Organic Semiconductors. II. The Electrical Resistivity of Organic Molecular Complexes

Abstract

Thirty molecular complexes involving quinones, halogens, polynitroaromatics, or tetracyanoethylene as electron acceptors and aromatic hydrocarbons or substituted aromatics as electron donors have been prepared and the room temperature electrical resistivities measured on compressed microcrystalline material. A lowering of electrical resistivity is generally associated with complex formation. The results are discussed in terms of crystal structure and charge transfer complex theory.

Utilizing Perylene in New Organic Donor–Acceptor Materials: Highlighting the Synthesis, Structure and Physical Properties of Perylene-pDNB and Perylene-TCNP

“…Due to the insulating nature of the compounds, the individual samples were placed in series with a 100 kOhm resistor across which the voltage was measured, thereby revealing the circuit current and subsequently the resistance of the samples. A rectangular sample of 1 was measured with dimensions (width 9 height 9 length) of 1.15 9 0.3590.85 mm 3 . The original complex of 2 yielded crystals too thin to effectively mount for electrical transport, so these materials were pressed into a polycrystalline thin pellet via application of 6.32 kbar of pressure slowly released over a time span of approximately 10 min.…”

“…The sample was brittle, and the resulting three pieces were of various rectangular dimensions measuring (width 9 height 9 length) of 0.0354 9 0.188 9 0.668 mm 3 , 0.407 9 0.188 9 0.464 mm 3 and 0.903 9 0.188 9 0.954 mm 3 .…”

“…This result was later followed by the discovery of metallic conductivity in a series of Perylene salts prepared via iodine oxidation that yielded two phases known as 2PÁ3I 2 and PÁ4I 2 (P = Perylene) [3][4][5]. Further studies on the former demonstrated that rather than being a molecular complex, it was really a partially oxidized mixed-valence salt having the formula (Perylene) ?0.4 [I 3 -Á2I 2 ] 0.4 [6].…”

“…This result was later followed by the discovery of metallic conductivity in a series of Perylene salts prepared via iodine oxidation that yielded two phases known as 2PÁ3I 2 and PÁ4I 2 (P = Perylene) [3][4][5]. Further studies on the former demonstrated that rather than being a molecular complex, it was really a partially oxidized mixed-valence salt having the formula (Perylene) ?0.4 [I 3 -Á2I 2 ] 0.4 [6]. When oxidized by iodine in the presence of bis(dithiolene) salts having the formula M(mnt) 2 2-(M = Pd, Pt, Ni, Fe, Au, Cu and Co; mnt = dicyano-1,2-ethylenedithiolato), salts having the formula a-(Perylene) 2 [M(mnt) 2 ] resulted that demonstrated conductivity values ranging from 200 to 700 SÁcm -1 depending on the identity of the metal center [7][8][9][10][11].…”

Effect of Ambient Oxygen on the Semiconductivities of Evaporated Films of Mesonaphthodianthrene and Mesonaphthodianthrone

“…While this would be consistent with our experimental results, evidently a good deal more experimental data are needed concerning the very interesting reaction of oxygen with the surfaces of quinones. Some interesting recent papers germane to these problems are listed in References (11,12,13,14).…”