55303-18-9Relevant academic research and scientific papers
A New Family of Indoaniline-Derived Calixarenes: Synthesis and Optical Recognition Properties as a Chromogenic Receptor
Kubo, Yuji,Tokita, Sumio,Kojima, Yuko,Osano, Yasuko T.,Matsuzaki, Takao
, p. 3758 - 3765 (1996)
A new family of indoaniline-derived calixarenes has been synthesized for the purpose of developing a new chromogenic receptor.A considering reaction of calixarene (1) with 4-(diethylamino)-2-methylaniline hydrochloride (2) in the presence of an oxidizing agent under alkaline conditions affords mono- (3), 1,2-bis- (4), 1,3-bis- (5), and tetrakisindoaniline-derived (6) calixarenes after careful column chromatography.Compound 3 is crystallized from a CHCl3-MeOH solution, and the crystal structure was determined by X-ray analysis.The crystal is monoclinic, space group P21/n, Z = 4, a = 19.507(6) Angstroem, b = 18.591(6) Angstroem, c = 8.524(2) Angstroem, β = 94.69(2) deg.The final R value for 2406 reflections of F0 > 3?(F0) is 0.085.A unique intramolecular hydrogen-bonding network involving the carbonyl oxygen of indoaniline for 3 implied that the quinone carbonyl group as an acceptor of the chromophore can easily be subjected to an electrostatic interaction in the lower rim.Indeed, 1,3-bis(indoaniline)-derived 2,4-bis((ethoxycarbonyl)methoxy)calixarene 7, prepared by the reaction of 5 with ethyl bromoacetate in the presence of NaH, is capable of undergoing an efficient ion-dipole interaction between the binding cation and the two quinone carbonyl groups of the chromophores, so that a selective Ca(2+)-induced pronounced color change (wavelength change > 100 nm) occurs with an association constant on the order of 106 in 99 percent EtOH, making 7 of potential use as an optical sensor for Ca(2+) detection.The IR and NMR studies have indicated that potential use as an optical sensor for Ca(2+) detection.The IR and NMR studies have indicated that Ca(2+) is encapsulated in the cavity made by the distally located OCH2CO2 groups on the lower rim of the cone-shaped calixarene segment.Interestingly, however, the shape of the cavity in which Ca(2+) has been encapsulated does not have a C2 axis of symmetry, as inferred from the 1H-1H COSY experiment.On the other hand, 1,2-bis(indoaniline)-derived analogue 8 shows no response with metal ions, which can be interpreted to mean the absecne of a cavity for encapsulation on the lower rim.
