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

Polynuclear and polymeric squarato-bridged coordination compounds

“…Many of these frameworks have been obtained using the squarate dianion and can be formulated as catena -[M II (μ 1,3 -C 4 O 4 )(μ 2 -L′)(H 2 O) 2 ], where L′ = dpe, M = Mn, Zn ( 70 , 71 ); 24,67 L′ = 4,4′-bpy: M = Fe, Co, Ni, Cd ( 72–75 ); 68–70 L′ = dpp, Fe ( 76 ); 71 L′ = L 4 , Cu ( 77 ); 72 L′ = L 6 , Cd, Zn ( 78 , 79 ); 74 L′ = L 7 , M = Fe ( 80 ); 71 catena -[Cu(μ 1,3 -C 4 O 4 )(μ 2 -L 8 )(H 2 O)] 75 ( 81 ); catena -[M II (μ 1,3 -C 4 O 4 )(μ 2 -pyz)] {M = Cu, Ni, Fe and Co ( 82–85 )}; 76 and catena -[Cu 2 (μ 1,3 -C 4 O 4 )(μ 2 -L 9 )(ClO 4 ) 2 ]·1.33H 2 O ( 86 ). 77 A complex of similar structure to the previous series of compounds was isolated with Ag( i ) and hydrogen squarate, catena -[Ag 2 (μ 1,3 -HC 4 O 4 ) 2 (μ 2 -pyz)] ( 87 ). 78 Compounds with μ 1,3 -squarato bonding modes are tabulated in Table 2.…”

“…, where L′ = dpe, M = Mn, Zn (70, 71); 24,67 L′ = 4,4′-bpy: M = Fe, Co, Ni, Cd (72-75); 68-70 L′ = dpp, Fe (76); 71 L′ = L 4 , Cu (77); 72 L′ = L 6 , Cd, Zn (78, 79); 74 L′ = L 7 , M = Fe (80); 71 (86). 77 A complex of similar structure to the previous series of compounds was isolated with AgIJI) and hydrogen squarate, catena-[Ag 2 IJμ 1,3 -HC 4 O 4 ) 2 IJμ 2 -pyz)] (87). 78 Compounds with μ 1,3 -squarato bonding modes are tabulated in Table 2.…”

Structural characterization of copper(II) complexes based on a new 10-membered binucleating 1,6-diazecine ligand

“…Some of these ligands have been used to extract the mechanistic details and to understand the role of metal ions in many biological reactions such as hemocyanin, hemoerythrin, monooxygenase tyrosinase, bovine erythrocyte SOD, urease, hydrolytic cleavage of DNA and RNA, and of phosphodiesters [1][2][3][4][5]. Also, metal complexes derived from binucleating ligands were designed with variable distances between the two metal ions that allows the magnetic centers to interact through extended bridging ligands [6,7], a property which is important in bioinorganic and coordination chemistry. In nature, a number of biologically important molecules such as CuZn-SOD, zinc finger, methane monooxygenase, urease, carbonic anhydrase, carboxypeptidase and hemoerythrin were found to contain imidazole group(s) coordinated to metal ions [8].…”

“…The perchlorato-, azidoand squarato-Cu(II) complexes of L endm were synthesized and structurally characterized. The azide and squarate ligands were selected because of their tendency to assemble metal ions through an [14,15], especially in the case of bridged-squarato compounds where the distance between the two metal centers could be as long as 8 Å [7,14]; this is about the same magnitude as the intramolecular bond lengths found between metal ions in 1,6-diazecine complexes (7-8 Å) [9,10].…”

Structure and magnetic characterization of some bicompartmental [N6O2] divalent metal(ii) complexes using bis(phenolato) ligands bearing two pendant bis(pyridyl) amine arms

“…Binucleating compounds bearing bis(pyridyl) groups assembled through m - or p -xylyl, pyridyl, 20,23,24 1,3,5-triazine 6 and in particular mono-phenolate spacers 2,7,8,10,12,17–19,25 have been reported (Scheme 1). Obviously, each of the pendant pyridyl arms in these molecules binds a metal ion (M 2+ or M 3+ ) leading to the formation of dinuclear species, which in some ligands may have an extra coordination donor atom (Scheme 1: l -py, bdpaT Cl , and HL R ).…”