Structure, spectroscopic and magnetic properties of a novel 1-D coordination copper(II) polymer containing BIMAM ligand [BIMAM=bis(imidazol-2-yl)methylaminomethane] and μ-1,3 squarato bridges

μ‐1,3‐ (trans) and μ‐1,2‐ (cis) Bonding in Squarato‐Bridged Dinuclear Copper(II) and Nickel(II) Complexes Derived from Polypyridyl Amines

“…The dinuclear squarato-bridged complexes [Cu 2 (TPA) 2 (3) were synthesized in reasonably good yield (50-80 %) by the direct reaction of an aqueous or a methanolic solution of the preformed 1:1 complex M(ClO 4 ) 2 /polypyridylamine (M = Cu II or Ni II ; polypyridylamine = TPA, MeDPA) and 1 equiv. of disodium squarate.…”

“…The presence of four donor oxygen atoms and the richness of the electron density on the squarate dianion enhance its capability to simultaneously bind more than one metal ion, hence acting as a bridging ligand. The bridging squarato ligand affords three types of coordination modes known as µ-1,3-(trans), [2][3][4]6,16,22] µ-1,2-(cis), [2,5,8,9,13,14,16,18] and µ- ronment in 2 is achieved by the three N-atoms of the MeDPA ligand, by an oxygen atom of a bridging squarato ligand and, at longest distances, by two oxygen atoms from coordinated water molecules. In the nickel complex 3, the geometry is attained by the four N-atoms of TPA and by two oxygen atoms supplied by a coordinated water molecule and by a bridging squarato ligand.…”

“…[7,19] Polymeric structures via µ-1,2-and µ-1,3-coordination have also been reported. [11,12,22,25] More recently, the trinuclear complex, [Cu 3 (pmap) 3 (µ 1,2,3 -C 4 O 4 )](ClO 4 ) 4 · 2H 2 O {pmap = bis[2-(2-pyridyl)ethyl][(2-pyridyl)methyl]-amine} with the µ-1,2,3-coordination mode has been structurally and magnetically characterized. [1] The different bonding modes in squarato-bridged metal(II) complexes are depicted in Scheme 1.…”

trans‐1,2‐Bis(N‐methylimidazol‐2‐yl)ethylene: Towards Building Blocks for 2D Fabrics and MML‐Type 1D Molecular Strands

“…[10] Surprisingly, so far no imidazole-or olefin-based N,N ligand has been described, except for one very early report regarding the chelating, but not bridging, cis-1,2-bis(N-methylimidazol-2-yl)ethylene ligand (cis-bie). [11] Because imidazoles exhibit s-donor, p-acceptor, and also p-donor capacities, 1D MML-type coordination polymers with imidazole-based ligands might exhibit promising physical properties.…”

A novel 1-D coordination Cu(II) polymer with alternating μ1,3-squarato and binucleating polypyridylamine bridges

“…The coordination geometry around the Cu(II) centers is a five-coordinate with a slightly distorted square pyramidal environment which is achieved by the three N-donor atoms of each arm of the ligand L, an oxygen atom of the bridging squarato moiety and by an oxygen atom of the ClO À 4 anion. The complex shows antiferromagnetic coupling between the squarato-bridged Cu(II) ions with J = À6.3 cm À1 .Ó 2009 Elsevier B.V. All rights reserved.The squarate dianion, C 4 O 2À 4 (3,4-dihydroxycyclobut-3-ene-1,2-dionate) is a very well known ligand that is capable of binding more than one metal ion at the same time leading to a variety of coordination modes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] where four types were recognized known as l-1,3-(trans) [1,3-6], l-1,2-(cis) [1,3,7-11], l-1,2,3-and l-1,2,3,4- [2,[12][13][14]. It has been pointed out that the ligand does not generally act as a bis-bidentate linker for the first raw divalent transition metal ions because of its very large bite angle relative to that observed in the oxalate dianion [15].…”