223689-61-0Relevant academic research and scientific papers
Highly selective optical-sensing membranes, containing calix[4]arene chromoionophores, for Pb2+ ions
Van Der Veen, Niels J.,Rozniecka, Ewa,Woldering, Leon A.,Chudy, Michal,Huskens, Jurriaan,Van Veggel, Frank C. J. M.,Reinhoudt, David N.
, p. 4878 - 4886 (2007/10/03)
Plasticized poly(vinyl chloride) (PVC) optode membranes containing novel calix[4]arene chromoionophores 1 or 2 and one equivalent of a lipophilic anion respond to Pb2+ ions with high selectivity over alkali, alkaline-earth, and other heavy meta
Synthesis of Calix[4]arenes with four different "lower rim" substituents
Shu, Chun-Mei,Chung, Wen-Sheng,Wu, Sing-Ho,Ho, Zong-Chia,Lin, Lee-Gin
, p. 2673 - 2679 (2007/10/03)
Calix[4]arenes with four different "lower rim" substituents were synthesized following six-step sequences. The first alkyl group (R1) was introduced using R1X and CH3ONa, and then reaction with R2X and K2CO3 led to the introduction of a second alkyl group (R2) at the 3-position. Benzoate was introduced as a protecting group at the 1,3-O-disubstituent stage and was removed under basic conditions after the incorporation of the third alkyl group (R3) with R3X and NaH. The final alkyl group (R4) was introduced with R4X and NaH to give the chiral title compounds.
