Soji Shimizu - Cochemist

Structurally-modified subphthalocyanines: molecular design towards realization of expected properties from the electronic structure and structural features of subphthalocyanine

Co-reporter:Soji Shimizu and Nagao Kobayashi

Chemical Communications 2014 vol. 50(Issue 53) pp:6949-6966

Publication Date(Web):07 Apr 2014

DOI:10.1039/C4CC01526F

This feature article summarizes recent contributions of the authors in the synthesis of structurally-modified subphthalocyanines. The structural modification covers (1) modification of the conjugated system of subphthalocyanines to create novel conjugated systems comprising three pyrroles or pyrrole-like subunits, (2) core-modification by expansion of the inner pyrrolic five-membered ring to larger six- and seven-membered ring units, and (3) exterior-modification by annulation of functional units to subphthalocyanines. These modifications in the structure of subphthalocyanines have been performed with the aim of demonstrating unique properties originating from the bowl-shaped C3v-symmetric structure as well as the electronic structure delineated by the 14π-electron conjugated system on the curved molecular surface. The possible structural modifications surveyed in this feature article and their concomitant properties will provide important future guidelines to the design of subphthalocyanine-based functional molecules, considering the fact that subphthalocyanines have recently been attracting considerable attention as potential candidates in the field of optoelectronics and molecular electronics.

Expanded dipyrrins with electron-withdrawing substituents: broad range of absorption in the visible region

Co-reporter:Xu Liang, Soji Shimizu, Nagao Kobayashi

Tetrahedron Letters 2014 Volume 55(Issue 1) pp:256-258

Publication Date(Web):1 January 2014

DOI:10.1016/j.tetlet.2013.11.013

Reaction of meso-aryl-substituted dipyrromethanes with tetracyanoethylene led to generation of a mono-tricyanovinyl-substituted species as well as an expanded dipyrrin analogue bearing both a dicyanomethylene and a tricyanovinyl substituent at the α-positions. These novel compounds exhibit absorption spectral features perturbed by the electron-withdrawing substituents. Unique protonation-induced spectral changes were also disclosed.

A Core-Expanded Subphthalocyanine Analogue with a Significantly Distorted Conjugated Surface and Unprecedented Properties

Co-reporter:Dr. Soji Shimizu;Shota Nakano;Ayaka Kojima ; Nagao Kobayashi

Angewandte Chemie 2014 Volume 126( Issue 9) pp:2440-2444

Publication Date(Web):

DOI:10.1002/ange.201310028

Abstract

The introduction of a seven-membered-ring unit in the place of a five-membered-ring unit in the structure of subphthalocyanine resulted in significant distortion of the bowl-shaped structure of the conjugated molecule as well as the following unprecedented properties: the preferential formation of the axially fluoro substituted species, the fluttering-dynamic-motion-induced rapid exchange of P and M enantiomers, markedly split Q-band absorption, and a clear difference in the ring-current effects arising from the convex and concave surfaces.

A Core-Expanded Subphthalocyanine Analogue with a Significantly Distorted Conjugated Surface and Unprecedented Properties

Co-reporter:Dr. Soji Shimizu;Shota Nakano;Ayaka Kojima ; Nagao Kobayashi

Angewandte Chemie International Edition 2014 Volume 53( Issue 9) pp:2408-2412

Publication Date(Web):

DOI:10.1002/anie.201310028

Abstract

The introduction of a seven-membered-ring unit in the place of a five-membered-ring unit in the structure of subphthalocyanine resulted in significant distortion of the bowl-shaped structure of the conjugated molecule as well as the following unprecedented properties: the preferential formation of the axially fluoro substituted species, the fluttering-dynamic-motion-induced rapid exchange of P and M enantiomers, markedly split Q-band absorption, and a clear difference in the ring-current effects arising from the convex and concave surfaces.

Pyrrolopyrrole aza-BODIPY analogues: a facile synthesis and intense fluorescence

Co-reporter:Soji Shimizu, Taku Iino, Yasuyuki Araki and Nagao Kobayashi

Chemical Communications 2013 vol. 49(Issue 16) pp:1621-1623

Publication Date(Web):09 Jan 2013

DOI:10.1039/C3CC38452G

Pyrrolopyrrole aza-BODIPY analogues were synthesized from diketopyrrolopyrrole and heteroaromatic amines in the presence of titanium tetrachloride. These novel compounds exhibit intense absorption in the visible region and strong emission with high fluorescence quantum yields greater than 0.8.

A μ-oxo hetero dimer of silicon phthalocyanine and naphthalocyanine

Co-reporter:Kazuaki Oniwa, Soji Shimizu, Yuta Shiina, Takamitsu Fukuda and Nagao Kobayashi

Chemical Communications 2013 vol. 49(Issue 75) pp:8341-8343

Publication Date(Web):18 Jul 2013

DOI:10.1039/C3CC44490B

A novel μ-oxo hetero dimer of silicon phthalocyanine and silicon naphthalocyanine was synthesized. Its unique optical properties, such as a single Q band, which is unusual for hetero dimer species, and solvatochromic behavior, were revealed to be better interpreted by taking interchromophore interactions into consideration.

