title: Stabilization of Cu7 clusters in azide networks: syntheses, structures and magnetic behaviour.
abstract: Two new azide bridged copper(II) coordination polymer compounds, [Cu7(N3)14(C3H10N2)(C4H13N3)]n (I) and [Cu7(N3)14(C3H10N2)(C5H15N3)2]n (II) [where C3H10N2 = 1,2-diaminopropane (1,2-DAP); C4H13N3 = diethylenetriamine (DETA); C5H15N3 = N-2-aminoethyl-1,3-propanediamine (AEDAP)] were prepared by employing a room temperature diffusion technique involving three layers. Single crystal studies reveal that both compounds I and II, have similar connectivity forming Cu7 clusters through end-on (EO) bonding of the azide. The Cu7 clusters are connected through end-to-end (EE) connectivity of the azides forming three-dimensional structures. Magnetic studies confirmed the ferromagnetic interactions within the Cu7 units and revealed the occurrence of concomitant ferro- and antiferro-magnetic interactions between these clusters. As a result I behaves as a weak-ferromagnet with TC = 10 K.
authors.affiliation: Framework solids laboratory, Solid State and Structural Chemistry unit, Indian Institute of Science, Bangalore-560012, India. snatarajan@sscu.iisc.ernet.in jean-pascal.sutter@lcc-toulouse.fr.
authors.forename: Subhradeep
authors.initials: S
authors.lastname: Mistry
authors.affiliation: CNRS, LCC (Laboratoire de Chimie de Coordination), 205, route de Narbonne, F-31077 Toulouse, France and Université de Toulouse, UPS, INPT, LCC, F-31077 Toulouse, France.
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Sutter
authors.affiliation: Framework solids laboratory, Solid State and Structural Chemistry unit, Indian Institute of Science, Bangalore-560012, India. snatarajan@sscu.iisc.ernet.in jean-pascal.sutter@lcc-toulouse.fr.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Natarajan