Vibrational spectra of tris(acetylacetonato)chromium(III)

Dolati, Fatemeh; Vakili, Mohamad; Ebrahimi, Ali; Tayyari, Sayyed Faramarz

doi:10.1016/j.molstruc.2015.05.058

Cited by 11 publications

(2 citation statements)

References 44 publications

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“…Our TPD, XPS, and reflection–absorption infrared spectroscopy (RAIRS) studies with 4 on silicon oxide and aluminum oxide flat surfaces (thin films) have indicated measurable thermal activation and decomposition, more extensive on the latter substrate. Figure provides RAIRS data for the adsorbed species obtained after dosing the precursor at different temperatures, and Table lists the peak assignment (based on published analysis for analogous complexes). ,− Only limited adsorption and decomposition were seen on silicon oxide, as indicated by the weak intensities of the peaks visible in the corresponding spectra. The spectrum recorded at 625 K matches closely that of the pure compound, suggesting the possibility of molecular bonding.…”

Section: Resultsmentioning

confidence: 80%

Thermal Chemistry of Metal Organic Compounds Adsorbed on Oxide Surfaces

et al. 2019

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The thermal chemistry of several metal organic compounds with amidinate, diketonate, or cyclopentadienyl (Cp) ligands on oxide surfaces, mainly on silicon dioxide but also on aluminum oxide, was studied by using surface sensitive techniques, including temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), reflection–absorption infrared spectroscopy (RAIRS), and static secondary ion mass spectrometry (SSIMS), and those studies were complemented with quantum mechanics calculations. With the amidinates, TPD experiments revealed complex decomposition pathways, starting with a ligand-exchange step with OH surface groups. That is followed by migration of the remaining ligands from the metal center to the surface, where decomposition occurs mainly via bond scission at the terminal alkyl groups and β-hydride elimination steps to produce the corresponding olefins. At that stage, XPS data show that the metal is partially, but not completely, reduced, indicating a partially ionic metal–oxygen surface bond. The diketonates display only limited reactivity on silica, again via an initial ligand exchange step, but much higher reactivity is seen on alumina, where subsequent decomposition and olefin production are observed. The Cp ligands proved to be the most stable, hindering in fact the effective adsorption of these metal organic compounds unless prior activation in the gas phase via electron-impact excitation is carried out. After adsorption, the Cp proved to be quite sturdy, surviving long exposures to outside atmospheres (as shown by SSIMS). They can, however, be protonated (deuterated) upon high-temperature exposure to H2O (D2O). All this chemistry is discussed in general terms and contrasted with known reactivity in solution.

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Section: Resultsmentioning

confidence: 80%

Thermal Chemistry of Metal Organic Compounds Adsorbed on Oxide Surfaces

et al. 2019

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“…The increased PDI of P1–Pt while the decreased PDI of P2–Pt for Pt(II)-incorporated copolymers may be attributed to the efficiency of polymerization. Fourier transform infrared (FTIR) spectra (Figures S10–S13) showed significant changes after the coordination of Pt(II) is considered to be mainly originate from the secondary acetylacetonate ligand. , Two strongest absorption bands appeared in the 1650–1400 cm –1 region, which can be assigned to the CO and C–C stretching modes. The thermal stability of copolymers was analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).…”

Section: Resultsmentioning

confidence: 99%

Significant Enhancement of Reverse Saturable Absorption Ability via Pt(II) Incorporation into the Conjugated Backbone of Benzo[1,2-b:4,5-b′]dithiophene-Based Donor–Acceptor Copolymers

Wang,

Zhao,

Han

et al. 2024

Macromolecules

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Organic nonlinear optical (NLO) materials with πconjugated electron donor (D) and/or acceptor (A) frameworks have attracted widespread attention because of their controllable performance through rationally structural tailoring, while optical limiting (OL) materials with reverse saturable absorption (RSA) ability is becoming a challenging focus in NLO research. Herein, 4,8-di(thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene (BDTT) was employed as an electron-rich building block to construct donor− acceptor (D−A)-type π-conjugated copolymers P1 and P2 and corresponding Pt(II)-incorporated copolymers P1−Pt and P2−Pt toward NLO materials. All copolymers exhibit typical RSA behavior toward a 532 nm nanosecond laser pulse. Interestingly, copolymers P1−Pt and P2−Pt show significantly superior RSA ability than P1 and P2, which is attributed to the synergistic effect of the extension of π-conjugation, enhancement of the ICT process, and especially the efficient formation of a triplet state caused by the novel Pt(II)-incorporated structure. Furthermore, copolymers show decreased band gaps with the tendency of P1 (2.48 eV) > P1−Pt (2.21 eV) > P2 (2.18 eV) > P2−Pt (1.94 eV). Correspondingly, P1−Pt and P2−Pt exhibit larger nonlinear absorption coefficients (β eff ) of 45 and 79 cm GW −1 , respectively, ca. 2.6 and 2.9 times higher than those of P1 (17 cm GW −1 ) and P2 (27 cm GW −1 ), respectively. This work presents an efficient strategy toward excellent organic NLO materials, facilitates the understanding of copolymer structure−property relationship, and promotes their advanced applications.

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