitals can be composed of a mixture of ruthenium orbitals and acetate ligands, as well as terpyridine. From the TDDFT calculations and the transitions energies obtained, the complex resonant Raman and Raman spectra were simulated using different excitation wavelengths (696, 785, and 1064 nm), where an unexpected intensification of oxygen stretching at the Ru3O center at 700 cm–1 was observed considering the excitation at 785 nm, even though there was no expected transition. The experimental SERS spectra of the complex in two redox states (Ru3 III, III, III and Ru3 III, III, II) were obtained experimentally using gold and silver nanoparticles with an excitation wavelength laser at 785 nm, where a very intense signal at 700 cm–1, for the Ru3 III, III, II redox state, was observed. The simulation of electronic states by TDDFT and SERS spectra by DFT, considering an Au20 cluster adduct, showed an intensification of the entire complex, with great emphasis on the Ru3O center and the 700 cm–1 mode that, however, was not as intense as the results obtained experimentally, indicating an anomalous intensification.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%