The synthesis of the two new linear hexa-amines 371014-tetraazahexadecane-116-diamine (L1) and 591216-tetraazaicosane-120-diamine (L2) has been reported. Ligand protonation and Cu(II) and Zn(II) coordination have been studied in aqueous solution by means of potentiometric microcalorimetric (298.1 K I = 0.1 mol dm-3) and spectrophotometric (UV-Vis 1H and 13C NMR) measurements. The species present in solution and their stability constants have been determined. L1 forms mono- and binuclear complexes in aqueous solution with Cu(II). In the [ML1]2+ complexes the metal ion is coordinated by five nitrogen atoms while in the [ML2]2+ complexes the metal ion is four-coordinate. This different behavior is explained in terms of the different numbers of methylene groups between adjacent nitrogen atoms. © 2002 Elsevier Science Ltd. All rights reserved.
Basicity and coordination ability of linear hexa-amines in relation to N-(CH2)n-N chain-link lengths. A solution study / A.Bencini; E.Berni; F.Chuburu; C.Giorgi; H.Handel; M.Le Baccon; P.Paoletti; B.Valtancoli. - In: POLYHEDRON. - ISSN 0277-5387. - STAMPA. - 21:(2002), pp. 1459-1467. [10.1016/s0277-5387(02)00950-6]
Basicity and coordination ability of linear hexa-amines in relation to N-(CH2)n-N chain-link lengths. A solution study
BENCINI, ANDREA;GIORGI, CLAUDIA;PAOLETTI, PIERO;VALTANCOLI, BARBARA
2002
Abstract
The synthesis of the two new linear hexa-amines 371014-tetraazahexadecane-116-diamine (L1) and 591216-tetraazaicosane-120-diamine (L2) has been reported. Ligand protonation and Cu(II) and Zn(II) coordination have been studied in aqueous solution by means of potentiometric microcalorimetric (298.1 K I = 0.1 mol dm-3) and spectrophotometric (UV-Vis 1H and 13C NMR) measurements. The species present in solution and their stability constants have been determined. L1 forms mono- and binuclear complexes in aqueous solution with Cu(II). In the [ML1]2+ complexes the metal ion is coordinated by five nitrogen atoms while in the [ML2]2+ complexes the metal ion is four-coordinate. This different behavior is explained in terms of the different numbers of methylene groups between adjacent nitrogen atoms. © 2002 Elsevier Science Ltd. All rights reserved.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
