Homoleptic copper(I) arylthiolates as a new class of p-type charge carriers: structures and charge mobility studies

Che, C.-M., Li, C.-H., Chui, S. S.-Y., Roy, V.A.L. and Low, K.-H. (2008) Homoleptic copper(I) arylthiolates as a new class of p-type charge carriers: structures and charge mobility studies. Chemistry: A European Journal, 14(10), pp. 2965-2975. (doi: 10.1002/chem.200700723) (PMID:18350558)

Abstract

Polymeric homoleptic copper(I) arylthiolates [Cu(p‐SC6H4‐X)]∞ (X=CH3 (1), H (2), CH3O (3), tBu (4), CF3 (5), NO2 (6), and COOH (7)) have been prepared as insoluble crystalline solids in good yields (75–95 %). Structure determinations by powder X‐ray diffraction analysis have revealed that 1–3 and 6 form polymers of infinite chain length, with the copper atoms bridged by arylthiolate ligands. Weak intra‐chain π⋅⋅⋅π stacking interactions are present in 1–3, as evidenced by the distances (3.210 Å in 1, 3.016 Å in 2, 3.401 Å in 3) between the mean planes of neighboring phenyl rings. In the structure of 6, the intra‐chain π⋅⋅⋅π interactions (d=3.711 Å) are insignificant and the chain polymers are associated through weak, non‐covalent CH⋅⋅⋅O hydrogen‐bonding interactions (d=2.586 Å). Samples of 1–7 in their polycrystalline forms proved to be thermally stable at 200–300 °C; their respective decomposition temperatures are around 100 °C higher than that of the aliphatic analogue [Cu(SCH3)]∞. Data from in situ variable‐temperature X‐ray diffractometry measurements indicated that the structures of both 1 and 7 are thermally more robust than that of [Cu(SCH3)]∞. TEM analysis revealed that the solid samples of 1–5 and [Cu(SCH3)]∞ contained homogeneously dispersed crystalline nanorods with widths of 20–250 nm, whereas smaller plate‐like nanocrystals were found for 6 and 7. SAED data showed that the chain polymers of 1–3 and [Cu(SCH3)]∞ similarly extend along the long axes of their nanorods. The nanorods of 1–5 and [Cu(SCH3)]∞ have been found to exhibit p‐type field‐effect transistor behavior, with charge mobility (μ) values of 10−2–10−5 cm2 V−1 s−1. Polycrystalline solid samples of 6 and 7 each showed a low charge mobility (<10−6 cm2 V−1 s−1). The charge mobility values of field‐effect transistors made from crystalline nanorods of 1–3 and [Cu(SCH3)]∞ could be correlated with their unique chain‐like copper–sulfur networks, with the para‐substituent of the arylthiolate ligand influencing the charge‐transport properties.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Vellaisamy, Professor Roy
• Authors: Che, C.-M., Li, C.-H., Chui, S. S.-Y., Roy, V.A.L., and Low, K.-H.
• College/School: College of Science and Engineering > School of Engineering
• Journal Name: Chemistry: A European Journal
• Publisher: Wiley
• ISSN: 0947-6539
• ISSN (Online): 1521-3765
• Published Online: 18 March 2008