Photoelectric Emission and Electrical Conductivity of the Cesium Complex with Pyrene Derivatives

Abstract

On the basis o the charge transfer process of the complexes, the photoemission and the electronic conduction of the complexes between cesium and pyrene derivatives, tetranitropyrene (TNO2P), tetrachloropyrene (TClP), tetrabromopyrene (TBrP) and tetracyanopyrene (TCNP) have been measured. A strong increase in the quantum yield of photoemission, from 10−3–10−4 to 10−1–102, resulting from the formation of the complexes, has been found. The promotion may take place by means of an electron transfer from cesium metal to a partner molecule; [Cs+] [Aromatics−]. The assumption is supported by the findings concerning electron spin resonance absorption and charge-transfer spectra. The electrical resistivity of the complexes, ρ at 15°C of pyrene-Cs=2.1×104 Ωcm., (TClP)-Cs=8Ωcm., (TBrP)-Cs=1.6×101 Ωcm., (TNO2P)-Cs=2×106 Ωcm. and (TCNP)-Cs=6×105 Ωcm., is strongly affected by the contribution of the, dative-bond character of the complexes.

UV absorption and fluorescence properties of fused aromatic hydrocarbons having trimethylsilyl, trimethylgermyl, and trimethylstannyl groups

“…1a: R 1 = SiMe 3 , R 2 = R 3 = R 4 = H 1b: R 1 = GeMe 3 , R 2 = R 3 = R 4 = H 1c: R 1 = SnMe 3 , R 2 = R 3 = R 4 = H 1d: R 1 = R 2 = R 3 = R 4 = H 1e: R 1 = R 3 = SiMe 3 , R 2 = R 4 = H Further bromination of the mixture of dibromopyrenes in nitrobenzene at 80°C afforded tri-and tetrabromopyrene [38], which were persilylated to give 1g and 1h. Bis-, tris-, and tetrakis(trimethylsilyl)pyrene (1e-h) could be isolated by recycling preparative HPLC.…”

“…To the solution was added bromine (2.7 mL, 51 mmol) in nitrobenzene (10 mL), and was stirred at 80°C overnight. After the reaction mixture was cooled to room temperature, precipitates were collected, which are characterized to a mixture of 1,3,6-tribromopyrene and 1,3,6,8-tetrabromopyrene [38]. Silylation of the mixture by…”

Pyrene as Chromophore and Electrophore: Encapsulation in a Rigid Polyphenylene Shell

“…Thus, fourfold bromination of pyrene (1) in the 1,3,6,8-positions was carried out according to the literature [12] to obtain 2 (Scheme 1).…”

Modulation of Gas Sorption Properties through Cation Exchange within an Anionic Metal–Organic Framework

“…[13] All other solvents and chemicals were commercially available and used without further purification. ESI mass spectra were recorded on a Thermo Finigan LCQ DECA XP ion trap mass spectrometer in DMF.…”

“…For example, lithium-doped MIL-53 has been reported to exhibit nearly double the hydrogen uptake capacity of undoped MOF. [9] Herein, we report a 3D anionic MOF, (Me 2 NH 2 ) 4 13 (1), which was constructed by the coordination of nickel(II) with a tetracarboxylate ligand, H 4 PTCA (H 4 PTCA = pyrene-1, 3,6,8-tetracarboxylic acid). Based on a cation-exchange strategy, in which Me 2 NH 2 + in 1 was exchanged by Li + , the desolvated Li-exchanged MOF shows an enhanced CO 2 , CH 4 , and H 2 uptake capability, relative to the original MOF.…”