Synthesis and structure of transition-metal bis(porphyrinato) complexes. Characterization of Zr(TPP) sub 2 and Zr(OEP) sub 2

Journal Article · Wed Jun 12 00:00:00 EDT 1991 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00012a017· OSTI ID:5714143

Kim, Kimoon; Lee, W S; Kim, Heejoon; Cho, Sunghee ^[1]; Girolami, G S; Gorlin, P A; Suslick, K S ^[2]

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1. Pohang Inst. of Science and Technology (South Korea)
2. Univ. of Illinois, Urbana (United States)

Treatment of Zr(Net{sub 2}){sub 4} with the free-base porphyrins 5, 10, 15, 20-tetraphenylporphyrin (H{sub 2}TPP) or 2,3,7,8,12,13,17,18-octaethylporphyrin (H{sub 2}OEP) gives the transition-metal bis(porphyrinato) complexes Zr(TPP){sub 2} and Zr(OEP){sub 2}. The hafnium analogue Hf(OEP){sub 2} may be prepared similarly from Hf(NEt{sub 2}){sub 4}. The complexes have been characterized by uv-vis and {sup 1}H NMR spectroscopy, and the molecular structure of Zr(TPP){sub 2} has been determined crystallographically. The Zr-N distances of 2.40 (1) {angstrom} and the porphyrin-porphyrin interplanar spacing of 2.56 {angstrom} are the shortest such distances in all known M(porphyrinato){sub 2} complexes. The cyclic voltammograms indicate that Zr(TPP){sub 2} and Zr(OEP){sub 2} each undergo two oxidations and two reductions; the redox potentials suggest that there is significant overlap between the {pi}-systems of the two porphyrin rings. Chemical oxidation of the Zr(porphyrinato){sub 2} complexes with phenoxathiinylium hexachloroantimonate has led to the isolation of the {pi}-radical-cation complexes (Zr(TPP){sub 2}{sup +})(SbCl{sub 6}{sup {minus}}) and (Zr(OEP){sub 2}{sup +})(SbCl{sub 6}{sup {minus}}). The uv-vis, near-IR, EPR, and IR spectra of these cations are consistent with oxidation of the porphyrin -porphyrin {pi}-system; most notable are the unusually high energy near-IR bands at 1,110 and 962 nm in the TPP and OEP complexes, respectively. The high energy of these bands with respect to those of other (M(porphyrinato){sub 2}{sup +}) cations with larger metal atoms again can be rationalized on the basis of unusually strong overlap between the {pi}-systems of the two porphyrin rings. Crystallographic data for Zr(TPP){sub 2}{times}C{sub 5}H{sub 12} is reported, 14 refs., 2 figs., 4 tabs.

• OSTI ID: 5714143
• Journal Information: Inorganic Chemistry; (United States), Vol. 30:12; ISSN 0020-1669
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AROMATICS
CHEMICAL PREPARATION
CRYSTAL STRUCTURE
MOLECULAR STRUCTURE
PORPHYRINS
ZIRCONIUM COMPLEXES
CHEMICAL BONDS
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
INFRARED SPECTRA
NMR SPECTRA
PROTONS
REDOX REACTIONS
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
BARYONS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
COMPLEXES
DATA
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
MAGNETIC RESONANCE
NUCLEONS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RESONANCE
SPECTRA
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
400500 - Photochemistry