Rectangular-shaped expanded phthalocyanines with two central metal atoms.
Expanded phthalocyanine (Pc) congeners with two Mo or W central metal ions and four isoindole ring moieties have been synthesized using normal Pc formation conditions in the presence of urea. The products have been characterized by electrochemistry; mass spectrometry (MS); IR, electron paramagnetic resonance (EPR), NMR, electronic absorption, and magnetic circular dichroism (MCD) spectroscopies; and X-ray analysis. The X-ray structures have rectangular C(2v) symmetry and provide evidence that the central Mo atoms are linked by a single bond and coordinated by two isoindole nitrogen atoms and two nitrogen atoms from the amine moieties. The electronic absorption bands extend into the 1200-1500 nm region. This can be explained using Gouterman's four-orbital theory. The experimental NMR data and theoretical calculations provide evidence for a heteroaromatic 22-π-electron conjugation system for the ring-expanded Pc system, which satisfies Hückel's (4n + 2)π aromaticity.
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
Osamu
O
Matsushita
Valentina M
VM
Derkacheva
Atsuya
A
Muranaka
Soji
S
Shimizu
Masanobu
M
Uchiyama
Evgeny A
EA
Luk'yanets
Nagao
N
Kobayashi
D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry*; D054833:Isoindoles / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008958:Models, Molecular; D008982:Molybdenum / Q000737:chemistry*; D014414:Tungsten / Q000737:chemistry*
D007211:Indoles; D054833:Isoindoles; D008982:Molybdenum; C013647:phthalocyanine; D014414:Tungsten