Synthesis and characterisation of two double EE azido and thiocyanato bridged dimeric Cu(II) complexes with tridentate Schiff bases as blocking ligands

Two new double end-to-end azido and thiocyanato bridged copper(II) dimers [Cu2(L1)2(N3)2(ClO4)2] (1) and [Cu2(L2)2(NCS)2](ClO4)2 (2), where L1 (N,N-dimethyl-N′-(1-pyridin-2-yl-ethylidene)-ethane-1,2-diamine) and L2 (N,N-diethyl-N′-(1-pyridin-2-yl-ethylidene)-ethane-1,2-diamine) are tridentate Schiff bases, have been synthesized and their molecular structures have been determined by X-ray crystallography. Copper(II) shows octahedral geometry in 1 and square–pyramidal in 2. The copper(II) in both the compounds are bonded to three nitrogen atoms of the tridentate ligands in mer orientations and the forth coordination sites of basal planes are occupied by the nitrogen atom of azide (in 1) or thiocyanate (in 2). The fifth coordination sites of central copper(II) are occupied by a symmetry related N or S of azide or thiocyanate respectively, thereby creating centrosymmetric dimers. Perchlorate oxygen occupies the sixth coordination site of copper(II) in 1. The octahedral geometry of copper(II) in 1 is facilitated by less steric crowding.

Two new double end-to-end azido and thiocyanato bridged copper(II) dimers, [Cu2(L1)2(N3)2(ClO4)2] (1) and [Cu2(L2)2(NCS)2](ClO4)2 (2), where L1 (N,N-dimethyl-N′-(1-pyridin-2-yl-ethylidene)-ethane-1,2-diamine) and L2 (N,N-diethyl-N′-(1-pyridin-2-yl-ethylidene)-ethane-1,2-diamine) are tridentate Schiff bases, have been synthesized and their molecular structures have been determined by X-ray crystallography. The copper(II) centre shows an octahedral geometry in 1 and square–pyramidal in 2.Figure optionsDownload as PowerPoint slideHighlights
► Two copper(II) compounds with tridentate Schiff bases have been prepared.
► The molecular structures have been elucidated on the basis of X-ray crystallography.
► The deprotonated di-Schiff base constitutes the equatorial plane.
► The copper(II) centre is square–pyramidal in compound 2 and octahedral in compound 1.