π-π Electron Interaction Property of HPLC Anion-Exchange Resin Modified with Cu2+-Phthalocyanine Derivative

Abstract

It has recently been reported that silica gels binding Cu 2+ -phthalocyanine (Cu-PCS) 1-3 and In 3+ -porphine 4 and pyrene 5 derivatives interact with π-electron-rich compounds, such as polyaromatic hydrocarbons (PAHs), through a π-π electron interaction (π-π interaction). They are useful for separating π-electron-rich compounds, although their preparation requires troublesome procedures.1-5 On the other hand, we have briefly reported that anionic Cu-PCS are easily bound on an ordinary anion-exchange resin through electrostatic and hydrophobic interactions, and that the modified resin exhibits a relatively strong π-π interaction with PAHs. 6 However, the modified resin was not completely suited for an HPLC stationary phase for an analytical purpose, because the theoretical plate number (N) is relatively low due to the irregular particle size of the resin. To develop a new HPLC stationary phase, we thus tried to modify an HPLC anion-exchange resin for HPLC with Cu-PCS.Consequently, we could increase hydrophobic interactions, including the π-π interaction of an HPLC anionexchange resin for large PAHs by an easy modification method with Cu-PCS. In the present paper, we report on the properties of the resultant modified resin as the HPLC stationary phase for the separation of π-electron-rich PAHs.

HPLC Retention Behavior of Poly-Aromatic-Hydrocarbons on Aminopropyl Silica Gels Modified with Cu(II)- and Ni(II)-Phthalocyanine Derivatives in Non-polar Eluent

“…Accordingly, the correlation diagram is expected to show a linear correla- tion, if underlying separation mechanism of the Cu-PCS D column for PAHs is the p-p interaction, by analogy with the case of anion-exchange silica gels modified with Cu-phthalocyanine tetrasulfonate. 18) As shown in Fig. 6, the k values on the Cu-PCS D column were almost in a linear correlation with those on both of the PYE ® and the NPE ® columns for respective PAHs.…”

Coordination Complexes of Copper in Mass Exchange of Biologically Active Substances

“…Available data show that it is expedient to use copper compounds predominantly for the separation of relatively more polar compounds. The pp interactions can be studied in detail by HPLC on anion exchangers modified by phthalocyanine copper derivatives [76,77].…”