Subphthalocyanines

Recently, subphthalocyanines, the "little sisters/brothers" of the well-known phthalocyanines have attracted considerable interest among material and synthetic chemists.


Subphthalocyanines, as well as phthalocyanines and the superphthalocyanines (in terms of family: the "bigger sisters/brothers"), belong to the family of circular polyisoindolenines, in which the isoindole units are linked by azamethine groups. These materials are now actively under investigation for their role as starting materials for the synthesis of unsymmetrically substituted phthalocyanines, or as materials with particularly high non-linear optical sensitivity in second-harmonic or third-harmonic generation.

We were interested in the arrangement behavior of non-planar aromatic macrocycles in single-crystals or thin films. We synthesized several subphthalocyanine compounds SubpcB-X (with X= phenyl, OMe, OSi(tBu)Me2) and could separate them from brominated by-products by extensive crystallization and/or chromatography. A by-product from the synthesis of the phenyl-substituted subphthalocyanine has been identified by single-crystal analysis as a boron-substituted beta-isoindigo complex. We could obtain single-crystal structures from all our compounds, from the methoxy-substituted compound even two different ones. An overview of our results is given in our publication:

Chem.Abstr: 130:39766 (1999)
Synthesis, Structural Characterization and Optical Properties of Several Boron Subphthalocyanines and a Boron beta-Isoindigo Complex.
Michael K. Engel, J. Yao, H. Maki, H. Takeuchi, H. Yonehara, C. Pac, Kawamura Rikagaku Kenkyusho Hokoku (1997), 1998, 53-65 (English)

pdf file (8 MB)

In addition to publishing our own work, this paper was the first review on the crystal chemistry of subphthalocyanines.

Corrections
P. 54, Figure 1b, the nitrogens of the aza-bridges of the subphthalocyanine are missing
p.63, second column, 9th line from the end: reference 6 should read reference 4
p. 64, chapter 4.2, line 3, refs 18,19 should read refs 17,18
p. 64, chapter 4.2, line 9, ref 19 should read ref 18
If you find additional mistakes, please let me know.

Crystal structures
The structures are available as CIF files from the Cambridge Crystallographic Data Centre (data request).

    UCIJOF
    CELL a 11.558(3) b 15.834(2) c 12.099(2) beta 110.15(1) z 4 sg P21/n cent 1
    FORMUL C25 H15 B1 N6 O1
    COMPND Methoxy-(7,12:14,19-di-imino-21,5-nitrilo-5H-tribenzo(c,h,m)(1,6,11)triazacyclopentadecinato)-boron
    SYNONM Methoxy-subphthalocyaninato-boron
    POLYMORPH: monoclinic polymorph

    UCIJOF01
    CELL a 12.317(3) b 15.279(2) c 10.5637(8) z 4 sg Pnma cent 1
    FORMUL C25 H15 B1 N6 O1
    COMPND Methoxy-(7,12:14,19-di-imino-21,5-nitrilo-5H-tribenzo(c,h,m)(1,6,11)triazacyclopentadecinato)-boron
    SYNONM Methoxy-subphthalocyaninato-boron
    POLYMORPH: orthorhombic polymorph

    UCIJUL
    CELL a 12.639(4) b 12.302(6) c 18.048(2) beta 100.27(2) z 4 sg P21/a cent 1
    FORMUL C30 H27 B1 N6 O1 Si1
    COMPND t-Butyldimethylsiloxy-(7,12:14,19-di-imino-21:5-nitrilo-5H-tribenzo(c,h,m)(1,6,11)triazacyclopentadecinato)-boron
    SYNONM t-Butyldimethylsiloxy-subphthalocyaninato-boron

    YOKMUG02
    CELL a 17.475(9) b 18.32(1) c 14.366(9) z 8 sg Pbca cent 1
    FORMUL C30 H17 B1 N6
    COMPND Phenyl-(7,12:14,19-di-imino-21,5-nitrilo-5H-tribenzo(c,h,m)(1,6,11)triazacyclopentadecinato)-boron
    SYNONM Phenyl-subphthalocyaninato-boron

    UCIKAS
    CELL a 35.649 b 9.616 c 18.791 beta 96.12 z 8 sg C2/c cent 1
    FORMUL C40 H28 B1 N2
    COMPND Diphenyl(3,3'-diphenyl-1,1'-bi-isoindolylidene-N,N')boron
    boron beta-isoindigo derivative

In this paper, I make reference (ref 26) to my review about single-crystal structures of phthalocyanines, you can find it on-line too (pcrev.htm). Other references to reports from Kawamura Institute of Chemical Research can be obtained as re-prints.

Structural Chemistry of Phthalocyanine Complexes
Phthalocyanine Complexes
Homepage of Michael K. Engel