Recognition of chiral catechols using oxo-titanium phthalocyanine.
Oxo-titanium phthalocyanine (TiOPc) derivatives of catechin and hematoxylin (natural ortho-diol type chiral compounds) have been prepared and characterized by spectral and chromatographic techniques. It is demonstrated that the TiOPc unit is an excellent template for chiral recognition through its isolated Q-transitions. The formation of a helical dimeric complex with hematoxylin induces strong CD-activity in the Q-band region. Ab initio geometry optimizations were combined with a Kuhn-Kirkwood coupled-oscillator mechanism to obtain the absolute configuration of hematoxylin. In addition, it is shown that the described chiroptical recognition method is sensitive to slight conformational changes.
Muranaka
Atsuya
A
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan.
Okuda
Masako
M
Kobayashi
Nagao
N
Somers
Ken
K
Ceulemans
Arnout
A
D002396:Catechols / Q000138:chemical synthesis / Q000737:chemistry*; D002942:Circular Dichroism; D006416:Hematoxylin / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry*; D054833:Isoindoles; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
D002396:Catechols; D007211:Indoles; D054833:Isoindoles; D014025:Titanium; C013647:phthalocyanine; D006416:Hematoxylin