LITHIUMPHTHALOCYANINES - SYNTHESIS, PROPERTIES, AND CRYSTAL-STRUCTURE OF BIS(TRIPHENYLPHOSPHINE)IMINIUMPHTHALOCYANINATOLITHATES WITH DIFFERENT CONFORMATIONS OF THE CATION

Reaction of tri(n-dodecyl)n-butylammoniumphthalocyaninatolithate, (TDBA)[LiPc(2-)] with bis(triphenylphosphin)iminiumbromide, (PNP)Br in dichloromethane yields (PNP)[LiPc(2-)]. It crystallizes in the triclinic space group P ($) over bar 1 as dichloromethane solvate (1) and in the monoclinic space group P2(1)/n as hydrate (2). The crystal structures of (1) and (2) are reported. Each salt contains two crystallographically slightly different discrete [LiPc(2-)](-) anions, in which the square-planar coordinated Li+ cation is centered within the planar Pc(2-) ligand (D-av.(Li-Ni-iso) = 1.945 Angstrom). There are three different conformations for the (PNP) cation: (1) only contains the bent conformer (d(av)(P-N) = 1.575 Angstrom; phi(P-N-P) = 140.8 degrees), while in (2) an hybrid (d(av)(P-N) = 1.562 Angstrom; phi(P-N-P) = 158.1 degrees) and the linear conformer (d(av)(P-N) = 1.547 Angstrom; phi(P-N-P) = 176.8 degrees) are present. The very soluble, blue-green salts melt at 265 degrees C without decomposition. In accordance with cyclovoltammetric data thin films of (PNP)[LiPc(2-)] are oxidized by NO2 or Br-2 to yield brown violet [LiPc(-)]. The electronic absorption spectra and the vibrational spectra are discussed.