Acid dissociation of 2,2 '-dipyridylamine in non-aqueous medium when chelated to some Ru(II)N-4 cores

Drew, M. G. B., Nag, S. and Datta, D. (2008) Acid dissociation of 2,2 '-dipyridylamine in non-aqueous medium when chelated to some Ru(II)N-4 cores. Inorganica Chimica Acta, 361 (1). pp. 417-421. ISSN 0020-1693 doi: 10.1016/j.ica.2007.07.014

Abstract/Summary

[Ru(2,2'-bipyridine)(2)(Hdpa)](BF4)(2) center dot 2H(2)O (1), [Ru(1,10-phenanthroline)(2)(Hdpa)] (PF6)(2) center dot CH2Cl2 (2) and [Ru(4,4,4',4'-tetramethyl-2,2'- bisoxazoline)(2)(Hdpa)] (PF6)(2) (3) are synthesized where Hdpa is 2,2'-dipyridylamine. The X-ray crystal structures of 1 and 2 have been determined. Hdpa in 1 and 2 is found to bind the metal via the two pyridyl N ends. Comparing the NMR spectra in DMSO-d(6), it is concluded that 3 has a similar structure. The pK(a) values (for the dissociation of the NH proton in Hdpa) of free Hdpa and its complexes are determined in acetonitrile by exploiting molar conductance. These correlate linearly with the chemical shift of the NH proton in the respective entities. (C) 2007 Elsevier B.V. All rights reserved.