Recognition of Chiral Catechols Using Oxo−Titanium Phthalocyanine

• Published in: Journal of the American Chemical Society Vol. 126; no. 14; pp. 4596 - 4604
• Main Authors: Muranaka, Atsuya, Okuda, Masako, Kobayashi, Nagao, Somers, Ken, Ceulemans, Arnout
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 14.04.2004; Amer Chemical Soc
• Subjects: Catechols - chemical synthesis; Catechols - chemistry; Chemistry; Chemistry, Multidisciplinary; Circular Dichroism; Exact sciences and technology; General and physical chemistry; Hematoxylin - chemistry; Indoles - chemical synthesis; Indoles - chemistry; Models, Molecular; Molecular Conformation; Physical Sciences; Quantum Theory; Science & Technology; Solution properties; Solutions; Thermodynamics; Titanium - chemistry; ENTEROBACTIN COMPLEX; SPECTROSCOPY; HEMATEIN; ABSOLUTE CONFIGURATIONAL ASSIGNMENTS; ZINC PORPHYRIN HOST; MAGNETIC CIRCULAR-DICHROISM; ABSORPTION; DERIVATIVES; SPECTRAL DATA; CNDO METHOD; Catechin; Conformational dynamics; Organic ligand; Theoretical study; Transition metal Complexes; Experimental study; Magnetic circular dichroism spectrometry; Oxo complex; Organic solvent; Titanium Complexes; Non aqueous solution; Metallophthalocyanine; Density functional method; Molecular recognition; Molecular complex; INDO S method; Methanol
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja039843r

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.