From Molecular Structures to Solid-state Arrangements

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From Molecular Structures to Solid-state
Arrangements
Phthalocyanines
Phthalocyanines
Pigments
Charge-generating materials
Molecular properties ? Solid-state properties
PcCu b-PcCu is greenish blue
e-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_at_ma.dic.co.j
  p)
• Dainippon Ink Chemicals, Inc.
• Central Research Laboratories Sakura-shi, Japan

ICPP-3, New Orleans, July 12, 2004
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Molecular Structures Basics
XCH Tetrabenzoporphyrin TBPH2 1) 139.0 pm 2)
249.5 pm 127.9 3) 295.5 pm 4) 688.6 pm XN
Phthalocyanine PcCo 1) 131.7 pm 2) 229.7 pm
121.5 3) 269.8 pm 4) 670.5 pm

• 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)

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Molecular Structures Basics
Coord.Nr. Oxid.Nr. Geometry Mol.Sym. Expl.
4 2 square planar D4h PcCu
5 2, 3, 4, 5 square pyramidal C4v PcSn PcAlCl PcTiO PcReN
6tr 4, 5, 6 octahedral Oh PcSiCl2 PcMoOCl
6cis 4 trigonal prismatic D3h PcNbCl2
7cis 5 capped trigonal prismatic C2v PcNbCl3
8cis/8bis 3, 4 cubic Oh Pc2La-
8cis/8bis 3, 4 square antiprismatic D4d Pc2Zr
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Molecular Structures Monomers
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Molecular Structures Dimers
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Increased possibilities of interactions
Aromatic hydrocarbons Interaction between
aromatic macrocycles p-p interactions and H-p
interactions
Phthalocyanines additional interaction possibilit
ies due to the presence of heteroatoms. Hydroge
n atoms ? electronegative atoms Nitrogen atoms ?
hydrogen atoms ? axial
ligands ? central
atoms Central atoms and axial ligands
? central atoms
? axial ligands ?
nitrogen atoms
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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
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Arrangements Group CN4 (PcM)
Orientation of phthalocyanines in neighboring
columns
a-PcPt
a-PcCu
2.7044 Å
Herringbone stacking
b-PcH2
x1-PcH2
2.6465 Å
S2 screw axis Intercolumnar hydrogen-bonding
intercolumnar distances NH gt 3.2 Å much weaker
bonding
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Arrangements Group CN4 (PcM)
a-PcPt
g-PcPt
(Nbr)
b-PcH2
2.6134 Å
3.0143 Å
3.0499 Å
(Ni)
2.8408 Å
x1-PcH2
a-PcCu
x2-PcH2
x1-PcH2
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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
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Arrangements Group CN6tr (PcMX2)

• Network structure
• view along the column axes

2.568 Å
a-PcGe(OH)2
Intercolumnar ? hydrogen bonding

• Network structure
• view along the column axes

x1-PcH2
b-PcGe(OH)2
2.592 Å
Intercolumnar ? hydrogen bonding
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Molecular Structures Group CN5 (PcMX)
Why do some phthalocyanines have a saucer-shaped
macrocycle ?
convex face
concave face

• 2 different faces
• each face leads to a different arrangement

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Arrangements Group CN5 (PcMX)
convex
concave
Ni
Nbr
no shift
sheet-type (or brickstone) arrangement columnar
(slipped-stacked) arrangements
layer-type arrangements
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Arrangements Group CN5 (PcMX)
molecular lego
? PcGaCl

Ni

? PcAlCl
Nbr

? PcZnCl
no shift
layer-type convex
concave
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Hydrogen bonding
not parallel
I-PcTiO
ca. 3.5 Å hydrogen bonding
orientation through hydrogen-bonding
parallel
2.746 Å
PcSn
2.736 Å
PcNbCl2
PcSnCl2
flattening through repulsive interaction
molecular deformation through hydrogen-bonding
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Mol. Structures Group CN8bis (Pc2M)
CCDC Molecule spacegroup angle
DPCYTH03 Pc2Th C2/c 37
DPCYTH Pc2Th C2/c 38
PHALCU Pc2U C2/c 37
JONZAN Pc2Ce C2/c 38
SNPTCY01 Pc2Sn C2/c 38
DPCYTH01 Pc2Th C2/c 38
CIZGIB02 Pc2Nd ? C2/c 38
GAWBEL Pc2Gd P212121 ca. 41
ZAKZOA Pc2In P212121 41.2
DULZAL Pc2Lu ? P212121 41
GAWBAH Pc2LuH P212121 41
SNPTCY Pc2Sn P212121 42
YUHSUP Pc2Er ? P4/nnc 41.4
CIZGIB08 Pc2Nd P4/nnc 41.3
KOBRUO02 Pc2Pr P4/nnc 41.7
ZUWDAW Pc2BiCH2Cl2 Pnma 45
ZEHTUB Pc2LaCH2Cl2 Pnma 45
DICBUM Pc2LuCH2Cl2 Pnma 45
JUVJIT Pc2YCH2Cl2 Pnma 45
bisphthalocyanines
until now defined by staggering
angle a but angle depends on which units
are used angle corresponds to
crystal structure staggering angle is not
a molecular property
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Arrangements Group CN8bis (Pc2M)
Pc2Lu CH2Cl2
2
12
a-Pc2Er
1
2
Pc2Ce
A1
A
1
A2
b-Pc2Pr
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Arrangements Group CN8bis (Pc2M)
Pc2LuCH2Cl2 (12)
b-Pc2Pr (A1)
Pc2Ce (A2)
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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 strongly
  influence 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
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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_at_ma.dic.co.jp
• http//phthalo.mkengel.de/pcrev.htm

ICPP-3, New Orleans, July 12, 2004