title: Synthesis, structure, spectroscopic properties, and electrochemistry of (1,8,15,22-tetrasubstituted phthalocyaninato)lead complexes.
abstract: Three (1,8,15,22-tetrasubstituted phthalocyaninato)lead complexes Pb[Pc(alpha-OR)(4)] [H(2)Pc(alpha-OC(5)H(11))(4) = 1,8,15,22-tetrakis(3-pentyloxy)phthalocyanine; H(2)Pc(alpha-OC(7)H(15))(4) = 1,8,15,22-tetrakis(2,4-dimethyl-3-pentyloxy)phthalocyanine; H(2)Pc(alpha-OC(10)H(7))(4) = 1,8,15,22-tetrakis(2-naphthyloxy)phthalocyanine] (1-3) have been prepared as racemic mixtures by treating the corresponding metal-free phthalocyanines H(2)Pc(alpha-OR)(4) (4-6) with Pb(OAc)(2).3H(2)O in refluxing n-pentanol. The molecular structure of Pb[Pc(alpha-OC(5)H(11))(4)] (1) in the solid state has been determined by single-crystal X-ray diffraction analysis. This compound, having a nonplanar structure, crystallizes in the monoclinic system with a P2(1)/c space group. Each unit cell contains two pairs of enantiomeric molecules, which are linked by weak coordination of the Pb atom of one molecule with an aza nitrogen atom and its neighboring oxygen atom from the alkoxy substituent of another molecule, forming a pseudo-double-decker supramolecular structure in the crystals with a short ring-to-ring separation, 2.726 A, and thus a strong ring-ring pi-pi interaction. The decreased molecular symmetry for these complexes has also been revealed by the NMR spectra of 1 and 2. The methyl protons of the 3-pentyloxy and 2,4-dimethyl-3-pentyloxy side chains of 1 and 2, respectively, are chemically inequivalent. In addition to the elemental analysis and various spectroscopic characterizations, these compounds have also been electrochemically studied. Two one-electron oxidations and up to five one-electron reductions have been revealed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods.
authors.affiliation: Department of Chemistry, Shandong University, Jinan 250100, China.
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Bian
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Jianmin
authors.initials: J
authors.lastname: Dou
authors.forename: Diana Y Y
authors.initials: DY
authors.lastname: Cheng
authors.forename: Renjie
authors.initials: R
authors.lastname: Li
authors.forename: Changqin
authors.initials: C
authors.lastname: Ma
authors.forename: Dennis K P
authors.initials: DK
authors.lastname: Ng
authors.forename: Nagao
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Jianzhuang
authors.initials: J
authors.lastname: Jiang