Synthesis, Structural Investigation, and Solid-State Properties of Iodine-Doped Zirconium Diphthalocyanine, [ZrPc₂]I₃·I₂

Abstract

Crystals of iodine-doped zirconium(IV) diphthalocyanine, [ZrPc(2)]I(3).I(2) (where Pc = C(32)H(16)N(8)), were grown directly in the reaction of pure zirconium powder with phthalonitrile under a stream of iodine at 260 degrees C. [ZrPc(2)]I(3).I(2) crystallizes in the space group P2(1)/m (No. 11) of the monoclinic system with lattice parameters of a = 6.735(1), b = 25.023(5), and c = 17.440(3) A, beta = 99.43(3) degrees, and Z = 2. The crystals of [ZrPc(2)]I(3).I(2) are built up from two pseudo-monodimensional aggregates: one-electron-oxidized [ZrPc(2)](+) units; weak interacting triiodide I(3)(-) ions with neutral diiodine molecules. The I(3)(-) ions and neutral I(2) molecules in the crystal of [ZrPc(2)]I(3).I(2) have been also detected by Raman spectroscopy. The [ZrPc(2)](+) units form stacks along the a axis, while the polymeric...I(3)(-)...I(2)...I(3)(-)...I(2)(-)... zigzag chains are located in the crystal along the b axis, so both pseudo-monodimensional aggregates are perpendicular to each other. This arrangement is different from that found in the tetragonal crystals of [ZrPc(2)](I(3))(2/3) in which both monodimensional aggregates, i.e., the stacks of partially oxidized [ZrPc(2)](2/3+) units and chains of symmetric triiodide ions, are parallel. EPR experiment together with the X-ray single-crystal analysis clearly shown that oxidation of the diamagnetic ZrPc(2) complex by iodine is ligand centered and homogeneously affecting both phthalocyaninato rings of ZrPc(2); thus, the formal oxidation state of both Pc rings in [ZrPc(2)]I(3).I(2) is nonintegral (-1.5). The UV-vis spectrum of [ZrPc(2)] I(3).I(2) is very similar to the spectrum of unoxidized ZrPc(2) complex in the B Soret and Q spectral region. However, in the spectrum of [ZrPc(2)] I(3).I(2) one additional band at approximately 502 nm is observed, which indicates the existence of the one-electron-oxidized phthalocyaninato(-) radical ligand and is assigned to the electronic transition from a deeper level to the half-occupied HOMO level. The single-crystal electrical conductivity data show anisotropy and nonmetallic character in conductivity (d sigma/dT > 0). The charge transport mainly proceeds along the pseudo-monodimensional stacks of [ZrPc(2)](+) units. The relatively high conductivity along the stacks of one-electron-oxidized [ZrPc(2)](+) units results from the staggering orientation of Pc rings (rotation angle 45.0(2) degrees ) that leads to the short inter-ring C(alpha)(pyrrole)[bond]C(alpha)(pyrrole) contacts (2.839(3)-3.024(3) A). These C(alpha)-pyrrole atoms make appreciable contribution to the partially occupied pi-molecular orbital of Pc macrocycle and the greatest overlap of the HOMO orbitals that form the conduction band of partially oxidized molecular crystals.

Two isomorphous complexes: dichloro[phthalocyaninato(2–)]tin(IV) and dichloro[phthalocyaninato(2–)]germanium(IV)

“…Continuing our investigation of the synthesis and characterization of metallophthalocyaninate complexes under a stream of halogen vapour (I 2 , IBr and ICl), we have obtained several metallophthalocyaninate complexes. Iodine-doped metallophthalocyaninate complexes have been reported previously (Kubiak & Janczak, 1997;Janczak et al, 1998Janczak et al, , 2000Janczak & Kubiak, 1999a,b,d;Janczak, Kubiak & Hahn, 1999;Janczak, Kubiak & Jezierski, 1999;Janczak, Razik & Kubiak, 1999;Janczak & Idemori, 2001a,b, 2002Janczak, 2003). Recently, we reported two Nb V ±diphthalocyaninate complexes, containing two inter-ring ' CÐC bonds, obtained under IBr vapour , and an [SbPcCl] complex obtained under ICl vapour (Janczak & Kubiak, 2001).…”

Bis{[phthalocyaninato(2–)]antimony(III)} tetradecaiodotetraantimonate(III)

“…GJP thanks the CNPq foundation (Brazil) for a scholarship. The present study is a continuation of our investigations on the synthesis, characterization and stereochemistry of metallophthalocyaninate complexes, which have been obtained under oxidation conditions of iodine vapour (Janczak & Idemori, 2001;Janczak, 2003 (Fig. 1).…”

“…The present study is a continuation of our investigations on the synthesis, characterization and stereochemistry of metallophthalocyaninate complexes, which have been obtained through oxidation by iodine vapour (Janczak & Idemori, 2001;Janczak, 2003). The title compound, (I), is an example of a complex containing the same metal ion in both parts of the complex, the cation and the anion, i.e.…”

Synthesis and Structural Characterisation of Hafnium(IV) Mono‐ and Diphthalocyanines Obtained under Oxidation Conditions with Halogens

“…Some of the zirconium(IV) mono‐ and diphthalocyaninato (Pc 2– ) complexes were previously synthesised and structurally characterised by us 12–15. An interesting example of a zirconium phthalocyaninato complex is ZrPcI 2 Pht (Pht = phthalonitrile) 13. Similar to the iodine‐doped zirconium diphthalocyaninato complexes ZrPc 2 (I 3 ) 2/3 and ZrPc 2 I 3 · I 2 , the compound ZrPcI 2 Pht was synthesised by a direct reaction of powdered zirconium metal with phthalonitrile under a stream of iodine vapour.…”