Classification of Phenothiazine Complexes by Structure and Electronic Properties

Abstract

Abstract Donor-acceptor complexes were prepared, and their structures and electronic properties were observed. Donors were phenothiazine and its four derivatives, and acceptors were metallic chlorides (Lewis acids), iodine, and two π-type acceptors. By the absorption edge of diffuse reflection spectra (λE) and crystal structure, the complexes were classified into four groups. Groups I, II, and III correspond to the complexes with Lewis acids or iodine, and group IV consists of complexes with π-type acceptors. The summarized characteristics of each group are as follows. Group I: λE≤950 nm, complete charge transfer, insulator, and alternate arrangement of cations and anions. Group II: 1200 nm≤λE≤1700 nm, complete charge transfer, semiconductive behavior, and oligomeric or columnar arrangement of cation radicals. Group III: λE>2500 nm, partial charge transfer, metallic conductor or semiconductor with small activation energy, and columnar arrangement. Group IV: λE≥1700 nm, and semiconductive behavior. Based on these classifications, we have proposed a mechanism for controlling the aggregate manner of cation radicals.