Highly deformed phthalocyanine as a suitable scaffold for pristine fullerenes

Co-reporter:Soji Shimizu, Akito Miura and Nagao Kobayashi

CrystEngComm 2013 vol. 15(Issue 19) pp:3759-3762

Publication Date(Web):10 Dec 2012

DOI:10.1039/C2CE26618K

1:1 co-crystallization of phthalocyanine with pristine C60 or C70 was achieved for the first time using a highly deformed phthalocyanine bearing phenyl substituents at α-positions. In the molecular packing diagrams of both cocrystallates, fullerene and phthalocyanine molecules are alternately arranged to form a one-dimensional array.

Tetrathiafulvalene-Annulated Subphthalocyanines

Co-reporter:Dr. Soji Shimizu;Yoko Yamazaki ; Nagao Kobayashi

Chemistry - A European Journal 2013 Volume 19( Issue 23) pp:7324-7327

Publication Date(Web):

DOI:10.1002/chem.201300709

Core-modified phthalocyanine analogues with a seven-membered ring unit in place of a five-membered ring unit

Co-reporter:Soji Shimizu, Kaoru Uemura, Hua Zhu, Nagao Kobayashi

Tetrahedron Letters 2012 Volume 53(Issue 5) pp:579-581

Publication Date(Web):1 February 2012

DOI:10.1016/j.tetlet.2011.11.092

A variety of phthalocyanine analogues with a seven-membered ring unit in place of a five-membered ring unit were synthesized from aromatic dicarbonitriles bearing cyano groups at 1,4-separate positions. Based on the spectroscopic analyses and theoretical calculations, tetraazachlorine-like electronic structures of these novel compounds stemming from severe twist of the conjugation system at the seven-membered ring unit have been revealed.A variety of phthalocyanine analogues with a seven-membered ring unit in place of a five-membered ring unit were synthesized from aromatic dicarbonitriles bearing cyano groups at 1,4-separate positions. Based on the spectroscopic analyses and theoretical calculations, tetraazachlorine-like electronic structures of these novel compounds stemming from severe twist of the conjugation system at the seven-membered ring unit have been revealed.

Gold(II) Phthalocyanine Revisited: Synthesis and Spectroscopic Properties of Gold(III) Phthalocyanine and an Unprecedented Ring-Contracted Phthalocyanine Analogue

Co-reporter:Edwin W. Y. Wong;Akito Miura;Mathew D. Wright;Qi He; Charles J. Walsby;Dr. Soji Shimizu; Nagao Kobayashi; Daniel B. Leznoff

Chemistry - A European Journal 2012 Volume 18( Issue 39) pp:12404-12410

Publication Date(Web):

DOI:10.1002/chem.201201701

Abstract

In 1965, gold(II) phthalocyanine (AuPc, 1) was described to be synthesized from unsubstituted 1,3-diiminoisoindoline and gold powder or AuBr. Compound 1 has been regarded as a rare example of a paramagnetic gold(II) complex. However, its chemistry, especially the oxidation state of the central gold ion, has not been previously explored due to the inherent insolubility of 1 caused by its unsubstituted structure. In our attempt to synthesize soluble AuPcs by using 5,6-di-substituted 1,3-diiminoisoindolines, gold(III) phthalocyanine chloride (3) and a gold(III) complex of an unprecedented ring-contracted phthalocyanine analogue ([18]tribenzo-pentaaza-triphyrin(4,1,1), 4) were isolated. With this discrepant result from the original literature in hand, a reinvestigation of the original AuPc synthesis by using unsubstituted 1,3-diiminoisoindoline and various gold salts (including gold powder and AuBr) was performed, finding that only unsubstituted analogues of 3 and 4 or free-base phthalocyanine were obtained. No gold(II)-containing species could be isolated.

Inside Cover: Gold(II) Phthalocyanine Revisited: Synthesis and Spectroscopic Properties of Gold(III) Phthalocyanine and an Unprecedented Ring-Contracted Phthalocyanine Analogue (Chem. Eur. J. 39/2012)

Co-reporter:Edwin W. Y. Wong;Akito Miura;Mathew D. Wright;Qi He; Charles J. Walsby;Dr. Soji Shimizu; Nagao Kobayashi; Daniel B. Leznoff

Chemistry - A European Journal 2012 Volume 18( Issue 39) pp:

Publication Date(Web):

DOI:10.1002/chem.201290168

Azepiphthalocyanine—an unprecedented large twist of a π-conjugation system upon core-modification with a seven-membered ring unit

Co-reporter:Soji Shimizu, Hua Zhu and Nagao Kobayashi

Chemical Communications 2011 vol. 47(Issue 11) pp:3072-3074

Publication Date(Web):07 Feb 2011

DOI:10.1039/C0CC05276K

Aromatic dicarbonitrile bearing cyano groups in a 1,4-relationship was utilized for a phthalocyanine synthesis to give azepiphthalocyanine having a seven-membered ring unit instead of a five-membered ring unit. This molecule exhibits a significantly twisted structure and large splitting of the Q band absorption, indicative of its azachlorin-like conjugation system.

