title: The effect of number and position of P=O/P=S bridging units on cavitand selectivity toward methyl ammonium salts.
abstract: The present work reports the synthesis and complexation properties of five mixed bridge P=O/P=S cavitands toward N,N-methyl butyl ammonium chloride (1) as prototype guest. The influence of number and position of P=O and P=S groups on the affinity of phosphonate cavitands toward 1 is assessed via ITC titrations in DCE as solvent. Comparison of the resulting Kass values, the enthalpic and entropic contributions to the overall binding with those of the parent tetraphosphonate Tiiii and tetrathiophosphonate TSiiii cavitands allows one to single out the simultaneous dual H-bond between the cavitand and the salt as the major player in complexation.
authors.affiliation: Dipartimento di Chimica, Università di Parma and INSTM UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. Daniela.Menozzi@altana.com.
authors.forename: Daniela
authors.initials: D
authors.lastname: Menozzi
authors.affiliation: Dipartimento di Chimica, Università di Parma and INSTM UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. roberta.pinalli@unipr.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Pinalli
authors.affiliation: Dipartimento di Chimica, Università di Parma and INSTM UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. chiara.massera@unipr.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Massera
authors.affiliation: Dipartimento di Chimica, Università di Parma and INSTM UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. framaffy@yahoo.com.
authors.forename: Francesca
authors.initials: F
authors.lastname: Maffei
authors.affiliation: Dipartimento di Chimica, Università di Parma and INSTM UdR Parma, Parco Area delle Scienze 17/A, 43124 Parma, Italy. enrico.dalcanale@unipr.it.
authors.forename: Enrico
authors.initials: E
authors.lastname: Dalcanale
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry*; D003461:Crystallography; D004988:Ethers, Cyclic / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D012118:Resorcinols / Q000737:chemistry*
chemical_list: D064751:Ammonium Compounds; D004988:Ethers, Cyclic; D012118:Resorcinols; C442939:cavitand