Stuart Corr

Molecular helicity in inorganic complexes: double helical binuclear complexes of 2,2′ : 6′,2″ : 6″,2‴ : 6‴,2â—-quinquepyridine (L): crystal structures of [Cu2L2(O2CMe)][PF6]3·H2O and [Cu2L2][PF6]3·2MeCN

The potentially pentadentate ligand 2,2′ : 6′,2″ : 6″,2‴,2â�—-quinquepyridine (L, quinquepy) forms complexes with first row transition-metal cations of 2 : 2 stoicheiometry. Crystallographic studies of the complexes [Cu2L2(O2CMe)][PF6]3·H2O and [Cu2L2][PF6]3·2MeCN reveal a double helical arrangement of the ligands about the metals.

A convenient, high yield synthesis of 2,2':6',2″-terpyridine and its iron(II) complex

2,2′:6′,2″-Terpyridine (3) is obtained in high yield (60%) from the condensation of N-{1-(2′-pyridyl)-1- oxo-2-ethyl}pyridinium iodide with 2-(2′-pyrrolidino- propionyl)-pyridine in the presence of ammonium acetate. The ligand is conveniently isolated as its iron(II) complex, from which it may be obtained in near-quantitative yield on treatment with alkali in oxidative conditions. Performing the condensation in the presence of an iron(II) template results in enhanced yields of the iron(II) complex, which is readily isolable as its hexafluorophosphate salt.

The hydrolytic behaviour of some pentadentate Schiff-base type macrocycles

Abstract The protonation constants of a series of pentadentate α,α′-diimine macrocycles based on 2,2′-bipyridine have been determined by potentiometric titration in aqueous solution, and are discussed with respect to the hydrolytic behaviour of these systems in alkaline solution.