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Phthalocyanines. Phthalocyanines:. From Molecular Structures to Solid-state Arrangements. Pigments. Charge-generating materials. Molecular properties Solid-state properties PcCu b -PcCu is greenish blue e -PcCu is reddish blue.
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Phthalocyanines Phthalocyanines: From Molecular Structures to Solid-state Arrangements Pigments Charge-generating materials Molecular properties Solid-state properties PcCu b-PcCu is greenish bluee-PcCu is reddish blue Classification of Phthalocyanine Molecular Structures Arrangement of the Phthalocyanine Units in Solid-state Start: Basic information about Phthalocyanine Molecular Structures Structure-Property Relationships Dr. Michael Klaus ENGEL (michael-engel@ma.dic.co.jp) Dainippon Ink & Chemicals, Inc. Central Research Laboratories; Sakura-shi, Japan ICPP-3, New Orleans, July 12, 2004
X=CH: Tetrabenzoporphyrin: TBPH2 1) 139.0 pm 2) 249.5 pm; 127.9° 3) 295.5 pm 4) 688.6 pm X=N: Phthalocyanine: PcCo 1) 131.7 pm 2) 229.7 pm; 121.5° 3) 269.8 pm 4) 670.5 pm Molecular Structures: Basics • Most of the metallic elements and semimetals can be coordinated in the • center of the macrocycle. • Molecular structure is influenced by • - the size of the central atom M, • - the oxidation state of the central atom M. • Two kinds of molecular axes: • - bridging-nitrogen molecular axis (Nbr) • isoindole-nitrogen molecular axis (Ni) ICPP-3, New Orleans, July 12, 2004
Molecular Structures: Basics ICPP-3, New Orleans, July 12, 2004
Molecular Structures: Monomers ICPP-3, New Orleans, July 12, 2004
Molecular Structures: Dimers ICPP-3, New Orleans, July 12, 2004
Aromatic hydrocarbons: Interaction between aromatic macrocycles: p-p interactions and H-p interactions Increased possibilities of interactions Phthalocyanines additional interaction possibilities due to the presence of heteroatoms. Hydrogen atoms electronegative atoms Nitrogen atoms hydrogen atoms axial ligands central atoms Central atoms and axial ligands central atoms axial ligands nitrogen atoms ICPP-3, New Orleans, July 12, 2004
Arrangements: Group CN4 (PcM) 4 Basic overlap geometries a-PcPt b-PcH2 a-PcCu x1-PcH2 the big confusion overlap along Ni molecular axis overlap along Nbr molecular axis intermolecular bonding between Nbr and center stabilizes b-polymorphs ICPP-3, New Orleans, July 12, 2004
Orientation of phthalocyanines in neighboring columns Arrangements: Group CN4 (PcM) a-PcPt a-PcCu 2.7044 Å Herringbone stacking b-PcH2 x1-PcH2 2.6465 Å S2 screw axis Intercolumnar hydrogen-bonding intercolumnar distances N…H > 3.2 Å much weaker bonding ICPP-3, New Orleans, July 12, 2004
a-PcPt g-PcPt (Nbr) 2.6134 Å b-PcH2 3.0143 Å 3.0499 Å Arrangements: Group CN4 (PcM) (Ni) 2.8408 Å x1-PcH2 a-PcCu x2-PcH2 x1-PcH2 ICPP-3, New Orleans, July 12, 2004
Arrangements: Group CN6tr (PcMX2) spatial need of axial ligands Intermol. hydrogen bonding + repulsive interaction much smaller in CN6tr overlap in CN4 x1-PcH2 PcCoCl2 PcSnI2 PcSnI2 ICPP-3, New Orleans, July 12, 2004
Network structure view along the column axes Arrangements: Group CN6tr (PcMX2) 2.568 Å a-PcGe(OH)2 Intercolumnar hydrogen bonding • Network structure view along the column axes b-PcGe(OH)2 x1-PcH2 2.592 Å Intercolumnar hydrogen bonding ICPP-3, New Orleans, July 12, 2004
Why do some phthalocyanines have a saucer-shaped macrocycle ? Molecular Structures: Group CN5 (PcMX) convex face concave face • 2 different faces • each face leads to a different arrangement ICPP-3, New Orleans, July 12, 2004
convex concave Arrangements: Group CN5 (PcMX) Ni Nbr no shift sheet-type (or brickstone) arrangement columnar (slipped-stacked) arrangements layer-type arrangements ICPP-3, New Orleans, July 12, 2004
molecular lego Arrangements: Group CN5 (PcMX) PcGaCl + Ni + PcAlCl Nbr + PcZnCl no shift layer-type convex concave ICPP-3, New Orleans, July 12, 2004
Hydrogen bonding not parallel I-PcTiO orientation through hydrogen-bonding ca. 3.5 Å hydrogen bonding parallel 2.746 Å PcSn 2.736 Å PcNbCl2 PcSnCl2 flattening through repulsive interaction molecular deformation through hydrogen-bonding ICPP-3, New Orleans, July 12, 2004
bisphthalocyanines Mol. Structures: Group CN8bis (Pc2M) until now: defined by staggeringanglea but: angle depends on which units are used angle corresponds to crystal structure staggering angle is not a molecular property ICPP-3, New Orleans, July 12, 2004
[Pc2Lu] [CH2Cl2] Arrangements: Group CN8bis (Pc2M) 2 12 a-Pc2Er 1 2 Pc2Ce A1 A 1 A2 b-Pc2Pr ICPP-3, New Orleans, July 12, 2004
[Pc2Lu][CH2Cl2] (12) Pc2Ce (A2) b-Pc2Pr (A1) Arrangements: Group CN8bis (Pc2M) ICPP-3, New Orleans, July 12, 2004
Final remarks • The central atom together with axial ligands controls • molecular structure and arrangement in the solid-state. • Phthalocyanines like to slip-stack. • Hydrogen-bonding is a major force. • Molecular properties (deformation) depend on the crystal arrangement • calculation of crystal structures need to use non-rigid molecules This talk covered only pure materials, no mixtures. Co-crystallizing materials (impurities, solvents) can stronglyinfluence the crystal structure. Further reading: M.K. Engel, J. Porph. Phthalocyanine, in preparation M.K. Engel, in "The Porphyrin Handbook", Vol. 20, 2003, 1-246 P. Erk et al., CrystEngComm, 2004, accepted ICPP-3, New Orleans, July 12, 2004
Thank you To you for listening. To Prof. Heiner Homborg for many discussions and giving me access to his unpublished crystal structures. To Dr. Peter Erk for preprints and unpublished structures. To Prof. Bob Scheidt for his work in porphyrin crystal structures which gave me many ideas for phthalocyanine crystal structures. To Dainippon Ink and Chemicals for having interest in my phthalocyanine research and allowing me to participate at this conference. Michael Klaus Engel michael-engel@ma.dic.co.jp http://phthalo.mkengel.de/pcrev.htm ICPP-3, New Orleans, July 12, 2004