Pyrene-fused subphthalocyanine

Co-reporter:Soji Shimizu, Shota Nakano, Takahisa Hosoya and Nagao Kobayashi

Chemical Communications 2011 vol. 47(Issue 1) pp:316-318

Publication Date(Web):23 Aug 2010

DOI:10.1039/C0CC01877E

A pyrene-fused subphthalocyanine synthesized from a reaction of 2,7-di-tert-butyl-4,5,9,10-tetracyanopyrene and tetrafluorophthalonitrile exhibits red-shifted Q-band absorption and a unique linear arrangement in the solid state caused by a π–π stacking interaction. The concave conjugation of the SubPc moiety and the planar conjugation of the pyrene moiety enhanced its co-crystallization with C60 molecules.

A μ-oxo hetero dimer of silicon phthalocyanine and naphthalocyanine

Co-reporter:Kazuaki Oniwa, Soji Shimizu, Yuta Shiina, Takamitsu Fukuda and Nagao Kobayashi

Chemical Communications 2013 - vol. 49(Issue 75) pp:NaN8343-8343

Publication Date(Web):2013/07/18

DOI:10.1039/C3CC44490B

A novel μ-oxo hetero dimer of silicon phthalocyanine and silicon naphthalocyanine was synthesized. Its unique optical properties, such as a single Q band, which is unusual for hetero dimer species, and solvatochromic behavior, were revealed to be better interpreted by taking interchromophore interactions into consideration.

Pyrrolopyrrole aza-BODIPY analogues: a facile synthesis and intense fluorescence

Co-reporter:Soji Shimizu, Taku Iino, Yasuyuki Araki and Nagao Kobayashi

Chemical Communications 2013 - vol. 49(Issue 16) pp:NaN1623-1623

Publication Date(Web):2013/01/09

DOI:10.1039/C3CC38452G

Pyrrolopyrrole aza-BODIPY analogues were synthesized from diketopyrrolopyrrole and heteroaromatic amines in the presence of titanium tetrachloride. These novel compounds exhibit intense absorption in the visible region and strong emission with high fluorescence quantum yields greater than 0.8.

Azepiphthalocyanine—an unprecedented large twist of a π-conjugation system upon core-modification with a seven-membered ring unit

Co-reporter:Soji Shimizu, Hua Zhu and Nagao Kobayashi

Chemical Communications 2011 - vol. 47(Issue 11) pp:NaN3074-3074

Publication Date(Web):2011/02/07

DOI:10.1039/C0CC05276K

Aromatic dicarbonitrile bearing cyano groups in a 1,4-relationship was utilized for a phthalocyanine synthesis to give azepiphthalocyanine having a seven-membered ring unit instead of a five-membered ring unit. This molecule exhibits a significantly twisted structure and large splitting of the Q band absorption, indicative of its azachlorin-like conjugation system.

Structurally-modified subphthalocyanines: molecular design towards realization of expected properties from the electronic structure and structural features of subphthalocyanine

Co-reporter:Soji Shimizu and Nagao Kobayashi

Chemical Communications 2014 - vol. 50(Issue 53) pp:NaN6966-6966

Publication Date(Web):2014/04/07

DOI:10.1039/C4CC01526F

This feature article summarizes recent contributions of the authors in the synthesis of structurally-modified subphthalocyanines. The structural modification covers (1) modification of the conjugated system of subphthalocyanines to create novel conjugated systems comprising three pyrroles or pyrrole-like subunits, (2) core-modification by expansion of the inner pyrrolic five-membered ring to larger six- and seven-membered ring units, and (3) exterior-modification by annulation of functional units to subphthalocyanines. These modifications in the structure of subphthalocyanines have been performed with the aim of demonstrating unique properties originating from the bowl-shaped C3v-symmetric structure as well as the electronic structure delineated by the 14π-electron conjugated system on the curved molecular surface. The possible structural modifications surveyed in this feature article and their concomitant properties will provide important future guidelines to the design of subphthalocyanine-based functional molecules, considering the fact that subphthalocyanines have recently been attracting considerable attention as potential candidates in the field of optoelectronics and molecular electronics.

Pyrene-fused subphthalocyanine

Co-reporter:Soji Shimizu, Shota Nakano, Takahisa Hosoya and Nagao Kobayashi

Chemical Communications 2011 - vol. 47(Issue 1) pp:NaN318-318

Publication Date(Web):2010/08/23

DOI:10.1039/C0CC01877E

A pyrene-fused subphthalocyanine synthesized from a reaction of 2,7-di-tert-butyl-4,5,9,10-tetracyanopyrene and tetrafluorophthalonitrile exhibits red-shifted Q-band absorption and a unique linear arrangement in the solid state caused by a π–π stacking interaction. The concave conjugation of the SubPc moiety and the planar conjugation of the pyrene moiety enhanced its co-crystallization with C60 molecules.